Bug 1464084 - Don't export std::thread::_M_start_thread symbols with --enable-stdcxx-compat. r=froydnj
This relies on the fact that providing multiple --version-script
combines them all, so we effectively create a new symbol version
that has no global symbol, but hides the std::thread::_M_start_thread
symbols.
This version script trick happens to work with BFD ld, gold, and lld.
The downside is that when providing multiple --version-script's, ld
doesn't want any of them to have no version at all. So for the libraries
that do already have a version script (through SYMBOLS_FILE), we use a
version where there used to be none, using the library name as the
version. Practically speaking, this binds the libraries a little closer
than they used to be, kind of non-flat namespace on OSX (which is the
default there), meaning the dynamic linker will actively want to use
symbols from those libraries instead of a system library that might
happen to have the same symbol name.
new file mode 100644
--- /dev/null
+++ b/build/unix/stdc++compat/hide_std.ld
@@ -0,0 +1,5 @@
+hidden {
+ local:
+ # std::thread::_M_start_thread(...)
+ _ZNSt6thread15_M_start_thread*;
+};
--- a/build/unix/stdc++compat/moz.build
+++ b/build/unix/stdc++compat/moz.build
@@ -18,8 +18,10 @@ FORCE_STATIC_LIB = True
NO_PGO = True
DisableStlWrapping()
COMPILE_FLAGS['CLANG_PLUGIN'] = []
DEFINES['MOZ_LIBSTDCXX_VERSION'] = CONFIG['MOZ_LIBSTDCXX_TARGET_VERSION']
HOST_DEFINES['MOZ_LIBSTDCXX_VERSION'] = CONFIG['MOZ_LIBSTDCXX_HOST_VERSION']
+
+OS_LIBS += ['-Wl,--version-script,%s/hide_std.ld' % SRCDIR]
--- a/python/mozbuild/mozbuild/action/generate_symbols_file.py
+++ b/python/mozbuild/mozbuild/action/generate_symbols_file.py
@@ -37,16 +37,18 @@ def generate_symbols_file(output, *args)
else:
pp.context['DATA'] = ''
pp.out = StringIO()
pp.do_filter('substitution')
pp.do_include(input)
symbols = [s.strip() for s in pp.out.getvalue().splitlines() if s.strip()]
+ libname, ext = os.path.splitext(os.path.basename(output.name))
+
if buildconfig.substs['OS_TARGET'] == 'WINNT':
# A def file is generated for MSVC link.exe that looks like the
# following:
# LIBRARY library.dll
# EXPORTS
# symbol1
# symbol2
# ...
@@ -61,31 +63,30 @@ def generate_symbols_file(output, *args)
# data_symbol1 @DATA@
# data_symbol2 @DATA@
# ...
# The DATA variable is "simply" expanded by the preprocessor, to
# nothing on non-Windows, such that we only get the symbol name on
# those platforms, and to DATA on Windows, so that the "DATA" part
# is, in fact, part of the symbol name as far as the symbols variable
# is concerned.
- libname, ext = os.path.splitext(os.path.basename(output.name))
assert ext == '.def'
output.write('LIBRARY %s\nEXPORTS\n %s\n'
% (libname, '\n '.join(symbols)))
elif buildconfig.substs['GCC_USE_GNU_LD']:
# A linker version script is generated for GNU LD that looks like the
# following:
- # {
+ # liblibrary.so {
# global:
# symbol1;
# symbol2;
# ...
# local:
# *;
# };
- output.write('{\nglobal:\n %s;\nlocal:\n *;\n};'
- % ';\n '.join(symbols))
+ output.write('%s {\nglobal:\n %s;\nlocal:\n *;\n};'
+ % (libname, ';\n '.join(symbols)))
elif buildconfig.substs['OS_TARGET'] == 'Darwin':
# A list of symbols is generated for Apple ld that simply lists all
# symbols, with an underscore prefix.
output.write(''.join('_%s\n' % s for s in symbols))
return set(pp.includes)
--- a/testing/cppunittest.ini
+++ b/testing/cppunittest.ini
@@ -38,17 +38,16 @@ skip-if = os == 'android' # Bug 1147630
[TestRollingMean]
[TestScopeExit]
[TestSegmentedVector]
[TestSHA1]
[TestSmallPointerArray]
[TestSaturate]
[TestSplayTree]
[TestSPSCQueue]
-skip-if = os == 'linux' # Bug 1464084
[TestSyncRunnable]
[TestTemplateLib]
[TestTuple]
[TestTypeTraits]
[TestTypedEnum]
[TestUniquePtr]
[TestVariant]
[TestVector]
