avoid overflow of symb buffer in 5a/6a/8a/5c/6c/8c

R=rsc
CC=golang-dev
https://golang.org/cl/194099

src/cmd/5a/a.h

@@ -142,6 +142,7 @@ EXTERN	int32	lineno;
 EXTERN	int	nerrors;
 EXTERN	int32	nhunk;
 EXTERN	int	ninclude;
+EXTERN	int32	nsymb;
 EXTERN	Gen	nullgen;
 EXTERN	char*	outfile;
 EXTERN	int	pass;
@@ -149,7 +150,7 @@ EXTERN	char*	pathname;
 EXTERN	int32	pc;
 EXTERN	int	peekc;
 EXTERN	int	sym;
-EXTERN	char	symb[NSYMB];
+EXTERN	char*	symb;
 EXTERN	int	thechar;
 EXTERN	char*	thestring;
 EXTERN	int32	thunk;
@@ -157,6 +158,7 @@ EXTERN	Biobuf	obuf;
 
 void*	alloc(int32);
 void*	allocn(void*, int32, int32);
+void    ensuresymb(int32);
 void	errorexit(void);
 void	pushio(void);
 void	newio(void);

src/cmd/5a/lex.c

@@ -57,6 +57,8 @@ main(int argc, char *argv[])
 
 	thechar = '5';
 	thestring = "arm";
+
+	ensuresymb(NSYMB);
 	memset(debug, 0, sizeof(debug));
 	cinit();
 	outfile = 0;

src/cmd/6a/a.h

@@ -155,6 +155,7 @@ EXTERN	int32	lineno;
 EXTERN	int	nerrors;
 EXTERN	int32	nhunk;
 EXTERN	int	ninclude;
+EXTERN	int32	nsymb;
 EXTERN	Gen	nullgen;
 EXTERN	char*	outfile;
 EXTERN	int	pass;
@@ -162,7 +163,7 @@ EXTERN	char*	pathname;
 EXTERN	int32	pc;
 EXTERN	int	peekc;
 EXTERN	int	sym;
-EXTERN	char	symb[NSYMB];
+EXTERN	char*	symb;
 EXTERN	int	thechar;
 EXTERN	char*	thestring;
 EXTERN	int32	thunk;
@@ -170,6 +171,7 @@ EXTERN	Biobuf	obuf;
 
 void*   alloc(int32);
 void*	allocn(void*, int32, int32);
+void    ensuresymb(int32);
 void	errorexit(void);
 void	pushio(void);
 void	newio(void);

src/cmd/6a/lex.c

@@ -61,6 +61,7 @@ main(int argc, char *argv[])
 	thechar = '6';
 	thestring = "amd64";
 
+	ensuresymb(NSYMB);
 	memset(debug, 0, sizeof(debug));
 	cinit();
 	outfile = 0;

src/cmd/8a/a.h

@@ -156,6 +156,7 @@ EXTERN	int32	lineno;
 EXTERN	int	nerrors;
 EXTERN	int32	nhunk;
 EXTERN	int	ninclude;
+EXTERN	int32	nsymb;
 EXTERN	Gen	nullgen;
 EXTERN	char*	outfile;
 EXTERN	int	pass;
@@ -163,7 +164,7 @@ EXTERN	char*	pathname;
 EXTERN	int32	pc;
 EXTERN	int	peekc;
 EXTERN	int	sym;
-EXTERN	char	symb[NSYMB];
+EXTERN	char*	symb;
 EXTERN	int	thechar;
 EXTERN	char*	thestring;
 EXTERN	int32	thunk;
@@ -171,6 +172,7 @@ EXTERN	Biobuf	obuf;
 
 void*   alloc(int32);
 void*	allocn(void*, int32, int32);
+void    ensuresymb(int32);
 void	errorexit(void);
 void	pushio(void);
 void	newio(void);

src/cmd/8a/lex.c

@@ -60,6 +60,8 @@ main(int argc, char *argv[])
 
 	thechar = '8';
 	thestring = "386";
+
+	ensuresymb(NSYMB);
 	memset(debug, 0, sizeof(debug));
 	cinit();
 	outfile = 0;

src/cmd/cc/cc.h

@@ -492,6 +492,7 @@ EXTERN	int32	nhunk;
 EXTERN	int	ninclude;
 EXTERN	Node*	nodproto;
 EXTERN	Node*	nodcast;
+EXTERN	int32	nsymb;
 EXTERN	Biobuf	outbuf;
 EXTERN	Biobuf	diagbuf;
 EXTERN	char*	outfile;
@@ -500,7 +501,7 @@ EXTERN	int	peekc;
 EXTERN	int32	stkoff;
 EXTERN	Type*	strf;
 EXTERN	Type*	strl;
-EXTERN	char	symb[NSYMB];
+EXTERN	char*	symb;
 EXTERN	Sym*	symstring;
 EXTERN	int	taggen;
 EXTERN	Type*	tfield;
@@ -573,6 +574,7 @@ int	mpatov(char*, vlong*);
  */
 void*	allocn(void*, int32, int32);
 void*	alloc(int32);
+void    ensuresymb(int32);
 void	cinit(void);
 int	compile(char*, char**, int);
 void	errorexit(void);

src/cmd/cc/lex.c

@@ -85,6 +85,7 @@ main(int argc, char *argv[])
 	char *defs[50], *p;
 	int nproc, nout, i, c, ndef;
 
+	ensuresymb(NSYMB);
 	memset(debug, 0, sizeof(debug));
 	tinit();
 	cinit();
@@ -392,7 +393,7 @@ newfile(char *s, int f)
 Sym*
 slookup(char *s)
 {
-
+	ensuresymb(strlen(s));
 	strcpy(symb, s);
 	return lookup();
 }
@@ -408,7 +409,9 @@ lookup(void)
 
 	if((uchar)symb[0] == 0xc2 && (uchar)symb[1] == 0xb7) {
 		// turn leading · into ""·
-		memmove(symb+2, symb, strlen(symb)+1);
+		h = strlen(symb);
+		ensuresymb(h+2);
+		memmove(symb+2, symb, h+1);
 		symb[0] = '"';
 		symb[1] = '"';
 	}
@@ -1584,3 +1587,17 @@ allocn(void *p, int32 n, int32 d)
 		memset((char*)p+n, 0, d);
 	return p;
 }
+
+void
+ensuresymb(int32 n)
+{
+	if(symb == nil) {
+		symb = alloc(NSYMB+1);
+		nsymb = NSYMB;
+	}	
+
+	if(n > nsymb) {
+		symb = allocn(symb, nsymb, n+1-nsymb);
+		nsymb = n;
+	}
+}

src/cmd/cc/lexbody

@@ -125,6 +125,20 @@ allocn(void *p, int32 on, int32 n)
 	return p;
 }
 
+void
+ensuresymb(int32 n)
+{
+	if(symb == nil) {
+		symb = alloc(NSYMB+1);
+		nsymb = NSYMB;
+	}
+
+	if(n > nsymb) {
+		symb = allocn(symb, nsymb, n+1-nsymb);
+		nsymb = n;
+	}
+}
+
 void
 setinclude(char *p)
 {
@@ -209,7 +223,7 @@ newfile(char *s, int f)
 Sym*
 slookup(char *s)
 {
-
+	ensuresymb(strlen(s));
 	strcpy(symb, s);
 	return lookup();
 }
@@ -225,7 +239,9 @@ lookup(void)
 
 	if((uchar)symb[0] == 0xc2 && (uchar)symb[1] == 0xb7) {
 		// turn leading · into ""·
-		memmove(symb+2, symb, strlen(symb)+1);
+		h = strlen(symb);
+		ensuresymb(h+2);
+		memmove(symb+2, symb, h+1);
 		symb[0] = '"';
 		symb[1] = '"';
 	}

src/cmd/cc/macbody

@@ -140,6 +140,7 @@ dodefine(char *cp)
 	char *p;
 	int32 l;
 
+	ensuresymb(strlen(cp));
 	strcpy(symb, cp);
 	p = strchr(symb, '=');
 	if(p) {
@@ -574,6 +575,7 @@ macinc(void)
 	for(i=0; i<ninclude; i++) {
 		if(i == 0 && c0 == '>')
 			continue;
+		ensuresymb(strlen(include[i])+strlen(str)+2);
 		strcpy(symb, include[i]);
 		strcat(symb, "/");
 		if(strcmp(symb, "./") == 0)