scc

commit a9645b102283223091826bff01b2441fb8514e41
parent 1448724dc8d932cb954e2910639106ee0b3f1406
Author: Michael Forney <mforney@mforney.org>
Date:   Mon, 30 Mar 2026 13:59:20 -0700

as: Use unsigned char for instruction buffers

`char` and `unsigned char` are not compatible types (on many systems),
so it is not legal to pass a `unsigned char *` to a function expecting
`char *` without an explicit cast.

These char arrays are often constructed from a multi-byte integer
(for example, tobytes()), relying on implementation-defined
conversions, so just use unsigned char to avoid this.

Diffstat:
M
src/cmd/scc-as/as.h
 | 
4
++--
M
src/cmd/scc-as/ins.c
 | 
8
++++----
M
src/cmd/scc-as/ppc/ins.c
 | 
2
+-
M
src/cmd/scc-as/symbol.c
 | 
2
+-
M
src/cmd/scc-as/x86/ins.c
 | 
8
++++----

5 files changed, 12 insertions(+), 12 deletions(-)
diff --git a/src/cmd/scc-as/as.h b/src/cmd/scc-as/as.h
@@ -100,7 +100,7 @@ union yylval {
 /* symbol.c */
 void cleansecs(void);
 void ibinfmt(void);
-void emit(char *, int);
+void emit(unsigned char *, int);
 Section *defsec(char *, char *);
 Symbol *tmpsym(unsigned long long);
 void killtmp(void);
@@ -139,7 +139,7 @@ int match(Op *, Node **);
 Node *moperand(void);
 
 /* ins.c */
-char *tobytes(unsigned long long, int, int);
+unsigned char *tobytes(unsigned long long, int, int);
 
 /* binfmt.c */
 void writeout(char *);
diff --git a/src/cmd/scc-as/ins.c b/src/cmd/scc-as/ins.c
@@ -25,10 +25,10 @@ reloc(Symbol *sym,
 {
 }
 
-char *
+unsigned char *
 tobytes(unsigned long long v, int nbytes, int inc)
 {
-	static char buf[sizeof(unsigned long long)];
+	static unsigned char buf[sizeof(unsigned long long)];
 	int idx;
 
 	idx = (inc < 0) ? nbytes-1 : 0;
@@ -60,7 +60,7 @@ xstring(int which, Node **args)
 		s = np->sym->name;
 		len = strlen(s);
 		len += which == XSTRING;
-		emit(s, len);
+		emit((unsigned char *)s, len);
 	}
 }
 
@@ -242,7 +242,7 @@ align(Op *op, Node **args)
 	pcal = pc+al & ~al;
 
 	for (al = pcal - pc; al > 0; --al)
-		emit((char []) {0}, 1);
+		emit((unsigned char []) {0}, 1);
 }
 
 void
diff --git a/src/cmd/scc-as/ppc/ins.c b/src/cmd/scc-as/ppc/ins.c
@@ -123,7 +123,7 @@ moperand(void)
 static void
 emit_packed(unsigned long ins)
 {
-	char buff[4];
+	unsigned char buff[4];
 
 	if (endian == BIG_ENDIAN) {
 		buff[0] = ins >> 24;
diff --git a/src/cmd/scc-as/symbol.c b/src/cmd/scc-as/symbol.c
@@ -417,7 +417,7 @@ cleansecs(void)
 }
 
 void
-emit(char *bytes, int n)
+emit(unsigned char *bytes, int n)
 {
 	struct lsection *lsec = (struct lsection *) cursec;
 
diff --git a/src/cmd/scc-as/x86/ins.c b/src/cmd/scc-as/x86/ins.c
@@ -302,7 +302,7 @@ void
 reg8_reg8(Op *op, Node **args)
 {
 	int src, dst;
-	char buf[op->size];
+	unsigned char buf[op->size];
 
 	src = reg8toint(args[0]);
 	dst = reg8toint(args[1]);
@@ -315,7 +315,7 @@ void
 imm8_reg8(Op *op, Node **args)
 {
 	int src, dst;
-	char buf[op->size];
+	unsigned char buf[op->size];
 
 	src = (*args)->sym->value;
 	dst = reg8toint(args[1]);
@@ -330,7 +330,7 @@ void
 reg16_reg16(Op *op, Node **args)
 {
 	int src, dst;
-	char buf[op->size];
+	unsigned char buf[op->size];
 
 	src = reg16toint(args[0]);
 	dst = reg16toint(args[1]);
@@ -344,7 +344,7 @@ void
 reg32_reg32(Op *op, Node **args)
 {
 	int src, dst;
-	char buf[op->size];
+	unsigned char buf[op->size];
 
 	src = reg32toint(args[0]);
 	dst = reg32toint(args[1]);