COFF section flags are not idempotent:
'rd' will make a read-write section because 'd' implies write
'dr' will make a read-only section because 'r' disables write
llvm-svn: 228490
We had a few bugs:
- We were considering the GVKind instead of just looking at the section
characteristics
- We would never print out 'y' when a section was meant to be unreadable
- We would never print out 's' when a section was meant to be shared
- We translated IMAGE_SCN_MEM_DISCARDABLE to 'n' when it should've meant
IMAGE_SCN_LNK_REMOVE
llvm-svn: 218189
A problem with our old behavior becomes observable under x86-64 COFF
when we need a read-only GV which has an initializer which is referenced
using a relocation: we would mark the section as writable. Marking the
section as writable interferes with section merging.
This fixes PR21009.
llvm-svn: 218179
* 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
Without this, assembling clang's disassembly would produce an object
file with the IMAGE_SCN_CNT_INITIALIZED_DATA section characteristic
rather than the uninitialized one. link.exe would warn when merging
comdats with different flags.
llvm-svn: 197529
With this patch we use simple names for COMDAT sections (like .text or .bss).
This matches the MSVC behavior.
When merging it is the COMDAT symbol that is used to decide if two sections
should be merged, so there is no point in building a fancy name.
This survived a bootstrap on mingw32.
llvm-svn: 195798
This caused the clang-native-mingw32-win7 buildbot to break.
The assembler was complaining about the following lines that were showing up
in the asm for CrashRecoveryContext.cpp:
movl $"__ZL16ExceptionHandlerP19_EXCEPTION_POINTERS@4", 4(%eax)
calll "_AddVectoredExceptionHandler@8"
.def "__ZL16ExceptionHandlerP19_EXCEPTION_POINTERS@4";
"__ZL16ExceptionHandlerP19_EXCEPTION_POINTERS@4":
calll "_RemoveVectoredExceptionHandler@4"
Reverting for now.
llvm-svn: 192940
The reason this got reverted was that the @feat.00 symbol which was emitted
for every TU became quoted, and on cygwin/mingw we use the gas assembler which
couldn't handle the quotes.
This commit fixes the problem by only emitting @feat.00 for win32, where we use
clang -cc1as to assemble. gas would just drop this symbol anyway, so there is no
loss there.
With @feat.00 gone, there shouldn't be quoted symbols showing up on cygwin since
it uses the Itanium ABI, which doesn't put these funny characters in symbols.
> Because of win32 mangling, we produce symbol and section names with
> funny characters in them, most notably @ characters.
>
> MC would choke on trying to parse its own assembly output. This patch addresses
> that by:
>
> - Making @ trigger quoting of symbol names
> - Also quote section names in the same way
> - Just parse section names like other identifiers (to allow for quotes)
> - Don't assume @ signifies a symbol variant if it is in a string.
llvm-svn: 192859
GNU AS didn't like quotes in symbol names.
Error: junk at end of line, first unrecognized character is `"'
.def "@feat.00";
"@feat.00" = 1
Reproduced on Cygwin's 2.23.52.20130309 and mingw32's 2.20.1.20100303.
llvm-svn: 192775
Because of win32 mangling, we produce symbol and section names with
funny characters in them, most notably @ characters.
MC would choke on trying to parse its own assembly output. This patch addresses
that by:
- Making @ trigger quoting of symbol names
- Also quote section names in the same way
- Just parse section names like other identifiers (to allow for quotes)
- Don't assume @ signifies a symbol variant if it is in a string.
Differential Revision: http://llvm-reviews.chandlerc.com/D1945
llvm-svn: 192758
Made a stylistic changed to the code/comments related to the unsupported COMDAT selection type IMAGE_COMDAT_SELECT_LARGEST based on from Anton Korobeynikov.
llvm-svn: 103590
Now, the .linkonce directive is emitted as part of MCSectionCOFF::PrintSwitchToSection instead of AsmPrinter::EmitLinkage since it is an attribute of the section the symbol was placed into not the symbol itself.
llvm-svn: 103568
David Majnemer