From 0e8de61d7311d6bc74fc244de44df9be452a112b Mon Sep 17 00:00:00 2001
From: Russ Cox <rsc@golang.org>
Date: Mon, 14 Apr 2014 13:20:51 -0400
Subject: [PATCH] liblink, cmd/link: add version number to object file

There are changes we know we want to make, but not before Go 1.3
Add a version number so that we can make them more easily later.

LGTM=iant
R=iant
CC=golang-codereviews
https://golang.org/cl/87670043
---
 src/cmd/link/testdata/Makefile                |  15 ++++++++++-----
 src/cmd/link/testdata/autosection.6           | Bin 909 -> 912 bytes
 src/cmd/link/testdata/autoweak.6              | Bin 428 -> 431 bytes
 src/cmd/link/testdata/dead.6                  | Bin 1062 -> 1065 bytes
 src/cmd/link/testdata/hello.6                 | Bin 269 -> 272 bytes
 src/cmd/link/testdata/layout.6                | Bin 431 -> 434 bytes
 src/cmd/link/testdata/link.hello.darwin.amd64 |   4 ++--
 src/cmd/link/testdata/pclntab.6               | Bin 4604 -> 4607 bytes
 src/liblink/objfile.c                         |   6 +++++-
 src/pkg/debug/goobj/read.go                   |   5 +++++
 10 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/src/cmd/link/testdata/Makefile b/src/cmd/link/testdata/Makefile
index 1d5810a800..3b1b15f731 100644
--- a/src/cmd/link/testdata/Makefile
+++ b/src/cmd/link/testdata/Makefile
@@ -1,10 +1,15 @@
-all: hello.6 pclntab.6
+ALL=\
+	autosection.6\
+	autoweak.6\
+	dead.6\
+	hello.6\
+	layout.6\
+	pclntab.6\
 
-hello.6: hello.s
-	go tool 6a hello.s
+all: $(ALL)
 
-pclntab.6: pclntab.s
-	go tool 6a pclntab.s
+%.6: %.s
+	go tool 6a $*.s
 
 pclntab.s: genpcln.go
 	go run genpcln.go >pclntab.s
diff --git a/src/cmd/link/testdata/autosection.6 b/src/cmd/link/testdata/autosection.6
index 62619a7ea3e36cdc72a8c89a4a59107a28269c2c..996268061bb8eae0b015b2c5796f6f755b66f40f 100644
GIT binary patch
delta 68
zcmeBWpTIsr&eGD<Fxk{J%`hp&%s|06KTpB2ph&^cM8VL=%GlV-)KJ050LardFflMt
W(B@L)Vqi$mH#E*kVcZyE$qWET=nvZf

delta 65
zcmbQh-pf8g&dkg-(J;v@(Ztv+F-;+)G*!VXF;Bt3T*1iL%GB7(*g(O^z|cfN*TB@k
UfJ>2!fgwHL&^RY$W4I+V03+BBxBvhE

diff --git a/src/cmd/link/testdata/autoweak.6 b/src/cmd/link/testdata/autoweak.6
index f7e9e69713090a69ebf1e32ba62ce2fb881de00b..7bf428b51dcc62577675796ecc31b1ede76c5cff 100644
GIT binary patch
delta 68
zcmZ3(yq<Z2oTa6yVX~=dnqg9knSp|Dex8D3L6L%?iGrb#m9epvsiA_A0g$I_U}9jP
Wpv|So#lVoBZ)lv8!niRcf)M~#P7p2t

delta 65
zcmZ3_yoPy#oSB(vqG6I*qKUCtVwyroX{v%(VxEG5xq^|gm8r3nv4Mh-fuV_lu7Rn6
U0hb~d14DYgp>a;i#_$M605O~p3jhEB

diff --git a/src/cmd/link/testdata/dead.6 b/src/cmd/link/testdata/dead.6
index f8eaf7ab8df8abd3416d27508dee24aa8b21f25a..a512543cba614b4497add9f81ef6d5883635fce4 100644
GIT binary patch
delta 76
zcmZ3+v65qgoUNs)VX~=dnqg9knSp|Dex8D3L6L%?iGrb#m9epvsiA_A0g$I_U}9jP
epv|So#lVoBZ)lv8!pQKCiEHwHMx~8aYnTD#I}<Aa

delta 65
zcmZ3<v5aGaoSB(vqG6I*qKUCtVwyroX{v%(VxEG5xq^|gm8r3nv4Mh-fuV_lu7Rn6
U0hb~d14DYgp>a;i#_&tb05S*=g#Z8m

diff --git a/src/cmd/link/testdata/hello.6 b/src/cmd/link/testdata/hello.6
index 26a04a20169dc8731970e9adf2c054424105aef9..c6435a5e6fd6d964cd87e456a99f087a97fe0e0a 100644
GIT binary patch
delta 88
zcmeBWn!q$c&eGD<Fxk{J%`hp&%s|06KTpB2ph&^cM8VL=%GlV-)KJ050LardFflMt
q(B@L)Vqi$mH#E*kVVoFJESRpJp08hAl&qheo1&kSnU_8BhA9Bhb{Dz;

delta 85
zcmbQh)XOwM&dk^}Dbc_nB`wX!(o(^#C{w{DHCe&PK*7++%E-XV*aXNnG*-|xFf}mX
nQsiP_NY6Jk&PkaVUMyHtoSdGoUtE-|pPZYbpOa!V@wO=dsM8mL

diff --git a/src/cmd/link/testdata/layout.6 b/src/cmd/link/testdata/layout.6
index b19491efc5cb4f5349f46b12419de50c6bd48635..0a600d7c74994a8ea741b7891f1d1e8b021fd93e 100644
GIT binary patch
delta 68
zcmZ3_yoq^&oTa6yVX~=dnqg9knSp|Dex8D3L6L%?iGrb#m9epvsiA_A0g$I_U}9jP
Wpv|So#lVoBZ)lv8!niRcnh^k3<`6dk

delta 65
zcmdnQyq<Z2oSB(vqG6I*qKUCtVwyroX{v%(VxEG5xq^|gm8r3nv4Mh-fuV_lu7Rn6
U0hb~d14DYgp>a;i#_(uH05c*G6aWAK

diff --git a/src/cmd/link/testdata/link.hello.darwin.amd64 b/src/cmd/link/testdata/link.hello.darwin.amd64
index 5d94af1d9c..b1f0a93b21 100644
--- a/src/cmd/link/testdata/link.hello.darwin.amd64
+++ b/src/cmd/link/testdata/link.hello.darwin.amd64
@@ -49,8 +49,8 @@
 00001080  02 20 00 04 20 00 06 05  02 05 02 05 02 05 02 02  |. .. ...........|
 00001090  02 02 02 05 02 02 02 01  00 00 00 00 00 00 00 00  |................|
 000010a0  02 00 00 00 88 00 00 00  2f 55 73 65 72 73 2f 72  |......../Users/r|
-000010b0  73 63 2f 72 73 63 67 6f  2f 73 72 63 2f 63 6d 64  |sc/rscgo/src/cmd|
-000010c0  2f 6c 64 32 2f 74 65 73  74 64 61 74 61 2f 68 65  |/ld2/testdata/he|
+000010b0  73 63 2f 67 2f 67 6f 2f  73 72 63 2f 63 6d 64 2f  |sc/g/go/src/cmd/|
+000010c0  6c 69 6e 6b 2f 74 65 73  74 64 61 74 61 2f 68 65  |link/testdata/he|
 000010d0  6c 6c 6f 2e 73 00 00 00  00 00 00 00 00 00 00 00  |llo.s...........|
 *
 00002000  68 65 6c 6c 6f 20 77 6f  72 6c 64 0a              |hello world.|
diff --git a/src/cmd/link/testdata/pclntab.6 b/src/cmd/link/testdata/pclntab.6
index bc889c964a0c346dd56b00f7f8698ad5b6c62128..722a7f806e8ddf84997c425a963fd77a06a718c4 100644
GIT binary patch
delta 68
zcmeyP{9k#3oTa6yVX~=dnqg9knSp|Dex8D3L6L%?iGrb#m9epvsiA_A0g$I_U}9jP
Wpv|So#lVoBZ)lv8!niSHg&+WtUJ-5p

delta 65
zcmeyb{6~3$oS9LoiAl1dL1JQZnx#TWMyY~VVxEGbnS!B#m7$@PftiAlfuV_lu7Rn6
U0hb~d14DYgp>a;i#_$z_0CJrXbN~PV

diff --git a/src/liblink/objfile.c b/src/liblink/objfile.c
index b602536251..f0f3f76223 100644
--- a/src/liblink/objfile.c
+++ b/src/liblink/objfile.c
@@ -16,6 +16,7 @@
 // The file format is:
 //
 //	- magic header: "\x00\x00go13ld"
+//	- byte 1 - version number
 //	- sequence of strings giving dependencies (imported packages)
 //	- empty string (marks end of sequence)
 //	- sequence of defined symbols
@@ -248,7 +249,8 @@ linkwriteobj(Link *ctxt, Biobuf *b)
 	Bputc(b, 0);
 	Bputc(b, 0);
 	Bprint(b, "go13ld");
-	
+	Bputc(b, 1); // version
+
 	// Emit autolib.
 	for(h = ctxt->hist; h != nil; h = h->link)
 		if(h->offset < 0)
@@ -453,6 +455,8 @@ ldobjfile(Link *ctxt, Biobuf *f, char *pkg, int64 len, char *pn)
 	Bread(f, buf, sizeof buf);
 	if(memcmp(buf, startmagic, sizeof buf) != 0)
 		sysfatal("%s: invalid file start %x %x %x %x %x %x %x %x", pn, buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
+	if((c = Bgetc(f)) != 1)
+		sysfatal("%s: invalid file version number %d", pn, c);
 
 	for(;;) {
 		lib = rdstring(f);
diff --git a/src/pkg/debug/goobj/read.go b/src/pkg/debug/goobj/read.go
index f65abb6c27..8882eae534 100644
--- a/src/pkg/debug/goobj/read.go
+++ b/src/pkg/debug/goobj/read.go
@@ -573,6 +573,11 @@ func (r *objReader) parseObject(prefix []byte) error {
 		return r.error(errCorruptObject)
 	}
 
+	b := r.readByte()
+	if b != 1 {
+		return r.error(errCorruptObject)
+	}
+
 	// Direct package dependencies.
 	for {
 		s := r.readString()
-- 
2.50.0