Commit Graph

3 Commits

Author SHA1 Message Date
Rafael Espindola 0766ae08e5 Fix a few issues with comdat handling on COFF.
* Section association cannot use just the section name as many
sections can have the same name. With this patch, the comdat symbol in
an assoc section is interpreted to mean a symbol in the associated
section and the mapping is discovered from it.

* Comdat symbols were not being set correctly. Instead we were getting
whatever was output first for that section.

A consequence is that associative sections now must use .section to
set the association. Using .linkonce would not work since it is not
possible to change a sections comdat symbol (it is used to decide if
we should create a new section or reuse an existing one).

This includes r210298, which was reverted because it was asserting
on an associated section having the same comdat as the associated
section.

llvm-svn: 210367
2014-06-06 19:26:12 +00:00
Timur Iskhodzhanov 460cf8891b Revert r210298 'Correctly set the comdat symbol on COFF' as it asserts on Windows
llvm-svn: 210317
2014-06-06 08:18:18 +00:00
Rafael Espindola 942f4bc488 Correctly set the comdat symbol on COFF.
We extended the .section syntax to allow multiple sections with the
same name but different comdats, but currently we don't make sure that
the output section has that comdat symbol.

That happens to work with the code llc produces currently because it looks like

.section secName, "dr", one_only, "COMDATSym"
.globl COMDATSym
COMDATSym:
....

but that is not very friendly to anyone coding in assembly or even to
llc once we get comdat support in the IR.

This patch changes the coff object writer to make sure the comdat symbol is
output just after the section symbol, as required by the coff spec.

llvm-svn: 210298
2014-06-05 23:09:25 +00:00