5l/6l/8l: use enums for header type and symbolic strings for -H option values

Thanks to rsc for the suggestion.

R=r
CC=golang-dev
https://golang.org/cl/4174060

4 files changed, 48 insertions, 4 deletions

diff --git a/src/cmd/ld/data.c b/src/cmd/ld/data.c
index 0551232cfc..a20b057ce5 100644
--- a/src/cmd/ld/data.c
+++ b/src/cmd/ld/data.c
@@ -241,7 +241,7 @@ dynrelocsym(Sym *s)
 {
 	Reloc *r;
 	
-	if(thechar == '8' && HEADTYPE == 10) { // Windows PE
+	if(HEADTYPE == Hwindows) {
 		Sym *rel, *targ;
 		
 		rel = lookup(".rel", 0);
@@ -898,9 +898,9 @@ address(void)
 	segdata.rwx = 06;
 	segdata.vaddr = va;
 	segdata.fileoff = va - segtext.vaddr + segtext.fileoff;
-	if((thechar == '6' || thechar == '8') && HEADTYPE == 10)	// Windows PE
+	if(HEADTYPE == Hwindows)
 		segdata.fileoff = segtext.fileoff + rnd(segtext.len, PEFILEALIGN);
-	if(thechar == '8' && HEADTYPE == 2) {	// Plan 9		
+	if(HEADTYPE == Hplan9x32) {
 		segdata.vaddr = va = rnd(va, 4096);
 		segdata.fileoff = segtext.fileoff + segtext.filelen;
 	}
diff --git a/src/cmd/ld/dwarf.c b/src/cmd/ld/dwarf.c
index 5df3515f5d..8c53d7d133 100644
--- a/src/cmd/ld/dwarf.c
+++ b/src/cmd/ld/dwarf.c
@@ -2302,7 +2302,7 @@ writegdbscript(void)
 static void
 align(vlong size)
 {
-	if((thechar == '6' || thechar == '8') && HEADTYPE == 10) // Only Windows PE need section align.
+	if(HEADTYPE == Hwindows) // Only Windows PE need section align.
 		strnput("", rnd(size, PEFILEALIGN) - size);
 }
 
diff --git a/src/cmd/ld/lib.c b/src/cmd/ld/lib.c
index 1838717bfe..998e28cf16 100644
--- a/src/cmd/ld/lib.c
+++ b/src/cmd/ld/lib.c
@@ -1264,3 +1264,16 @@ stkprint(Chain *ch, int limit)
 	if(ch->limit != limit)
 		print("\t%d\tafter %s uses %d\n", limit, name, ch->limit - limit);
 }
+
+int
+headtype(char *name)
+{
+	int i;
+
+	for(i=0; headers[i].name; i++)
+		if(strcmp(name, headers[i].name) == 0)
+			return headers[i].val;
+	fprint(2, "unknown header type -H %s\n", name);
+	errorexit();
+	return -1;  // not reached
+}
diff --git a/src/cmd/ld/lib.h b/src/cmd/ld/lib.h
index 1b37202271..234ea3198f 100644
--- a/src/cmd/ld/lib.h
+++ b/src/cmd/ld/lib.h
@@ -208,3 +208,34 @@ enum {
 	ArchiveObj,
 	Pkgdef
 };
+
+/* executable header types */
+enum {
+   Hgarbunix = 0,	// garbage unix
+   Hnoheader,		// no header
+   Hunixcoff,		// unix coff
+   Hrisc,		// aif for risc os
+   Hplan9x32,		// plan 9 32-bit format
+   Hplan9x64,		// plan 9 64-bit format
+   Hmsdoscom,		// MS-DOS .COM
+   Hnetbsd,		// NetBSD
+   Hmsdosexe,		// fake MS-DOS .EXE
+   Hixp1200,		// IXP1200 (raw)
+   Helf,		// ELF32
+   Hipaq,		// ipaq
+   Hdarwin,		// Apple Mach-O
+   Hlinux,		// Linux ELF
+   Hnacl,		// Google Native Client
+   Hfreebsd,		// FreeBSD ELF
+   Hwindows,		// MS Windows PE
+   Htiny		// tiny (os image)
+};
+
+typedef struct Header Header;
+struct Header {
+   char *name;
+   int val;
+};
+
+extern Header headers[];
+int headtype(char*);