ports/177224: building www/firefox fails

[Jan Beich]

The following reply was made to PR ports/177224; it has been noted by GNATS.

From: Jan Beich <jbeich at tormail.org>
To: Tsurutani Naoki <turutani at scphys.kyoto-u.ac.jp>
Cc: bug-followup at FreeBSD.org, toolchain at freebsd.org
Subject: Re: ports/177224: building www/firefox fails
Date: Sun, 31 Mar 2013 08:20:46 +0200

 (toolchain@ may know more about clang-devel behavior)
 
 Tsurutani Naoki <turutani at scphys.kyoto-u.ac.jp> writes:
 
 > building with lang/clang successfully finishes, but firefox crashes
 >  with segmentation fault just after running it.
 
 I've asked (privately) devel/llvm maintainer to incorporate r175057 but
 so far he hasn't responded.
 
 http://lists.freebsd.org/pipermail/freebsd-ports/2013-February/081635.html
 
 > building without clang successfully finishes, and no errors.
 
 > I want a knob to choice the compiler.
 
 By setting CC/CXX/CPP you've made the choice. There is no need for a
 superfluous option for what every port must allow to do.
 
 It's just the compiler chosen by default doesn't work.
 
 >> ../../dist/bin/libxul.so: undefined reference to `PrepareAndDispatch'
 >> ../../dist/bin/libxul.so: undefined reference to `invoke_copy_to_stack'
 >> clang: error: linker command failed with exit code 1 (use -v to see invocation)
 >
 > building with lang/clang-devel fails (*1).
 > (*1) __attribute__((used)) might be ignored with clang-devel (clang 3.3) ?
 
 Perhaps, a compiler bug? The following workaround seems to work for
 clang 3.3 but breaks the build for clang 3.2 / gcc 4.6.
 
 --- xpcom/reflect/xptcall/src/md/unix/xptcinvoke_gcc_x86_unix.cpp~
 +++ xpcom/reflect/xptcall/src/md/unix/xptcinvoke_gcc_x86_unix.cpp
 @@ -82,7 +82,7 @@ __asm__ (
  	"pushl %edx\n\t"                /* push this. esp % 16 == 0 */
  
  	"movl  0x14(%ebp), %edx\n\t"
 -	"call  " SYMBOL_UNDERSCORE "invoke_copy_to_stack\n\t"
 +	"call  " SYMBOL_UNDERSCORE "_Z20invoke_copy_to_stackjP13nsXPTCVariantPj\n\t"
  	"movl  0x08(%ebp), %ecx\n\t"	/* 'that' */
  	"movl  (%ecx), %edx\n\t"
  	"movl  0x0c(%ebp), %eax\n\t"    /* function index */
 --- xpcom/reflect/xptcall/src/md/unix/xptcstubs_gcc_x86_unix.cpp~
 +++ xpcom/reflect/xptcall/src/md/unix/xptcstubs_gcc_x86_unix.cpp
 @@ -118,7 +118,7 @@ asm(".text\n\t"
      SYMBOL_UNDERSCORE "SharedStub:\n\t"
      "leal	0x08(%esp), %ecx\n\t"
      "movl	0x04(%esp), %edx\n\t"
 -    "jmp	" SYMBOL_UNDERSCORE "PrepareAndDispatch\n\t"
 +    "jmp	" SYMBOL_UNDERSCORE "_Z18PrepareAndDispatchjP14nsXPTCStubBasePj\n\t"
  #if !defined(XP_MACOSX)
      ".size	" SYMBOL_UNDERSCORE "SharedStub,.-" SYMBOL_UNDERSCORE "SharedStub"
  #endif
 
 > using [[gnu::used]] instead of above failed:
 > % make
 > ...
 > /usr/local/work/usr/ports/www/firefox/work/mozilla-
 > release/xpcom/reflect/xptcall/src/md/unix/xptcinvoke_gcc_x86_unix.cpp:12:13: error:
 >       '__used__' attribute cannot be applied to types
 > static void ATTRIBUTE_USED __attribute__ ((regparm(3)))
 >             ^
 > ../../../../../../../xpcom/reflect/xptcall/src/md/unix/xptc_gcc_x86_unix.h:19:26: note:
 >       expanded from macro 'ATTRIBUTE_USED'
 > #define ATTRIBUTE_USED [[gnu::__used__]]
 >                          ^
 > 1 error generated.
 > %
 
 It may be clang 3.3 is more strict with c++11 attributes. clang 3.2 and
 gcc 4.8 would still warn about incorrect placement.
 
 > In file included from xpcom/reflect/xptcall/src/md/unix/xptcinvoke_gcc_x86_unix.cpp:9:0:
 > xpcom/reflect/xptcall/src/md/unix/xptcinvoke_gcc_x86_unix.cpp: At global scope:
 > xpcom/reflect/xptcall/src/md/unix/xptc_gcc_x86_unix.h:19:24: warning: attribute ignored [-Wattributes]
 >  #define ATTRIBUTE_USED [[gnu::used]]
 >                         ^
 > xpcom/reflect/xptcall/src/md/unix/xptcinvoke_gcc_x86_unix.cpp:12:13: note: in expansion of macro 'ATTRIBUTE_USED'
 >  static void ATTRIBUTE_USED __attribute__ ((regparm(3)))
 >              ^
 > xpcom/reflect/xptcall/src/md/unix/xptc_gcc_x86_unix.h:19:24: note: an attribute that appertains to a type-specifier is ignored
 >  #define ATTRIBUTE_USED [[gnu::used]]
 >                         ^
 > xpcom/reflect/xptcall/src/md/unix/xptcinvoke_gcc_x86_unix.cpp:12:13: note: in expansion of macro 'ATTRIBUTE_USED'
 >  static void ATTRIBUTE_USED __attribute__ ((regparm(3)))
 >              ^
 
 And if you put [[gnu::used]] between invoke_copy_to_stack and ()
 the mangling issue happens again.