8l: pe generation fixes

Restore ability to have different file and
section alignment in generated pe file.

Stop generating .bss pe section, it is
part of .data now.

Some code refactoring.

R=rsc, vcc
CC=golang-dev
https://golang.org/cl/2731041

src/cmd/8l/asm.c

@@ -397,10 +397,14 @@ asmb(void)
 			symo = rnd(HEADR+segtext.filelen, INITRND)+rnd(segdata.filelen, INITRND)+machlink;
 			break;
 		Elfsym:
-		case 10:
 			symo = rnd(HEADR+segtext.filelen, INITRND)+segdata.filelen;
 			symo = rnd(symo, INITRND);
 			break;
+		case 10:
+			// TODO(brainman): not sure what symo meant to be, but it is not used for Windows PE for now anyway
+			symo = rnd(HEADR+segtext.filelen, PEFILEALIGN)+segdata.filelen;
+			symo = rnd(symo, PEFILEALIGN);
+			break;
 		}
 		if(HEADTYPE != 10 && !debug['s']) {
 			seek(cout, symo, 0);

src/cmd/8l/obj.c

@@ -265,13 +265,13 @@ main(int argc, char *argv[])
 		break;
 	case 10: /* PE executable */
 		peinit();
-		HEADR = PERESERVE;
+		HEADR = PEFILEHEADR;
 		if(INITTEXT == -1)
-			INITTEXT = PEBASE+0x1000;
+			INITTEXT = PEBASE+PESECTHEADR;
 		if(INITDAT == -1)
 			INITDAT = 0;
 		if(INITRND == -1)
-			INITRND = 4096;
+			INITRND = PESECTALIGN;
 		break;
 	case 11:
 		tlsoffset = 0;
@@ -332,8 +332,6 @@ main(int argc, char *argv[])
 	dodata();
 	address();
 	reloc();
-	if(HEADTYPE == 10)
-		dope();
 	asmb();
 	undef();
 	if(debug['v']) {

src/cmd/ld/data.c

@@ -33,6 +33,7 @@
 #include	"l.h"
 #include	"../ld/lib.h"
 #include	"../ld/elf.h"
+#include	"../ld/pe.h"
 
 /*
  * divide-and-conquer list-link
@@ -736,6 +737,8 @@ address(void)
 	segdata.rwx = 06;
 	segdata.vaddr = va;
 	segdata.fileoff = va - segtext.vaddr + segtext.fileoff;
+	if(thechar == '8' && HEADTYPE == 10)	// Windows PE
+		segdata.fileoff = segtext.fileoff + rnd(segtext.len, PEFILEALIGN);
 	for(s=segdata.sect; s != nil; s=s->next) {
 		s->vaddr = va;
 		va += s->len;

src/cmd/ld/pe.c

@@ -33,18 +33,20 @@ static char dosstub[] =
 	0x24, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
 };
 
+int32 PESECTHEADR;
+int32 PEFILEHEADR;
+
 static int pe64;
 static int nsect;
-static int sect_virt_begin;
-static int sect_raw_begin = PERESERVE;
+static int nextsectoff;
+static int nextfileoff;
 
 static IMAGE_FILE_HEADER fh;
 static IMAGE_OPTIONAL_HEADER oh;
 static IMAGE_SECTION_HEADER sh[16];
-static IMAGE_SECTION_HEADER *textsect, *datsect, *bsssect;
 
 static IMAGE_SECTION_HEADER*
-new_section(char *name, int size, int noraw)
+addpesection(char *name, int sectsize, int filesize, Segment *s)
 {
 	IMAGE_SECTION_HEADER *h;
 
@@ -54,15 +56,23 @@ new_section(char *name, int size, int noraw)
 	}
 	h = &sh[nsect++];
 	strncpy((char*)h->Name, name, sizeof(h->Name));
-	h->VirtualSize = size;
-	if(!sect_virt_begin)
-		sect_virt_begin = 0x1000;
-	h->VirtualAddress = sect_virt_begin;
-	sect_virt_begin = rnd(sect_virt_begin+size, 0x1000);
-	if(!noraw) {
-		h->SizeOfRawData = rnd(size, PEALIGN);
-		h->PointerToRawData = sect_raw_begin;
-		sect_raw_begin += h->SizeOfRawData;
+	h->VirtualSize = sectsize;
+	h->VirtualAddress = nextsectoff;
+	nextsectoff = rnd(nextsectoff+sectsize, PESECTALIGN);
+	h->PointerToRawData = nextfileoff;
+	if(filesize > 0) {
+		h->SizeOfRawData = rnd(filesize, PEFILEALIGN);
+		nextfileoff += h->SizeOfRawData;
+	}
+	if(s) {
+		if(s->vaddr-PEBASE != h->VirtualAddress) {
+			diag("%s.VirtualAddress = %#llux, want %#llux", name, (vlong)h->VirtualAddress, (vlong)(s->vaddr-PEBASE));
+			errorexit();
+		}
+		if(s->fileoff != h->PointerToRawData) {
+			diag("%s.PointerToRawData = %#llux, want %#llux", name, (vlong)h->PointerToRawData, (vlong)(s->fileoff));
+			errorexit();
+		}
 	}
 	return h;
 }
@@ -79,6 +89,11 @@ peinit(void)
 	default:
 		break;
 	}
+
+	PEFILEHEADR = rnd(sizeof(dosstub)+sizeof(fh)+sizeof(oh)+sizeof(sh), PEFILEALIGN);
+	PESECTHEADR = rnd(PEFILEHEADR, PESECTALIGN);
+	nextsectoff = PESECTHEADR;
+	nextfileoff = PEFILEHEADR;
 }
 
 static void
@@ -97,26 +112,6 @@ pewrite(void)
 	for (i=0; i<nsect; i++)
 		for (j=0; j<sizeof(sh[i]); j++)
 			cput(((char*)&sh[i])[j]);
-	strnput("", PERESERVE-0x400);
-}
-
-void
-dope(void)
-{
-	textsect = new_section(".text", segtext.len, 0);
-	textsect->Characteristics = IMAGE_SCN_CNT_CODE|
-		IMAGE_SCN_CNT_INITIALIZED_DATA|
-		IMAGE_SCN_MEM_EXECUTE|IMAGE_SCN_MEM_READ;
-
-	datsect = new_section(".data", segdata.filelen, 0);
-	datsect->Characteristics = IMAGE_SCN_CNT_INITIALIZED_DATA|
-		IMAGE_SCN_MEM_READ|IMAGE_SCN_MEM_WRITE;
-	if(segdata.vaddr != PEBASE+datsect->VirtualAddress)
-		diag("segdata.vaddr = %#llux, want %#llux", (vlong)segdata.vaddr, (vlong)(PEBASE+datsect->VirtualAddress));
-
-	bsssect = new_section(".bss", segdata.len - segdata.filelen, 1);
-	bsssect->Characteristics = IMAGE_SCN_CNT_UNINITIALIZED_DATA|
-		IMAGE_SCN_MEM_READ|IMAGE_SCN_MEM_WRITE;
 }
 
 static void
@@ -128,7 +123,7 @@ strput(char *s)
 }
 
 static void
-add_import_table(void)
+addimports(vlong fileoff)
 {
 	IMAGE_IMPORT_DESCRIPTOR ds[2], *d;
 	char *dllname = "kernel32.dll";
@@ -155,7 +150,7 @@ add_import_table(void)
 		size += sizeof(fs[0].thunk);
 
 	IMAGE_SECTION_HEADER *isect;
-	isect = new_section(".idata", size, 0);
+	isect = addpesection(".idata", size, size, 0);
 	isect->Characteristics = IMAGE_SCN_CNT_INITIALIZED_DATA|
 		IMAGE_SCN_MEM_READ|IMAGE_SCN_MEM_WRITE;
 	
@@ -168,7 +163,7 @@ add_import_table(void)
 	for(f=fs; f->name; f++)
 		f->thunk += va;
 
-	seek(cout, 0, 2);
+	seek(cout, fileoff, 0);
 	for(d=ds; ; d++) {
 		lputl(d->OriginalFirstThunk);
 		lputl(d->TimeDateStamp);
@@ -192,7 +187,7 @@ add_import_table(void)
 void
 asmbpe(void)
 {
-	vlong eof;
+	IMAGE_SECTION_HEADER *t, *d;
 
 	switch(thechar) {
 	default:
@@ -206,11 +201,16 @@ asmbpe(void)
 		break;
 	}
 
-	// make sure the end of file is INITRND-aligned.
-	eof = seek(cout, 0, 2);
-	strnput("", rnd(eof, INITRND) - eof);
+	t = addpesection(".text", segtext.len, segtext.len, &segtext);
+	t->Characteristics = IMAGE_SCN_CNT_CODE|
+		IMAGE_SCN_CNT_INITIALIZED_DATA|
+		IMAGE_SCN_MEM_EXECUTE|IMAGE_SCN_MEM_READ;
+
+	d = addpesection(".data", segdata.len, segdata.filelen, &segdata);
+	d->Characteristics = IMAGE_SCN_CNT_INITIALIZED_DATA|
+		IMAGE_SCN_MEM_READ|IMAGE_SCN_MEM_WRITE;
 
-	add_import_table();
+	addimports(nextfileoff);
 
 	fh.NumberOfSections = nsect;
 	fh.TimeDateStamp = time(0);
@@ -223,24 +223,24 @@ asmbpe(void)
 	oh.Magic = 0x10b;	// PE32
 	oh.MajorLinkerVersion = 1;
 	oh.MinorLinkerVersion = 0;
-	oh.SizeOfCode = textsect->SizeOfRawData;
-	oh.SizeOfInitializedData = datsect->SizeOfRawData;
-	oh.SizeOfUninitializedData = bsssect->SizeOfRawData;
+	oh.SizeOfCode = t->SizeOfRawData;
+	oh.SizeOfInitializedData = d->SizeOfRawData;
+	oh.SizeOfUninitializedData = 0;
 	oh.AddressOfEntryPoint = entryvalue()-PEBASE;
-	oh.BaseOfCode = textsect->VirtualAddress;
-	oh.BaseOfData = datsect->VirtualAddress;
+	oh.BaseOfCode = t->VirtualAddress;
+	oh.BaseOfData = d->VirtualAddress;
 
 	oh.ImageBase = PEBASE;
-	oh.SectionAlignment = 0x00001000;
-	oh.FileAlignment = PEALIGN;
+	oh.SectionAlignment = PESECTALIGN;
+	oh.FileAlignment = PEFILEALIGN;
 	oh.MajorOperatingSystemVersion = 4;
 	oh.MinorOperatingSystemVersion = 0;
 	oh.MajorImageVersion = 1;
 	oh.MinorImageVersion = 0;
 	oh.MajorSubsystemVersion = 4;
 	oh.MinorSubsystemVersion = 0;
-	oh.SizeOfImage = sect_virt_begin;
-	oh.SizeOfHeaders = PERESERVE;
+	oh.SizeOfImage = nextsectoff;
+	oh.SizeOfHeaders = PEFILEHEADR;
 	oh.Subsystem = 3;	// WINDOWS_CUI
 	oh.SizeOfStackReserve = 0x00200000;
 	oh.SizeOfStackCommit = 0x00001000;

src/cmd/ld/pe.h

@@ -72,9 +72,16 @@ typedef struct {
 	uint32 FirstThunk;
 } IMAGE_IMPORT_DESCRIPTOR;
 
-#define PERESERVE	0x1000
-#define PEALIGN		0x1000
 #define PEBASE		0x00400000
+// SectionAlignment must be greater than or equal to FileAlignment.
+// The default is the page size for the architecture.
+#define PESECTALIGN	0x1000
+// FileAlignment should be a power of 2 between 512 and 64 K, inclusive.
+// The default is 512. If the SectionAlignment is less than
+// the architecture's page size, then FileAlignment must match SectionAlignment.
+#define PEFILEALIGN	(2<<8)
+extern	int32	PESECTHEADR;
+extern	int32	PEFILEHEADR;
 
 enum {
 	IMAGE_FILE_MACHINE_I386 = 0x14c,
@@ -112,5 +119,4 @@ enum {
 };
 
 void peinit(void);
-void dope(void);
 void asmbpe(void);