ref: 432127aad4a212d5d02dd74d9c7340ef68a85804
parent: 06411a4af49b020ced2d40e295afe72605caaec8
author: Roberto E. Vargas Caballero <k0ga@shike2.com>
date: Sat May 23 16:03:06 EDT 2015
Improve ifdef/ifndef
--- a/cc1/cc1.h
+++ b/cc1/cc1.h
@@ -290,7 +290,7 @@
extern Node *expr(void), *negate(Node *np);
/* cpp.c */
-extern char *preprocessor(char *s);
+extern bool preprocessor(char *s);
extern bool expand(Symbol *sym);
/*
--- a/cc1/cpp.c
+++ b/cc1/cpp.c
@@ -13,8 +13,16 @@
static char *argp;
static unsigned arglen;
-static unsigned numif;
+static unsigned numif, iffalse;
static Symbol *lastmacro;
+static void
+cleanup(char *s)
+{+ while (isspace(*s))
+ ++s;
+ if (*s != '\0')
+ error("trailing characters after preprocessor directive");+}
static void
nextcpp(void)
@@ -264,7 +272,7 @@
return s;
}
-static char *
+static bool
define(char *s)
{char *t;
@@ -291,7 +299,9 @@
/* nothing */;
for (t = s + strlen(s); isspace(*--t); *t = '\0')
/* nothing */;
- return mkdefine(s, sym);
+ s = mkdefine(s, sym);
+ cleanup(s);
+ return 1;
too_long:
error("macro identifier too long");@@ -299,7 +309,7 @@
error("macro names must be identifiers");}
-static char *
+static bool
include(char *s)
{char fname[FILENAME_MAX], delim, c, *p;
@@ -329,7 +339,8 @@
abort();
}
- return p+1;
+ cleanup(p+1);
+ return 1;
not_found:
error("included file '%s' not found", fname);@@ -339,7 +350,7 @@
error("#include expects \"FILENAME\" or <FILENAME>");}
-static char *
+static bool
line(char *s)
{char *p, *q;
@@ -364,8 +375,10 @@
p = q+1;
/* passthrough */
case '\0':
+ /* TODO: check this atoi */
setfline(atoi(s)-1);
- return p;
+ cleanup(p);
+ return 1;
default:
goto bad_file;
}
@@ -376,22 +389,20 @@
error("first parameter of #line is not a positive integer");}
-static char *
+static bool
pragma(char *s)
{- while (*s)
- ++s;
- return s;
+ cleanup(s);
+ return 1;
}
-static char *
+static bool
usererr(char *s)
{- fprintf(stderr, "%s:%u:error: #error %s\n", getfname(), getfline(), s);
- exit(-1);
+ error("#error %s", s);}
-static char *
+static bool
ifclause(char *s, int isdef)
{unsigned curif, len;
@@ -398,7 +409,6 @@
char *endp;
Symbol *sym;
-
while (isspace(*s))
++s;
for (endp = s; isalnum(*endp) || *endp == '_'; ++endp)
@@ -407,44 +417,47 @@
error("...");memcpy(yytext, s, len);
yytext[len] = '\0';
- while (isspace(*endp))
- ++endp;
- if (*endp != '\0')
- error("trailing characters after preprocessor directive");-
+ cleanup(endp);
curif = numif++;
- sym = lookup(NS_CPP);
- if ((sym->flags & ISDEFINED) != 0 == isdef)
- return endp;
+
+ if (iffalse != 0) {+ sym = lookup(NS_CPP);
+ if ((sym->flags & ISDEFINED) != 0 == isdef)
+ return 1;
+ }
+
+ ++iffalse;
while (curif != numif) {if (!moreinput())
error("found EOF while ...");}
- return "";
+ --iffalse;
+
+ return 1;
}
-static char *
+static bool
ifdef(char *s)
{return ifclause(s, 1);
}
-static char *
+static bool
ifndef(char *s)
{return ifclause(s, 0);
}
-static char *
+static bool
endif(char *s)
{if (numif == 0)
error("#endif without #if");--numif;
- return NULL;
+ return iffalse == 0;
}
-char *
+bool
preprocessor(char *p)
{char *q;
@@ -451,7 +464,7 @@
unsigned short n;
static struct {char *name;
- char *(*fun)(char *);
+ bool (*fun)(char *);
} *bp, cmds[] = {"define", define,
"include", include,
@@ -467,11 +480,11 @@
while (isspace(*p))
++p;
if (*p != '#')
- return p;
+ return 0;
for (++p; isspace(*p); ++p)
/* nothing */;
if (*p == '\0')
- return p;
+ return 1;
for (q = p; isalpha(*q); ++q)
/* nothing */;
if ((n = q - p) == 0)
@@ -481,13 +494,7 @@
for (bp = cmds; bp->name; ++bp) {if (strncmp(bp->name, p, n))
continue;
- if ((q = (*bp->fun)(q)) == NULL)
- return NULL;
- while (isspace(*q))
- ++q;
- if (*q != '\0')
- error("trailing characters after preprocessor directive");- return q;
+ return (*bp->fun)(q);
}
incorrect:
error("incorrect preprocessor directive");--- a/cc1/lex.c
+++ b/cc1/lex.c
@@ -202,9 +202,7 @@
*(p = input->line) = '\0';
readline();
- if ((p = preprocessor(p)) == NULL)
- return 1;
- if (*p == '\0')
+ if (preprocessor(p))
goto repeat;
input->p = input->begin = p;
return 1;