Bug #68114 [Asn]: Build fails with gcc: Undefined symbols: ___extendsddf ___extendsfsd

Edit report at https://bugs.php.net/bug.php?id=68114&edit=1 ID: 68114 User updated by: php-bugs-2014 at ryandesign dot com Reported by: php-bugs-2014 at ryandesign dot com Summary: Build fails with gcc: Undefined symbols: ___extendsddf ___extendsfsd Status: Assigned Type: Bug Package: MySQL related Operating System: OS X PHP Version: 5.5.17 Assigned To: keyur Block user comment: N Private report: N New Comment: My assumption is that the fact that the configure test compiles and links is an error. Disabling optimizations for the duration of the configure test works around that error and allows the configure test to properly detect the absence of decimal fp support. Yes, this is papering over a bug in the compiler and/or linker but that's the best we can hope for since Apple is not going to be releasing any updated versions of the developer tools for the affected OS X versions because they are several major versions old by now. Inspecting the value of __APPLE_CC__ doesn't seem likely to help identify the broken compilers in this situation. With an affected version of gcc from OS X 10.6 ("gcc version 4.2.1 (Apple Inc. build 5666) (dot 3)"), the value of __APPLE_CC__ is "5666". However that OS X version also includes the llvm-gcc compiler ("gcc version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2335.6)") which is not affected by the problem and its __APPLE_CC__ value is "5658". An early version of clang is also included ("Apple clang version 1.7 (tags/Apple/clang-77) (based on LLVM 2.9svn)"); it is not affected by the bug and its __APPLE_CC__ value is "5621". The version of gcc-4.2 on OS X 10.5 ("gcc version 4.2.1 (Apple Inc. build 5577)") is affected; its __APPLE_CC__ value is 5577. It doesn't seem necessary to identify the affected compilers in any way; just disable optimizations for this configure test. This should not have any adverse effects on the test's ability to detect the feature on other platforms nor would it have any effect on the final executable's performance. You previously asked me to compile and run a snippet. Here's the result on OS X 10.5: $ gcc-4.2 snippet.c Undefined symbols: "___extendsddf", referenced from: _main in ccODpbxz.o ld: symbol(s) not found collect2: ld returned 1 exit status $ gcc-4.2 -O1 snippet.c $ ./a.out Expected: 99.49, Actual: 99.490000 $ echo $? 0 $ Previous Comments: ------------------------------------------------------------------------ [2014-11-04 03:56:50] keyur@php.net The config.log for the (default) -O2 case shows the test compiles *and* links *and* runs *and* exits with 0. So the same should happen for the main PHP executable...I don't understand why that linking fails. I am a bit hesitant to change the optimizer level since that seems just paper over the bug in the compiler/linker. I'd rather add a check for #if defined(__APPLE__CC__) && __APPLE_CC__ > N Can you tell me what the value of that macro is on your system? ------------------------------------------------------------------------ [2014-11-04 02:18:55] php-bugs-2014 at ryandesign dot com Here is the config.log for php-5.6.3RC1 on OS X 10.6.8: https://gist.github.com/ryandesign/4c4721cf740c014129e4 Here is the config.log after applying the patch I just attached, which fixes the problem as I suggested earlier: https://gist.github.com/ryandesign/4b2d1a5e082f3cb90994 ------------------------------------------------------------------------ [2014-11-03 21:59:12] keyur@php.net I don't have a Mac OS box, so I'm having the commands run by a friend. Here's the config it works on: $ uname -a Darwin 2414 13.4.0 Darwin Kernel Version 13.4.0: Sun Aug 17 19:50:11 PDT 2014; root:xnu-2422.115.4~1/RELEASE_X86_64 x86_64 $ gcc --version Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1 Apple LLVM version 6.0 (clang-600.0.54) (based on LLVM 3.5svn) Target: x86_64-apple-darwin13.4.0 Thread model: posix I see it is Clang. If you're available on IRC somewhere, let me know. We can work through this faster. ------------------------------------------------------------------------ [2014-11-03 21:50:05] keyur@php.net Can you paste the config.log of a failed build for me to look at on pastebin? ------------------------------------------------------------------------ [2014-11-03 21:37:55] php-bugs-2014 at ryandesign dot com You can revert that change; it doesn't help, as I said above on 2014-10-08. It is not possible that you tested that fix on Mac OS X 10.9 with gcc 4.2.1 from XCode because the versions of Xcode for Mac OS X 10.7 and later do not include any version of gcc. (Xcode 4 for those OS X versions include llvm-gcc42 which is different. Xcode 5 and later provide only clang.) The fix I propose is to modify the configure script so that "-O0" is added to the CFLAGS for this test, as apparently old gcc optimizes the test away somehow, as I said above on 2014-10-10. ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at https://bugs.php.net/bug.php?id=68114 -- Edit this bug report at https://bugs.php.net/bug.php?id=68114&edit=1