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rttlex.c
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C/C++ Source or Header
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2002-01-18
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14KB
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362 lines
/*
* This lexical analyzer uses the preprocessor to convert text into tokens.
* The lexical anayser discards white space, checks to see if identifiers
* are reserved words or typedef names, makes sure single characters
* are valid tokens, and converts preprocessor constants into the
* various C constants.
*/
#include "rtt.h"
/*
* Prototype for static function.
*/
static int int_suffix (char *s);
int lex_state = DfltLex;
char *ident = "ident";
/*
* Characters are used as token id's for single character tokens. The
* following table indicates which ones can be valid for RTL.
*/
#define GoodChar(c) ((c) < 127 && good_char[c])
static int good_char[128] = {
0 /* \000 */, 0 /* \001 */, 0 /* \002 */, 0 /* \003 */,
0 /* \004 */, 0 /* \005 */, 0 /* \006 */, 0 /* \007 */,
0 /* \b */, 0 /* \t */, 0 /* \n */, 0 /* \v */,
0 /* \f */, 0 /* \r */, 0 /* \016 */, 0 /* \017 */,
0 /* \020 */, 0 /* \021 */, 0 /* \022 */, 0 /* \023 */,
0 /* \024 */, 0 /* \025 */, 0 /* \026 */, 0 /* \027 */,
0 /* \030 */, 0 /* \031 */, 0 /* \032 */, 0 /* \e */,
0 /* \034 */, 0 /* \035 */, 0 /* \036 */, 0 /* \037 */,
0 /* */, 1 /* ! */, 0 /* \ */, 0 /* # */,
0 /* $ */, 1 /* % */, 1 /* & */, 0 /* ' */,
1 /* ( */, 1 /* ) */, 1 /* * */, 1 /* + */,
1 /* , */, 1 /* - */, 1 /* . */, 1 /* / */,
0 /* 0 */, 0 /* 1 */, 0 /* 2 */, 0 /* 3 */,
0 /* 4 */, 0 /* 5 */, 0 /* 6 */, 0 /* 7 */,
0 /* 8 */, 0 /* 9 */, 1 /* : */, 1 /* ; */,
1 /* < */, 1 /* = */, 1 /* > */, 1 /* ? */,
0 /* @ */, 0 /* A */, 0 /* B */, 0 /* C */,
0 /* D */, 0 /* E */, 0 /* F */, 0 /* G */,
0 /* H */, 0 /* I */, 0 /* J */, 0 /* K */,
0 /* L */, 0 /* M */, 0 /* N */, 0 /* O */,
0 /* P */, 0 /* Q */, 0 /* R */, 0 /* S */,
0 /* T */, 0 /* U */, 0 /* V */, 0 /* W */,
0 /* X */, 0 /* Y */, 0 /* Z */, 1 /* [ */,
1 /* \\ */, 1 /* ] */, 1 /* ^ */, 0 /* _ */,
0 /* ` */, 0 /* a */, 0 /* b */, 0 /* c */,
0 /* d */, 0 /* e */, 0 /* f */, 0 /* g */,
0 /* h */, 0 /* i */, 0 /* j */, 0 /* k */,
0 /* l */, 0 /* m */, 0 /* n */, 0 /* o */,
0 /* p */, 0 /* q */, 0 /* r */, 0 /* s */,
0 /* t */, 0 /* u */, 0 /* v */, 0 /* w */,
0 /* x */, 0 /* y */, 0 /* z */, 1 /* { */,
1 /* | */, 1 /* } */, 1 /* ~ */, 0 /* \d */
};
/*
* init_lex - initialize lexical analyzer.
*/
void init_lex()
{
struct sym_entry *sym;
int i;
static int first_time = 1;
if (first_time) {
first_time = 0;
ident = spec_str(ident); /* install ident in string table */
/*
* install C keywords into the symbol table
*/
sym_add(Auto, spec_str("auto"), OtherDcl, 0);
sym_add(Break, spec_str("break"), OtherDcl, 0);
sym_add(Case, spec_str("case"), OtherDcl, 0);
sym_add(TokChar, spec_str("char"), OtherDcl, 0);
sym_add(Const, spec_str("const"), OtherDcl, 0);
sym_add(Continue, spec_str("continue"), OtherDcl, 0);
sym_add(Default, spec_str("default"), OtherDcl, 0);
sym_add(Do, spec_str("do"), OtherDcl, 0);
sym_add(Doubl, spec_str("double"), OtherDcl, 0);
sym_add(Else, spec_str("else"), OtherDcl, 0);
sym_add(TokEnum, spec_str("enum"), OtherDcl, 0);
sym_add(Extern, spec_str("extern"), OtherDcl, 0);
sym_add(Float, spec_str("float"), OtherDcl, 0);
sym_add(For, spec_str("for"), OtherDcl, 0);
sym_add(Goto, spec_str("goto"), OtherDcl, 0);
sym_add(If, spec_str("if"), OtherDcl, 0);
sym_add(Int, spec_str("int"), OtherDcl, 0);
sym_add(TokLong, spec_str("long"), OtherDcl, 0);
sym_add(TokRegister, spec_str("register"), OtherDcl, 0);
sym_add(Return, spec_str("return"), OtherDcl, 0);
sym_add(TokShort, spec_str("short"), OtherDcl, 0);
sym_add(Signed, spec_str("signed"), OtherDcl, 0);
sym_add(Sizeof, spec_str("sizeof"), OtherDcl, 0);
sym_add(Static, spec_str("static"), OtherDcl, 0);
sym_add(Struct, spec_str("struct"), OtherDcl, 0);
sym_add(Switch, spec_str("switch"), OtherDcl, 0);
sym_add(Typedef, spec_str("typedef"), OtherDcl, 0);
sym_add(Union, spec_str("union"), OtherDcl, 0);
sym_add(Unsigned, spec_str("unsigned"), OtherDcl, 0);
sym_add(Void, spec_str("void"), OtherDcl, 0);
sym_add(Volatile, spec_str("volatile"), OtherDcl, 0);
sym_add(While, spec_str("while"), OtherDcl, 0);
/*
* Install keywords from run-time interface language.
*/
sym_add(Abstract, spec_str("abstract"), OtherDcl, 0);
sym_add(All_fields, spec_str("all_fields"), OtherDcl, 0);
sym_add(Any_value, spec_str("any_value"), OtherDcl, 0);
sym_add(Arith_case, spec_str("arith_case"), OtherDcl, 0);
sym_add(Body, spec_str("body"), OtherDcl, 0);
sym_add(C_Double, spec_str("C_double"), OtherDcl, 0);
sym_add(C_Integer, spec_str("C_integer"), OtherDcl, 0);
sym_add(C_String, spec_str("C_string"), OtherDcl, 0);
sym_add(Cnv, spec_str("cnv"), OtherDcl, 0);
sym_add(Constant, spec_str("constant"), OtherDcl, 0);
sym_add(Declare, spec_str("declare"), OtherDcl, 0);
sym_add(Def, spec_str("def"), OtherDcl, 0);
sym_add(Empty_type, spec_str("empty_type"), OtherDcl, 0);
sym_add(End, spec_str("end"), OtherDcl, 0);
sym_add(Errorfail, spec_str("errorfail"), OtherDcl, 0);
sym_add(Exact, spec_str("exact"), OtherDcl, 0);
sym_add(Fail, spec_str("fail"), OtherDcl, 0);
sym_add(TokFunction, spec_str("function"), OtherDcl, 0);
sym_add(Inline, spec_str("inline"), OtherDcl, 0);
sym_add(Is, spec_str("is"), OtherDcl, 0);
sym_add(Keyword, spec_str("keyword"), OtherDcl, 0);
sym_add(Len_case, spec_str("len_case"), OtherDcl, 0);
sym_add(Named_var, spec_str("named_var"), OtherDcl, 0);
sym_add(New, spec_str("new"), OtherDcl, 0);
sym_add(Of, spec_str("of"), OtherDcl, 0);
sym_add(Operator, spec_str("operator"), OtherDcl, 0);
str_rslt = spec_str("result");
sym_add(Runerr, spec_str("runerr"), OtherDcl, 0);
sym_add(Store, spec_str("store"), OtherDcl, 0);
sym_add(Struct_var, spec_str("struct_var"), OtherDcl, 0);
sym_add(Suspend, spec_str("suspend"), OtherDcl, 0);
sym_add(Tended, spec_str("tended"), OtherDcl, 0);
sym_add(Then, spec_str("then"), OtherDcl, 0);
sym_add(Tmp_cset, spec_str("tmp_cset"), OtherDcl, 0);
sym_add(Tmp_string, spec_str("tmp_string"), OtherDcl, 0);
sym_add(TokType, spec_str("type"), OtherDcl, 0);
sym_add(Type_case, spec_str("type_case"), OtherDcl, 0);
sym_add(Underef, spec_str("underef"), OtherDcl, 0);
sym_add(Variable, spec_str("variable"), OtherDcl, 0);
for (i = 0; i < num_typs; ++i) {
icontypes[i].id = spec_str(icontypes[i].id);
sym = sym_add(IconType, icontypes[i].id, OtherDcl, 0);
sym->u.typ_indx = i;
}
for (i = 0; i < num_cmpnts; ++i) {
typecompnt[i].id = spec_str(typecompnt[i].id);
sym = sym_add(Component, typecompnt[i].id, OtherDcl, 0);
sym->u.typ_indx = i;
}
}
}
/*
* int_suffix - we have reached the end of what seems to be an integer
* constant. check for a valid suffix.
*/
static int int_suffix(s)
char *s;
{
int tok_id;
if (*s == 'u' || *s == 'U') {
++s;
if (*s == 'l' || *s == 'L') {
++s;
tok_id = ULIntConst; /* unsigned long */
}
else
tok_id = UIntConst; /* unsigned */
}
else if (*s == 'l' || *s == 'L') {
++s;
if (*s == 'u' || *s == 'U') {
++s;
tok_id = ULIntConst; /* unsigned long */
}
else
tok_id = LIntConst; /* long */
}
else
tok_id = IntConst; /* plain int */
if (*s != '\0')
errt2(yylval.t, "invalid integer constant: ", yylval.t->image);
return tok_id;
}
/*
* yylex - lexical analyzer, called by yacc-generated parser.
*/
int yylex()
{
register char *s;
struct sym_entry *sym;
struct token *lk_ahead = NULL;
int is_float;
struct str_buf *sbuf;
/*
* See if the last call to yylex() left a token from looking ahead.
*/
if (lk_ahead == NULL)
yylval.t = preproc();
else {
yylval.t = lk_ahead;
lk_ahead = NULL;
}
/*
* Skip white space, then check for end-of-input.
*/
while (yylval.t != NULL && yylval.t->tok_id == WhiteSpace) {
free_t(yylval.t);
yylval.t = preproc();
}
if (yylval.t == NULL)
return 0;
/*
* The rtt recognizes ** as an operator in abstract type computations.
* The parsing context is indicated by lex_state.
*/
if (lex_state == TypeComp && yylval.t->tok_id == '*') {
lk_ahead = preproc();
if (lk_ahead != NULL && lk_ahead->tok_id == '*') {
free_t(lk_ahead);
lk_ahead = NULL;
yylval.t->tok_id = Intersect;
yylval.t->image = spec_str("**");
}
}
/*
* Some tokens are passed along without change, but some need special
* processing: identifiers, numbers, PpKeep tokens, and single
* character tokens.
*/
if (yylval.t->tok_id == Identifier) {
/*
* See if this is an identifier, a reserved word, or typedef name.
*/
sym = sym_lkup(yylval.t->image);
if (sym != NULL)
yylval.t->tok_id = sym->tok_id;
}
else if (yylval.t->tok_id == PpNumber) {
/*
* Determine what kind of numeric constant this is.
*/
s = yylval.t->image;
if (*s == '0' && (*++s == 'x' || *s == 'X')) {
/*
* Hex integer constant.
*/
++s;
while (isxdigit(*s))
++s;
yylval.t->tok_id = int_suffix(s);
}
else {
is_float = 0;
while (isdigit(*s))
++s;
if (*s == '.') {
is_float = 1;
++s;
while (isdigit(*s))
++s;
}
if (*s == 'e' || *s == 'E') {
is_float = 1;
++s;
if (*s == '+' || *s == '-')
++s;
while (isdigit(*s))
++s;
}
if (is_float) {
switch (*s) {
case '\0':
yylval.t->tok_id = DblConst; /* double */
break;
case 'f': case 'F':
yylval.t->tok_id = FltConst; /* float */
break;
case 'l': case 'L':
yylval.t->tok_id = LDblConst; /* long double */
break;
default:
errt2(yylval.t, "invalid float constant: ", yylval.t->image);
}
}
else {
/*
* This appears to be an integer constant. If it starts
* with '0', it should be an octal constant.
*/
if (yylval.t->image[0] == '0') {
s = yylval.t->image;
while (*s >= '0' && *s <= '7')
++s;
}
yylval.t->tok_id = int_suffix(s);
}
}
}
else if (yylval.t->tok_id == PpKeep) {
/*
* This is a non-standard preprocessor directive that must be
* passed on to the output.
*/
keepdir(yylval.t);
return yylex();
}
else if (lex_state == OpHead && yylval.t->tok_id != '}' &&
GoodChar((int)yylval.t->image[0])) {
/*
* This should be the operator symbol in the header of an operation
* declaration. Concatenate all operator symbols into one token
* of type OpSym.
*/
sbuf = get_sbuf();
for (s = yylval.t->image; *s != '\0'; ++s)
AppChar(*sbuf, *s);
lk_ahead = preproc();
while (lk_ahead != NULL && GoodChar((int)lk_ahead->image[0])) {
for (s = lk_ahead->image; *s != '\0'; ++s)
AppChar(*sbuf, *s);
free_t(lk_ahead);
lk_ahead = preproc();
}
yylval.t->tok_id = OpSym;
yylval.t->image = str_install(sbuf);
rel_sbuf(sbuf);
}
else if (yylval.t->tok_id < 256) {
/*
* This is a one-character token, make sure it is valid.
*/
if (!GoodChar(yylval.t->tok_id))
errt2(yylval.t, "invalid character: ", yylval.t->image);
}
#if EBCDIC
if (yylval.t->tok_id < 256)
return FromEBCDIC[yylval.t->tok_id];
#endif
return yylval.t->tok_id;
}