Crank WARNS.

Cast sizeof() to (int), as it's being compared against an int, not a size_t.
If i is changed to a size_t, it means the logic must be slightly changed later
in the flow, where --i is checked to be >= 0.  I am not sure I want to make a
logic change to account for clearing up a warning, when an aesthetic one will
keep from modifying the logic.

Other harmless casts, that I think I've made in the right directions.

Make gpbc() an inline function, rather than an obfuscated macro, make its
scratch space local, rather than global.  The previous macro used a dirty
hack (logical AND in place of a conditional) which would lead GCC to throw
a fit (rightly so) as the logical check, as well as the incrementation of
a variable, were not used for anything.

const'ify a few places where gcc3 yells. xstrdup() some global consts in
places where we xstrdup() when not using consts, but tried to assign them
to non-consts before.

Don't use execv(2) if we don't have the kind of arguments it wants.

Reviewed by:    asmodai obrien tjr
Submitted by:   tjr (a gcc3 build log)

1 files changed, 20 insertions, 4 deletions

diff --git a/usr.bin/m4/extern.h b/usr.bin/m4/extern.h
index 79c3a29..57a0600 100644
--- a/usr.bin/m4/extern.h
+++ b/usr.bin/m4/extern.h
@@ -71,7 +71,7 @@ extern void	remhash(const char *, int);
 /* main.c */
 extern void outputstr(const char *);
 extern int builtin_type(const char *);
-extern char *builtin_realname(int);
+extern const char *builtin_realname(int);
 extern void emitline(void);
 
 /* misc.c */
@@ -148,11 +148,27 @@ extern char *bbase[];		/* buffer base per ilevel */
 extern char ecommt[MAXCCHARS+1];/* end character for comment */
 extern char *ep;		/* first free char in strspace */
 extern char lquote[MAXCCHARS+1];/* left quote character (`) */
-extern char *m4wraps;		/* m4wrap string default. */
-extern char *null;		/* as it says.. just a null. */
+extern const char *m4wraps;	/* m4wrap string default. */
+extern const char *null;	/* as it says.. just a null. */
 extern char rquote[MAXCCHARS+1];/* right quote character (') */
 extern char scommt[MAXCCHARS+1];/* start character for comment */
 extern int synccpp;		/* Line synchronisation for C preprocessor */
-extern int chscratch;		/* Scratch space for gpbc() macro */
 
 extern int mimic_gnu;		/* behaves like gnu-m4 */
+
+/* get a possibly pushed-back-character, increment lineno if need be */
+static __inline int gpbc(void)
+{
+	int chscratch;		/* Scratch space. */
+
+	if (bp > bufbase) {
+		if (*--bp) 
+			return (*bp);
+		else
+			return (EOF);
+	}
+	chscratch = obtain_char(infile+ilevel);
+	if (chscratch == '\n')
+		++inlineno[ilevel];
+	return (chscratch);
+}