commit e9ccea1272ee0193a50d7288fdddd55ed45ad53e
parent 06276ba4738710b02df4c81803655ea777ed52c9
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date: Sun, 24 May 2015 13:05:43 +0200
Factorize the code in the preprocessor
This version is shorter and is clearer in a lot of places.
Diffstat:
| M | cc1/cpp.c | | | 183 | +++++++++++++++++++++++++++++++++++++------------------------------------------ |
1 file changed, 85 insertions(+), 98 deletions(-)
diff --git a/cc1/cpp.c b/cc1/cpp.c
@@ -1,6 +1,7 @@
#include <ctype.h>
#include <inttypes.h>
+#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@@ -15,6 +16,48 @@ static char *argp;
static unsigned arglen;
static unsigned numif, iffalse;
static Symbol *lastmacro;
+
+static bool
+iden(char **str)
+{
+ char c, *bp, *s = *str;
+
+ for (bp = yytext; bp < &yytext[IDENTSIZ]; *bp++ = c) {
+ if ((c = *s) == '\0' || !isalnum(c) && c != '_')
+ break;
+ ++s;
+ }
+ if (bp == &yytext[IDENTSIZ])
+ error("identifier too long");
+ if (bp - yytext == 0)
+ return 0;
+ *bp = '\0';
+
+ while (isspace(*s))
+ ++s;
+
+ *str = s;
+ return 1;
+}
+
+static bool
+string(char **input, char **str, char delim)
+{
+ char c, *s = *input;
+
+ if (str)
+ *str = s;
+
+ while ((c = *s) && c != delim)
+ ++s;
+ if (c == '\0')
+ return 0;
+ *s++ = '\0';
+ *input = s;
+
+ return 1;
+}
+
static void
cleanup(char *s)
{
@@ -276,17 +319,11 @@ static bool
define(char *s)
{
char *t;
- size_t len;
Symbol *sym;
- if (!isalnum(*s) && *s != '_')
- goto bad_define;
- for (t = s; isalnum(*t) || *t == '_'; ++t)
- /* nothing */;
- if ((len = t - s) > IDENTSIZ)
- goto too_long;
- strncpy(yytext, s, len);
- yytext[len] = '\0';
+ if (!iden(&s))
+ error("macro names must be identifiers");
+
sym = lookup(NS_CPP);
if ((sym->flags & ISDEFINED) && sym->ns == NS_CPP) {
warn("'%s' redefined", yytext);
@@ -295,25 +332,16 @@ define(char *s)
sym->flags |= ISDEFINED;
sym->ns = NS_CPP;
- for (s = t; isspace(*s); ++s)
+ for (t = s + strlen(s) + 1; isspace(*--t); *t = '\0')
/* nothing */;
- for (t = s + strlen(s); isspace(*--t); *t = '\0')
- /* nothing */;
- s = mkdefine(s, sym);
- cleanup(s);
+ mkdefine(s, sym);
return 1;
-
-too_long:
- error("macro identifier too long");
-bad_define:
- error("macro names must be identifiers");
}
static bool
include(char *s)
{
- char fname[FILENAME_MAX], delim, c, *p;
- size_t len;
+ char delim, c, *p, *file;
if ((c = *s++) == '>')
delim = '>';
@@ -322,30 +350,15 @@ include(char *s)
else
goto bad_include;
- for (p = s; (c = *p) && c != delim; ++p)
- /* nothing */;
- if (c == '\0')
+ if (!string(&s, &file, delim))
goto bad_include;
-
- len = p - s;
- if (delim == '"') {
- if (len >= FILENAME_MAX)
- goto too_long;
- strncpy(fname, s, len);
- fname[len] = '\0';
- if (!addinput(fname))
- goto not_found;
- } else {
- abort();
- }
-
- cleanup(p+1);
- return 1;
+ cleanup(s);
+ if (delim == '"' && addinput(file))
+ return 1;
+ abort();
not_found:
- error("included file '%s' not found", fname);
-too_long:
- error("file name in include too long");
+ error("included file '%s' not found", s);
bad_include:
error("#include expects \"FILENAME\" or <FILENAME>");
}
@@ -353,46 +366,36 @@ bad_include:
static bool
line(char *s)
{
- char *p, *q;
+ char *file;
+ long n;
- if (!isdigit(*s))
- goto bad_line;
- for (p = s; isdigit(*p); ++p)
- /* nothing */;
- switch (*p) {
+ if ((n = strtol(s, &s, 10)) <= 0 || n > USHRT_MAX)
+ error("first parameter of #line is not a positive integer");
+
+ switch (*s) {
case ' ':
case '\t':
- while (isspace(*p))
- ++p;
- if (*p != '"')
- goto bad_line;
- for (q = p+1; *q && *q != '"'; ++q)
- /* nothing */;
- if (*q == '\0')
- goto bad_line;
- *q = '\0';
- setfname(p);
- p = q+1;
- /* passthrough */
+ while (isspace(*s))
+ ++s;
+ if (*s == '\0')
+ goto end_string;
+ if (*s++ != '"' && !string(&s, &file, '"'))
+ goto bad_file;
+ setfname(file);
+ cleanup(s);
case '\0':
- /* TODO: check this atoi */
- setfline(atoi(s)-1);
- cleanup(p);
+ end_string:
+ setfline(n-1);
return 1;
default:
- goto bad_file;
+ bad_file:
+ error("second parameter of #line is not a valid filename");
}
-
-bad_file:
- error("second parameter of #line is not a valid filename");
-bad_line:
- error("first parameter of #line is not a positive integer");
}
static bool
pragma(char *s)
{
- cleanup(s);
return 1;
}
@@ -405,21 +408,15 @@ usererr(char *s)
static bool
ifclause(char *s, int isdef)
{
- unsigned curif, len;
+ unsigned curif;
char *endp;
Symbol *sym;
- while (isspace(*s))
- ++s;
- for (endp = s; isalnum(*endp) || *endp == '_'; ++endp)
- /* nothing */;
- if ((len = endp - s) > IDENTSIZ)
+ if (iden(&s))
error("...");
- memcpy(yytext, s, len);
- yytext[len] = '\0';
- cleanup(endp);
- ++numif;
+ cleanup(s);
+ ++numif;
if (iffalse == 0) {
sym = lookup(NS_CPP);
if ((sym->flags & ISDEFINED) != 0 == isdef)
@@ -479,10 +476,8 @@ elseclause(char *s)
}
bool
-preprocessor(char *p)
+preprocessor(char *s)
{
- char *q;
- unsigned short n;
static struct {
char *name;
bool (*fun)(char *);
@@ -499,25 +494,17 @@ preprocessor(char *p)
NULL, NULL
};
- while (isspace(*p))
- ++p;
- if (*p != '#')
+ if (*s++ != '#')
return 0;
- for (++p; isspace(*p); ++p)
- /* nothing */;
- if (*p == '\0')
- return 1;
- for (q = p; isalpha(*q); ++q)
- /* nothing */;
- if ((n = q - p) == 0)
+ while (isspace(*s))
+ ++s;
+ if (!iden(&s))
goto incorrect;
- while (isspace(*q))
- ++q;
for (bp = cmds; bp->name; ++bp) {
- if (strncmp(bp->name, p, n))
+ if (strcmp(bp->name, yytext))
continue;
- return (*bp->fun)(q);
+ return (*bp->fun)(s);
}
incorrect:
- error("incorrect preprocessor directive");
+ error("invalid preprocessor directive #%s", yytext);
}
