From f687fb7e7379c73e0050982f9e1b4848ff689787 Mon Sep 17 00:00:00 2001
From: Rob Pike <r@golang.org>
Date: Mon, 20 Jul 2009 13:19:47 -0700
Subject: [PATCH] 6l cleanup: last set of magic numbers for elf64 moved to
 ld/elf64*.

R=rsc
DELTA=68  (21 added, 28 deleted, 19 changed)
OCL=31857
CL=31864
---
 src/cmd/6l/asm.c   | 16 +++++++-------
 src/cmd/6l/obj.c   |  2 +-
 src/cmd/ld/elf64.c | 54 ++++++++++++++++++----------------------------
 src/cmd/ld/elf64.h | 13 +++++++----
 4 files changed, 39 insertions(+), 46 deletions(-)

diff --git a/src/cmd/6l/asm.c b/src/cmd/6l/asm.c
index 3db010a788..c1d0a4d97a 100644
--- a/src/cmd/6l/asm.c
+++ b/src/cmd/6l/asm.c
@@ -196,6 +196,7 @@ asmb(void)
 		debug['8'] = 1;	/* 64-bit addresses */
 		v = rnd(HEADR+textsize, INITRND);
 		seek(cout, v, 0);
+		elf64init();
 		break;
 	}
 
@@ -545,15 +546,14 @@ asmb(void)
 		eh->machine = 62;	/* machine = AMD64 */
 		eh->version = EV_CURRENT;
 		eh->entry = entryvalue();
-		eh->phoff = 64L;
-		eh->shoff = 64L+56*eh->phnum;
-		eh->ehsize = 64;
-		eh->phentsize = 56;
-		eh->shentsize = 64;
 
-		elf64writehdr();
-		elf64writephdrs();
-		elf64writeshdrs();
+		a = 0;
+		a += elf64writehdr();
+		a += elf64writephdrs();
+		a += elf64writeshdrs();
+		if (a > ELF64FULLHDRSIZE) {
+			diag("ELF64FULLHDRSIZE too small:", a);
+		}
 		cflush();
 
 		/* string table */
diff --git a/src/cmd/6l/obj.c b/src/cmd/6l/obj.c
index a2a520396f..8538e064e4 100644
--- a/src/cmd/6l/obj.c
+++ b/src/cmd/6l/obj.c
@@ -197,7 +197,7 @@ main(int argc, char *argv[])
 			INITRND = 4096;
 		break;
 	case 7:	/* elf64 executable */
-		HEADR = elf64headr();
+		HEADR = ELF64FULLHDRSIZE;
 		if(INITTEXT == -1)
 			INITTEXT = (1<<22)+HEADR;
 		if(INITDAT == -1)
diff --git a/src/cmd/ld/elf64.c b/src/cmd/ld/elf64.c
index 9b191693d9..ea1a39b418 100644
--- a/src/cmd/ld/elf64.c
+++ b/src/cmd/ld/elf64.c
@@ -7,13 +7,23 @@
 #include "../ld/elf64.h"
 
 #define	NSECT	16
-static	int	nume64str;
+static	int	numstr;
 static	Elf64Hdr	hdr;
 static	Elf64PHdr	*phdr[NSECT];
 static	Elf64SHdr	*shdr[NSECT];
 static	char	*sname[NSECT];
 static	char	*str[NSECT];
 
+void
+elf64init(void)
+{
+	hdr.phoff = ELF64HDRSIZE;
+	hdr.shoff = ELF64HDRSIZE;
+	hdr.ehsize = ELF64HDRSIZE;
+	hdr.phentsize = ELF64PHDRSIZE;
+	hdr.shentsize = ELF64SHDRSIZE;
+}
+
 void
 elf64phdr(Elf64PHdr *e)
 {
@@ -56,10 +66,10 @@ void
 elf64writestrtable(void)
 {
 	int i;
-	int size;
+	uint32 size;
 
 	size = 0;
-	for (i = 0; i < nume64str; i++)
+	for (i = 0; i < numstr; i++)
 		size += putelf64strtab(str[i]);
 	if (size > STRTABSIZE)
 		diag("elf64 string table overflow");
@@ -68,56 +78,32 @@ elf64writestrtable(void)
 void
 e64addstr(char *name)
 {
-	if (nume64str >= NSECT) {
+	if (numstr >= NSECT) {
 		diag("too many elf strings");
 		return;
 	}
-	str[nume64str++] = strdup(name);
+	str[numstr++] = strdup(name);
 	stroffset += strlen(name)+1;
 }
 
 uint32
-elf64headr(void)
-{
-	uint32 a;
-
-	a = 64;		/* a.out header */
-
-	/* TODO: calculate these byte counts properly */
-	a += 56;	/* page zero seg */
-	a += 56;	/* text seg */
-	a += 56;	/* stack seg */
-
-	a += 64;	/* nil sect */
-	a += 64;	/* .text sect */
-	a += 64;	/* .data seg */
-	a += 64;	/* .bss sect */
-	a += 64;	/* .shstrtab sect - strings for headers */
-	if (!debug['s']) {
-		a += 56;	/* symdat seg */
-		a += 64;	/* .gosymtab sect */
-		a += 64;	/* .gopclntab sect */
-	}
-
-	return a;
-}
-
-void
 elf64writeshdrs(void)
 {
 	int i;
 
 	for (i = 0; i < hdr.shnum; i++)
 		elf64shdr(sname[i], shdr[i]);
+	return hdr.shnum * ELF64SHDRSIZE;
 }
 
-void
+uint32
 elf64writephdrs(void)
 {
 	int i;
 
 	for (i = 0; i < hdr.phnum; i++)
 		elf64phdr(phdr[i]);
+	return hdr.phnum * ELF64PHDRSIZE;
 }
 
 Elf64PHdr*
@@ -131,6 +117,7 @@ newElf64PHdr(void)
 		diag("too many phdrs");
 	else
 		phdr[hdr.phnum++] = e;
+	hdr.shoff += ELF64PHDRSIZE;
 	return e;
 }
 
@@ -159,7 +146,7 @@ getElf64Hdr(void)
 	return &hdr;
 }
 
-void
+uint32
 elf64writehdr()
 {
 	int i;
@@ -179,4 +166,5 @@ elf64writehdr()
 	WPUT(hdr.shentsize);
 	WPUT(hdr.shnum);
 	WPUT(hdr.shstrndx);
+	return ELF64HDRSIZE;
 }
diff --git a/src/cmd/ld/elf64.h b/src/cmd/ld/elf64.h
index fc71744e64..f42ae94252 100644
--- a/src/cmd/ld/elf64.h
+++ b/src/cmd/ld/elf64.h
@@ -67,6 +67,7 @@ struct Elf64Hdr
 	Elf64_Half	shnum;	/* Number of section header entries */
 	Elf64_Half	shstrndx;	/* Section name string table index */
 };
+#define	ELF64HDRSIZE	64
 
 /* E ident indexes */
 #define	EI_MAG0	0 	/* File identification */
@@ -112,6 +113,7 @@ struct Elf64PHdr
 	Elf64_Xword	memsz;	/* Size of segment in memory */
 	Elf64_Xword	align;	/* Alignment of segment */
 };
+#define	ELF64PHDRSIZE	56
 
 /* P types */
 #define	PT_NULL		0	/* Unused entry */
@@ -140,6 +142,7 @@ struct Elf64SHdr
 	Elf64_Xword	addralign;	/* Address alignment boundary */
 	Elf64_Xword	entsize;	/* Size of entries, if section has table */
 };
+#define	ELF64SHDRSIZE	64
 
 /* S types */
 #define SHT_NULL	0	/* Unused section header */
@@ -166,16 +169,18 @@ struct Elf64SHdr
 #define	SHF_MASKOS	0x0F000000	/* Environment-specific use */
 #define	SHF_MASKPROC	0xF0000000	/* Processor-specific use */
 
+void	elf64init(void);
 Elf64Hdr	*getElf64Hdr();
 Elf64SHdr	*newElf64SHdr(char*);
 Elf64PHdr	*newElf64PHdr();
-uint32	elf64headr(void);
-void	elf64writehdr(void);
-void	elf64writephdrs(void);
-void	elf64writeshdrs(void);
+uint32	elf64writehdr(void);
+uint32	elf64writephdrs(void);
+uint32	elf64writeshdrs(void);
 void	elf64writestrtable(void);
 
 extern	int	nume64phdr;
 extern	int	nume64shdr;
 
 #define	STRTABSIZE	256
+/* Amount of space to reserve at the start of the file; may waste some */
+#define	ELF64FULLHDRSIZE	2048