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[cc1] Remove scalar use of char

Using scalar char is a bad idea because char are always promoted to
int in all the operations, they use the same space than an int in
the stack and since they may be signed, any operation over them
bigger than 127 produces an overflow with undefined behaviour.

--- a/cc1/cc1.h

+++ b/cc1/cc1.h

@@ -412,7 +412,7 @@

 extern void decl(void);

 /* lex.c */

-extern char ahead(void);

+extern int ahead(void);

 extern unsigned next(void);

 extern void expect(unsigned tok);

 extern void discard(void);

--- a/cc1/code.c

+++ b/cc1/code.c

@@ -188,7 +188,7 @@

 static void

 emitvar(Symbol *sym)

 {

-	char c;

+	int c;

 	short flags = sym->flags;

 	if (flags & SLOCAL)

--- a/cc1/cpp.c

+++ b/cc1/cpp.c

@@ -184,7 +184,8 @@

 static size_t

 copymacro(char *buffer, char *s, size_t bufsiz, char *arglist[])

 {

-	char delim, prevc, c, *p, *arg, *bp = buffer;

+	int delim, prevc, c;

+	char *p, *arg, *bp = buffer;

 	size_t size;

 	for (prevc = '\0'; c = *s; prevc = c, ++s) {

@@ -797,7 +798,8 @@

 void

 outcpp(void)

 {

-	char c, *s, *t;

+	int c;

+	char *s, *t;

 	for (next(); yytoken != EOFTOK; next()) {

 		if (onlyheader)

--- a/cc1/lex.c

+++ b/cc1/lex.c

@@ -377,7 +377,7 @@

 }

 static unsigned

-integer(char *s, char base)

+integer(char *s, int base)

 {

 	Type *tp;

 	Symbol *sym;

@@ -414,7 +414,8 @@

 static char *

 digits(unsigned base)

 {

-	char c, *p;

+	char *p;

+	int c;

 	for (p = input->p; c = *p; ++p) {

 		switch (base) {

@@ -441,7 +442,7 @@

 static unsigned

 number(void)

 {

-	char base;

+	int base;

 	if (*input->p != '0') {

 		base = 10;

@@ -457,7 +458,7 @@

 	return integer(digits(base), base);

 }

-static char

+static int

 escape(void)

 {

 	int c, base;

@@ -506,7 +507,7 @@

 static unsigned

 character(void)

 {

-	char c;

+	int c;

 	Symbol *sym;

 	if ((c = *++input->p) == '\\')

@@ -530,7 +531,8 @@

 static unsigned

 string(void)

 {

-	char *bp = yytext, c;

+	char *bp = yytext;

+	int c;

 	*bp++ = '"';

 	for (++input->p; (c = *input->p) != '"'; ++input->p) {

@@ -614,7 +616,7 @@

 static unsigned

 relational(int op, int equal, int shift, int assig)

 {

-	char c;

+	int c;

 	if ((c = *input->p++) == '=')

 		return equal;

@@ -627,7 +629,7 @@

 static unsigned

 logic(int op, int equal, int logic)

 {

-	char c;

+	int c;

 	if ((c = *input->p++) == '=')

 		return equal;

@@ -640,7 +642,7 @@

 static unsigned

 dot(void)

 {

-	char c;

+	int c;

 	if ((c = *input->p) != '.')

 		return '.';

@@ -753,7 +755,7 @@

 	}

 }

-char

+int

 ahead(void)

 {

 	skipspaces();

@@ -770,7 +772,7 @@

 discard(void)

 {

 	extern jmp_buf recover;

-	char c;

+	int c;

 	input->begin = input->p;

 	for (c = yytoken; ; c = *input->begin++) {

--- a/cc1/symbol.c

+++ b/cc1/symbol.c

@@ -276,8 +276,8 @@

 lookup(int ns, char *name, int alloc)

 {

 	Symbol *sym;

-	int sns;

-	char *t, c;

+	int sns, c;

+	char *t;

 	c = *name;

 	for (sym = *hash(name, ns); sym; sym = sym->hash) {