scc

commit 6212cd97ef3b5311a8245131e8bf5f9957e4fd67
parent 73b42fa96c7f6580d0cc18a4611c620e3ec28e44
Author: Roberto E. Vargas Caballero <k0ga@shike2.net>
Date:   Fri,  8 May 2026 15:34:16 +0200

libmach: Encode number of bits in OBJ()

Some formats have different versions based in being a 32 or 64
bit version, and deriving it from the arch has corner cases and
it requires continous maintainance.

Diffstat:
M
include/scc/bits/scc/mach.h
 | 
11
+++++++++--
M
src/libmach/coff32/coff32archs.c
 | 
4
++--
M
src/libmach/elf/elfarchs.c
 | 
2
+-
M
src/libmach/elf/elfprobe.c
 | 
7
++++---

4 files changed, 16 insertions(+), 8 deletions(-)
diff --git a/include/scc/bits/scc/mach.h b/include/scc/bits/scc/mach.h
@@ -6,10 +6,11 @@
 #undef BIG_ENDIAN
 
 #define NBYTES 32
-#define OBJ(format,arch,order) ((order) << 10 | (arch) << 5 | (format))
+#define OBJ(fmt,arch,order,bits) ((bits) << 11 | (order) << 10 | (arch) << 5 | (fmt))
 #define FORMAT(t) ((t) & 0x1f)
 #define ARCH(t) (((t) >> 5) & 0x1f)
-#define ORDER(t) (((t) >> 10) & 0x1f)
+#define ORDER(t) (((t) >> 10) & 0x1)
+#define BITS(t) (((t) >> 11) & 0x3)
 #define objfmt(o) FORMAT((o)->type)
 
 typedef struct section Section;
@@ -24,6 +25,12 @@ enum objformat {
 	NFORMATS,
 };
 
+enum objbits {
+	OBJ16,
+	OBJ32,
+	OBJ64,
+};
+
 enum objarch {
 	ARCH286,
 	ARCH386,
diff --git a/src/libmach/coff32/coff32archs.c b/src/libmach/coff32/coff32archs.c
@@ -6,7 +6,7 @@
 #include "../libmach.h"
 
 struct arch coff32archs[] = {
-	{"coff-i386", "\x4c\x01", OBJ(COFF32, ARCH386, LITTLE_ENDIAN), 0x0105},
-	{"coff-z80", "\x5a\x80", OBJ(COFF32, ARCHZ80, LITTLE_ENDIAN), 0x3105},
+	{"coff-i386", "\x4c\x01", OBJ(COFF32, ARCH386, LITTLE_ENDIAN, OBJ32), 0x0105},
+	{"coff-z80", "\x5a\x80", OBJ(COFF32, ARCHZ80, LITTLE_ENDIAN, OBJ32), 0x3105},
 	NULL,
 };
diff --git a/src/libmach/elf/elfarchs.c b/src/libmach/elf/elfarchs.c
@@ -13,7 +13,7 @@ struct arch elfarchs[] = {
 		.name = "elf-amd64",
 		.mach = EM_X86_64,
 		.endian = ELFDATA2LSB,
-		.type = OBJ(ELF, ARCHAMD64, LITTLE_ENDIAN),
+		.type = OBJ(ELF, ARCHAMD64, LITTLE_ENDIAN, OBJ64),
 		.is32 = 0,
 	},
 	NULL,
diff --git a/src/libmach/elf/elfprobe.c b/src/libmach/elf/elfprobe.c
@@ -11,13 +11,14 @@
 int
 elfprobe(unsigned char *buf, char **name)
 {
-	int arch, data, endian;
+	int arch, data, endian, bits;
 	struct elfhdr32 hdr;
 	struct arch *ap;
 
 	data = buf[EI_DATA];
 	endian = (data == ELFDATA2LSB) ? LITTLE_ENDIAN : BIG_ENDIAN;
 	arch = (buf[EI_CLASS] == ELFCLASS32) ? ARCHUNK32 : ARCHUNK64;
+	bits = (buf[EI_CLASS] == ELFCLASS32) ? OBJ32 : OBJ64;
 
 	unpack(endian,
 	       buf,
@@ -36,7 +37,7 @@ elfprobe(unsigned char *buf, char **name)
 	}
 
 	for (ap = elfarchs; ap->name; ap++) {
-		if (ap->mach == hdr.e_machine &&  ap->endian == data) {
+		if (ap->mach == hdr.e_machine && ap->endian == data) {
 			if (name)
 				*name = ap->name;
 			return ap->type;
@@ -46,5 +47,5 @@ elfprobe(unsigned char *buf, char **name)
 	if  (name)
 		*name = "elf-unknown";
 
-	return OBJ(ELF, arch, endian);
+	return OBJ(ELF, arch, endian, bits);
 }