8l: emit DWARF in Windows PE.

R=rsc, lvd, brainman, Joe Poirier
CC=golang-dev
https://golang.org/cl/2124041

src/cmd/ld/dwarf.c

@@ -19,6 +19,7 @@
 #include	"../ld/dwarf_defs.h"
 #include	"../ld/elf.h"
 #include	"../ld/macho.h"
+#include	"../ld/pe.h"
 
 /*
  * Offsets and sizes of the debug_* sections in the cout file.
@@ -2277,6 +2278,13 @@ writegdbscript(void)
 	return sectionstart;
 }
 
+static void
+align(vlong size)
+{
+	if((thechar == '6' || thechar == '8') && HEADTYPE == 10) // Only Windows PE need section align.
+		strnput("", rnd(size, PEFILEALIGN) - size);
+}
+
 /*
  * This is the main entry point for generating dwarf.  After emitting
  * the mandatory debug_abbrev section, it calls writelines() to set up
@@ -2316,8 +2324,11 @@ dwarfemitdebugsections(void)
 	genasmsym(defdwsymb);
 
 	writeabbrev();
+	align(abbrevsize);
 	writelines();
+	align(linesize);
 	writeframes();
+	align(framesize);
 
 	synthesizestringtypes(dwtypes.child);
 	synthesizeslicetypes(dwtypes.child);
@@ -2350,16 +2361,23 @@ dwarfemitdebugsections(void)
 		}
 	}
 	infosize = infoe - infoo;
+	align(infosize);
 
 	pubnameso  = writepub(ispubname);
+	pubnamessize  = cpos() - pubnameso;
+	align(pubnamessize);
+
 	pubtypeso  = writepub(ispubtype);
+	pubtypessize  = cpos() - pubtypeso;
+	align(pubtypessize);
+
 	arangeso   = writearanges();
-	gdbscripto = writegdbscript();
+	arangessize   = cpos() - arangeso;
+	align(arangessize);
 
-	pubnamessize  = pubtypeso - pubnameso;
-	pubtypessize  = arangeso - pubtypeso;
-	arangessize   = gdbscripto - arangeso;
+	gdbscripto = writegdbscript();
 	gdbscriptsize = cpos() - gdbscripto;
+	align(gdbscriptsize);
 }
 
 /*
@@ -2541,3 +2559,24 @@ dwarfaddmachoheaders(void)
 		ms->filesize += msect->size;
 	}
 }
+
+/*
+ * Windows PE
+ */
+void
+dwarfaddpeheaders(void)
+{
+	dwarfemitdebugsections();
+	newPEDWARFSection(".debug_abbrev", abbrevsize);
+	newPEDWARFSection(".debug_line", linesize);
+	newPEDWARFSection(".debug_frame", framesize);
+	newPEDWARFSection(".debug_info", infosize);
+	if (pubnamessize > 0)
+		newPEDWARFSection(".debug_pubnames", pubnamessize);
+	if (pubtypessize > 0)
+		newPEDWARFSection(".debug_pubtypes", pubtypessize);
+	if (arangessize > 0)
+		newPEDWARFSection(".debug_aranges", arangessize);
+	if (gdbscriptsize > 0)
+		newPEDWARFSection(".debug_gdb_scripts", gdbscriptsize);
+}

src/cmd/ld/dwarf.h

@@ -27,3 +27,4 @@ void dwarfaddshstrings(Sym *shstrtab);
  */
 void dwarfaddelfheaders(void);
 void dwarfaddmachoheaders(void);
+void dwarfaddpeheaders(void);

src/cmd/ld/pe.c

@@ -10,6 +10,7 @@
 #include "l.h"
 #include "../ld/lib.h"
 #include "../ld/pe.h"
+#include "../ld/dwarf.h"
 
 // DOS stub that prints out
 // "This program cannot be run in DOS mode."
@@ -33,6 +34,9 @@ static char dosstub[] =
 	0x24, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
 };
 
+static char symnames[256]; 
+static int  nextsymoff;
+
 int32 PESECTHEADR;
 int32 PEFILEHEADR;
 
@@ -307,6 +311,60 @@ dope(void)
 	initdynimport();
 }
 
+/*
+ * For more than 8 characters section names, name contains a slash (/) that is 
+ * followed by an ASCII representation of a decimal number that is an offset into 
+ * the string table. 
+ * reference: pecoff_v8.docx Page 24.
+ * <http://www.microsoft.com/whdc/system/platform/firmware/PECOFFdwn.mspx>
+ */
+IMAGE_SECTION_HEADER*
+newPEDWARFSection(char *name, vlong size)
+{
+	IMAGE_SECTION_HEADER *h;
+	char s[8];
+
+	if(nextsymoff+strlen(name)+1 > sizeof(symnames)) {
+		diag("pe string table is full");
+		errorexit();
+	}
+
+	strcpy(&symnames[nextsymoff], name);
+	sprint(s, "/%d\0", nextsymoff+4);
+	nextsymoff += strlen(name);
+	symnames[nextsymoff] = 0;
+	nextsymoff ++;
+	h = addpesection(s, size, size, 0);
+	h->Characteristics = IMAGE_SCN_MEM_READ|
+		IMAGE_SCN_MEM_DISCARDABLE;
+
+	return h;
+}
+
+static void
+addsymtable(void)
+{
+	IMAGE_SECTION_HEADER *h;
+	int i, size;
+	
+	if(nextsymoff == 0)
+		return;
+	
+	size  = nextsymoff + 4;
+	h = addpesection(".symtab", size, size, 0);
+	h->Characteristics = IMAGE_SCN_MEM_READ|
+		IMAGE_SCN_MEM_DISCARDABLE;
+	fh.PointerToSymbolTable = cpos();
+	fh.NumberOfSymbols = 0;
+	// put symbol string table
+	lputl(size);
+	for (i=0; i<nextsymoff; i++)
+		cput(symnames[i]);
+	strnput("", h->SizeOfRawData - size);
+	cflush();
+}
+
+
 void
 asmbpe(void)
 {
@@ -334,7 +392,12 @@ asmbpe(void)
 		IMAGE_SCN_MEM_READ|IMAGE_SCN_MEM_WRITE;
 
 	addimports(nextfileoff, d);
+	
+	if(!debug['s'])
+		dwarfaddpeheaders();
 
+	addsymtable();
+		
 	fh.NumberOfSections = nsect;
 	fh.TimeDateStamp = time(0);
 	fh.Characteristics = IMAGE_FILE_RELOCS_STRIPPED|
@@ -402,3 +465,4 @@ asmbpe(void)
 
 	pewrite();
 }
+

src/cmd/ld/pe.h

@@ -99,6 +99,7 @@ enum {
 	IMAGE_SCN_MEM_EXECUTE = 0x20000000,
 	IMAGE_SCN_MEM_READ = 0x40000000,
 	IMAGE_SCN_MEM_WRITE = 0x80000000,
+	IMAGE_SCN_MEM_DISCARDABLE = 0x2000000,
 
 	IMAGE_DIRECTORY_ENTRY_EXPORT = 0,
 	IMAGE_DIRECTORY_ENTRY_IMPORT = 1,
@@ -122,6 +123,8 @@ void peinit(void);
 void asmbpe(void);
 void dope(void);
 
+IMAGE_SECTION_HEADER* newPEDWARFSection(char *name, vlong size);
+
 // X64
 typedef struct {
 	uint16 Magic;