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cpp.arc
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CPP2.C
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1985-11-27
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21KB
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638 lines
/*
* C P P 2 . C
*
* Process #control lines
*
* Edit history
* 13-Nov-84 MM Split from cpp1.c
* 06-Jun-85 KR fixed #include bug in doinclude()
*/
#include <stdio.h>
#include <ctype.h>
#include "cppdef.h"
#include "cpp.h"
#if HOST == SYS_VMS
/*
* Include the rms stuff. (We can't just include rms.h as it uses the
* VaxC-specific library include syntax that Decus CPP doesn't support.
* By including things by hand, we can CPP ourself.)
*/
#include <nam.h>
#include <fab.h>
#include <rab.h>
#include <rmsdef.h>
#endif
/*
* Generate (by hand-inspection) a set of unique values for each control
* operator. Note that this is not guaranteed to work for non-Ascii
* machines. CPP won't compile if there are hash conflicts.
*/
#define L_assert ('a' + ('s' << 1))
#define L_define ('d' + ('f' << 1))
#define L_elif ('e' + ('i' << 1))
#define L_else ('e' + ('s' << 1))
#define L_endif ('e' + ('d' << 1))
#define L_if ('i' + (EOS << 1))
#define L_ifdef ('i' + ('d' << 1))
#define L_ifndef ('i' + ('n' << 1))
#define L_include ('i' + ('c' << 1))
#define L_line ('l' + ('n' << 1))
#define L_nogood (EOS + (EOS << 1)) /* To catch #i */
#define L_pragma ('p' + ('a' << 1))
#define L_undef ('u' + ('d' << 1))
#if DEBUG
#define L_debug ('d' + ('b' << 1)) /* #debug */
#endif
int
control(counter)
int counter; /* Pending newline counter */
/*
* Process #control lines. Simple commands are processed inline,
* while complex commands have their own subroutines.
*
* The counter is used to force out a newline before #line, and
* #pragma commands. This prevents these commands from ending up at
* the end of the previous line if cpp is invoked with the -C option.
*/
{
register int c;
register char *tp;
register int hash;
char *ep;
c = skipws();
if (c == '\n' || c == EOF_CHAR)
return (counter + 1);
if (!isdigit(c))
scanid(c); /* Get #word to token[] */
else {
unget(); /* Hack -- allow #123 as a */
strcpy(token, "line"); /* synonym for #line 123 */
}
hash = (token[1] == EOS) ? L_nogood : (token[0] + (token[2] << 1));
switch (hash) {
case L_assert: tp = "assert"; break;
case L_define: tp = "define"; break;
case L_elif: tp = "elif"; break;
case L_else: tp = "else"; break;
case L_endif: tp = "endif"; break;
case L_if: tp = "if"; break;
case L_ifdef: tp = "ifdef"; break;
case L_ifndef: tp = "ifndef"; break;
case L_include: tp = "include"; break;
case L_line: tp = "line"; break;
case L_pragma: tp = "pragma"; break;
case L_undef: tp = "undef"; break;
#if DEBUG
case L_debug: tp = "debug"; break;
#endif
default: hash = L_nogood;
case L_nogood: tp = ""; break;
}
if (!streq(tp, token))
hash = L_nogood;
/*
* hash is set to a unique value corresponding to the
* control keyword (or L_nogood if we think it's nonsense).
*/
if (infile->fp == NULL)
cwarn("Control line \"%s\" within macro expansion", token);
if (!compiling) { /* Not compiling now */
switch (hash) {
case L_if: /* These can't turn */
case L_ifdef: /* compilation on, but */
case L_ifndef: /* we must nest #if's */
if (++ifptr >= &ifstack[BLK_NEST])
goto if_nest_err;
*ifptr = 0; /* !WAS_COMPILING */
case L_line: /* Many */
/*
* Are pragma's always processed?
*/
case L_pragma: /* options */
case L_include: /* are uninteresting */
case L_define: /* if we */
case L_undef: /* aren't */
case L_assert: /* compiling. */
dump_line: skipnl(); /* Ignore rest of line */
return (counter + 1);
}
}
/*
* Make sure that #line and #pragma are output on a fresh line.
*/
if (counter > 0 && (hash == L_line || hash == L_pragma)) {
putchar('\n');
counter--;
}
switch (hash) {
case L_line:
/*
* Parse the line to update the line number and "progname"
* field and line number for the next input line.
* Set wrongline to force it out later.
*/
c = skipws();
workp = work; /* Save name in work */
while (c != '\n' && c != EOF_CHAR) {
save(c);
c = get();
}
unget();
save(EOS);
/*
* Split #line argument into <line-number> and <name>
* We subtract 1 as we want the number of the next line.
*/
line = atoi(work) - 1; /* Reset line number */
for (tp = work; isdigit(*tp) || type[*tp] == SPA; tp++)
; /* Skip over digits */
if (*tp != EOS) { /* Got a filename, so: */
if (*tp == '"' && (ep = strrchr(tp + 1, '"')) != NULL) {
tp++; /* Skip over left quote */
*ep = EOS; /* And ignore right one */
}
if (infile->progname != NULL) /* Give up the old name */
free(infile->progname); /* if it's allocated. */
infile->progname = savestring(tp);
}
wrongline = TRUE; /* Force output later */
break;
case L_include:
doinclude();
break;
case L_define:
dodefine();
break;
case L_undef:
doundef();
break;
case L_else:
if (ifptr == &ifstack[0])
goto nest_err;
else if ((*ifptr & ELSE_SEEN) != 0)
goto else_seen_err;
*ifptr |= ELSE_SEEN;
if ((*ifptr & WAS_COMPILING) != 0) {
if (compiling || (*ifptr & TRUE_SEEN) != 0)
compiling = FALSE;
else {
compiling = TRUE;
}
}
break;
case L_elif:
if (ifptr == &ifstack[0])
goto nest_err;
else if ((*ifptr & ELSE_SEEN) != 0) {
else_seen_err: cerror("#%s may not follow #else", token);
goto dump_line;
}
if ((*ifptr & (WAS_COMPILING | TRUE_SEEN)) != WAS_COMPILING) {
compiling = FALSE; /* Done compiling stuff */
goto dump_line; /* Skip this clause */
}
doif(L_if);
break;
case L_if:
case L_ifdef:
case L_ifndef:
if (++ifptr >= &ifstack[BLK_NEST])
if_nest_err: cfatal("Too many nested #%s statements", token);
*ifptr = WAS_COMPILING;
doif(hash);
break;
case L_endif:
if (ifptr == &ifstack[0]) {
nest_err: cerror("#%s must be in an #if", token);
goto dump_line;
}
if (!compiling && (*ifptr & WAS_COMPILING) != 0)
wrongline = TRUE;
compiling = ((*ifptr & WAS_COMPILING) != 0);
--ifptr;
break;
case L_assert:
if (eval() == 0)
cerror("Preprocessor assertion failure", NULLST);
break;
case L_pragma:
/*
* #pragma is provided to pass "options" to later
* passes of the compiler. cpp doesn't have any yet.
*/
printf("#pragma ");
while ((c = get()) != '\n' && c != EOF_CHAR)
cput(c);
unget();
break;
#if DEBUG
case L_debug:
c = skipws();
unget();
c = (isdigit(c)) ? eval() : 1;
if (debug == 0)
dumpdef("debug set on");
debug = c;
break;
#endif
default:
/*
* Undefined #control keyword.
* Note: the correct behavior may be to warn and
* pass the line to a subsequent compiler pass.
* This would allow #asm or similar extensions.
*/
cerror("Illegal # command \"%s\"", token);
break;
}
if (hash != L_include) {
#if OK_IF_JUNK
/*
* Ignore the rest of the #control line so you can write
* #if foo
* #endif foo
*/
skipnl();
#else
if (skipws() != '\n') {
cwarn("Unexpected text in #control line ignored", NULLST);
skipnl();
}
#endif
}
return (counter + 1);
}
FILE_LOCAL
doif(hash)
int hash;
/*
* Process an #if, #ifdef, or #ifndef. The latter two are straightforward,
* while #if needs a subroutine of its own to evaluate the expression.
*
* doif() is called only if compiling is TRUE. If false, compilation
* is always supressed, so we don't need to evaluate anything. This
* supresses unnecessary warnings.
*/
{
register int c;
register int found;
if ((c = skipws()) == '\n' || c == EOF_CHAR) {
unget();
goto badif;
}
if (hash == L_if) {
unget();
found = (eval() != 0); /* Evaluate expr, != 0 is TRUE */
hash = L_ifdef; /* #if is now like #ifdef */
}
else {
if (type[c] != LET) /* Next non-blank isn't letter */
goto badif; /* ... is an error */
found = (lookid(c) != NULL); /* Look for it in symbol table */
}
if (found == (hash == L_ifdef)) {
compiling = TRUE;
*ifptr |= TRUE_SEEN;
}
else {
compiling = FALSE;
}
return;
badif: cerror("#if, #ifdef, or #ifndef without an argument", NULLST);
#if !OK_IF_JUNK
skipnl(); /* Prevent an extra */
unget(); /* Error message */
#endif
return;
}
FILE_LOCAL
doinclude()
/*
* Process the #include control line.
* There are three variations:
* #include "file" search somewhere relative to the
* current source file, if not found,
* treat as #include <file>.
* #include <file> Search in an implementation-dependent
* list of places.
* #include token Expand the token, it must be one of
* "file" or <file>, process as such.
*
* Note: the November 12 draft forbids '>' in the #include <file> format.
* This restriction is unnecessary and not implemented.
*/
{
register int c;
register int delim;
#if HOST == SYS_VMS
char def_filename[NAM$C_MAXRSS + 1];
#endif
delim = macroid(skipws());
if (delim != '<' && delim != '"')
goto incerr;
if (delim == '<')
delim = '>';
workp = work;
instring = TRUE; /* Accept all characters */
while ((c = get()) != '\n' && c != EOF_CHAR)
save(c); /* Put it away. */
unget(); /* Force nl after includee */
/*
* The draft is unclear if the following should be done.
*/
#if OK_IF_JUNK
while (--workp >= work && *workp == ' ')
; /* Trim blanks from filename */
#else
--workp;
#endif
if (*workp != delim)
goto incerr;
*workp = EOS; /* Terminate filename */
instring = FALSE;
#if HOST == SYS_VMS
/*
* Assume the default .h filetype.
*/
if (!vmsparse(work, ".H", def_filename)) {
perror(work); /* Oops. */
goto incerr;
}
else if (openinclude(def_filename, (delim == '"')))
return;
#else
if (openinclude(work, (delim == '"')))
return;
#endif
/*
* No sense continuing if #include file isn't there.
*/
cfatal("Cannot open include file \"%s\"", work);
incerr: cerror("#include syntax error", NULLST);
return;
}
FILE_LOCAL int
openinclude(filename, searchlocal)
char *filename; /* Input file name */
int searchlocal; /* TRUE if #include "file" */
/*
* Actually open an include file. This routine is only called from
* doinclude() above, but was written as a separate subroutine for
* programmer convenience. It searches the list of directories
* and actually opens the file, linking it into the list of
* active files. Returns TRUE if the file was opened, FALSE
* if openinclude() fails. No error message is printed.
*/
{
register char **incptr;
#if HOST == SYS_VMS
#if NWORK < (NAM$C_MAXRSS + 1)
<< error, NWORK isn't greater than NAM$C_MAXRSS >>
#endif
#endif
char tmpname[NWORK]; /* Filename work area */
if (searchlocal) {
/*
* Look in local directory first
*/
#if HOST == SYS_UNIX
/*
* Try to open filename relative to the directory of the current
* source file (as opposed to the current directory). (ARF, SCK).
*/
if (filename[0] != '/'
&& hasdirectory(infile->filename, tmpname))
strcat(tmpname, filename);
else {
strcpy(tmpname, filename);
}
#else
if (!hasdirectory(filename, tmpname)
&& hasdirectory(infile->filename, tmpname))
strcat(tmpname, filename);
else {
strcpy(tmpname, filename);
}
#endif
if (openfile(tmpname))
return (TRUE);
}
/*
* Look in any directories specified by -I command line
* arguments, then in the builtin search list.
*/
for (incptr = incdir; incptr < incend; incptr++) {
if (strlen(*incptr) + strlen(filename) >= (NWORK - 1))
cfatal("Filename work buffer overflow", NULLST);
else {
#if HOST == SYS_UNIX
if (filename[0] == '/')
strcpy(tmpname, filename);
else {
sprintf(tmpname, "%s/%s", *incptr, filename);
}
#else
if (!hasdirectory(filename, tmpname))
sprintf(tmpname, "%s%s", *incptr, filename);
#endif
if (openfile(tmpname))
return (TRUE);
}
}
return (FALSE);
}
FILE_LOCAL int
hasdirectory(source, result)
char *source; /* Directory to examine */
char *result; /* Put directory stuff here */
/*
* If a device or directory is found in the source filename string, the
* node/device/directory part of the string is copied to result and
* hasdirectory returns TRUE. Else, nothing is copied and it returns FALSE.
*/
{
#if HOST == SYS_UNIX
register char *tp;
if ((tp = strrchr(source, '/')) == NULL)
return (FALSE);
else {
strncpy(result, source, tp - source + 1);
result[tp - source + 1] = EOS;
return (TRUE);
}
#else
#if HOST == SYS_VMS
if (vmsparse(source, NULLST, result)
&& result[0] != EOS)
return (TRUE);
else {
return (FALSE);
}
#else
/*
* Random DEC operating system (RSX, RT11, RSTS/E)
*/
register char *tp;
if ((tp = strrchr(source, ']')) == NULL
&& (tp = strrchr(source, ':')) == NULL)
return (FALSE);
else {
strncpy(result, source, tp - source + 1);
result[tp - source + 1] = EOS;
return (TRUE);
}
#endif
#endif
}
#if HOST == SYS_VMS
FILE_LOCAL int
vmsparse(source, defstring, result)
char *source;
char *defstring; /* non-NULL -> default string. */
char *result; /* Size is at least NAM$C_MAXRSS + 1 */
/*
* Parse the source string, applying the default (properly, using
* the system parse routine), storing it in result.
* TRUE if it parsed, FALSE on error.
*
* If defstring is NULL, there are no defaults and result gets
* (just) the node::[directory] part of the string (possibly "")
*/
{
struct FAB fab = cc$rms_fab; /* File access block */
struct NAM nam = cc$rms_nam; /* File name block */
char fullname[NAM$C_MAXRSS + 1];
register char *rp; /* Result pointer */
fab.fab$l_nam = &nam; /* fab -> nam */
fab.fab$l_fna = source; /* Source filename */
fab.fab$b_fns = strlen(source); /* Size of source */
fab.fab$l_dna = defstring; /* Default string */
if (defstring != NULLST)
fab.fab$b_dns = strlen(defstring); /* Size of default */
nam.nam$l_esa = fullname; /* Expanded filename */
nam.nam$b_ess = NAM$C_MAXRSS; /* Expanded name size */
if (sys$parse(&fab) == RMS$_NORMAL) { /* Parse away */
fullname[nam.nam$b_esl] = EOS; /* Terminate string */
result[0] = EOS; /* Just in case */
rp = &result[0];
/*
* Remove stuff added implicitly, accepting node names and
* dev:[directory] strings (but not process-permanent files).
*/
if ((nam.nam$l_fnb & NAM$M_PPF) == 0) {
if ((nam.nam$l_fnb & NAM$M_NODE) != 0) {
strncpy(result, nam.nam$l_node, nam.nam$b_node);
rp += nam.nam$b_node;
*rp = EOS;
}
if ((nam.nam$l_fnb & NAM$M_EXP_DEV) != 0) {
strncpy(rp, nam.nam$l_dev, nam.nam$b_dev);
rp += nam.nam$b_dev;
}
if ((nam.nam$l_fnb & NAM$M_EXP_DIR) != 0) {
strncpy(rp, nam.nam$l_dir, nam.nam$b_dir);
rp += nam.nam$b_dir;
*rp = EOS;
}
}
if (defstring != NULLST) {
strncpy(rp, nam.nam$l_name, nam.nam$b_name + nam.nam$b_type);
rp += nam.nam$b_name + nam.nam$b_type;
*rp = EOS;
if ((nam.nam$l_fnb & NAM$M_EXP_VER) != 0) {
strncpy(rp, nam.nam$l_ver, nam.nam$b_ver);
rp[nam.nam$b_ver] = EOS;
}
}
return (TRUE);
}
return (FALSE);
}
#endif