scc

Simple C99 Compiler
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commit 3a4b6eedd35f30fc914d7e21270f659e11d1a318
parent 5bfb14d894427d16c3118cfc16b6f8b72138785a
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Thu, 21 May 2015 21:35:28 +0200

Simplify fill() and convert it to moreinput()

Diffstat:
cc1/cpp.c | 4++--
cc1/lex.c | 94+++++++++++++++++++++++++++++++++++--------------------------------------------
2 files changed, 43 insertions(+), 55 deletions(-)

diff --git a/cc1/cpp.c b/cc1/cpp.c @@ -281,7 +281,7 @@ preprocessor(char *p) for (++p; isspace(*p); ++p) /* nothing */; if (*p == '\0') - return NULL; + return p; for (q = p; isalpha(*q); ++q) /* nothing */; if ((n = q - p) == 0) @@ -296,7 +296,7 @@ preprocessor(char *p) /* nothing */; if (*q != '\0') error("trailing characters after preprocessor directive"); - return NULL; + return q; } incorrect: error("incorrect preprocessor directive"); diff --git a/cc1/lex.c b/cc1/lex.c @@ -59,7 +59,8 @@ addinput(char *fname) ip = xmalloc(sizeof(Input)); ip->fname = fname; ip->next = input; - ip->line = NULL; + ip->begin = ip->p = ip->line = xmalloc(INPUTSIZ); + *ip->begin = '\0'; ip->nline = nline; ip->fp = fp; input = ip; @@ -116,7 +117,7 @@ readchar(void) { int c; FILE *fp; - + repeat: while (feof(input->fp) && !eof) delinput(); @@ -129,9 +130,11 @@ repeat: goto repeat; ungetc(c, fp); c = '\\'; - } - if (c == '\n' && ++input->nline == 0) + } else if (c == EOF) { + goto repeat; + } else if (c == '\n' && ++input->nline == 0) { die("input file '%s' too long", getfname()); + } return c; } @@ -185,25 +188,17 @@ readline(void) } static bool -fill(void) +moreinput(void) { char *p; - int c; repeat: - if (eof) - return 0; - if (input->begin && *input->begin != '\0') - return 1; - if (!input->line) - input->line = xmalloc(INPUTSIZ); + *(p = input->line) = '\0'; readline(); - if (*input->line == '\0') - goto repeat; - if ((p = preprocessor(input->line)) == NULL) + if ((p = preprocessor(p)) == '\0') goto repeat; input->p = input->begin = p; - return 1; + return *p != '\0'; } static void @@ -369,21 +364,10 @@ repeat: if (c == '\0') error("missing terminating '\"' character"); - ++input->p; - - for (;;) { - input->begin = input->p; - if (isspace((c = *input->p))) { - ++input->p; - } else if (c == '\0' && fill()) { - continue; - } else if (c == '"') { - goto repeat; - } else { - break; - } - } + input->begin = input->p + 1; + if (ahead() == '"') + goto repeat; *bp = '\0'; sym = newsym(NS_IDEN); sym->u.s = xstrdup(buf); @@ -506,32 +490,44 @@ setnamespace(int ns) lex_ns = ns; } +static void +skipspaces(void) +{ + char *p; + +repeat: + for (p = input->begin; isspace(*p); ++p) + /* nothing */; + if (*p == '\0') { + if (!moreinput()) + return; + goto repeat; + } + input->begin = input->p = p; +} + unsigned next(void) { char c; -repeat: - if (!fill()) { + skipspaces(); + if (eof) { strcpy(yytext, "<EOF>"); return yytoken = EOFTOK; } - while (isspace(*input->begin)) - ++input->begin; - if ((c = *(input->p = input->begin)) == '\0') - goto repeat; - if (isalpha(c) || c == '_') { + c = *input->begin; + if (isalpha(c) || c == '_') yytoken = iden(); - } else if (isdigit(c)) { + else if (isdigit(c)) yytoken = number(); - } else if (c == '"') { + else if (c == '"') yytoken = string(); - } else if (c == '\'') { + else if (c == '\'') yytoken = character(); - } else { + else yytoken = operator(); - } lex_ns = NS_IDEN; return yytoken; } @@ -552,16 +548,8 @@ expect(unsigned tok) char ahead(void) { - int c; - -repeat: - if (!fill()) - return EOFTOK; - while (isspace(c = *input->begin)) - ++input->begin; - if (c == '\0') - goto repeat; - return c; + skipspaces(); + return *input->begin; } void @@ -596,7 +584,7 @@ discard(void) goto jump; break; } - if (!fill()) + if (!moreinput()) exit(-1); } jump: