The attached patch adds support for the -rdynamic compiler flag on darwin12 and later. The darwin linker, starting with Xcode 5 on darwin12, added support for the associated new -export_dynamic linker flag.
-export_dynamic
Preserves all global symbols in main executables
during LTO. Without this option, Link Time Optimization is
allowed to inline and remove global functions. This
option is used when a main executable may load a plug-in
which requires certain symbols from the main executable.
This patch emulates the behavior of clang from Xcode 5 and later which
accepts the -rdynamic flag. Note that the emission of -export_dynamic
by -rdynamic is unaffected by the use of -mmacosx-version-min.
These changes are achieved by the addition of rdynamic to
gcc/config/darwin.opt, addition of a new gcc/config/darwin12.h file
with additional spec handling for rdynamic in LINK_GCC_C_SEQUENCE_SPEC
and changes to gcc/config.gcc to use this new file on darwin12 or
later. Bootstrap tested on both x86_64-apple-darwin11 and
x86_64-apple-darwin14. Confirmed that on darwin11, the -rdynamic flag
retains the current behavior of issuing the compiler error "error:
unrecognized command line option ‘-rdynamic’". Confirmed that on
darwin12 and later, invoking -rdynamic emits the expected
-export_dynamc linker flag. Okay for gcc trunk?
Jack
darwin12_rdynamic.patch
Description: Binary data
