Prevent the early elimination of sections in the object writer. There may be
references to the section itself by other symbols, which may potentially not be
possible to resolve. ML (Visual Studio's Macro Assembler) also seems to retain
empty sections.
The elimination of symbols and sections which are unused should really occur at
the link phase. This will not cause any change in the resulting binary, simply
in the generated object files.
The adjustments to the other unit tests account for the fluctuating section
index caused by the appearance of sections which were previously discarded.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210373 91177308-0d34-0410-b5e6-96231b3b80d8
* 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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210367 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210298 91177308-0d34-0410-b5e6-96231b3b80d8
We would previously assert here when trying to figure out the section
for the global.
This makes us handle the situation more gracefully since the IR isn't
malformed.
Differential Revision: http://reviews.llvm.org/D4022
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210215 91177308-0d34-0410-b5e6-96231b3b80d8
Rafael correctly pointed out that the restriction is unnecessary. Although the
tests are intended to ensure that we dont abort due to an assertion, running the
tests in all modes is better since it also ensures that we dont crash without
assertions. Always run these tests to ensure that we can handle invalid input
correctly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209496 91177308-0d34-0410-b5e6-96231b3b80d8
Now that clang can be used as an assembler via the IAS, invalid assembler inputs
would cause the assertions to trigger. Although we cannot recover from the
errors here, nor provide caret diagnostics, attempt to handle them slightly more
gracefully by reporting a fatal error.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209387 91177308-0d34-0410-b5e6-96231b3b80d8
The .drectve section should be marked as IMAGE_SCN_LNK_REMOVE. This matches what
the MSVC toolchain does and accurately reflects that this section should not be
emitted into the final binary. This section is merely information for the
linker, comprising of additional linker directives.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209273 91177308-0d34-0410-b5e6-96231b3b80d8
This allows us to put dynamic initializers for weak data into the same
comdat group as the data being initialized. This is necessary for MSVC
ABI compatibility. Once we have comdats for guard variables, we can use
the combination to help GlobalOpt fire more often for weak data with
guarded initialization on other platforms.
Reviewers: nlewycky
Differential Revision: http://reviews.llvm.org/D3499
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209015 91177308-0d34-0410-b5e6-96231b3b80d8
.file records are supposed to have a section identifier of 65534
(IMAGE_SCN_DEBUG) rather than 0. This is spelt out clearly within the PE/COFF
specification. Fix this minor oversight with the implementation for support for
.file records.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207851 91177308-0d34-0410-b5e6-96231b3b80d8
This matches gas' behaviour on COFF.
I think that this yak is now sufficiently shaved for aliases with offset
to work.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207786 91177308-0d34-0410-b5e6-96231b3b80d8
This fixes pr19147.
There are a few more related issues to fix, but the testcase in the bug now
passes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207763 91177308-0d34-0410-b5e6-96231b3b80d8
This makes the coff writer compute the correct symbol value for the test in
pr19147. The section is still incorrect, that will be fixed in a followup patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207728 91177308-0d34-0410-b5e6-96231b3b80d8
Introduce support for WoA PE/COFF object file emission from LLVM. Add the new
target specific PE/COFF Streamer (ARMWinCOFFStreamer) that handles the ARM
specific behaviour of PE/COFF object emission. ARM exception information is not
yet emitted and is a TODO item.
The ARM specific object writer (ARMWinCOFFObjectWriter) handles the ARM specific
relocation handling in conjunction with the WinCOFFObjectWriter in the MC layer.
The MC layer needs to be updated to deal with the relocation adjustments.
Branch relocations are adjusted by 4 bytes (unlikely their ELF counterparts).
Minor tweaks to switch multiple conditional checks into equivalent switch
statements. The ObjectFileInfo is updated to relax the object file setup for
Windows COFF. Move the architecture checks into an assertion. Windows COFF is
currently only supported on x86, x86_64, and ARM (thumb). Rather than
defaulting to ELF, we will refuse to generate an object file. This is better
though as you do not get an (arbitrary) object file which is different from the
request.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207345 91177308-0d34-0410-b5e6-96231b3b80d8
This is dependent on changes that are not fully ready to be merged yet (WoA
object file emission). The test can be re-enabled for that target later.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207038 91177308-0d34-0410-b5e6-96231b3b80d8
Emit the flag to indicate to the assembler that a section contains data if there
is pre-populated data present.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207028 91177308-0d34-0410-b5e6-96231b3b80d8
Adjust the tests to validate the number of auxiliary entries used to store the
filename.
Thanks to majnemer's sharp eye for catching the missing - 1 in the round up
calculation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206359 91177308-0d34-0410-b5e6-96231b3b80d8
Add support for emitting .file records. This is mostly a quality of
implementation change (more complete support for COFF file emission) that was
noticed while working on COFF file emission for Windows on ARM.
A .file record is emitted as a symbol with storage class FILE (103) and the name
".file". A series of auxiliary format 4 records follow which contain the file
name. The filename is stored as an ANSI string and is padded with NULL if the
length is not a multiple of COFF::SymbolSize (18).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206355 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Local common symbols were properly inserted into the .bss section.
However, putting external common symbols in the .bss section would give
them a strong definition.
Instead, encode them as undefined, external symbols who's symbol value
is equivalent to their size.
Reviewers: Bigcheese, rafael, rnk
CC: llvm-commits
Differential Revision: http://reviews.llvm.org/D3324
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205811 91177308-0d34-0410-b5e6-96231b3b80d8
Microsoft PE/COFF Spec clearly states that the field is of signed interger
type. However, in reality, it's unsigned. If cl.exe needs to create a large
number of sections for COMDAT sections, it will just create more than 32768
sections. Handling large section number as negative number is not correct.
I think this is a spec bug.
Differential Revision: http://llvm-reviews.chandlerc.com/D3088
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203986 91177308-0d34-0410-b5e6-96231b3b80d8
Offsets past the range of single-slash encoding are encoded as base64,
padded to 6 characters, and prefixed with two slashes. This encoding is
undocumented but used by MSVC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201940 91177308-0d34-0410-b5e6-96231b3b80d8
Sweep the codebase for common typos. Includes some changes to visible function
names that were misspelt.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200018 91177308-0d34-0410-b5e6-96231b3b80d8
MSVC on x64 requires that we create image relative symbol
references to refer to RTTI data. Seeing as how there is no way to
explicitly make reference to a given relocation type in LLVM IR, pattern
match expressions of the form &foo - &__ImageBase.
Differential Revision: http://llvm-reviews.chandlerc.com/D2523
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199312 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197529 91177308-0d34-0410-b5e6-96231b3b80d8
We currently error in clang with:
"error: thread-local storage is unsupported for the current target", but we
can start to get the llvm level ready.
When compiling
template<typename T>
struct foo {
static __declspec(thread) int bar;
};
template<typename T>
__declspec(therad) int foo<T>::bar;
template struct foo<int>;
msvc produces
SECTION HEADER #3
.tls$ name
0 physical address
0 virtual address
4 size of raw data
12F file pointer to raw data (0000012F to 00000132)
0 file pointer to relocation table
0 file pointer to line numbers
0 number of relocations
0 number of line numbers
C0301040 flags
Initialized Data
COMDAT; sym= "public: static int foo<int>::bar" (?bar@?$foo@H@@2HA)
4 byte align
Read Write
gcc produces a ".data$__emutls_v.<symbol>" for the testcase with
__declspec(thread) replaced with thread_local.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195849 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195798 91177308-0d34-0410-b5e6-96231b3b80d8
These should not use COMDATs. GNU as uses .bss for .lcomm and section 0 for
.comm.
Given
static int a;
int b;
MSVC puts both in .bss. This patch then puts both .comm and .lcomm on .bss. With
this change we agree with gas on .lcomm, are much closer on .comm and clang-cl
matches msvc on the above example.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195654 91177308-0d34-0410-b5e6-96231b3b80d8
This is the first step to fix pr17918.
It extends the .section directive a bit, inspired by what the ELF one looks
like. The problem with using linkonce is that given
.section foo
.linkonce....
.section foo
.linkonce
we would already have switched sections when getting to .linkonce. The cleanest
solution seems to be to add the comdat information in the .section itself.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195148 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r190888, to fix PR17967. The original change wasn't
the right way to get @feat.00 into the object file. The right fix is to
make @feat.00 be a global symbol.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195053 91177308-0d34-0410-b5e6-96231b3b80d8
This is another (final?) stab at making us able to parse our own asm output
on Windows.
Symbols on Windows often contain @'s and ?'s in their names. Our asm parser
didn't like this. ?'s were not allowed, and @'s were intepreted as trying to
reference PLT/GOT/etc.
We can't just add quotes around the bad names, since e.g. for MinGW, we use gas
to assemble, and it doesn't like quotes in some places (notably in .def
directives).
This commit makes us allow ?'s in symbol names, and @'s in symbol names for MS
assembly.
Differential Revision: http://llvm-reviews.chandlerc.com/D1978
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193000 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192940 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192859 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192775 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192758 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
We indicate that the object files are safe by emitting a @feat.00
absolute address symbol. The address is presumably interpreted as a
bitfield of features that the compiler would like to enable. Bit 0 is
documented in the PE COFF spec to opt in to "registered SEH", which is
what /safeseh enables.
LLVM's object files are safe by default because LLVM doesn't know how to
produce SEH handlers.
Reviewers: Bigcheese
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1691
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190898 91177308-0d34-0410-b5e6-96231b3b80d8
In particular, this means we emit non-external symbols defined to
variables, such as aliases or absolute addresses.
This is needed to implement /safeseh, and it appears there was some
confusion about what symbols to emit previously.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190888 91177308-0d34-0410-b5e6-96231b3b80d8
For alignment purposes, the instruction array will always have an even
number of entries, with the final entry potentially unused (in which
case the array will be one longer than indicated by the count of unwind
codes field).
Reviewed by Anton Korobeynikov, Charles Davis and Nico Rieck.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190767 91177308-0d34-0410-b5e6-96231b3b80d8
data structures.
The Win64 EH data structures must be of type IMAGE_REL_AMD64_ADDR32NB
instead of IMAGE_REL_AMD64_ADDR32. This is easiely achieved by adding
the VK_COFF_IMGREL32 modifier to the symbol reference.
Change also references to start and end of the SEH range of a function
as offsets to start of the function.
Reviewed by Jim Grosbach, Charles Davis and Nico Rieck.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190766 91177308-0d34-0410-b5e6-96231b3b80d8
The code offset for unwind code SET_FPREG is wrong because it is set
to constant 0. The fix is to do the same as for the other unwind
codes: emit a label and later the absolute difference between the
label and the begin of the prologue.
Also enables the failing test case MC/COFF/seh.s
Reviewed by Jim Grosbach, Charles Davis and Nico Rieck.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189309 91177308-0d34-0410-b5e6-96231b3b80d8
- Instead of setting the suffixes in a bunch of places, just set one master
list in the top-level config. We now only modify the suffix list in a few
suites that have one particular unique suffix (.ml, .mc, .yaml, .td, .py).
- Aside from removing the need for a bunch of lit.local.cfg files, this enables
4 tests that were inadvertently being skipped (one in
Transforms/BranchFolding, a .s file each in DebugInfo/AArch64 and
CodeGen/PowerPC, and one in CodeGen/SI which is now failing and has been
XFAILED).
- This commit also fixes a bunch of config files to use config.root instead of
older copy-pasted code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188513 91177308-0d34-0410-b5e6-96231b3b80d8
