RFR: 8264449: Enable reproducible builds with SOURCE_DATE_EPOCH [v5]

John Neffenger jgneff at openjdk.java.net
Mon Nov 22 21:28:11 UTC 2021 

On Sat, 18 Sep 2021 15:15:10 GMT, Kevin Rushforth <kcr at openjdk.org> wrote:

> I did a CI build yesterday and again today on all three platforms and compared the sdk between the two builds for each platform. On all three platforms the results are the same: All files were identical except the native jfxwebkit library. So there is something in the WebKit build that is affected by an external input (perhaps the system date or similar).

I can recreate this difference, but only on macOS.

**Lesson learned:** When testing reproducible builds on a permanent system, never use the Gradle Daemon!

I always get a different `libjfxwebkit.dylib` file when I run the build with `bash gradlew --no-daemon`. Shown below are the versions of the compilers I'm using:


john at linux:~$ gcc --version
gcc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0

john at macos:~$ gcc --version
Apple clang version 13.0.0 (clang-1300.0.29.3)

john at win10:~$ gcc --version
gcc (GCC) 11.2.0


When I dump each of the shared libraries with the following script, I get a text file with 10,413,716 lines, yet there are only 108 lines different between the two output files.


#!/bin/bash
# Dumps macOS shared libraries
# Diffoscope fails due to missing '=' after '--arch-name' option:
#     llvm-objdump: error: unknown argument '--arch-name'
llvm-objdump --arch-name=x86_64 --section="__TEXT,__text" --macho \
    --demangle --no-leading-addr --no-show-raw-insn "$@"


The differences are shown below:


diff --git a/libjfxwebkit.5.txt b/libjfxwebkit.6.txt
index 9d6932a..63f2b70 100644
--- a/libjfxwebkit.5.txt
+++ b/libjfxwebkit.6.txt
@@ -1,4 +1,4 @@
-libjfxwebkit.5.dylib:
+libjfxwebkit.6.dylib:
 Contents of (__TEXT,__text) section
 __ZN6WebKit15StorageAreaImplD2Ev:
 	pushq	%rbp
@@ -881412,30 +881412,22 @@ __ZN7WebCore30isCSSPropertyEnabledBySettingsENS_13CSSPropertyIDEPKNS_8SettingsE:
 	movq	%rsp, %rbp
 	movb	$1, %al
 	testq	%rsi, %rsi
-	je	0x319ee0
+	je	0x319ee7
 	leal	-258(%rdi), %ecx
 	cmpw	$37, %cx
-	ja	0x319eb7
+	ja	0x319eb2
 	movzwl	%cx, %ecx
-	leaq	79(%rip), %rdx
+	leaq	75(%rip), %rdx
 	movslq	(%rdx,%rcx,4), %rcx
 	addq	%rdx, %rcx
 	jmpq	*%rcx
 	movb	466(%rsi), %al
-	andb	$4, %al
-	shrb	$2, %al
-	popq	%rbp
-	retq
+	jmp	0x319ee2
+	cmpw	$43, %di
+	je	0x319edc
 	movzwl	%di, %ecx
 	cmpl	$366, %ecx
-	je	0x319ed5
-	cmpw	$43, %di
-	jne	0x319ee0
-	movb	451(%rsi), %al
-	andb	$4, %al
-	shrb	$2, %al
-	popq	%rbp
-	retq
+	jne	0x319ee7
 	movb	454(%rsi), %al
 	andb	$32, %al
 	shrb	$5, %al
@@ -881446,46 +881438,52 @@ __ZN7WebCore30isCSSPropertyEnabledBySettingsENS_13CSSPropertyIDEPKNS_8SettingsE:
 	shrb	%al
 	popq	%rbp
 	retq
+	movb	451(%rsi), %al
+	andb	$4, %al
+	shrb	$2, %al
+	popq	%rbp
+	retq
+	nopl	(%rax)
+	.long 4294967230	@ KIND_JUMP_TABLE32
+	.long 4294967230	@ KIND_JUMP_TABLE32
+	.long 4294967230	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967255	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967291	@ KIND_JUMP_TABLE32
+	.long 4294967255	@ KIND_JUMP_TABLE32
+	.long 4294967268	@ KIND_JUMP_TABLE32
+	nopw	%cs:(%rax,%rax)
 	nop
-	.long 4294967226	@ KIND_JUMP_TABLE32
-	.long 4294967226	@ KIND_JUMP_TABLE32
-	.long 4294967226	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967269	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967280	@ KIND_JUMP_TABLE32
-	.long 4294967269	@ KIND_JUMP_TABLE32
-	.long 4294967282	@ KIND_JUMP_TABLE32
-	nopl	(%rax,%rax)
 __ZN7WebCore15getPropertyNameENS_13CSSPropertyIDE:
 	leal	-2(%rdi), %eax
 	movzwl	%ax, %eax


@bmwiedemann Bernhard, does this look familiar? It appears to be similar to the [problem you fixed in WebKit][1] (twice).

[1]: https://github.com/WebKit/WebKit/commits?author=bmwiedemann

-------------

PR: https://git.openjdk.java.net/jfx/pull/446

More information about the openjfx-dev mailing list