6l/8l: emit DWARF in macho.

R=rsc, r, ken2
CC=golang-dev
https://golang.org/cl/2128041

src/cmd/6l/asm.c

@@ -929,7 +929,7 @@ asmb(void)
                         sh->size = elfstrsize;
                         sh->addralign = 1;
 
-                        dwarfaddheaders();
+                        dwarfaddelfheaders();
 		}
 
 		sh = newElfShstrtab(elfstr[ElfStrShstrtab]);

src/cmd/8l/asm.c

@@ -1050,7 +1050,7 @@ asmb(void)
 			sh->addralign = 1;
 			sh->addr = symdatva + 8 + symsize;
 
-                        dwarfaddheaders();
+                        dwarfaddelfheaders();
 		}
 
 		sh = newElfShstrtab(elfstr[ElfStrShstrtab]);

src/cmd/ld/dwarf.c

@@ -7,6 +7,7 @@
 #include	"../ld/dwarf.h"
 #include	"../ld/dwarf_defs.h"
 #include	"../ld/elf.h"
+#include	"../ld/macho.h"
 
 /*
  * Offsets and sizes of the .debug_* sections in the cout file.
@@ -835,7 +836,7 @@ dwarfemitdebugsections(void)
 }
 
 void
-dwarfaddheaders(void)
+dwarfaddelfheaders(void)
 {
 	ElfShdr *sh;
 
@@ -857,3 +858,32 @@ dwarfaddheaders(void)
 	sh->size = infosize;
 	sh->addralign = 1;
 }
+
+void
+dwarfaddmachoheaders(void)
+{
+	MachoSect *msect;
+	MachoSeg *ms;
+
+	vlong fakestart;
+
+        // Zero vsize segments won't be loaded in memory, even so they
+        // have to be page aligned in the file.
+	fakestart = abbrevo & ~0xfff;
+
+        ms = newMachoSeg("__DWARF", 3);
+	ms->fileoffset = fakestart;
+	ms->filesize = abbrevo-fakestart + abbrevsize+linesize+infosize;
+
+	msect = newMachoSect(ms, "__debug_abbrev");
+	msect->off = abbrevo;
+	msect->size = abbrevsize;
+
+	msect = newMachoSect(ms, "__debug_line");
+	msect->off = lineo;
+	msect->size = linesize;
+
+	msect = newMachoSect(ms, "__debug_info");
+	msect->off = infoo;
+	msect->size = infosize;
+}

src/cmd/ld/dwarf.h

@@ -22,7 +22,8 @@ void dwarfaddshstrings(Sym *shstrtab);
 void dwarfemitdebugsections(void);
 
 /*
- * Add ELF section headers pointing to the sections emitted in
+ * Add section headers pointing to the sections emitted in
  * dwarfemitdebugsections.
  */
-void dwarfaddheaders(void);
+void dwarfaddelfheaders(void);
+void dwarfaddmachoheaders(void);

src/cmd/ld/macho.c

@@ -6,6 +6,7 @@
 // http://developer.apple.com/mac/library/DOCUMENTATION/DeveloperTools/Conceptual/MachORuntime/Reference/reference.html
 
 #include "l.h"
+#include "../ld/dwarf.h"
 #include "../ld/lib.h"
 #include "../ld/macho.h"
 
@@ -129,7 +130,7 @@ machowrite(void)
 	MachoDebug *d;
 	MachoLoad *l;
 
-	o1 = Boffset(&bso);
+	o1 = cpos();
 
 	loadsize = 4*4*ndebug;
 	for(i=0; i<nload; i++)
@@ -229,7 +230,7 @@ machowrite(void)
 		LPUT(d->filesize);
 	}
 
-	return Boffset(&bso) - o1;
+	return cpos() - o1;
 }
 
 static void*
@@ -617,6 +618,8 @@ asmbmacho(vlong symdatva, vlong symo)
 		md = newMachoDebug();
 		md->fileoffset = symo+8+symsize;
 		md->filesize = lcsize;
+
+                dwarfaddmachoheaders();
 	}
 
 	a = machowrite();