scc

Simple C99 Compiler
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commit 5bfb14d894427d16c3118cfc16b6f8b72138785a
parent bbdf237f3cb79ff55281f9a31c0a57068a375687
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Thu, 21 May 2015 15:15:46 +0200

Detect EOF condition and don't enter in infinite loops

Once we found the EOF condition in the lowest level we should
not try to read more characters, because it made impossible
to finish the exection when input is reading from stdin.

Diffstat:
cc1/cc1.h | 1-
cc1/lex.c | 70++++++++++++++++++++++++++++++++++------------------------------------
2 files changed, 34 insertions(+), 37 deletions(-)

diff --git a/cc1/cc1.h b/cc1/cc1.h @@ -272,7 +272,6 @@ extern unsigned short getfline(void); extern void setfname(char *name); extern void setfline(unsigned short line); extern bool addinput(char *fname); -extern void delinput(void); extern void setnamespace(int ns); extern void setsafe(int type); #define accept(t) ((yytoken == (t)) ? next() : 0) diff --git a/cc1/lex.c b/cc1/lex.c @@ -23,14 +23,15 @@ struct input { struct input *next; }; -static unsigned lex_ns = NS_IDEN; - unsigned yytoken; struct yystype yylval; char yytext[IDENTSIZ + 1]; unsigned short yylen; + +static unsigned lex_ns = NS_IDEN; static int safe; static Input *input; +static int eof; bool addinput(char *fname) @@ -71,13 +72,14 @@ delinput(void) Input *ip = input; FILE *fp = ip->fp; + if (!ip->next) + eof = 1; if (fp) { if (fclose(fp)) die("error reading from input file '%s'", ip->fname); - if (!ip->next) + if (eof) return; - if (ip->fp != stdin) - free(ip->fname); + free(ip->fname); } input = ip->next; free(ip->line); @@ -113,22 +115,30 @@ static int readchar(void) { int c; - FILE *fp = input->fp; - + FILE *fp; + repeat: + while (feof(input->fp) && !eof) + delinput(); + if (eof) + return EOF; + fp = input->fp; + if ((c = getc(fp)) == '\\') { if ((c = getc(fp)) == '\n') goto repeat; ungetc(c, fp); c = '\\'; } + if (c == '\n' && ++input->nline == 0) + die("input file '%s' too long", getfname()); return c; } static void readline(void) { - static int comment, commentline; + int comment = 0, commentline = 0; char *bp, *lim; int c; @@ -156,8 +166,8 @@ readline(void) if (c == '\n') break; if (bp == lim) - die("line %d too big in file '%s'", - input->nline, input->fname); + die("line %u too big in file '%s'", + getfline(), getfname()); if (c == '/') { if ((c = readchar()) == '*') { comment = 1; @@ -171,40 +181,28 @@ readline(void) } *bp++ = c; } - ungetc(c, input->fp); *bp = '\0'; } static bool fill(void) { - int c; char *p; - FILE *fp; + int c; repeat: - if (!input) + if (eof) return 0; if (input->begin && *input->begin != '\0') return 1; - - fp = input->fp; if (!input->line) input->line = xmalloc(INPUTSIZ); - - while ((c = getc(fp)) != EOF && (c == '\n')) { - if (++input->nline == 0) - die("input file '%s' too long", input->fname); - } - if (c == EOF) { - delinput(); - goto repeat; - } - ungetc(c, fp); readline(); + if (*input->line == '\0') + goto repeat; if ((p = preprocessor(input->line)) == NULL) goto repeat; - input->begin = input->p = p; + input->p = input->begin = p; return 1; } @@ -377,8 +375,8 @@ repeat: input->begin = input->p; if (isspace((c = *input->p))) { ++input->p; - } else if (c == '\0') { - fill(); + } else if (c == '\0' && fill()) { + continue; } else if (c == '"') { goto repeat; } else { @@ -513,12 +511,15 @@ next(void) { char c; - if (!fill()) +repeat: + if (!fill()) { + strcpy(yytext, "<EOF>"); return yytoken = EOFTOK; - + } while (isspace(*input->begin)) ++input->begin; - c = *(input->p = input->begin); + if ((c = *(input->p = input->begin)) == '\0') + goto repeat; if (isalpha(c) || c == '_') { yytoken = iden(); @@ -553,16 +554,13 @@ ahead(void) { int c; - /* FIX: It will break all the error messages */ repeat: if (!fill()) return EOFTOK; while (isspace(c = *input->begin)) ++input->begin; - if (c == '\0') { - fill(); + if (c == '\0') goto repeat; - } return c; }