r218141 - In the Itanium ABI, move stuff to the comdat of variables with static init.

[Ulrich Weigand]

Rafael Espindola wrote:

+    // The ABI says: It is suggested that it be emitted in the same COMDAT
group
+    // as the associated data object

This (together with the other recent comdat patches) seems to trigger a bug
in binutils when building with -g.

The problem is that having multiple initializer functions in the same file
can lead to assembler along these line:

         .file 1 "test.c"

         .section        .text.startup,"axG", at progbits,test,comdat
         .loc 1 1
         nop

         .section        .text.startup,"ax", at progbits
         .loc 1 1
         nop

This will cause multiple sections named ".text.startup" to exist in the
output object, one within the comdat group and one outside of it.   This in
turn triggers a bug in dwarf2dbg.c in GAS, where it gets confused in
looking up the section name in a hash table and assumes there can only be
one section with the same name, resulting in an internal error.

This causes compile failures in the tramp3d-v4 and CoyoteBench/fftbench
test cases in test-suite when using -g to build the suite.


The bug is fixed in mainline GAS here:
https://sourceware.org/ml/binutils/2014-09/msg00211.html
but that hasn't made it into any release (or distro) yet.


Mit freundlichen Gruessen / Best Regards

Ulrich Weigand

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