Created attachment 7821 [details] Patch to fix build error Minix3 builds Gold as part of its build process. When cross compiling on OSX10.9, it fails to build Gold with the following error: In file included from /Users/thomas/minix/tools/binutils/../../external/gpl3/binutils/dist/gold/binary.cc:31: In file included from /Users/thomas/minix/tools/binutils/../../external/gpl3/binutils/dist/gold/stringpool.h:23: In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/string:438: In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cwchar:107: In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cwctype:54: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cctype:51:72: error: use of undeclared identifier 'do_not_use_isalnum_with_safe_ctype' inline _LIBCPP_INLINE_VISIBILITY int __libcpp_isalnum(int __c) {return isalnum(__c);} This is fixed by #include'ing <sstream>.
> Minix3 builds Gold as part of its build process. When cross compiling on > OSX10.9, it fails to build Gold with the following error: > > In file included from > /Users/thomas/minix/tools/binutils/../../external/gpl3/binutils/dist/gold/binary.cc:31: > In file included from > /Users/thomas/minix/tools/binutils/../../external/gpl3/binutils/dist/gold/stringpool.h:23: > In file included from > /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/string:438: > In file included from > /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cwchar:107: > In file included from > /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cwctype:54: > /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cctype:51:72: > error: use of undeclared identifier 'do_not_use_isalnum_with_safe_ctype' > inline _LIBCPP_INLINE_VISIBILITY int __libcpp_isalnum(int __c) {return > isalnum(__c);} > > This is fixed by #include'ing <sstream>. How does including <sstream> fix the problem? Neither binary.cc nor stringpool.h use any API from <sstream>, so I don't see how this is an appropriate fix. Even if it does fix it somehow, I don't see how that would be anything but an accident that might break again at any point in the future. Libiberty's safe-ctype.h is clearly doing something very dangerous here, so it seems to me that there's a portability issue that needs to be fixed there, not in gold. Can you compile binary.cc (without your patch) with --save-temps, and send me the .ii file? -cary
I was inspired by a thread [0] on the GCC mailing list where a similar error message was produced, and it was suggested to move the include of <sstream> higher up in the file. That 'fix' was actually meant to fix something entirely else [1]. Now, why does this work? <sstream> includes <string>, which includes <cwchar>, which in turn includes <cwctype> that finally includes <cctype>. cctype in the OSX toolchain does among other things: #ifdef isalnum inline _LIBCPP_INLINE_VISIBILITY int __libcpp_isalnum(int __c) {return isalnum(__c);} #undef isalnum inline _LIBCPP_INLINE_VISIBILITY int isalnum(int __c) {return __libcpp_isalnum(__c);} #else // isalnum using ::isalnum; #endif // isalnum By including <sstream> before "safe-ctype.h", isalnum is not yet #defined and so the #undef branch is taken. If safe-ctype is included it will redefine isalnum to 'do_not_use_isalnum_with_safe_ctype'. However, safe-ctype first includes <ctype.h> which includes <cctype>, so that shouldn't be a problem. But the latter is only true for the GNU toolchain and I'm using OSX's toolchain which doesn't have <ctype.h> (or I'm not looking in the right place). This should normally fail, but I think the Gold build system when invoked from Minix' build system picks up a <ctype.h> that's included by GCC (which is also built by Minix). This <ctype.h> includes a <cctype> which has a different header guard than the cctype in OSX toolchain. binary.cc includes "stringpool.h" a few lines down of "safe-ctype.h", which eventually includes <string> -> <cwchar> -> <cwctype> -> <cctype> from the OSX toolchain. Due to the inclusion of "safe-ctype.h" earlier, isalnum has now been defined to 'do_not_use_isalnum_with_safe_ctype', and <cctype> while now take the #ifdef branch and cause a compilation error. <cctype> is included twice due to the difference in header guards. Now, I didn't realize all of this when I made the patch, but since you asked why it fixed the problem I investigated it. I agree it's dirty to include a header that has nothing to do with the file. It appears that moving the inclusion of "stringpool.h" above "safe-ctype.h" does the job as well. [0] https://gcc.gnu.org/ml/gcc/2014-05/msg00006.html [1] PR 61026 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61026
Created attachment 7823 [details] Second version of the patch fixing the build error
Created attachment 7824 [details] Requested saved temp version of binary.cc
The binutils-2_25-branch branch has been updated by Roland McGrath <roland@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=aae60b2c1f276263ad100952e3c3364c7baa6a2b commit aae60b2c1f276263ad100952e3c3364c7baa6a2b Author: Roland McGrath <mcgrathr@chromium.org> Date: Wed Dec 16 16:35:43 2015 -0800 PR gold/17473: Fix gold build with system C++ headers that use <ctype.h>. gold/ PR gold/17473 * binary.cc: Move #include "safe-ctype.h" to be last #include. (cherry picked from commit 95c29a83ebadd0038fd304539a83c5e90798c1b9)
The binutils-2_26-branch branch has been updated by Roland McGrath <roland@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=03f87942b6a216bc5cd07c5cfbb5ce5ad8185133 commit 03f87942b6a216bc5cd07c5cfbb5ce5ad8185133 Author: Roland McGrath <mcgrathr@chromium.org> Date: Wed Dec 16 16:35:59 2015 -0800 PR gold/17473: Fix gold build with system C++ headers that use <ctype.h>. gold/ PR gold/17473 * binary.cc: Move #include "safe-ctype.h" to be last #include. (cherry picked from commit 95c29a83ebadd0038fd304539a83c5e90798c1b9)
The master branch has been updated by Roland McGrath <roland@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=95c29a83ebadd0038fd304539a83c5e90798c1b9 commit 95c29a83ebadd0038fd304539a83c5e90798c1b9 Author: Roland McGrath <mcgrathr@chromium.org> Date: Wed Dec 16 16:35:27 2015 -0800 PR gold/17473: Fix gold build with system C++ headers that use <ctype.h>. gold/ PR gold/17473 * binary.cc: Move #include "safe-ctype.h" to be last #include.