Disable coalesce sections when using GCC with -Wa,-q and Clang integrated assembler?

Jeffrey Walton <noloader@xxxxxxxxx> · Mon, 4 Jul 2016 20:30:41 -0400

Hi Everyone,

I'm working with MacPorts GCC 6.1 on OS X. Apple's assembler is
version 1.38, so we need to use the Clang integrated assembler to
assemble streams with roughly SSE3 and above. -march=native pretty
much ensures SSE3 and above is produced.

We can enlist the Clang integrated assembler with -Wa,-q. Using GCC
6.1 with Clang is producing a stream of warnings (hundred per file):

/opt/local/bin/g++-mp-6 -DNDEBUG -g2 -O2 -fPIC -march=native -Wa,-q
-pipe -c cryptlib.cpp
<stdin>:3:11: warning: section "__textcoal_nt" is deprecated
        .section __TEXT,__textcoal_nt,coalesced,pure_instructions
                 ^      ~~~~~~~~~~~~~
<stdin>:3:11: note: change section name to "__text"
        .section __TEXT,__textcoal_nt,coalesced,pure_instructions
                 ^      ~~~~~~~~~~~~~
...

I believe this is the relevant Clang check-in:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151012/305992.html
.

My question is, how do I tell GCC to stop producing the coalesce
attributes for the assembler?

Thanks in advance.