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GCC(1) GNU Tools GCC(1) NNAAMMEE gcc, g++ - GNU project C and C++ Compiler (v2 preliminary) SSYYNNOOPPSSIISS gcc [[_o_p_t_i_o_n | _f_i_l_e_n_a_m_e ]... g++ [[_o_p_t_i_o_n | _f_i_l_e_n_a_m_e ]... WWAARRNNIINNGG The information in this man page is an extract from the full documentation of the GNU C compiler, and is limited to the meaning of the options. This man page is not kept up to date except when volunteers want to maintain it. For complete and current documentation, refer to the Info file `ggcccc' or the manual _U_s_i_n_g _a_n_d _P_o_r_t_i_n_g _G_N_U _C_C _(_f_o_r _v_e_r_s_i_o_n _2_._0_). Both are made from the Texinfo source file ggcccc..tteexxiinnffoo. DDEESSCCRRIIPPTTIIOONN The C and C++ compilers are integrated. Both process input files through one or more of four stages: prepro- cessing, compilation, assembly, and linking. Source file- name suffixes identify the source language, but which name you use for the compiler governs default assumptions: ggcccc assumes preprocessed (..ii) files are C and assumes C style linking. gg++++ assumes preprocessed (..ii) files are C++ and assumes C++ style linking. Suffixes of source file names indicate the language and kind of processing to be done: ..cc C source; preprocess, compile, assemble ..CC C++ source; preprocess, compile, assemble ..cccc C++ source; preprocess, compile, assemble ..ccxxxx C++ source; preprocess, compile, assemble ..mm Objective-C source; preprocess, compile, assemble ..ii preprocessed C; compile, assemble ..iiii preprocessed C++; compile, assemble ..ss Assembler source; assemble ..SS Assembler source; preprocess, assemble ..hh Preprocessor file; not usually named on command line _?_? Other (unrecognized) files passed to linker. Common cases: ..oo Object file ..aa Archive file Linking is always the last stage unless you use one of the --cc, --SS, or --EE options to avoid it (or unless compilation errors stop the whole process). For the link stage, all GNU Tools 28may1992 1 GCC(1) GNU Tools GCC(1) ..oo files corresponding to source files, --ll libraries, unrecognized filenames (including named ..oo object files and ..aa archives) are passed to the linker in command-line order. OOPPTTIIOONNSS Options must be separate: `--ddrr' is quite different from `--dd --rr '. Most `--ff' and `--WW' options have two contrary forms: --ff_n_a_m_e and --ffnnoo--_n_a_m_e (or --WW_n_a_m_e and --WWnnoo--_n_a_m_e). Only the non- default forms are shown here. Here is a summary of all the options, grouped by type. Explanations are in the following sections. OOvveerraallll OOppttiioonnss -c -S -E -o _f_i_l_e -pipe -v -x _l_a_n_g_u_a_g_e LLaanngguuaaggee OOppttiioonnss -ansi -fall-virtual -fcond-mismatch -fdollars-in-identifiers -fenum-int-equiv -fno-asm -fno-builtin -fno-strict-prototype -fsigned-bitfields -fsigned-char -fthis-is-variable -funsigned-bitfields -funsigned-char -fwritable-strings -traditional -traditional-cpp -trigraphs WWaarrnniinngg OOppttiioonnss -fsyntax-only -pedantic -pedantic-errors -w -W -Wall -Waggregate-return -Wcast-align -Wcast-qual -Wcomment -Wconversion -Wenum-clash -Werror -Wformat -Wid-clash-_l_e_n -Wimplicit -Winline -Wmissing-prototypes -Wparentheses -Wpointer-arith -Wreturn-type -Wshadow -Wstrict-prototypes -Wswitch -Wtraditional -Wtrigraphs -Wuninitialized -Wunused -Wwrite-strings DDeebbuuggggiinngg OOppttiioonnss -a -d_l_e_t_t_e_r_s -fpretend-float -g -gstabs -gdwarf -ggdb -gsdb -p -pg -save-temps OOppttiimmiizzaattiioonn OOppttiioonnss -fcaller-saves -fcse-follow-jumps -fdelayed-branch -felide-constructors -fexpensive-optimizations -ffloat-store -fforce-addr -fforce-mem -finline -finline-functions -fkeep-inline-functions -fmemoize-lookups -fno-default-inline GNU Tools 28may1992 2 GCC(1) GNU Tools GCC(1) -fno-defer-pop -fno-function-cse -fomit-frame-pointer -frerun-cse-after-loop -fschedule-insns -fschedule-insns2 -fstrength-reduce -fthread-jumps -funroll-all-loops -funroll-loops -O -O2 PPrreepprroocceessssoorr OOppttiioonnss -C -dD -dM -dN -D_m_a_c_r_o[=_d_e_f_n] -E -H -i _f_i_l_e -M -MD -MM -MMD -nostdinc -P -U_m_a_c_r_o -undef LLiinnkkeerr OOppttiioonnss -l_l_i_b_r_a_r_y -nostdlib -static DDiirreeccttoorryy OOppttiioonnss -B_p_r_e_f_i_x -I_d_i_r -I- -L_d_i_r TTaarrggeett OOppttiioonnss -b _m_a_c_h_i_n_e -V _v_e_r_s_i_o_n MMaacchhiinnee DDeeppeennddeenntt OOppttiioonnss _M_6_8_0_x_0 _O_p_t_i_o_n_s -m68000 -m68020 -m68881 -mbitfield -mc68000 -mc68020 -mfpa -mnobitfield -mrtd -mshort -msoft-float _V_A_X _O_p_t_i_o_n_s -mg -mgnu -munix _S_P_A_R_C _O_p_t_i_o_n_s -mfpu -mno-epilogue _C_o_n_v_e_x _O_p_t_i_o_n_s -margcount -mc1 -mc2 -mnoargcount _A_M_D_2_9_K _O_p_t_i_o_n_s -m29000 -m29050 -mbw -mdw -mkernel-registers -mlarge -mnbw -mnodw -msmall -mstack-check -muser-registers _M_8_8_K _O_p_t_i_o_n_s -mbig-pic -mcheck-zero-division -mhandle-large-shift -midentify-revision -mno-check-zero-division -mno-ocs-debug-info -mno-ocs-frame-position -mno-optimize-arg-area -mno-underscores -mocs-debug-info -mocs-frame-position -moptimize-arg-area -mshort-data-_n_u_m -msvr3 -msvr4 -mtrap-large-shift -muse-div-instruction -mversion-03.00 -mwarn-passed-structs GNU Tools 28may1992 3 GCC(1) GNU Tools GCC(1) _R_S_6_0_0_0 _O_p_t_i_o_n_s -mfp-in-toc -mno-fop-in-toc _R_T _O_p_t_i_o_n_s -mcall-lib-mul -mfp-arg-in-fpregs -mfp-arg-in-gregs -mfull-fp-blocks -mhc-struct-return -min-line-mul -mminimum-fp-blocks -mnohc-struct-return _M_I_P_S _O_p_t_i_o_n_s -mcpu=_c_p_u _t_y_p_e -mips2 -mips3 -mint64 -mlong64 -mlonglong128 -mmips-as -mgas -mrnames -mno-rnames -mgpopt -mno-gpopt -mstats -mno-stats -mmemcpy -mno-memcpy -mno-mips-tfile -mmips-tfile -msoft-float -mhard-float -mabicalls -mno-abicalls -mhalf-pic -mno-half-pic -G _n_u_m _i_3_8_6 _O_p_t_i_o_n_s -m486 -mno486 -msoft-float CCooddee GGeenneerraattiioonn OOppttiioonnss +e_N -fcall-saved-_r_e_g -fcall-used-_r_e_g -ffixed-_r_e_g -fno-common -fno-gnu-binutils -fnonnull-objects -fpcc-struct-return -fpic -fPIC -fshared-data -fshort-enums -fshort-double -fvolatile OOVVEERRAALLLL OOPPTTIIOONNSS --xx _l_a_n_g_u_a_g_e Specify explicitly the _l_a_n_g_u_a_g_e for the following input files (rather than choosing a default based on the file name suffix) . This option applies to all following input files until the next `--xx' op- tion. Possible values of _l_a_n_g_u_a_g_e are `cc', `oobbjjeeccttiivvee--cc', `cc--hheeaaddeerr', `cc++++', `ccpppp--oouuttppuutt', `aasssseemmbblleerr', and `aasssseemmbblleerr--wwiitthh--ccpppp'. --xx nnoonnee Turn off any specification of a language, so that subsequent files are handled according to their file name suffixes (as they are if `--xx' has not been used at all). If you want only some of the four stages (preprocess, com- pile, assemble, link), you can use `--xx' (or filename suf- fixes) to tell ggcccc where to start, and one of the options `--cc', `--SS', or `--EE' to say where ggcccc is to stop. Note that some combinations (for example, `--xx ccpppp--oouuttppuutt --EE') instruct ggcccc to do nothing at all. --cc Compile or assemble the source files, but do not link. The compiler output is an object file corre- sponding to each source file. GNU Tools 28may1992 4 GCC(1) GNU Tools GCC(1) By default, GCC makes the object file name for a source file by replacing the suffix `..cc', `..ii', `..ss', etc., with `..oo'. Use --oo to select another name. GCC ignores any unrecognized input files (those that do not require compilation or assembly) with the --cc option. --SS Stop after the stage of compilation proper; do not assemble. The output is an assembler code file for each non-assembler input file specified. By default, GCC makes the assembler file name for a source file by replacing the suffix `..cc', `..ii', etc., with `..ss'. Use --oo to select another name. GCC ignores any input files that don't require com- pilation. --EE Stop after the preprocessing stage; do not run the compiler proper. The output is preprocessed source code, which is sent to the standard output. GCC ignores input files which don't require prepro- cessing. --oo _f_i_l_e Place output in file _f_i_l_e. This applies regard- less to whatever sort of output GCC is producing, whether it be an executable file, an object file, an assembler file or preprocessed C code. Since only one output file can be specified, it does not make sense to use `--oo' when compiling more than one input file, unless you are producing an executable file as output. If you do not specify `--oo', the default is to put an executable file in `aa..oouutt', the object file for `_s_o_u_r_c_e._s_u_f_f_i_x' in `_s_o_u_r_c_e.o', its assembler file in `_s_o_u_r_c_e.s', and all preprocessed C source on standard output. --vv Print (on standard error output) the commands exe- cuted to run the stages of compilation. Also print the version number of the compiler driver program and of the preprocessor and the compiler proper. --ppiippee Use pipes rather than temporary files for communi- cation between the various stages of compilation. This fails to work on some systems where the assem- bler cannot read from a pipe; but the GNU assembler GNU Tools 28may1992 5 GCC(1) GNU Tools GCC(1) has no trouble. LLAANNGGUUAAGGEE OOPPTTIIOONNSS The following options control the dialect of C that the compiler accepts: --aannssii _S_u_p_p_o_r_t _a_l_l _A_N_S_I _s_t_a_n_d_a_r_d _C _p_r_o_g_r_a_m_s_. _T_h_i_s _t_u_r_n_s _o_f_f _c_e_r_t_a_i_n _f_e_a_t_u_r_e_s _o_f _G_N_U _C _t_h_a_t _a_r_e _i_n_c_o_m_p_a_t_i_b_l_e _w_i_t_h ANSI C, such as the aassmm, iinnlliinnee and ttyyppeeooff keywords, and predefined macros such as uunniixx and vvaaxx that identify the type of system you are using. It also enables the undesirable and rarely used ANSI trigraph feature, and makes the preprocessor accept `$$' as part of identifiers. The alternate keywords ____aassmm____, ____eexxtteennssiioonn____, ____iinnlliinnee____ and ____ttyyppeeooff____ continue to work despite `--aannssii'. You would not want to use them in an ANSI C program, of course, but it is useful to put them in header files that might be included in compila- tions done with `--aannssii'. Alternate predefined macros such as ____uunniixx____ and ____vvaaxx____ are also avail- able, with or without `--aannssii'. The `--aannssii' option does not cause non-ANSI programs to be rejected gratuitously. For that, `--ppeeddaannttiicc' is required in addition to `--aannssii'. The preprocessor predefines a macro ____SSTTRRIICCTT__AANNSSII____ when you use the `--aannssii' option. Some header files may notice this macro and refrain from declaring certain functions or defining certain macros that the ANSI standard doesn't call for; this is to avoid interfering with any programs that might use these names for other things. --ffnnoo--aassmm Do not recognize aassmm, iinnlliinnee or ttyyppeeooff as a key- word. These words may then be used as identifiers. You can use ____aassmm____, ____iinnlliinnee____ and ____ttyyppeeooff____ in- stead. `--aannssii' implies `--ffnnoo--aassmm'. --ffnnoo--bbuuiillttiinn _(_I_g_n_o_r_e_d _f_o_r _C_+_+_._) Don't recognize non-ANSI built- in functions. `--aannssii' also has this effect. Cur- rently, the only function affected is aallllooccaa. --ffnnoo--ssttrriicctt--pprroottoottyyppee _(_C_+_+ _o_n_l_y_._) Consider the declaration iinntt ffoooo (());;. In C++, this means that the function ffoooo takes no arguments. In ANSI C, this is declared iinntt GNU Tools 28may1992 6 GCC(1) GNU Tools GCC(1) ffoooo((vvooiidd));;. With the flag `--ffnnoo--ssttrriicctt--pprroottoottyyppee', declaring functions with no arguments is equivalent to declaring its argument list to be untyped, i.e., iinntt ffoooo (());; is equivalent to saying iinntt ffoooo ((......));;. --ttrriiggrraapphhss Support ANSI C trigraphs. The `--aannssii' option im- plies `--ttrriiggrraapphhss'. --ttrraaddiittiioonnaall Attempt to support some aspects of traditional C compilers. For details, see the GNU C Manual; the duplicate list here has been deleted so that we won't get complaints when it is out of date. But one note about C++ programs only (not C). `--ttrraaddiittiioonnaall' has one additional effect for C++: assignment to tthhiiss is permitted. This is the same as the effect of `--fftthhiiss--iiss--vvaarriiaabbllee'. --ttrraaddiittiioonnaall--ccpppp Attempt to support some aspects of traditional C preprocessors. This includes the items that specifically mention the preprocessor above, but none of the other effects of `--ttrraaddiittiioonnaall'. --ffddoollllaarrss--iinn--iiddeennttiiffiieerrss _(_C_+_+ _o_n_l_y_._) Permit the use of `$$' in identifiers. (For GNU C, this is the default, and you can forbid it with `--aannssii'.) Traditional C allowed the char- acter `$$' to form part of identifiers; by default, GNU C also allows this. However, ANSI C forbids `$$' in identifiers, and GNU C++ also forbids it by default on most platforms (though on some platforms it's enabled by default for GNU C++ as well). --ffeennuumm--iinntt--eeqquuiivv _(_C_+_+ _o_n_l_y_._) Normally GNU C++ allows conversion of eennuumm to iinntt, but not the other way around. Use this option if you want GNU C++ to allow conversion of iinntt to eennuumm as well. --ffaallll--vviirrttuuaall _(_C_+_+ _o_n_l_y_._) When you use the `--ffaallll--vviirrttuuaall', all member functions (except for constructor functions and new/delete member operators) declared in the same class with a ``method-call'' operator method are treated as virtual functions of the given class. In effect, all of these methods become ``implicitly virtual.'' This does _n_o_t mean that all calls to these methods will be made through the internal table of virtual functions. There are some circumstances under GNU Tools 28may1992 7 GCC(1) GNU Tools GCC(1) which it is obvious that a call to a given virtual function can be made directly, and in these cases the calls still go direct. The effect of making all methods of a class with a declared `ooppeerraattoorr-->>(())(())' implicitly virtual using `--ffaallll--vviirrttuuaall' extends also to all non-constructor methods of any class derived from such a class. --ffccoonndd--mmiissmmaattcchh Allow conditional expressions with mismatched types in the second and third arguments. The value of such an expression is void. --fftthhiiss--iiss--vvaarriiaabbllee _(_C_+_+ _o_n_l_y_._) The incorporation of user-defined free store management into C++ has made assignment to tthhiiss an anachronism. Therefore, by default GNU C++ treats the type of tthhiiss in a member function of ccllaassss XX to be XX **ccoonnsstt. In other words, it is il- legal to assign to tthhiiss within a class member func- tion. However, for backwards compatibility, you can invoke the old behavior by using `--fftthhiiss--iiss--vvaarriiaabbllee'. --ffuunnssiiggnneedd--cchhaarr Let the type cchhaarr be unsigned, like uunnssiiggnneedd cchhaarr. Each kind of machine has a default for what cchhaarr should be. It is either like uunnssiiggnneedd cchhaarr by de- fault or like ssiiggnneedd cchhaarr by default. Ideally, a portable program should always use ssiiggnneedd cchhaarr or uunnssiiggnneedd cchhaarr when it depends on the signedness of an object. But many programs have been written to use plain cchhaarr and expect it to be signed, or expect it to be unsigned, depending on the machines they were written for. This option, and its inverse, let you make such a program work with the opposite default. The type cchhaarr is always a distinct type from each of ssiiggnneedd cchhaarr and uunnssiiggnneedd cchhaarr, even though its behavior is always just like one of those two. --ffssiiggnneedd--cchhaarr Let the type cchhaarr be signed, like ssiiggnneedd cchhaarr. Note that this is equivalent to `--ffnnoo--uunnssiiggnneedd--cchhaarr', which is the negative form of `--ffuunnssiiggnneedd--cchhaarr'. Likewise, `--ffnnoo--ssiiggnneedd--cchhaarr' is equivalent to `--ffuunnssiiggnneedd--cchhaarr'. GNU Tools 28may1992 8 GCC(1) GNU Tools GCC(1) --ffssiiggnneedd--bbiittffiieellddss --ffuunnssiiggnneedd--bbiittffiieellddss --ffnnoo--ssiiggnneedd--bbiittffiieellddss --ffnnoo--uunnssiiggnneedd--bbiittffiieellddss These options control whether a bitfield is signed or unsigned, when declared with no explicit `ssiiggnneedd' or `uunnssiiggnneedd' qualifier. By default, such a bitfield is signed, because this is consistent: the basic integer types such as iinntt are signed types. However, when you specify `--ttrraaddiittiioonnaall', bitfields are all unsigned no matter what. --ffwwrriittaabbllee--ssttrriinnggss Store string constants in the writable data segment and don't uniquize them. This is for compatibility with old programs which assume they can write into string constants. `--ttrraaddiittiioonnaall' also has this ef- fect. Writing into string constants is a very bad idea; ``constants'' should be constant. PPRREEPPRROOCCEESSSSOORR OOPPTTIIOONNSS These options control the C preprocessor, which is run on each C source file before actual compilation. If you use the `--EE' option, GCC does nothing except pre- processing. Some of these options make sense only togeth- er with `--EE' because they cause the preprocessor output to be unsuitable for actual compilation. --ii _f_i_l_e Process _f_i_l_e as input, discarding the resulting output, before processing the regular input file. Because the output generated from _f_i_l_e is discard- ed, the only effect of `--ii _f_i_l_e' is to make the macros defined in _f_i_l_e available for use in the main input. The preprocessor evaluates any `--DD' and `--UU' options on the command line before pro- cessing `--ii' _f_i_l_e. --nnoossttddiinncc Do not search the standard system directories for header files. Only the directories you have speci- fied with `--II' options (and the current directory, if appropriate) are searched. GNU Tools 28may1992 9 GCC(1) GNU Tools GCC(1) By using both `--nnoossttddiinncc' and `--II--', you can limit the include-file search file to only those directo- ries you specify explicitly. --uunnddeeff Do not predefine any nonstandard macros. (Includ- ing architecture flags). --EE Run only the C preprocessor. Preprocess all the C source files specified and output the results to standard output or to the specified output file. --CC Tell the preprocessor not to discard comments. Used with the `--EE' option. --PP Tell the preprocessor not to generate `##lliinnee' com- mands. Used with the `--EE' option. --MM Tell the preprocessor to output a rule suitable for mmaakkee describing the dependencies of each object file. For each source file, the preprocessor out- puts one mmaakkee-rule whose target is the object file name for that source file and whose dependencies are all the files `##iinncclluuddee'd in it. This rule may be a single line or may be continued with `\\'-new- line if it is long. The list of rules is printed on standard output instead of the preprocessed C program. `--MM' implies `--EE'. --MMMM Like `--MM' but the output mentions only the user header files included with `##iinncclluuddee _f_i_l_e"'. Sys- tem header files included with `##iinncclluuddee <<_f_i_l_e>' are omitted. --MMDD Like `--MM' but the dependency information is written to files with names made by replacing `..cc' with `..dd' at the end of the input file names. This is in addition to compiling the file as specified--`--MMDD' does not inhibit ordinary compila- tion the way `--MM' does. The Mach utility `mmdd' can be used to merge the `..dd' files into a single dependency file suitable for using with the `mmaakkee' command. --MMMMDD Like `--MMDD' except mention only user header files, not system header files. --HH Print the name of each header file used, in addi- tion to other normal activities. --DD_m_a_c_r_o Define macro _m_a_c_r_o with the string `11' as its defi- GNU Tools 28may1992 10 GCC(1) GNU Tools GCC(1) nition. --DD_m_a_c_r_o==_d_e_f_n Define macro _m_a_c_r_o as _d_e_f_n. All instances of `--DD' on the command line are processed before any `--UU' or `--ii' options. --UU_m_a_c_r_o Undefine macro _m_a_c_r_o. `--UU' options are evaluated after all `--DD' options, but before any `--ii' op- tions. --ddMM Tell the preprocessor to output only a list of the macro definitions that are in effect at the end of preprocessing. Used with the `--EE' option. --ddDD Tell the preprocessing to pass all macro defini- tions into the output, in their proper sequence in the rest of the output. --ddNN Like `--ddDD' except that the macro arguments and con- tents are omitted. Only `##ddeeffiinnee _n_a_m_e' is included in the output. LLIINNKKEERR OOPPTTIIOONNSS These options come into play when the compiler links ob- ject files into an executable output file. They are mean- ingless if the compiler is not doing a link step. _o_b_j_e_c_t_-_f_i_l_e_-_n_a_m_e A file name that does not end in a special recog- nized suffix is considered to name an object file or library. (Object files are distinguished from libraries by the linker according to the file con- tents.) If GCC does a link step, these object files are used as input to the linker. --ll_l_i_b_r_a_r_y Use the library named _l_i_b_r_a_r_y when linking. The linker searches a standard list of directories for the library, which is actually a file named `lliibb_l_i_b_r_a_r_y.a'. The linker then uses this file as if it had been specified precisely by name. The directories searched include several standard system directories plus any that you specify with `--LL'. Normally the files found this way are library files--archive files whose members are object files. The linker handles an archive file by scan- GNU Tools 28may1992 11 GCC(1) GNU Tools GCC(1) ning through it for members which define symbols that have so far been referenced but not defined. However, if the linker finds an ordinary object file rather than a library, the object file is linked in the usual fashion. The only difference between using an `--ll' option and specifying a file name is that `--ll' surrounds _l_i_b_r_a_r_y with `lliibb' and `..aa' and searches several directories. --nnoossttddlliibb Don't use the standard system libraries and startup files when linking. Only the files you specify will be passed to the linker. --ssttaattiicc On systems that support dynamic linking, this pre- vents linking with the shared libraries. On other systems, this option has no effect. DDIIRREECCTTOORRYY OOPPTTIIOONNSS These options specify directories to search for header files, for libraries and for parts of the compiler: --II_d_i_r Append directory _d_i_r to the list of directories searched for include files. --II-- Any directories you specify with `--II' options be- fore the `--II--' option are searched only for the case of `##iinncclluuddee ""_f_i_l_e""'; they are not searched for `##iinncclluuddee <<_f_i_l_e>'. If additional directories are specified with `--II' options after the `--II--', these directories are searched for all `##iinncclluuddee' directives. (Ordinari- ly _a_l_l `--II' directories are used this way.) In addition, the `--II--' option inhibits the use of the current directory (where the current input file came from) as the first search directory for `##iinn-- cclluuddee ""_f_i_l_e""'. There is no way to override this effect of `--II--'. With `--II..' you can specify searching the directory which was current when the compiler was invoked. That is not exactly the same as what the preprocessor does by default, but it is often satisfactory. `--II--' does not inhibit the use of the standard sys- tem directories for header files. Thus, `--II--' and `--nnoossttddiinncc' are independent. --LL_d_i_r Add directory _d_i_r to the list of directories to be searched for `--ll'. GNU Tools 28may1992 12 GCC(1) GNU Tools GCC(1) --BB_p_r_e_f_i_x This option specifies where to find the executa- bles, libraries and data files of the compiler it- self. The compiler driver program runs one or more of the subprograms `ccpppp', `cccc11' (or, for C++, `cccc11pplluuss'), `aass' and `lldd'. It tries _p_r_e_f_i_x as a prefix for each program it tries to run, both with and without `_m_a_c_h_i_n_e/_v_e_r_s_i_o_n/'. For each subprogram to be run, the compiler driver first tries the `--BB' prefix, if any. If that name is not found, or if `--BB' was not specified, the driver tries two standard prefixes, which are `//uussrr//lliibb//ggcccc//' and `//uussrr//llooccaall//lliibb//ggcccc--lliibb//'. If neither of those results in a file name that is found, the compiler driver searches for the unmodi- fied program name, using the directories specified in your `PPAATTHH' environment variable. The run-time support file `lliibbggcccc..aa' is also searched for using the `--BB' prefix, if needed. If it is not found there, the two standard prefixes above are tried, and that is all. The file is left out of the link if it is not found by those means. Most of the time, on most machines, `lliibbggcccc..aa' is not actually necessary. You can get a similar result from the environment variable GGCCCC__EEXXEECC__PPRREEFFIIXX; if it is defined, its value is used as a prefix in the same way. If both the `--BB' option and the GGCCCC__EEXXEECC__PPRREEFFIIXX variable are present, the `--BB' option is used first and the environment variable value second. WWAARRNNIINNGG OOPPTTIIOONNSS Warnings are diagnostic messages that report constructions which are not inherently erroneous but which are risky or suggest there may have been an error. These options control the amount and kinds of warnings produced by GNU CC: --ffssyynnttaaxx--oonnllyy Check the code for syntax errors, but don't emit any output. --ww Inhibit all warning messages. --ppeeddaannttiicc Issue all the warnings demanded by strict ANSI GNU Tools 28may1992 13 GCC(1) GNU Tools GCC(1) standard C; reject all programs that use forbidden extensions. Valid ANSI standard C programs should compile prop- erly with or without this option (though a rare few will require `--aannssii'). However, without this op- tion, certain GNU extensions and traditional C fea- tures are supported as well. With this option, they are rejected. There is no reason to _u_s_e this option; it exists only to satisfy pedants. `--ppeeddaannttiicc' does not cause warning messages for use of the alternate keywords whose names begin and end with `____'. Pedantic warnings are also disabled in the expression that follows ____eexxtteennssiioonn____. Howev- er, only system header files should use these es- cape routes; application programs should avoid them. --ppeeddaannttiicc--eerrrroorrss Like `--ppeeddaannttiicc', except that errors are produced rather than warnings. --WW Print extra warning messages for these events: o A nonvolatile automatic variable might be changed by a call to lloonnggjjmmpp. These warnings are possible only in optimizing compilation. The compiler sees only the calls to sseettjjmmpp. It cannot know where lloonnggjjmmpp will be called; in fact, a signal handler could call it at any point in the code. As a result, you may get a warning even when there is in fact no problem because lloonnggjjmmpp cannot in fact be called at the place which would cause a problem. o A function can return either with or without a val- ue. (Falling off the end of the function body is considered returning without a value.) For exam- ple, this function would evoke such a warning: foo (a) { if (a > 0) return a; } Spurious warnings can occur because GNU CC does not realize that certain functions (including aabboorrtt and lloonnggjjmmpp) will never return. o An expression-statement contains no side effects. GNU Tools 28may1992 14 GCC(1) GNU Tools GCC(1) o An unsigned value is compared against zero with `>>' or `<<=='. --WWiimmpplliicciitt Warn whenever a function or parameter is implicitly declared. --WWrreettuurrnn--ttyyppee Warn whenever a function is defined with a return- type that defaults to iinntt. Also warn about any rree-- ttuurrnn statement with no return-value in a function whose return-type is not vvooiidd. --WWuunnuusseedd Warn whenever a local variable is unused aside from its declaration, whenever a function is declared static but never defined, and whenever a statement computes a result that is explicitly not used. --WWsswwiittcchh Warn whenever a sswwiittcchh statement has an index of enumeral type and lacks a ccaassee for one or more of the named codes of that enumeration. (The presence of a ddeeffaauulltt label prevents this warning.) ccaassee labels outside the enumeration range also provoke warnings when this option is used. --WWccoommmmeenntt Warn whenever a comment-start sequence `//**' appears in a comment. --WWttrriiggrraapphhss Warn if any trigraphs are encountered (assuming they are enabled). --WWffoorrmmaatt Check calls to pprriinnttff and ssccaannff, etc., to make sure that the arguments supplied have types appropriate to the format string specified. --WWuunniinniittiiaalliizzeedd An automatic variable is used without first being initialized. These warnings are possible only in optimizing com- pilation, because they require data flow informa- tion that is computed only when optimizing. If you don't specify `--OO', you simply won't get these warnings. These warnings occur only for variables that are candidates for register allocation. Therefore, they do not occur for a variable that is declared GNU Tools 28may1992 15 GCC(1) GNU Tools GCC(1) vvoollaattiillee, or whose address is taken, or whose size is other than 1, 2, 4 or 8 bytes. Also, they do not occur for structures, unions or arrays, even when they are in registers. Note that there may be no warning about a variable that is used only to compute a value that itself is never used, because such computations may be delet- ed by data flow analysis before the warnings are printed. These warnings are made optional because GNU CC is not smart enough to see all the reasons why the code might be correct despite appearing to have an error. Here is one example of how this can happen: { int x; switch (y) { case 1: x = 1; break; case 2: x = 4; break; case 3: x = 5; } foo (x); } If the value of yy is always 1, 2 or 3, then xx is always initialized, but GNU CC doesn't know this. Here is another common case: { int save_y; if (change_y) save_y = y, y = new_y; ... if (change_y) y = save_y; } This has no bug because ssaavvee__yy is used only if it is set. Some spurious warnings can be avoided if you de- clare as vvoollaattiillee all the functions you use that never return. GNU Tools 28may1992 16 GCC(1) GNU Tools GCC(1) --WWppaarreenntthheesseess Warn if parentheses are omitted in certain con- texts. --WWaallll All of the above `--WW' options combined. These are all the options which pertain to usage that we rec- ommend avoiding and that we believe is easy to avoid, even in conjunction with macros. The remaining `--WW......' options are not implied by `--WWaallll' because they warn about constructions that we consider reasonable to use, on occasion, in clean programs. --WWttrraaddiittiioonnaall Warn about certain constructs that behave differ- ently in traditional and ANSI C. o Macro arguments occurring within string constants in the macro body. These would substitute the ar- gument in traditional C, but are part of the con- stant in ANSI C. o A function declared external in one block and then used after the end of the block. o A sswwiittcchh statement has an operand of type lloonngg. --WWsshhaaddooww Warn whenever a local variable shadows another lo- cal variable. --WWiidd--ccllaasshh--_l_e_n Warn whenever two distinct identifiers match in the first _l_e_n characters. This may help you pre- pare a program that will compile with certain obso- lete, brain-damaged compilers. --WWppooiinntteerr--aarriitthh Warn about anything that depends on the ``size of'' a function type or of vvooiidd. GNU C assigns these types a size of 1, for convenience in calculations with vvooiidd ** pointers and pointers to functions. --WWccaasstt--qquuaall Warn whenever a pointer is cast so as to remove a type qualifier from the target type. For example, warn if a ccoonnsstt cchhaarr ** is cast to an ordinary cchhaarr **. --WWccaasstt--aalliiggnn Warn whenever a pointer is cast such that the re- quired alignment of the target is increased. For GNU Tools 28may1992 17 GCC(1) GNU Tools GCC(1) example, warn if a cchhaarr ** is cast to an iinntt ** on machines where integers can only be accessed at two- or four-byte boundaries. --WWwwrriittee--ssttrriinnggss Give string constants the type ccoonnsstt cchhaarr[[_l_e_n_g_t_h] so that copying the address of one into a non-ccoonnsstt cchhaarr ** pointer will get a warning. These warnings will help you find at compile time code that can try to write into a string constant, but only if you have been very careful about using ccoonnsstt in declarations and prototypes. Otherwise, it will just be a nuisance; this is why we did not make `--WWaallll' request these warnings. --WWccoonnvveerrssiioonn Warn if a prototype causes a type conversion that is different from what would happen to the same ar- gument in the absence of a prototype. This in- cludes conversions of fixed point to floating and vice versa, and conversions changing the width or signedness of a fixed point argument except when the same as the default promotion. --WWaaggggrreeggaattee--rreettuurrnn Warn if any functions that return structures or unions are defined or called. (In languages where you can return an array, this also elicits a warn- ing.) --WWssttrriicctt--pprroottoottyyppeess Warn if a function is declared or defined without specifying the argument types. (An old-style func- tion definition is permitted without a warning if preceded by a declaration which specifies the argu- ment types.) --WWmmiissssiinngg--pprroottoottyyppeess Warn if a global function is defined without a pre- vious prototype declaration. This warning is is- sued even if the definition itself provides a pro- totype. The aim is to detect global functions that fail to be declared in header files. --WWeennuumm--ccllaasshh _(_C_+_+ _o_n_l_y_._) Warn when converting between different enumeration types. --WWoovveerrllooaaddeedd--vviirrttuuaall _(_C_+_+ _o_n_l_y_._) In a derived class, the definitions of virtual functions must match the type signature of a virtual function declared in the base class. Use this option to request warnings when a derived class declares a function that may be an erroneous GNU Tools 28may1992 18 GCC(1) GNU Tools GCC(1) attempt to define a virtual function: that is, warn when a function with the same name as a virtual function in the base class, but with a type signa- ture that doesn't match any virtual functions from the base class. --WWiinnlliinnee Warn if a function can not be inlined, and either it was declared as inline, or else the --ffiinn-- lliinnee--ffuunnccttiioonnss option was given. --WWeerrrroorr Treat warnings as errors; abort compilation after any warning. DDEEBBUUGGGGIINNGG OOPPTTIIOONNSS GNU CC has various special options that are used for de- bugging either your program or GCC: --gg Produce debugging information in the operating sys- tem's native format (for DBX or SDB or DWARF). GDB also can work with this debugging information. On most systems that use DBX format, `--gg' enables use of extra debugging information that only GDB can use; if you want to control for certain whether to generate this information, use `--ggggddbb' or `--ggddbbxx'. Unlike most other C compilers, GNU CC allows you to use `--gg' with `--OO'. The shortcuts taken by opti- mized code may occasionally produce surprising re- sults: some variables you declared may not exist at all; flow of control may briefly move where you did not expect it; some statements may not be executed because they compute constant results or their val- ues were already at hand; some statements may exe- cute in different places because they were moved out of loops. Nevertheless it proves possible to debug optimized output. This makes it reasonable to use the opti- mizer for programs that might have bugs. The following options are useful when GNU CC is configured and compiled with the capability for more than one debugging format. --ggggddbb Produce debugging information in DBX format (if that is supported), including GDB extensions. --ggddbbxx Produce debugging information in DBX format (if that is supported), without GDB extensions. GNU Tools 28may1992 19 GCC(1) GNU Tools GCC(1) --ggssddbb Produce debugging information in SDB format (if that is supported). --ggddwwaarrff Produce debugging information in DWARF format (if that is supported). --gg_l_e_v_e_l --ggggddbb_l_e_v_e_l --ggddbbxx_l_e_v_e_l --ggssddbb_l_e_v_e_l --ggddwwaarrff_l_e_v_e_l Request debugging information and also use _l_e_v_e_l to specify how much information. The default level is 2. Level 1 produces minimal information, enough for making backtraces in parts of the program that you don't plan to debug. This includes descriptions of functions and external variables, but no informa- tion about local variables and no line numbers. --pp Generate extra code to write profile information suitable for the analysis program pprrooff. --ppgg Generate extra code to write profile information suitable for the analysis program ggpprrooff. --aa Generate extra code to write profile information for basic blocks, which will record the number of times each basic block is executed. This data could be analyzed by a program like ttccoovv. Note, however, that the format of the data is not what ttccoovv expects. Eventually GNU ggpprrooff should be ex- tended to process this data. --dd_l_e_t_t_e_r_s Says to make debugging dumps during compilation at times specified by _l_e_t_t_e_r_s. This is used for de- bugging the compiler. The file names for most of the dumps are made by appending a word to the source file name (e.g. `ffoooo..cc..rrttll' or `ffoooo..cc..jjuummpp'). --ddMM Dump all macro definitions, at the end of prepro- cessing, and write no output. --ddNN Dump all macro names, at the end of preprocessing. --ddDD Dump all macro definitions, at the end of prepro- cessing, in addition to normal output. --ddyy Dump debugging information during parsing, to stan- GNU Tools 28may1992 20 GCC(1) GNU Tools GCC(1) dard error. --ddrr Dump after RTL generation, to `_f_i_l_e.rtl'. --ddxx Just generate RTL for a function instead of compil- ing it. Usually used with `rr'. --ddjj Dump after first jump optimization, to `_f_i_l_e.jump'. --ddss Dump after CSE (including the jump optimization that sometimes follows CSE), to `_f_i_l_e.cse'. --ddLL Dump after loop optimization, to `_f_i_l_e.loop'. --ddtt Dump after the second CSE pass (including the jump optimization that sometimes follows CSE), to `_f_i_l_e.cse2'. --ddff Dump after flow analysis, to `_f_i_l_e.flow'. --ddcc Dump after instruction combination, to `_f_i_l_e.combine'. --ddSS Dump after the first instruction scheduling pass, to `_f_i_l_e.sched'. --ddll Dump after local register allocation, to `_f_i_l_e.lreg'. --ddgg Dump after global register allocation, to `_f_i_l_e.greg'. --ddRR Dump after the second instruction scheduling pass, to `_f_i_l_e.sched2'. --ddJJ Dump after last jump optimization, to `_f_i_l_e.jump2'. --dddd Dump after delayed branch scheduling, to `_f_i_l_e.dbr'. --ddkk Dump after conversion from registers to stack, to `_f_i_l_e.stack'. --ddmm Print statistics on memory usage, at the end of the run, to standard error. --ddpp Annotate the assembler output with a comment indi- cating which pattern and alternative was used. --ffpprreetteenndd--ffllooaatt When running a cross-compiler, pretend that the target machine uses the same floating point format as the host machine. This causes incorrect output of the actual floating constants, but the actual GNU Tools 28may1992 21 GCC(1) GNU Tools GCC(1) instruction sequence will probably be the same as GNU CC would make when running on the target ma- chine. --ssaavvee--tteemmppss Store the usual ``temporary'' intermediate files permanently; place them in the current directory and name them based on the source file. Thus, com- piling `ffoooo..cc' with `--cc --ssaavvee--tteemmppss' would produce files `ffoooo..ccpppp' and `ffoooo..ss', as well as `ffoooo..oo'. OOPPTTIIMMIIZZAATTIIOONN OOPPTTIIOONNSS These options control various sorts of optimizations: --OO Optimize. Optimizing compilation takes somewhat more time, and a lot more memory for a large func- tion. Without `--OO', the compiler's goal is to reduce the cost of compilation and to make debugging produce the expected results. Statements are independent: if you stop the program with a breakpoint between statements, you can then assign a new value to any variable or change the program counter to any other statement in the function and get exactly the re- sults you would expect from the source code. Without `--OO', only variables declared rreeggiisstteerr are allocated in registers. The resulting compiled code is a little worse than produced by PCC without `--OO'. With `--OO', the compiler tries to reduce code size and execution time. When you specify `--OO', `--fftthhrreeaadd--jjuummppss' and `--ffddeellaayyeedd--bbrraanncchh' are turned on. On some machines other flags may also be turned on. --OO22 Highly optimize. As compared to `--OO', this option will increase both compilation time and the perfor- mance of the generated code. All `--ff_f_l_a_g' options that control optimization are turned on when you specify `--OO22', except `--ffuunnrroollll--llooooppss' and `--ffuunnrroollll--aallll--llooooppss'. Options of the form `--ff_f_l_a_g' specify machine-independent flags. Most flags have both positive and negative forms; the negative form of `--ffffoooo' would be `--ffnnoo--ffoooo'. The following list shows only one form--the one which is not GNU Tools 28may1992 22 GCC(1) GNU Tools GCC(1) the default. You can figure out the other form by either removing `nnoo--' or adding it. --ffffllooaatt--ssttoorree Do not store floating point variables in registers. This prevents undesirable excess precision on ma- chines such as the 68000 where the floating regis- ters (of the 68881) keep more precision than a ddoouu-- bbllee is supposed to have. For most programs, the excess precision does only good, but a few programs rely on the precise defi- nition of IEEE floating point. Use `--ffffllooaatt--ssttoorree' for such programs. --ffmmeemmooiizzee--llooookkuuppss --ffssaavvee--mmeemmooiizzeedd _(_C_+_+ _o_n_l_y_._) These flags are used to get the com- piler to compile programs faster using heuristics. They are not on by default since they are only ef- fective about half the time. The other half of the time programs compile more slowly (and take more memory). The first time the compiler must build a call to a member function (or reference to a data member), it must (1) determine whether the class implements member functions of that name; (2) resolve which member function to call (which involves figuring out what sorts of type conversions need to be made); and (3) check the visibility of the member function to the caller. All of this adds up to slower compilation. Normally, the second time a call is made to that member function (or reference to that data member), it must go through the same lengthy process again. This means that code like this cout << "This " << p << " has " << n << " legs.\n"; makes six passes through all three steps. By using a software cache, a ``hit'' significantly reduces this cost. Unfortunately, using the cache intro- duces another layer of mechanisms which must be im- plemented, and so incurs its own overhead. `--ffmmeemmooiizzee--llooookkuuppss' enables the software cache. Because access privileges (visibility) to members and member functions may differ from one function context to the next, gg++++ may need to flush the cache. With the `--ffmmeemmooiizzee--llooookkuuppss' flag, the cache is flushed after every function that is compiled. The `-fsave-memoized' flag enables the same soft- GNU Tools 28may1992 23 GCC(1) GNU Tools GCC(1) ware cache, but when the compiler determines that the context of the last function compiled would yield the same access privileges of the next func- tion to compile, it preserves the cache. This is most helpful when defining many member functions for the same class: with the exception of member functions which are friends of other classes, each member function has exactly the same access privi- leges as every other, and the cache need not be flushed. --ffnnoo--ddeeffaauulltt--iinnlliinnee _(_C_+_+ _o_n_l_y_._) If `--ffddeeffaauulltt--iinnlliinnee' is enabled then member functions defined inside class scope are compiled inline by default; i.e., you don't need to add `iinnlliinnee' in front of the member function name. By popular demand, this option is now the default. To keep GNU C++ from inlining these member func- tions, specify `--ffnnoo--ddeeffaauulltt--iinnlliinnee'. --ffnnoo--ddeeffeerr--ppoopp Always pop the arguments to each function call as soon as that function returns. For machines which must pop arguments after a function call, the com- piler normally lets arguments accumulate on the stack for several function calls and pops them all at once. --ffffoorrccee--mmeemm Force memory operands to be copied into registers before doing arithmetic on them. This may produce better code by making all memory references poten- tial common subexpressions. When they are not com- mon subexpressions, instruction combination should eliminate the separate register-load. I am inter- ested in hearing about the difference this makes. --ffffoorrccee--aaddddrr Force memory address constants to be copied into registers before doing arithmetic on them. This may produce better code just as `--ffffoorrccee--mmeemm' may. I am interested in hearing about the difference this makes. --ffoommiitt--ffrraammee--ppooiinntteerr Don't keep the frame pointer in a register for functions that don't need one. This avoids the in- structions to save, set up and restore frame point- ers; it also makes an extra register available in many functions. _I_t _a_l_s_o _m_a_k_e_s _d_e_b_u_g_g_i_n_g _i_m_p_o_s_s_i_b_l_e _o_n most machines. On some machines, such as the Vax, this flag has no effect, because the standard calling sequence auto- GNU Tools 28may1992 24 GCC(1) GNU Tools GCC(1) matically handles the frame pointer and nothing is saved by pretending it doesn't exist. The machine- description macro FFRRAAMMEE__PPOOIINNTTEERR__RREEQQUUIIRREEDD controls whether a target machine supports this flag. --ffiinnlliinnee Pay attention the iinnlliinnee keyword. Normally the negation of this option `--ffnnoo--iinnlliinnee' is used to keep the compiler from expanding any functions in- line. However, the opposite effect may be desir- able when compiling with `--gg', since `--gg' normally turns off all inline function expansion. --ffiinnlliinnee--ffuunnccttiioonnss Integrate all simple functions into their callers. The compiler heuristically decides which functions are simple enough to be worth integrating in this way. If all calls to a given function are integrated, and the function is declared ssttaattiicc, then GCC nor- mally does not output the function as assembler code in its own right. --ffccaalllleerr--ssaavveess Enable values to be allocated in registers that will be clobbered by function calls, by emitting extra instructions to save and restore the regis- ters around such calls. Such allocation is done only when it seems to result in better code than would otherwise be produced. This option is enabled by default on certain ma- chines, usually those which have no call-preserved registers to use instead. --ffkkeeeepp--iinnlliinnee--ffuunnccttiioonnss Even if all calls to a given function are integrat- ed, and the function is declared ssttaattiicc, neverthe- less output a separate run-time callable version of the function. --ffnnoo--ffuunnccttiioonn--ccssee Do not put function addresses in registers; make each instruction that calls a constant function contain the function's address explicitly. This option results in less efficient code, but some strange hacks that alter the assembler output may be confused by the optimizations performed when this option is not used. The following options control specific optimizations. The GNU Tools 28may1992 25 GCC(1) GNU Tools GCC(1) `--OO22' option turns on all of these optimizations except `--ffuunnrroollll--llooooppss' and `--ffuunnrroollll--aallll--llooooppss'. The `--OO' option usually turns on the `--fftthhrreeaadd--jjuummppss' and `--ffddeellaayyeedd--bbrraanncchh' options, but specific machines may change the default optimizations. You can use the following flags in the rare cases when ``fine-tuning'' of optimizations to be performed is de- sired. --ffssttrreennggtthh--rreedduuccee Perform the optimizations of loop strength reduc- tion and elimination of iteration variables. --fftthhrreeaadd--jjuummppss Perform optimizations where we check to see if a jump branches to a location where another compari- son subsumed by the first is found. If so, the first branch is redirected to either the destina- tion of the second branch or a point immediately following it, depending on whether the condition is known to be true or false. --ffuunnrroollll--llooooppss Perform the optimization of loop unrolling. This is only done for loops whose number of iterations can be determined at compile time or run time. --ffuunnrroollll--aallll--llooooppss Perform the optimization of loop unrolling. This is done for all loops. This usually makes programs run more slowly. --ffccssee--ffoollllooww--jjuummppss In common subexpression elimination, scan through jump instructions in certain cases. This is not as powerful as completely global CSE, but not as slow either. --ffrreerruunn--ccssee--aafftteerr--lloooopp Re-run common subexpression elimination after loop optimizations has been performed. --ffeelliiddee--ccoonnssttrruuccttoorrss _(_C_+_+ _o_n_l_y_._) Use this option to instruct the com- piler to be smarter about when it can elide con- structors. Without this flag, GNU C++ and cfront both generate effectively the same code for: A foo (); A x (foo ()); // x initialized by `foo ()', no ctor called A y = foo (); // call to `foo ()' heads to tempo- rary, GNU Tools 28may1992 26 GCC(1) GNU Tools GCC(1) // y is initialized from the tempo- rary. Note the difference! With this flag, GNU C++ ini- tializes `yy' directly from the call to ffoooo (()) with- out going through a temporary. --ffeexxppeennssiivvee--ooppttiimmiizzaattiioonnss Perform a number of minor optimizations that are relatively expensive. --ffddeellaayyeedd--bbrraanncchh If supported for the target machine, attempt to re- order instructions to exploit instruction slots available after delayed branch instructions. --ffsscchheedduullee--iinnssnnss If supported for the target machine, attempt to re- order instructions to eliminate execution stalls due to required data being unavailable. This helps machines that have slow floating point or memory load instructions by allowing other instructions to be issued until the result of the load or floating point instruction is required. --ffsscchheedduullee--iinnssnnss22 Similar to `--ffsscchheedduullee--iinnssnnss', but requests an ad- ditional pass of instruction scheduling after reg- ister allocation has been done. This is especially useful on machines with a relatively small number of registers and where memory load instructions take more than one cycle. TTAARRGGEETT OOPPTTIIOONNSS By default, GNU CC compiles code for the same type of ma- chine that you are using. However, it can also be in- stalled as a cross-compiler, to compile for some other type of machine. In fact, several different configura- tions of GNU CC, for different target machines, can be in- stalled side by side. Then you specify which one to use with the `--bb' option. In addition, older and newer versions of GNU CC can be in- stalled side by side. One of them (probably the newest) will be the default, but you may sometimes wish to use an- other. --bb _m_a_c_h_i_n_e The argument _m_a_c_h_i_n_e specifies the target machine for compilation. This is useful when you have in- stalled GNU CC as a cross-compiler. GNU Tools 28may1992 27 GCC(1) GNU Tools GCC(1) The value to use for _m_a_c_h_i_n_e is the same as was specified as the machine type when configuring GNU CC as a cross-compiler. For example, if a cross- compiler was configured with `ccoonnffiigguurree i386v', meaning to compile for an 80386 running System V, then you would specify `--bb ii338866vv' to run that cross compiler. When you do not specify `--bb', it normally means to compile for the same type of machine that you are using. --VV _v_e_r_s_i_o_n The argument _v_e_r_s_i_o_n specifies which version of GNU CC to run. This is useful when multiple ver- sions are installed. For example, _v_e_r_s_i_o_n might be `22..00', meaning to run GNU CC version 2.0. The default version, when you do not specify `--VV', is controlled by the way GNU CC is installed. Nor- mally, it will be a version that is recommended for general use. MMAACCHHIINNEE DDEEPPEENNDDEENNTT OOPPTTIIOONNSS Each of the target machine types can have its own special options, starting with `--mm', to choose among various hard- ware models or configurations--for example, 68010 vs 68020, floating coprocessor or none. A single installed version of the compiler can compile for any model or con- figuration, according to the options specified. These are the `--mm' options defined for the 68000 series: --mm6688002200 --mmcc6688002200 Generate output for a 68020 (rather than a 68000). This is the default if you use the unmodified sources. --mm6688000000 --mmcc6688000000 Generate output for a 68000 (rather than a 68020). --mm6688888811 Generate output containing 68881 instructions for floating point. This is the default if you use the unmodified sources. --mmffppaa Generate output containing Sun FPA instructions for floating point. GNU Tools 28may1992 28 GCC(1) GNU Tools GCC(1) --mmssoofftt--ffllooaatt Generate output containing library calls for float- ing point. _W_A_R_N_I_N_G_: the requisite libraries are not part of GNU CC. Normally the facilities of the machine's usual C compiler are used, but this can't be done directly in cross-compilation. You must make your own arrangements to provide suitable li- brary functions for cross-compilation. --mmsshhoorrtt Consider type iinntt to be 16 bits wide, like sshhoorrtt iinntt. --mmnnoobbiittffiieelldd Do not use the bit-field instructions. `--mm6688000000' implies `--mmnnoobbiittffiieelldd'. --mmbbiittffiieelldd Do use the bit-field instructions. `--mm6688002200' im- plies `--mmbbiittffiieelldd'. This is the default if you use the unmodified sources. --mmrrttdd Use a different function-calling convention, in which functions that take a fixed number of argu- ments return with the rrttdd instruction, which pops their arguments while returning. This saves one instruction in the caller since there is no need to pop the arguments there. This calling convention is incompatible with the one normally used on Unix, so you cannot use it if you need to call libraries compiled with the Unix compiler. Also, you must provide function prototypes for all functions that take variable numbers of arguments (including pprriinnttff); otherwise incorrect code will be generated for calls to those functions. In addition, seriously incorrect code will result if you call a function with too many arguments. (Normally, extra arguments are harmlessly ignored.) The rrttdd instruction is supported by the 68010 and 68020 processors, but not by the 68000. These `--mm' options are defined for the Vax: --mmuunniixx Do not output certain jump instructions (aaoobblleeqq and so on) that the Unix assembler for the Vax cannot handle across long ranges. --mmggnnuu Do output those jump instructions, on the assump- GNU Tools 28may1992 29 GCC(1) GNU Tools GCC(1) tion that you will assemble with the GNU assembler. --mmgg Output code for g-format floating point numbers in- stead of d-format. These `--mm' switches are supported on the Sparc: --mmffppuu Generate output containing floating point instruc- tions. This is the default if you use the unmodi- fied sources. --mmnnoo--eeppiilloogguuee Generate separate return instructions for rreettuurrnn statements. This has both advantages and disadvan- tages; I don't recall what they are. These `--mm' options are defined for the Convex: --mmcc11 Generate output for a C1. This is the default when the compiler is configured for a C1. --mmcc22 Generate output for a C2. This is the default when the compiler is configured for a C2. --mmaarrggccoouunntt Generate code which puts an argument count in the word preceding each argument list. Some non- portable Convex and Vax programs need this word. (Debuggers don't, except for functions with vari- able-length argument lists; this info is in the symbol table.) --mmnnooaarrggccoouunntt Omit the argument count word. This is the default if you use the unmodified sources. These `--mm' options are defined for the AMD Am29000: --mmddww Generate code that assumes the DW bit is set, i.e., that byte and halfword operations are directly sup- ported by the hardware. This is the default. --mmnnooddww Generate code that assumes the DW bit is not set. --mmbbww Generate code that assumes the system supports byte and halfword write operations. This is the de- fault. --mmnnbbww Generate code that assumes the systems does not support byte and halfword write operations. This implies `--mmnnooddww'. GNU Tools 28may1992 30 GCC(1) GNU Tools GCC(1) --mmssmmaallll Use a small memory model that assumes that all function addresses are either within a single 256 KB segment or at an absolute address of less than 256K. This allows the ccaallll instruction to be used instead of a ccoonnsstt, ccoonnsstthh, ccaallllii sequence. --mmllaarrggee Do not assume that the ccaallll instruction can be used; this is the default. --mm2299005500 Generate code for the Am29050. --mm2299000000 Generate code for the Am29000. This is the de- fault. --mmkkeerrnneell--rreeggiisstteerrss Generate references to registers ggrr6644--ggrr9955 instead of ggrr9966--ggrr112277. This option can be used when com- piling kernel code that wants a set of global reg- isters disjoint from that used by user-mode code. Note that when this option is used, register names in `--ff' flags must use the normal, user-mode, names. --mmuusseerr--rreeggiisstteerrss Use the normal set of global registers, ggrr9966--ggrr112277. This is the default. --mmssttaacckk--cchheecckk Insert a call to ____mmsspp__cchheecckk after each stack ad- justment. This is often used for kernel code. These `--mm' options are defined for Motorola 88K architec- tures: --mmbbiigg--ppiicc Emit position-independent code, suitable for dynam- ic linking, even if branches need large displace- ments. Equivalent to the general-use option `--ffPPIICC'. The general-use option `--ffppiicc', by con- trast, only emits valid 88k code if all branches involve small displacements. GCC does not emit po- sition-independent code by default. --mmiiddeennttiiffyy--rreevviissiioonn Include an iiddeenntt directive in the assembler output recording the source file name, compiler name and version, timestamp, and compilation flags used. GNU Tools 28may1992 31 GCC(1) GNU Tools GCC(1) --mmnnoo--uunnddeerrssccoorreess In assembler output, emit symbol names without adding an underscore character at the beginning of each name. The default is to use an underscore as prefix on each name. --mmnnoo--cchheecckk--zzeerroo--ddiivviissiioonn --mmcchheecckk--zzeerroo--ddiivviissiioonn Early models of the 88K architecture had problems with division by zero; in particular, many of them didn't trap. Use these options to avoid including (or to include explicitly) additional code to de- tect division by zero and signal an exception. All GCC configurations for the 88K use `--mmcchheecckk--zzeerroo--ddiivviissiioonn' by default. --mmooccss--ddeebbuugg--iinnffoo --mmnnoo--ooccss--ddeebbuugg--iinnffoo Include (or omit) additional debugging information (about registers used in each stack frame) as spec- ified in the 88Open Object Compatibility Standard, ``OCS''. This extra information is not needed by GDB. The default for DG/UX, SVr4, and Delta 88 SVr3.2 is to include this information; other 88k configurations omit this information by default. --mmooccss--ffrraammee--ppoossiittiioonn --mmnnoo--ooccss--ffrraammee--ppoossiittiioonn Force (or do not require) register values to be stored in a particular place in stack frames, as specified in OCS. The DG/UX, Delta88 SVr3.2, and BCS configurations use `--mmooccss--ffrraammee--ppoossiittiioonn'; oth- er 88k configurations have the default `--mmnnoo--ooccss--ffrraammee--ppoossiittiioonn'. --mmooppttiimmiizzee--aarrgg--aarreeaa --mmnnoo--ooppttiimmiizzee--aarrgg--aarreeaa Control how to store function arguments in stack frames. `--mmooppttiimmiizzee--aarrgg--aarreeaa' saves space, but may break some debuggers (not GDB). `--mmnnoo--ooppttiimmiizzee--aarrgg--aarreeaa' conforms better to stan- dards. By default GCC does not optimize the argu- ment area. --mmsshhoorrtt--ddaattaa--_n_u_m _n_u_m Generate smaller data references by making them relative to rr00, which allows loading a value using a single instruction (rather than the usual two). You control which data references are af- fected by specifying _n_u_m with this option. For ex- GNU Tools 28may1992 32 GCC(1) GNU Tools GCC(1) ample, if you specify `--mmsshhoorrtt--ddaattaa--551122', then the data references affected are those involving dis- placements of less than 512 bytes. `--mmsshhoorrtt--ddaattaa--_n_u_m' is not effective for _n_u_m greater than 64K. --mmssvvrr44 --mmssvvrr33 Turn on (`--mmssvvrr44') or off (`--mmssvvrr33') compiler ex- tensions related to System V release 4 (SVr4). This controls the following: o Which variant of the assembler syntax to emit (which you can select independently using `--mmvveerrssiioonn0033..0000'). o `--mmssvvrr44' makes the C preprocessor recognize `##pprraagg-- mmaa wweeaakk' o `--mmssvvrr44' makes GCC issue additional declaration di- rectives used in SVr4. `--mmssvvrr33' is the default for all m88K configurations except the SVr4 configuration. --mmttrraapp--llaarrggee--sshhiifftt --mmhhaannddllee--llaarrggee--sshhiifftt Include code to detect bit-shifts of more than 31 bits; respectively, trap such shifts or emit code to handle them properly. By default GCC makes no special provision for large bit shifts. --mmuussee--ddiivv--iinnssttrruuccttiioonn Very early models of the 88K architecture didn't have a divide instruction, so GCC avoids that in- struction by default. Use this option to specify that it's safe to use the divide instruction. --mmvveerrssiioonn--0033..0000 Use alternative assembler syntax for the assembler version corresponding to SVr4, but without enabling the other features triggered by `--ssvvrr44'. This is implied by `--ssvvrr44', is the default for the SVr4 configuration of GCC, and is permitted by the DG/UX configuration only if `--ssvvrr44' is also specified. The Delta 88 SVr3.2 configuration ignores this op- tion. --mmwwaarrnn--ppaasssseedd--ssttrruuccttss Warn when a function passes a struct as an argument or result. Structure-passing conventions have changed during the evolution of the C language, and are often the source of portability problems. By GNU Tools 28may1992 33 GCC(1) GNU Tools GCC(1) default, GCC issues no such warning. These options are defined for the IBM RS6000: --mmffpp--iinn--ttoocc --mmnnoo--ffpp--iinn--ttoocc Control whether or not floating-point constants go in the Table of Contents (TOC), a table of all global variable and function addresses. By default GCC puts floating-point constants there; if the TOC overflows, `--mmnnoo--ffpp--iinn--ttoocc' will reduce the size of the TOC, which may avoid the overflow. These `--mm' options are defined for the IBM RT PC: --mmiinn--lliinnee--mmuull Use an in-line code sequence for integer multi- plies. This is the default. --mmccaallll--lliibb--mmuull Call llmmuull$$$$ for integer multiples. --mmffuullll--ffpp--bblloocckkss Generate full-size floating point data blocks, in- cluding the minimum amount of scratch space recom- mended by IBM. This is the default. --mmmmiinniimmuumm--ffpp--bblloocckkss Do not include extra scratch space in floating point data blocks. This results in smaller code, but slower execution, since scratch space must be allocated dynamically. --mmffpp--aarrgg--iinn--ffpprreeggss Use a calling sequence incompatible with the IBM calling convention in which floating point argu- ments are passed in floating point registers. Note that vvaarraarrggss..hh and ssttddaarrggss..hh will not work with floating point operands if this option is speci- fied. --mmffpp--aarrgg--iinn--ggrreeggss Use the normal calling convention for floating point arguments. This is the default. --mmhhcc--ssttrruucctt--rreettuurrnn Return structures of more than one word in memory, rather than in a register. This provides compati- bility with the MetaWare HighC (hc) compiler. Use `--ffppcccc--ssttrruucctt--rreettuurrnn' for compatibility with the Portable C Compiler (pcc). GNU Tools 28may1992 34 GCC(1) GNU Tools GCC(1) --mmnnoohhcc--ssttrruucctt--rreettuurrnn Return some structures of more than one word in registers, when convenient. This is the default. For compatibility with the IBM-supplied compilers, use either `--ffppcccc--ssttrruucctt--rreettuurrnn' or `--mmhhcc--ssttrruucctt--rreettuurrnn'. These `--mm' options are defined for the MIPS family of com- puters: --mmccppuu==_c_p_u_-_t_y_p_e Assume the defaults for the machine type _c_p_u_-_t_y_p_e when scheduling instructions. The default _c_p_u_-_t_y_p_e is ddeeffaauulltt, which picks the longest cycles times for any of the machines, in order that the code run at reasonable rates on all MIPS cpu's. Other choices for _c_p_u_-_t_y_p_e are rr22000000, rr33000000, rr44000000, and rr66000000. While picking a specific _c_p_u_-_t_y_p_e will schedule things appropriately for that particular chip, the compiler will not generate any code that does not meet level 1 of the MIPS ISA (instruction set architecture) without the --mmiippss22 or --mmiippss33 switches being used. --mmiippss22 Issue instructions from level 2 of the MIPS ISA (branch likely, square root instructions). The --mmccppuu==rr44000000 or --mmccppuu==rr66000000 switch must be used in conjunction with --mmiippss22. --mmiippss33 Issue instructions from level 3 of the MIPS ISA (64 bit instructions). The --mmccppuu==rr44000000 switch must be used in conjunction with --mmiippss22. --mmiinntt6644 --mmlloonngg6644 --mmlloonngglloonngg112288 These options don't work at present. --mmmmiippss--aass Generate code for the MIPS assembler, and invoke mmiippss--ttffiillee to add normal debug information. This is the default for all platforms except for the OSF/1 reference platform, using the OSF/rose object format. If any of the --ggggddbb, --ggssttaabbss, or --ggssttaabbss++ switches are used, the mmiippss--ttffiillee program will en- capsulate the stabs within MIPS ECOFF. --mmggaass Generate code for the GNU assembler. This is the default on the OSF/1 reference platform, using the OSF/rose object format. GNU Tools 28may1992 35 GCC(1) GNU Tools GCC(1) --mmrrnnaammeess --mmnnoo--rrnnaammeess The --mmrrnnaammeess switch says to output code using the MIPS software names for the registers, instead of the hardware names (ie, aa00 instead of $$44). The GNU assembler does not support the --mmrrnnaammeess switch, and the MIPS assembler will be instructed to run the MIPS C preprocessor over the source file. The --mmnnoo--rrnnaammeess switch is default. --mmggppoopptt --mmnnoo--ggppoopptt The --mmggppoopptt switch says to write all of the data declarations before the instructions in the text section, to all the MIPS assembler to generate one word memory references instead of using two words for short global or static data items. This is on by default if optimization is selected. --mmssttaattss --mmnnoo--ssttaattss For each non-inline function processed, the --mmssttaattss switch causes the compiler to emit one line to the standard error file to print statistics about the program (number of registers saved, stack size, etc.). --mmmmeemmccppyy --mmnnoo--mmeemmccppyy The --mmmmeemmccppyy switch makes all block moves call the appropriate string function (mmeemmccppyy or bbccooppyy) in- stead of possibly generating inline code. --mmmmiippss--ttffiillee --mmnnoo--mmiippss--ttffiillee The --mmnnoo--mmiippss--ttffiillee switch causes the compiler not postprocess the object file with the mmiippss--ttffiillee program, after the MIPS assembler has generated it to add debug support. If mmiippss--ttffiillee is not run, then no local variables will be available to the debugger. In addition, ssttaaggee22 and ssttaaggee33 objects will have the temporary file names passed to the assembler embedded in the object file, which means the objects will not compare the same. --mmssoofftt--ffllooaatt Generate output containing library calls for float- ing point. _W_A_R_N_I_N_G_: the requisite libraries are not part of GNU CC. Normally the facilities of the GNU Tools 28may1992 36 GCC(1) GNU Tools GCC(1) machine's usual C compiler are used, but this can't be done directly in cross-compilation. You must make your own arrangements to provide suitable li- brary functions for cross-compilation. --mmhhaarrdd--ffllooaatt Generate output containing floating point instruc- tions. This is the default if you use the unmodi- fied sources. --mmffpp6644 Assume that the FFRR bit in the status word is on, and that there are 32 64-bit floating point regis- ters, instead of 32 32-bit floating point regis- ters. You must also specify the --mmccppuu==rr44000000 and --mmiippss33 switches. --mmffpp3322 Assume that there are 32 32-bit floating point reg- isters. This is the default. --mmaabbiiccaallllss The --mmaabbiiccaallllss switch says to emit the ..aabbiiccaallllss, ..ccppllooaadd, and ..ccpprreessttoorree pseudo operations that some System V.4 ports use for position independent code. --mmhhaallff--ppiicc --mmnnoo--hhaallff--ppiicc The --mmhhaallff--ppiicc switch says to put pointers to ex- tern references into the data section and load them up, rather than put the references in the text sec- tion. This option does not work at present. --GG_n_u_m Put global and static items less than or equal to _n_u_m bytes into the small data or bss sections in- stead of the normal data or bss section. This al- lows the assembler to emit one word memory refer- ence instructions based on the global pointer (ggpp or $$2288), instead of the normal two words used. By default, _n_u_m is 8 when the MIPS assembler is used, and 0 when the GNU assembler is used. The --GG_n_u_m switch is also passed to the assembler and linker. All modules should be compiled with the same --GG_n_u_m value. CCOODDEE GGEENNEERRAATTIIOONN OOPPTTIIOONNSS These machine-independent options control the interface conventions used in code generation. Most of them begin with `-f'. These options have both positive and negative forms; the negative form of `--ffffoooo' would be `--ffnnoo--ffoooo'. In the table below, only one of the forms is listed--the one which is not the default. You can figure out the other form by either removing `nnoo--' or GNU Tools 28may1992 37 GCC(1) GNU Tools GCC(1) adding it. ++ee_N _(_C_+_+ _o_n_l_y_._) control whether virtual function defi- nitions in classes are used to generate code, or only to define interfaces for their callers. These options are provided for compatibility with cfront 1.x usage; the recommended GNU C++ usage is to use ##pprraaggmmaa iinntteerrffaaccee and ##pprraaggmmaa iimmpplleemmeennttaattiioonn, in- stead. With `++ee00', virtual function definitions in classes are declared extern; the declaration is used only as an interface specification, not to generate code for the virtual functions (in this compilation). With `++ee11', gg++++ actually generates the code imple- menting virtual functions defined in the code, and makes them publicly visible. --ffnnoonnnnuullll--oobbjjeeccttss _(_C_+_+ _o_n_l_y_._) Normally, GNU C++ makes conservative assumptions about objects reached through refer- ences. For example, the compiler must check that `aa' is not null in code like the following: obj &a = g (); a.f (2); Checking that references of this sort have non-null values requires extra code, however, and it is un- necessary for many programs. You can use `--ffnnoonnnnuullll--oobbjjeeccttss' to omit the checks for null, if your program doesn't require the default checking. --ffppcccc--ssttrruucctt--rreettuurrnn Use the same convention for returning ssttrruucctt and uunniioonn values that is used by the usual C compiler on your system. This convention is less efficient for small structures, and on many machines it fails to be reentrant; but it has the advantage of allow- ing intercallability between GCC-compiled code and PCC-compiled code. --ffsshhoorrtt--eennuummss Allocate to an eennuumm type only as many bytes as it needs for the declared range of possible values. Specifically, the eennuumm type will be equivalent to the smallest integer type which has enough room. --ffsshhoorrtt--ddoouubbllee Use the same size for ddoouubbllee as for ffllooaatt . --ffsshhaarreedd--ddaattaa Requests that the data and non-ccoonnsstt variables of this compilation be shared data rather than private data. The distinction makes sense only on certain GNU Tools 28may1992 38 GCC(1) GNU Tools GCC(1) operating systems, where shared data is shared be- tween processes running the same program, while private data exists in one copy per process. --ffnnoo--ccoommmmoonn Allocate even uninitialized global variables in the bss section of the object file, rather than gener- ating them as common blocks. This has the effect that if the same variable is declared (without eexx-- tteerrnn) in two different compilations, you will get an error when you link them. The only reason this might be useful is if you wish to verify that the program will work on other systems which always work this way. --ffvvoollaattiillee Consider all memory references through pointers to be volatile. --ffppiicc If supported for the target machines, generate po- sition-independent code, suitable for use in a shared library. --ffPPIICC If supported for the target machine, emit position- independent code, suitable for dynamic linking, even if branches need large displacements. --ffffiixxeedd--_r_e_g Treat the register named _r_e_g as a fixed register; generated code should never refer to it (except perhaps as a stack pointer, frame pointer or in some other fixed role). _r_e_g must be the name of a register. The register names accepted are machine-specific and are defined in the RREEGGIISSTTEERR__NNAAMMEESS macro in the machine descrip- tion macro file. This flag does not have a negative form, because it specifies a three-way choice. --ffccaallll--uusseedd--_r_e_g Treat the register named _r_e_g as an allocatable register that is clobbered by function calls. It may be allocated for temporaries or variables that do not live across a call. Functions compiled this way will not save and restore the register _r_e_g. Use of this flag for a register that has a fixed pervasive role in the machine's execution model, such as the stack pointer or frame pointer, will produce disastrous results. This flag does not have a negative form, because it GNU Tools 28may1992 39 GCC(1) GNU Tools GCC(1) specifies a three-way choice. --ffccaallll--ssaavveedd--_r_e_g Treat the register named _r_e_g as an allocatable register saved by functions. It may be allocated even for temporaries or variables that live across a call. Functions compiled this way will save and restore the register _r_e_g if they use it. Use of this flag for a register that has a fixed pervasive role in the machine's execution model, such as the stack pointer or frame pointer, will produce disastrous results. A different sort of disaster will result from the use of this flag for a register in which function values may be returned. This flag does not have a negative form, because it specifies a three-way choice. --ffggnnuu--bbiinnuuttiillss --ffnnoo--ggnnuu--bbiinnuuttiillss _(_C_+_+ _o_n_l_y_._) `--ffggnnuu--bbiinnuuttiillss ' (the default for most, but not all, platforms) makes GNU C++ emit extra information for static initialization and fi- nalization. This information has to be passed from the assembler to the GNU linker. Some assemblers won't pass this information; you must either use GNU aass or specify the option `--ffnnoo--ggnnuu--bbiinnuuttiillss'. With `--ffnnoo--ggnnuu--bbiinnuuttiillss', you must use the program ccoolllleecctt (part of the GCC distribution) for linking. PPRRAAGGMMAASS Two `##pprraaggmmaa' directives are supported for GNU C++, to permit using the same header file for two purposes: as a definition of interfaces to a given object class, and as the full definition of the contents of that object class. ##pprraaggmmaa iinntteerrffaaccee _(_C_+_+ _o_n_l_y_._) Use this directive in header files that define object classes, to save space in most of the object files that use those classes. Nor- mally, local copies of certain information (backup copies of inline member functions, debugging infor- mation, and the internal tables that implement vir- tual functions) must be kept in each object file that includes class definitions. You can use this pragma to avoid such duplication. When a header file containing `##pprraaggmmaa iinntteerrffaaccee' is included in GNU Tools 28may1992 40 GCC(1) GNU Tools GCC(1) a compilation, this auxiliary information will not be generated (unless the main input source file it- self uses `##pprraaggmmaa iimmpplleemmeennttaattiioonn'). Instead, the object files will contain references to be resolved at link time. ##pprraaggmmaa iimmpplleemmeennttaattiioonn ##pprraaggmmaa iimmpplleemmeennttaattiioonn ""_o_b_j_e_c_t_s..hh"" _(_C_+_+ _o_n_l_y_._) Use this pragma in a main input file, when you want full output from included header files to be generated (and made globally visible). The included header file, in turn, should use `##pprraaggmmaa iinntteerrffaaccee'. Backup copies of inline mem- ber functions, debugging information, and the in- ternal tables used to implement virtual functions are all generated in implementation files. If you use `##pprraaggmmaa iimmpplleemmeennttaattiioonn' with no argu- ment, it applies to an include file with the same basename as your source file; for example, in `aallllccllaassss..cccc', `##pprraaggmmaa iimmpplleemmeennttaattiioonn' by itself is equivalent to `##pprraaggmmaa iimmpplleemmeennttaattiioonn ""aallllccllaassss..hh""'. Use the string argument if you want a single implementation file to include code from multiple header files. There is no way to split up the contents of a sin- gle header file into multiple implementation files. FFIILLEESS file.c C source file file.h C header (preprocessor) file file.i preprocessed C source file file.C C++ source file file.cc C++ source file file.cxx C++ source file file.m Objective-C source file file.s assembly language file file.o object file a.out link edited output _T_M_P_D_I_R/cc* temporary files _L_I_B_D_I_R/cpp preprocessor _L_I_B_D_I_R/cc1 compiler for C _L_I_B_D_I_R/cc1plus compiler for C++ _L_I_B_D_I_R/collect linker front end needed on some ma- chines _L_I_B_D_I_R/libgcc.a GCC subroutine library /lib/crt[01n].o start-up routine _L_I_B_D_I_R/ccrt0 additional start-up routine for C++ /lib/libc.a standard C library, see _i_n_t_r_o(3) /usr/include standard directory for ##iinncclluuddee files _L_I_B_D_I_R/include standard gcc directory for ##iinncclluuddee files GNU Tools 28may1992 41 GCC(1) GNU Tools GCC(1) _L_I_B_D_I_R/g++-include additional g++ directory for ##iinncclluuddee _L_I_B_D_I_R is usually //uussrr//llooccaall//lliibb//_m_a_c_h_i_n_e/_v_e_r_s_i_o_n. _T_M_P_D_I_R comes from the environment variable TTMMPPDDIIRR (default //uussrr//ttmmpp if available, else //ttmmpp). SSEEEE AALLSSOO cpp(1), as(1), ld(1), gdb(1), adb(1), dbx(1), sdb(1). `ggcccc', `ccpppp', `aass',``ld'',, and `ggddbb' entries in iinnffoo. _U_s_i_n_g _a_n_d _P_o_r_t_i_n_g _G_N_U _C_C _(_f_o_r _v_e_r_s_i_o_n _2_._0_), Richard M. Stallman, November 1990; _T_h_e _C _P_r_e_p_r_o_c_e_s_s_o_r, Richard M. Stallman, July 1990; _U_s_i_n_g _G_D_B_: _A _G_u_i_d_e _t_o _t_h_e _G_N_U _S_o_u_r_c_e_- _L_e_v_e_l _D_e_b_u_g_g_e_r, Richard M. Stallman and Roland H. Pesch, December 1991; _U_s_i_n_g _a_s_: _t_h_e _G_N_U _A_s_s_e_m_b_l_e_r, Dean Elsner, Jay Fenlason & friends, March 1991; _g_l_d_: _t_h_e _G_N_U _l_i_n_k_e_r, Steve Chamberlain and Roland Pesch, April 1991. BBUUGGSS Report bugs to bbuugg--ggcccc@@pprreepp..aaii..mmiitt..eedduu. Bugs tend actual- ly to be fixed if they can be isolated, so it is in your interest to report them in such a way that they can be easily reproduced. CCOOPPYYIINNGG Copyright (c) 1991 Free Software Foundation, Inc. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified ver- sions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this manual into another language, under the above con- ditions for modified versions, except that this permission notice may be included in translations approved by the Free Software Foundation instead of in the original En- glish. AAUUTTHHOORRSS See the GNU CC Manual for the contributors to GNU CC. GNU Tools 28may1992 42