Commit Graph

281 Commits

Author SHA1 Message Date
Reid Kleckner 98bbd07cc3 [MC] Enable .file support on COFF and diagnose it on unsupported targets
Summary:
The "single parameter" .file directive appears to be an ELF-only feature
that is intended to insert the main source filename into the string
table table.

I noticed that if you assemble an ELF .s file for COFF, typically it
will assert right away on a .file directive near the top of the file. My
first change was to make this emit a proper error in the asm parser so
that we don't assert so easily.

However, COFF actually does have some support for this directive, and if
you emit an object file, llvm-mc does not assert. When emitting a COFF
object, MC will take those file names and create "debug" symbol table
entries for them. I'm not familiar with these kinds of symbol table
entries, and I'm not aware of any users of them, but @compnerd added
them a while ago. They don't introduce absolute paths, and most main
source file paths are short enough that this extra entry shouldn't cause
any problems, so I enabled the flag in MCAsmInfoCOFF that indicates that
it's supported.

This has the side effect of adding an extra debug symbol to every object
produced by clang, which is a pretty big functional change. My question
is, should we keep the functionality or remove it in the name of symbol
table minimalism?

Reviewers: mstorsjo, compnerd

Subscribers: hiraditya, compnerd, llvm-commits

Differential Revision: https://reviews.llvm.org/D55900

llvm-svn: 349976
2018-12-21 23:35:48 +00:00
Reid Kleckner 94ee0728e5 [codeview] Flush labels before S_DEFRANGE* fragments
This was a pre-existing bug that could be triggered with assembly like
this:
  .p2align 2
  .LtmpN:
  .cv_def_range "..."

I noticed this when attempting to change clang to emit aligned symbol
records.

llvm-svn: 349403
2018-12-17 21:49:35 +00:00
Martin Storsjo 1aa7e900b3 [COFF] Don't mark mingw .eh_frame sections writable
This improves compatibility with GCC produced object files, where
the .eh_frame sections are read only. With mixed flags for the
involved .eh_frame sections, LLD creates two separate .eh_frame
sections in the output binary, one for each flag combination,
while ld.bfd probably merges them.

The previous setup of flags can be traced back to SVN r79346.

Differential Revision: https://reviews.llvm.org/D55209

llvm-svn: 348177
2018-12-03 20:02:05 +00:00
Martin Storsjo 37b742e208 [COFF] [X86] Don't use llvm_unreachable for unsupported relocation types
This can happen if assembling a reference to _GLOBAL_OFFSET_TABLE_.

While it doesn't make sense to try to assemble that for COFF,
the fact that we previously used llvm_unreachable meant that the code
had undefined behaviour if something tried to assemble that.

The configure script of libgmp would try to assemble such a snippet
(which should signal a failure). If llvm is built without assertions,
the undefined behaviour meant a (near) infinite loop.

Differential Revision: https://reviews.llvm.org/D52903

llvm-svn: 343811
2018-10-04 20:43:38 +00:00
Reid Kleckner d5e4ec74e3 [codeview] Fix 32-bit x86 variable locations in realigned stack frames
Add the .cv_fpo_stackalign directive so that we can define $T0, or the
VFRAME virtual register, with it. This was overlooked in the initial
implementation because unlike MSVC, we push CSRs before allocating stack
space, so this value is only needed to describe local variable
locations. Variables that the compiler now addresses via ESP are instead
described as being stored at offsets from VFRAME, which for us is ESP
after alignment in the prologue.

This adds tests that show that we use the VFRAME register properly in
our S_DEFRANGE records, and that we emit the correct FPO data to define
it.

Fixes PR38857

llvm-svn: 343603
2018-10-02 16:43:52 +00:00
Reid Kleckner 06d02d0306 [codeview] Add .cv_string directive for testing purposes
The main use case for this directive is to allow assembly writers to
write their own FPO data strings without going through the .cv_fpo*
directive family.

I'm experimenting with different RPN programs to fix PR38857, and I
figured I should go ahead and make this directive permanent.

llvm-svn: 341712
2018-09-07 21:30:52 +00:00
Reid Kleckner ee0e8bab2a [codeview] Improve readobj FPO dumper and pdbutil register names
The improved dumping helps me investigate PR38857.

llvm-svn: 341695
2018-09-07 18:48:27 +00:00
Reid Kleckner c8074aa654 [codeview] Emit labels for .cv_loc immediately
Previously we followed the DWARF implementation, which waits until the
next instruction or data to emit the label to use in the .debug_loc
section. We might want to consider re-evaluating that design choice as
well, since it means the .loc skips alignment padding, for better or
worse.

This was the most minimal fix I could come up with, but we should be
able to do a lot of cleanups now that we don't need to save a pending CV
location on the CodeViewContext. I plan to do those next, but this
immediately fixes an assertion for some of our users.

llvm-svn: 340878
2018-08-28 22:29:12 +00:00
Peter Collingbourne a67161fffa MC: Don't align COFF section contents.
Aligning section contents is not required, but only
recommended, by the specification. Microsoft's documentation says
(https://docs.microsoft.com/en-us/windows/desktop/debug/pe-format#section-table-section-headers):
"For object files, the value should be aligned on a 4-byte boundary
for best performance."

However, according to my measurements, aligning section contents has
a neutral to negative effect on performance.

I measured the median run time of 100 links of Chromium's
base_unittests on Linux with lld-link and on Windows with link.exe with
both aligned and unaligned sections. On Linux I didn't see a measurable
performance difference, and on Windows the link was slightly faster
with unaligned sections (presumably because on Windows the bottleneck
is I/O).

Also, the sections created by cl.exe are unaligned, so we should expect
tools to broadly accept unaligned sections.

Differential Revision: https://reviews.llvm.org/D51149

llvm-svn: 340514
2018-08-23 05:39:36 +00:00
Peter Collingbourne bc3089f45f MC: Teach the COFF object writer to write address-significance tables.
The format is the same as in ELF: a sequence of ULEB128-encoded
symbol indexes.

Differential Revision: https://reviews.llvm.org/D51047

llvm-svn: 340499
2018-08-22 23:58:16 +00:00
Reid Kleckner 602c0dafdd [MC] Improve COFF associative section lookup
Handle the case when the symbol is private. Private symbols are not in
the COFF object file symbol table, so they aren't inserted into
SymbolMap. We can't look up the section of the symbol that way. Instead,
get the MCSection from the MCSymbol and map that to the object file
section.

Print a better error message when the symbol has no section, like when
the symbol is undefined.

Fixes PR38607

llvm-svn: 339942
2018-08-16 21:34:41 +00:00
Reid Kleckner bd5d71229d [codeview] Use push_macro to avoid conflicts instead of a prefix
Summary:
This prefix was added in r333421, and it changed our dumper output to
say things like "CVRegEAX" instead of just "EAX". That's a functional
change that I'd rather avoid.

I tested GCC, Clang, and MSVC, and all of them support #pragma
push_macro. They don't issue warnings whem the macro is not defined
either.

I don't have a Mac so I can't test the real termios.h header, but I
looked at the termios.h sources online and looked for other conflicts.
I saw only the CR* macros, so those are the ones we work around.

Reviewers: zturner, JDevlieghere

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D50851

llvm-svn: 339907
2018-08-16 17:34:31 +00:00
Martin Storsjo 390bce4322 [MC] Add support for the .rva assembler directive for COFF targets
Even though gas doesn't document it, it has been supported there for
a very long time.

This produces the 32 bit relative virtual address (aka image relative
address) for a given symbol. ".rva foo" is essentially equal to
".long foo@imgrel".

Differential Revision: https://reviews.llvm.org/D49821

llvm-svn: 338063
2018-07-26 20:11:26 +00:00
Jonas Devlieghere 43dce3edbe [CodeView] Add prefix to CodeView registers.
Adds CVReg to CodeView register names to prevent a duplicate symbol with
CR3 defined in termios.h, as suggested by Zachary on the mailing list.

http://lists.llvm.org/pipermail/llvm-dev/2018-May/123372.html

Differential revision: https://reviews.llvm.org/D47478

rdar://39863705

llvm-svn: 333421
2018-05-29 14:35:34 +00:00
Shiva Chen 2c864551df [DebugInfo] Add DILabel metadata and intrinsic llvm.dbg.label.
In order to set breakpoints on labels and list source code around
labels, we need collect debug information for labels, i.e., label
name, the function label belong, line number in the file, and the
address label located. In order to keep these information in LLVM
IR and to allow backend to generate debug information correctly.
We create a new kind of metadata for labels, DILabel. The format
of DILabel is

!DILabel(scope: !1, name: "foo", file: !2, line: 3)

We hope to keep debug information as much as possible even the
code is optimized. So, we create a new kind of intrinsic for label
metadata to avoid the metadata is eliminated with basic block.
The intrinsic will keep existing if we keep it from optimized out.
The format of the intrinsic is

llvm.dbg.label(metadata !1)

It has only one argument, that is the DILabel metadata. The
intrinsic will follow the label immediately. Backend could get the
label metadata through the intrinsic's parameter.

We also create DIBuilder API for labels to be used by Frontend.
Frontend could use createLabel() to allocate DILabel objects, and use
insertLabel() to insert llvm.dbg.label intrinsic in LLVM IR.

Differential Revision: https://reviews.llvm.org/D45024

Patch by Hsiangkai Wang.

llvm-svn: 331841
2018-05-09 02:40:45 +00:00
Reid Kleckner 2c6430fe3c [codeview] Ignore .cv_loc directives at the end of a function
If no data or instructions are emitted after a location directive, we
should clear the cv_loc when we change sections, or it will be emitted
at the beginning of the next section. This violates our invariant that
all .cv_loc directives belong to the same section. Add clearer
assertions for this.

llvm-svn: 330884
2018-04-25 23:34:15 +00:00
Reid Kleckner f8b51c5f90 [IR] Avoid the need to prefix MS C++ symbols with '\01'
Now the Windows mangling modes ('w' and 'x') do not do any mangling for
symbols starting with '?'. This means that clang can stop adding the
hideous '\01' leading escape. This means LLVM debug logs are less likely
to contain ASCII escape characters and it will be easier to copy and
paste MS symbol names from IR.

Finally.

For non-Windows platforms, names starting with '?' still get IR
mangling, so once clang stops escaping MS C++ names, we will get extra
'_' prefixing on MachO. That's fine, since it is currently impossible to
construct a triple that uses the MS C++ ABI in clang and emits macho
object files.

Differential Revision: https://reviews.llvm.org/D7775

llvm-svn: 327734
2018-03-16 20:13:32 +00:00
Reid Kleckner 5a5ac65768 [MC] Always emit relocations for same-section function references
Summary:
We already emit relocations in this case when the "incremental linker
compatible" flag is set, but it turns out these relocations are also
required for /guard:cf. Now that we have two use cases for this
behavior, let's make it unconditional to try to keep things simple.

We never hit this problem in Clang because it always sets the
"incremental linker compatible" flag when targeting MSVC. However, LLD
LTO doesn't set this flag, so we'd get CFG failures at runtime when
using ThinLTO and /guard:cf. We probably don't want LLD LTO to set the
"incremental linker compatible" assembler flag, since this has nothing
to do with incremental linking, and we don't need to timestamp LTO
temporary objects.

Fixes PR36624.

Reviewers: inglorion, espindola, majnemer

Subscribers: mehdi_amini, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D44485

llvm-svn: 327557
2018-03-14 19:24:32 +00:00
Nico Weber 73a699e592 MC intel asm parser: Allow @ at the start of function names.
Ports parts of r193000 to the intel parser. Fixes part of PR36676.

https://reviews.llvm.org/D44359

llvm-svn: 327262
2018-03-12 12:47:27 +00:00
Reid Kleckner 7897a789e7 [CodeView] Add line numbers for inlined call sites
We did this for inline call site line tables, but we hadn't done it for
regular function line tables yet. This patch copies that logic from
encodeInlineLineTable.

llvm-svn: 322905
2018-01-18 22:55:43 +00:00
Adrian McCarthy db2736ddd8 Reland "Emit Function IDs table for Control Flow Guard"
Adds option /guard:cf to clang-cl and -cfguard to cc1 to emit function IDs
of functions that have their address taken into a section named .gfids$y for
compatibility with Microsoft's Control Flow Guard feature.

The original patch didn't have the lit.local.cfg file that restricts the new
test to x86, thus the new test was failing on the non-x86 bots.

Differential Revision: https://reviews.llvm.org/D40531

The reverts r322008, which was a revert of r322005.

This reverts commit a05b89f9aca70597dc79fe97bc49b50b51f525ba.

llvm-svn: 322136
2018-01-09 23:49:30 +00:00
Adrian McCarthy ce63a925cc Revert "Emit Function IDs table for Control Flow Guard"
The new test fails on the Hexagon bot.  Reverting while I investigate.

This reverts https://reviews.llvm.org/rL322005

This reverts commit b7e0026b4385180c378edc658ec91a39566f2942.

llvm-svn: 322008
2018-01-08 17:12:01 +00:00
Adrian McCarthy cf6e6c82c1 Emit Function IDs table for Control Flow Guard
Adds option /guard:cf to clang-cl and -cfguard to cc1 to emit function IDs
of functions that have their address taken into a section named .gfids$y for
compatibility with Microsoft's Control Flow Guard feature.

Differential Revision: https://reviews.llvm.org/D40531

llvm-svn: 322005
2018-01-08 16:33:42 +00:00
Craig Topper 4802d4e23e [X86] Don't use NOPL when the assembler is passed an empty CPU string. Update tests to force a CPU with NOPL
Empty string should be equivalent to "generic" which doesn't allow NOPL. Force tests to use specificy 'pentiumpro' to guarantee NOPL.

Fixes PR35686

llvm-svn: 321026
2017-12-18 21:37:27 +00:00
Francis Visoiu Mistrih 25528d6de7 [CodeGen] Unify MBB reference format in both MIR and debug output
As part of the unification of the debug format and the MIR format, print
MBB references as '%bb.5'.

The MIR printer prints the IR name of a MBB only for block definitions.

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g'
* find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g'
* grep -nr 'BB#' and fix

Differential Revision: https://reviews.llvm.org/D40422

llvm-svn: 319665
2017-12-04 17:18:51 +00:00
Francis Visoiu Mistrih 9d7bb0cb40 [CodeGen] Print register names in lowercase in both MIR and debug output
As part of the unification of the debug format and the MIR format,
always print registers as lowercase.

* Only debug printing is affected. It now follows MIR.

Differential Revision: https://reviews.llvm.org/D40417

llvm-svn: 319187
2017-11-28 17:15:09 +00:00
Reid Kleckner 9cdd4df81a [codeview] Implement FPO data assembler directives
Summary:
This adds a set of new directives that describe 32-bit x86 prologues.
The directives are limited and do not expose the full complexity of
codeview FPO data. They are merely a convenience for the compiler to
generate more readable assembly so we don't need to generate tons of
labels in CodeGen. If our prologue emission changes in the future, we
can change the set of available directives to suit our needs. These are
modelled after the .seh_ directives, which use a different format that
interacts with exception handling.

The directives are:
  .cv_fpo_proc _foo
  .cv_fpo_pushreg ebp/ebx/etc
  .cv_fpo_setframe ebp/esi/etc
  .cv_fpo_stackalloc 200
  .cv_fpo_endprologue
  .cv_fpo_endproc
  .cv_fpo_data _foo

I tried to follow the implementation of ARM EHABI CFI directives by
sinking most directives out of MCStreamer and into X86TargetStreamer.
This helps avoid polluting non-X86 code with WinCOFF specific logic.

I used cdb to confirm that this can show locals in parent CSRs in a few
cases, most importantly the one where we use ESI as a frame pointer,
i.e. the one in http://crbug.com/756153#c28

Once we have cdb integration in debuginfo-tests, we can add integration
tests there.

Reviewers: majnemer, hans

Subscribers: aemerson, mgorny, kristof.beyls, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D38776

llvm-svn: 315513
2017-10-11 21:24:33 +00:00
Reid Kleckner e52d1e6787 [SEH] Use reportError instead of report_fatal_error for bad directives
This makes the .seh_ directives slightly more usable from standalone
assembly files.

This removes a large number of report_fatal_errors and recovers from the
error by ignoring the directive.

llvm-svn: 315262
2017-10-10 01:26:25 +00:00
Hans Wennborg ea89ff7c25 CodeView symbol dumper: use symbolic names for registers
https://reviews.llvm.org/D38469

llvm-svn: 314690
2017-10-02 17:44:47 +00:00
Reid Kleckner 8d8888ff42 [codeview] Change readobj symbol dumping format
Avoid duplicating DictScope with hand-written names everywhere.  Print
the S_-prefixed symbol kind for every record. This should make it easier
to search for certain kinds of records when debugging PDB linking.

llvm-svn: 307732
2017-07-11 23:41:41 +00:00
Rafael Espindola 8c1fc04f3f Use @LINE in two more tests.
llvm-svn: 307318
2017-07-06 21:33:23 +00:00
Rafael Espindola 58173b9720 COFF: Produce an error on invalid pcrel relocs.
X86_64 COFF only has support for 32 bit pcrel relocations. Produce an
error on all others.

Note that gnu as has extended the relocation values to support
this. It is not clear if we should support the gnu extension.

llvm-svn: 306082
2017-06-23 04:07:44 +00:00
Rafael Espindola 13811b0605 Make the test a bit more strict. NFC.
llvm-svn: 306080
2017-06-23 03:48:01 +00:00
Rafael Espindola 34e94a8783 COFF: handle "undef - ." expressions.
This is another thing that the ELF implementation can do but is
missing from COFF.

llvm-svn: 306078
2017-06-23 02:15:56 +00:00
Rafael Espindola d2edd137df Change creation of relative relocations on COFF.
For whatever reason, when processing

  .globl foo
foo:
  .data
bar:
  .long foo-bar

llvm-mc creates a relocation with the section:

0x0 IMAGE_REL_I386_REL32 .text

This is different than when the relocation is relative from the
beginning. For example, a file with

call foo

produces

0x0 IMAGE_REL_I386_REL32 foo

I would like to refactor the logic for converting "foo - ." into a
relative relocation so that it is shared with ELF. This is the first
step and just changes the coff implementation to match what ELF (and
COFF in the case of calls) does.

llvm-svn: 306063
2017-06-22 21:57:04 +00:00
Reid Kleckner 40a47a8702 [MC] Allow assembling .secidx and .secrel32 for undefined symbols
There's nothing incorrect about emitting such relocations against
symbols defined in other objects. The code in EmitCOFFSec* was missing
the visitUsedExpr part of MCStreamer::EmitValueImpl, so these symbols
were not being registered with the object file assembler.

This will be used to make reduced test cases for LLD.

llvm-svn: 306057
2017-06-22 21:02:14 +00:00
Peter Collingbourne 89061b2224 IR: Replace the "Linker Options" module flag with "llvm.linker.options" named metadata.
The new metadata is easier to manipulate than module flags.

Differential Revision: https://reviews.llvm.org/D31349

llvm-svn: 305227
2017-06-12 20:10:48 +00:00
Rui Ueyama ac20c17962 MC/COFF: Do not emit forward associative section referenceds.
MSVC link.exe cannot handle associative sections that refer later
sections in the section header. Technically, such COFF object doesn't
violate the Microsoft COFF spec, as the spec doesn't say anything
about that, but still we should avoid doing that to make it compatible
with MS tools.

This patch assigns smaller section numbers to non-associative sections
and larger numbers to associative sections. This should resolve the
compatibility issue.

Differential Revision: https://reviews.llvm.org/D30080

llvm-svn: 295464
2017-02-17 17:32:54 +00:00
Reid Kleckner 11cf053bd1 [CodeView] Fix off-by-one error in def range gap emission
Also fixes a much worse bug where we emitted the wrong gap size for the
def range uncovered by the test for this issue.

Fixes PR31726.

llvm-svn: 292949
2017-01-24 16:57:55 +00:00
Adrian McCarthy 4333daab1c Emit S_COMPILE3 record once per TU rather than once per function
This has some ripple effects in several tests.

llvm-svn: 285862
2016-11-02 21:30:35 +00:00
Bernard Ogden c5164132fe Let test pass for builds that support X86, but do not default to it
Differential Revision: https://reviews.llvm.org/D25471

llvm-svn: 283902
2016-10-11 16:34:49 +00:00
Adrian McCarthy c64acfd4c2 Emit S_COMPILE3 CodeView record
CodeView has an S_COMPILE3 record to identify the compiler and source language of the compiland.  This record comes first in the debug$S section for the compiland. The debuggers rely on this record to know the source language of the code.

There was a little test fallout from introducing a new record into the symbols subsection.

Differential Revision: https://reviews.llvm.org/D24317

llvm-svn: 281990
2016-09-20 17:20:51 +00:00
Reid Kleckner be82d3ec0c [codeview] Optimize the size of defranges with gaps
For small, discontiguous local variable regions, CodeView can use a
single defrange record with a gap, rather than having two defrange
records. I expect that this optimization will only have a minor impact
on debug info size.

llvm-svn: 281664
2016-09-15 22:05:08 +00:00
Reid Kleckner 31263731da [MC] Handle discardable COFF sections in assembly
Summary:
This fixes a dumpbin warning on objects produced by the MC assembler
when starting from text. All .debug$S sections are supposed to be marked
IMAGE_SCN_MEM_DISCARDABLE. The main, non-COMDAT .debug$S section had
this set, but any comdat ones were not being marked discardable because
there was no .section flag for it.

This change does two things:

- If the section name starts with .debug, implicitly mark the section as
  discardable. This means we do the same thing as gas on .s files with
  DWARF from GCC, which is important.

- Adds the 'D' flag to the .section directive on COFF to explicitly say
  a section is discardable. We only emit this flag if the section name
  does not start with .debug. This allows the user to explicitly tweak
  their section flags without worrying about magic section names.

The only thing you can't do in this scheme is to create a
non-discardable section with a name starting with ".debug", but
hopefully users don't need that.

Reviewers: majnemer, rafael

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D24582

llvm-svn: 281554
2016-09-14 22:41:50 +00:00
Reid Kleckner cb5c98b14a Give an x86 assembler test a triple
llvm-svn: 280950
2016-09-08 15:40:43 +00:00
Reid Kleckner a9f4cc9510 [codeview] Add new directives to record inlined call site line info
Summary:
Previously we were trying to represent this with the "contains" list of
the .cv_inline_linetable directive, which was not enough information.
Now we directly represent the chain of inlined call sites, so we know
what location to emit when we encounter a .cv_loc directive of an inner
inlined call site while emitting the line table of an outer function or
inlined call site. Fixes PR29146.

Also fixes PR29147, where we would crash when .cv_loc directives crossed
sections. Now we write down the section of the first .cv_loc directive,
and emit an error if any other .cv_loc directive for that function is in
a different section.

Also fixes issues with discontiguous inlined source locations, like in
this example:

  volatile int unlikely_cond = 0;
  extern void __declspec(noreturn) abort();
  __forceinline void f() {
    if (!unlikely_cond) abort();
  }
  int main() {
    unlikely_cond = 0;
    f();
    unlikely_cond = 0;
  }

Previously our tables gave bad location information for the 'abort'
call, and the debugger wouldn't snow the inlined stack frame for 'f'.
It is important to emit good line tables for this code pattern, because
it comes up whenever an asan bug occurs in an inlined function. The
__asan_report* stubs are generally placed after the normal function
epilogue, leading to discontiguous regions of inlined code.

Reviewers: majnemer, amccarth

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D24014

llvm-svn: 280822
2016-09-07 16:15:31 +00:00
Reid Kleckner c29b4f07f9 [codeview] Shrink inlined call site line info tables
For a fully inlined call chain like a -> b -> c -> d, we were emitting
line info for 'd' 3 separate times: once for d's actual InlineSite line
table, and twice for 'b' and 'c'. This is particularly inefficient when
all these functions are in different headers, because now we need to
encode the file change. Windbg was coping with our suboptimal output, so
this should not be noticeable from the debugger.

llvm-svn: 275502
2016-07-14 23:47:15 +00:00
David Majnemer 230bbfbeec [MC, COFF] Permit a variable to be redefined
Our assertions in WinCOFFStreamer had unexpected side effects resulting
in symbols getting unexpectedly marked as used.

This fixes PR28462.

llvm-svn: 274941
2016-07-08 21:54:16 +00:00
Rafael Espindola b34cba97b7 Don't crash trying to relax 32 loads on COFF.
Fixes pr28452.

llvm-svn: 274754
2016-07-07 14:00:07 +00:00
Reid Kleckner ee641c20ca [codeview] Avoid emitting an empty file checksum table
Again, the Microsoft linker does not like empty substreams.

We still emit an empty string table if CodeView is enabled, but that
doesn't cause problems because it always contains at least one null
byte.

llvm-svn: 272183
2016-06-08 17:50:29 +00:00
Rafael Espindola 4f1062adb8 Fix a crash when producing COFF.
llvm-svn: 271229
2016-05-30 20:18:53 +00:00
Rafael Espindola 732eeaf2a9 coff: fix weak alias to local.
We were creating a weak external that tried to reference a static symbol. That
would always fail to link with link.exe.

We now create an external symbol in the same position as the local and refer
to that. This works with link.exe and matches what gas does.

llvm-svn: 270906
2016-05-26 20:31:00 +00:00
Rafael Espindola 30c080a085 coff: fix the section of weak symbols.
llvm-svn: 270889
2016-05-26 18:48:23 +00:00
Rafael Espindola 6ddf5f4437 coff: fix the value of weak definitions.
It looks like this doesn't get a lot of use.

llvm-svn: 270883
2016-05-26 18:04:53 +00:00
Reid Kleckner 97837b7b09 [MC] Create unique .pdata sections for every .text section
Summary:
This adds a unique ID to the COFF section uniquing map, similar to the
one we have for ELF.  The unique id is not currently exposed via the
assembler because we don't have a use case for it yet. Users generally
create .pdata with the .seh_* family of directives, and the assembler
internally needs to produce .pdata and .xdata sections corresponding to
the code section.

The association between .text sections and the assembler-created .xdata
and .pdata sections is maintained as an ID field of MCSectionCOFF. The
CFI-related sections are created with the given unique ID, so if more
code is added to the same text section, we can find and reuse the CFI
sections that were already created.

Reviewers: majnemer, rafael

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D19376

llvm-svn: 268331
2016-05-02 23:22:18 +00:00
Peter Collingbourne 265ebd7d70 CodeGen: Use PLT relocations for relative references to unnamed_addr functions.
The relative vtable ABI (PR26723) needs PLT relocations to refer to virtual
functions defined in other DSOs. The unnamed_addr attribute means that the
function's address is not significant, so we're allowed to substitute it
with the address of a PLT entry.

Also includes a bonus feature: addends for COFF image-relative references.

Differential Revision: http://reviews.llvm.org/D17938

llvm-svn: 267211
2016-04-22 20:40:10 +00:00
Reid Kleckner 4ab992d1b4 [codeview] Dump def range lengths in hex
It makes it easier to correlate with assembly dumps, which are typically
given with hex offsets.

llvm-svn: 260619
2016-02-11 23:40:14 +00:00
David Majnemer 408b5e6603 [MC] Add support for encoding CodeView variable definition ranges
CodeView, like most other debug formats, represents the live range of a
variable so that debuggers might print them out.

They use a variety of records to represent how a particular variable
might be available (in a register, in a frame pointer, etc.) along with
a set of ranges where this debug information is relevant.

However, the format only allows us to use ranges which are limited to a
maximum of 0xF000 in size.  This means that we need to split our debug
information into chunks of 0xF000.

Because the layout of code is not known until *very* late, we must use a
new fragment to record the information we need until we can know
*exactly* what the range is.

llvm-svn: 259868
2016-02-05 01:55:49 +00:00
Reid Kleckner cb91e7d395 [codeview] Don't attempt a cross-section label diff
This only comes up when we're trying to find the next .cv_loc label.

Fixes PR26467

llvm-svn: 259733
2016-02-04 00:21:42 +00:00
David Majnemer c9911f28e5 [codeview] Correctly handle inlining functions post-dominated by unreachable
CodeView requires us to accurately describe the extent of the inlined
code.  We did this by grabbing the next debug location in source order
and using *that* to denote where we stopped inlining.  However, this is
not sufficient or correct in instances where there is no next debug
location or the next debug location belongs to the start of another
function.

To get this correct, use the end symbol of the function to denote the
last possible place the inlining could have stopped at.

llvm-svn: 259548
2016-02-02 19:22:34 +00:00
Reid Kleckner 1fcd610c94 [codeview] Wire up the .cv_inline_linetable directive
This directive emits the binary annotations that describe line and code
deltas in inlined call sites. Single-stepping through inlined frames in
windbg now works.

llvm-svn: 259535
2016-02-02 17:41:18 +00:00
David Majnemer 8b68a6cabd [CodeView] Properly handle empty line tables
Don't crash when there are no appropriate line table entries for a given
function.

llvm-svn: 259277
2016-01-30 00:36:09 +00:00
David Majnemer 6fcbd7e909 [CodeView] Implement .cv_inline_linetable
This support is _very_ rudimentary, just enough to get some basic data
into the CodeView debug section.

Left to do is:
- Use the combined opcodes to save space.
- Do something about code offsets.

llvm-svn: 259230
2016-01-29 19:24:12 +00:00
Reid Kleckner 828883b86c [CodeView] Fix dumping the is_stmt bit from the line table
Bug pointed out by George Rimar.

llvm-svn: 259205
2016-01-29 16:39:04 +00:00
Reid Kleckner 2214ed8937 Reland "[CodeView] Use assembler directives for line tables"
This reverts commit r259126 and relands r259117.

This time with updated library dependencies.

llvm-svn: 259130
2016-01-29 00:49:42 +00:00
Reid Kleckner 00d9639c24 Revert "[CodeView] Use assembler directives for line tables"
This reverts commit r259117.

The LineInfo constructor is defined in the codeview library and we have
to link against it now. Doing that isn't trivial, so reverting for now.

llvm-svn: 259126
2016-01-29 00:13:28 +00:00
Reid Kleckner c62e379d22 [CodeView] Use assembler directives for line tables
Adds a new family of .cv_* directives to LLVM's variant of GAS syntax:

- .cv_file: Similar to DWARF .file directives

- .cv_loc: Similar to the DWARF .loc directive, but starts with a
  function id. CodeView line tables are emitted by function instead of
  by compilation unit, so we needed an extra field to communicate this.
  Rather than overloading the .loc direction further, we decided it was
  better to have our own directive.

- .cv_stringtable: Emits the codeview string table at the current
  position. Currently this just contains the filenames as
  null-terminated strings.

- .cv_filechecksums: Emits the file checksum table for all files used
  with .cv_file so far. There is currently no support for emitting
  actual checksums, just filenames.

This moves the line table emission code down into the assembler.  This
is in preparation for implementing the inlined call site line table
format. The inline line table format encoding algorithm requires knowing
the absolute code offsets, so it must run after the assembler has laid
out the code.

David Majnemer collaborated on this patch.

llvm-svn: 259117
2016-01-28 23:31:52 +00:00
Nico Weber 891419adc2 Make WinCOFFObjectWriter.cpp's timestamp writing not use ENABLE_TIMESTAMPS
LLVM_ENABLE_TIMESTAMPS controls if timestamps are embedded into llvm's
binaries. Turning it off is useful for deterministic builds.

r246905 made it so that the define suddenly also controls if the binaries that
the llvm binaries _create_ embed timestamps or not – but this shouldn't be a
configure-time option. r256203/r256204 added a driver option to toggle this on
and off, so this patch now passes this driver option in LLVM_ENABLE_TIMESTAMPS
builds so that if LLVM_ENABLE_TIMESTAMPS is set, the build of LLVM is
deterministic – but the built clang can still write timestamps into other
executables when requested.

This also allows removing some of the test machinery added in r292012 to work
around this problem.

See PR24740 for background.
http://reviews.llvm.org/D15783

llvm-svn: 256958
2016-01-06 19:05:19 +00:00
David Majnemer ff1d084aa2 [MC] Don't use the architecture to govern which object file format to use
InitMCObjectFileInfo was trying to override the triple in awkward ways.
For example, a triple specifying COFF but not Windows was forced as ELF.
This makes it easy for internal invariants to get violated, such as
those which triggered PR25912.

This fixes PR25912.

llvm-svn: 256226
2015-12-22 01:39:04 +00:00
David Majnemer 03e2cc3007 [MC, COFF] Support link /incremental conditionally
Today, we always take into account the possibility that object files
produced by MC may be consumed by an incremental linker.  This results
in us initialing fields which vary with time (TimeDateStamp) which harms
hermetic builds (e.g. verifying a self-host went well) and produces
sub-optimal code because we cannot assume anything about the relative
position of functions within a section (call sites can get redirected
through incremental linker thunks).

Let's provide an MCTargetOption which controls this behavior so that we
can disable this functionality if we know a-priori that the build will
not rely on /incremental.

llvm-svn: 256203
2015-12-21 22:09:27 +00:00
David Majnemer 18663f8787 [MC, COFF] Unbreak support for COFF timestamps
Support for COFF timestamps was unintentionally broken in r246905 when
it was conditionally available depending on whether or not LLVM was
configured with LLVM_ENABLE_TIMESTAMPS.  However, Config/config.h was
never included which essentially broke the feature.  Due to lax testing,
the breakage was never identified until we observed strange failures
during incremental links of Chromium.

This issue is resolved by simply including Config/config.h in
WinCOFFObjectWriter and teaching lit that the MC/COFF/timestamp.s test
is conditionally supported depending on LLVM_ENABLE_TIMESTAMPS.  With
this in place, we can strengthen the test to ensure that it will not
accidentally get broken in the future.

This fixes PR25891.

llvm-svn: 256137
2015-12-21 08:03:07 +00:00
Peter Collingbourne 8359a6a83e MC: Simplify handling of temporary symbols in COFF writer.
The COFF object writer was previously adding unnecessary symbols to its
temporary data structures and cleaning them up later. This made the code
harder to understand and caused a bug (aliases classed as temporary symbols
would cause an assertion failure). A much simpler way of handling such
symbols is to ask the layout for their section-relative position when needed.

Tested with a bootstrap on Windows and by building Chrome.

Differential Revision: http://reviews.llvm.org/D14975

llvm-svn: 254183
2015-11-26 23:29:27 +00:00
Manuel Klimek 272d3f17fc Fix bug where WinCOFFObjectWriter would assume starting from an empty output.
Starting on an input stream that is not at offset 0 would trigger the
assert in WinCOFFObjectWriter.cpp:1065:

  assert(getStream().tell() <= (*i)->Header.PointerToRawData &&
               "Section::PointerToRawData is insane!");

llvm-svn: 253464
2015-11-18 15:24:17 +00:00
Oliver Stannard 9be59af3ab [Assembler] Make fatal assembler errors non-fatal
Currently, if the assembler encounters an error after parsing (such as an
out-of-range fixup), it reports this as a fatal error, and so stops after the
first error. However, for most of these there is an obvious way to recover
after emitting the error, such as emitting the fixup with a value of zero. This
means that we can report on all of the errors in a file, not just the first
one. MCContext::reportError records the fact that an error was encountered, so
we won't actually emit an object file with the incorrect contents.

Differential Revision: http://reviews.llvm.org/D14717

llvm-svn: 253328
2015-11-17 10:00:43 +00:00
Rafael Espindola e3a20f57d9 Fix pr24486.
This extends the work done in r233995 so that now getFragment (in addition to
getSection) also works for variable symbols.

With that the existing logic to decide if a-b can be computed works even if
a or b are variables. Given that, the expression evaluation can avoid expanding
variables as aggressively and that in turn lets the relocation code see the
original variable.

In order for this to work with the asm streamer, there is now a dummy fragment
per section. It is used to assign a section to a symbol when no other fragment
exists.

This patch is a joint work by Maxim Ostapenko andy myself.

llvm-svn: 249303
2015-10-05 12:07:05 +00:00
Reid Kleckner 85dfb68e50 Add assembler fatal error for undefined assembler labels in COFF writer
llvm-svn: 247814
2015-09-16 16:26:29 +00:00
David Majnemer 088ba020dd [MC] Generate a timestamp for COFF object files
The MS incremental linker seems to inspect the timestamp written into
the object file to determine whether or not it's contents need to be
considered.  Failing to set the timestamp to a date newer than the
executable will result in the object file not participating in
subsequent links.  To ameliorate this, write the current time into the
object file's TimeDateStamp field.

llvm-svn: 246607
2015-09-01 23:46:11 +00:00
David Majnemer 6ddc636862 [MC] Add support for generating COFF CRCs
COFF sections are accompanied with an auxiliary symbol which includes a
checksum.  This checksum used to be filled with just zero but this seems
to upset LINK.exe when it is processing a /INCREMENTAL link job.
Instead, fill the CheckSum field with the JamCRC of the section
contents.  This matches MSVC's behavior.

This fixes PR19666.

N.B.  A rather simple implementation of JamCRC is given.  It implements
a byte-wise calculation using the method given by Sarwate.  There are
implementations with higher throughput like slice-by-eight and making
use of PCLMULQDQ.  We can switch to one of those techniques if it turns
out to be a significant use of time.

llvm-svn: 246590
2015-09-01 21:23:58 +00:00
Rafael Espindola dbaf0498a9 Revert "Centralize the information about which object format we are using."
This reverts commit r245047.

It was failing on the darwin bots. The problem was that when running

./bin/llc -march=msp430

llc gets to

  if (TheTriple.getTriple().empty())
    TheTriple.setTriple(sys::getDefaultTargetTriple());

Which means that we go with an arch of msp430 but a triple of
x86_64-apple-darwin14.4.0 which fails badly.

That code has to be updated to select a triple based on the value of
march, but that is not a trivial fix.

llvm-svn: 245062
2015-08-14 15:48:41 +00:00
Rafael Espindola 90eb70c8a7 Centralize the information about which object format we are using.
Other than some places that were handling unknown as ELF, this should
have no change. The test updates are because we were detecting
arm-coff or x86_64-win64-coff as ELF targets before.

It is not clear if the enum should live on the Triple. At least now it lives
in a single location and should be easier to move somewhere else.

llvm-svn: 245047
2015-08-14 13:31:17 +00:00
David Majnemer 1305e2c0f5 [MC] Correctly escape .safeseh's symbol
This fixes PR24107.

llvm-svn: 242050
2015-07-13 18:51:15 +00:00
Gabor Ballabas 5fe650c5e1 Reworking the test part of r241149
The test part of r241149 has been reverted in r241451, due to misplaced test cases.
This patch splits those test cases among the appropriate targets.

Differential Revision: http://reviews.llvm.org/D10897

llvm-svn: 241283
2015-07-02 16:53:23 +00:00
Andy Ayers b63298e0c8 Revise test to run llc and llvm-mc separately.
Differential Revision: http://reviews.llvm.org/D10066

llvm-svn: 238508
2015-05-28 21:49:50 +00:00
Andy Ayers 9e5c851419 Don't omit the constant when computing a cross-section relative relocation.
Differential Revision: http://reviews.llvm.org/D9692

llvm-svn: 237327
2015-05-14 01:10:41 +00:00
Rafael Espindola 88af411117 Add a proper fix for pr23025.
Instead of avoiding looking past every global symbol, only do so
if the symbol is in a comdat.

llvm-svn: 235181
2015-04-17 11:27:13 +00:00
Rafael Espindola 6b1997cdf5 Add a reduced testcase from pr23025.
llvm-svn: 235168
2015-04-17 09:05:25 +00:00
David Blaikie f72d05bc7b [opaque pointer type] Add textual IR support for explicit type parameter to gep operator
Similar to gep (r230786) and load (r230794) changes.

Similar migration script can be used to update test cases, which
successfully migrated all of LLVM and Polly, but about 4 test cases
needed manually changes in Clang.

(this script will read the contents of stdin and massage it into stdout
- wrap it in the 'apply.sh' script shown in previous commits + xargs to
apply it over a large set of test cases)

import fileinput
import sys
import re

rep = re.compile(r"(getelementptr(?:\s+inbounds)?\s*\()((<\d*\s+x\s+)?([^@]*?)(|\s*addrspace\(\d+\))\s*\*(?(3)>)\s*)(?=$|%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|zeroinitializer|<|\[\[[a-zA-Z]|\{\{)", re.MULTILINE | re.DOTALL)

def conv(match):
  line = match.group(1)
  line += match.group(4)
  line += ", "
  line += match.group(2)
  return line

line = sys.stdin.read()
off = 0
for match in re.finditer(rep, line):
  sys.stdout.write(line[off:match.start()])
  sys.stdout.write(conv(match))
  off = match.end()
sys.stdout.write(line[off:])

llvm-svn: 232184
2015-03-13 18:20:45 +00:00
David Majnemer b61f4e403d X86: Form IMGREL relocations for LLVM Functions
We supported forming IMGREL relocations from ConstantExprs involving
__ImageBase if the minuend was a GlobalVariable.  Extend this
functionality to all GlobalObjects.

llvm-svn: 231456
2015-03-06 08:11:32 +00:00
David Blaikie a79ac14fa6 [opaque pointer type] Add textual IR support for explicit type parameter to load instruction
Essentially the same as the GEP change in r230786.

A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)

import fileinput
import sys
import re

pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")

for line in sys.stdin:
  sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7649

llvm-svn: 230794
2015-02-27 21:17:42 +00:00
David Blaikie 79e6c74981 [opaque pointer type] Add textual IR support for explicit type parameter to getelementptr instruction
One of several parallel first steps to remove the target type of pointers,
replacing them with a single opaque pointer type.

This adds an explicit type parameter to the gep instruction so that when the
first parameter becomes an opaque pointer type, the type to gep through is
still available to the instructions.

* This doesn't modify gep operators, only instructions (operators will be
  handled separately)

* Textual IR changes only. Bitcode (including upgrade) and changing the
  in-memory representation will be in separate changes.

* geps of vectors are transformed as:
    getelementptr <4 x float*> %x, ...
  ->getelementptr float, <4 x float*> %x, ...
  Then, once the opaque pointer type is introduced, this will ultimately look
  like:
    getelementptr float, <4 x ptr> %x
  with the unambiguous interpretation that it is a vector of pointers to float.

* address spaces remain on the pointer, not the type:
    getelementptr float addrspace(1)* %x
  ->getelementptr float, float addrspace(1)* %x
  Then, eventually:
    getelementptr float, ptr addrspace(1) %x

Importantly, the massive amount of test case churn has been automated by
same crappy python code. I had to manually update a few test cases that
wouldn't fit the script's model (r228970,r229196,r229197,r229198). The
python script just massages stdin and writes the result to stdout, I
then wrapped that in a shell script to handle replacing files, then
using the usual find+xargs to migrate all the files.

update.py:
import fileinput
import sys
import re

ibrep = re.compile(r"(^.*?[^%\w]getelementptr inbounds )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")
normrep = re.compile(       r"(^.*?[^%\w]getelementptr )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")

def conv(match, line):
  if not match:
    return line
  line = match.groups()[0]
  if len(match.groups()[5]) == 0:
    line += match.groups()[2]
  line += match.groups()[3]
  line += ", "
  line += match.groups()[1]
  line += "\n"
  return line

for line in sys.stdin:
  if line.find("getelementptr ") == line.find("getelementptr inbounds"):
    if line.find("getelementptr inbounds") != line.find("getelementptr inbounds ("):
      line = conv(re.match(ibrep, line), line)
  elif line.find("getelementptr ") != line.find("getelementptr ("):
    line = conv(re.match(normrep, line), line)
  sys.stdout.write(line)

apply.sh:
for name in "$@"
do
  python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name"
  rm -f "$name.tmp"
done

The actual commands:
From llvm/src:
find test/ -name *.ll | xargs ./apply.sh
From llvm/src/tools/clang:
find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}"
From llvm/src/tools/polly:
find test/ -name *.ll | xargs ./apply.sh

After that, check-all (with llvm, clang, clang-tools-extra, lld,
compiler-rt, and polly all checked out).

The extra 'rm' in the apply.sh script is due to a few files in clang's test
suite using interesting unicode stuff that my python script was throwing
exceptions on. None of those files needed to be migrated, so it seemed
sufficient to ignore those cases.

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7636

llvm-svn: 230786
2015-02-27 19:29:02 +00:00
Michael Kuperstein fc3e626752 Fix quoting of #pragma comment for MS compat, LLVM part.
For #pragma comment(linker, ...) MSVC expects the comment string to be quoted, but for #pragma comment(lib, ...) the compiler itself quotes the library name.
Since this distinction disappears by the time the directive reaches the backend, move quoting for the "lib" version to the frontend.

Differential Revision: http://reviews.llvm.org/D7652

llvm-svn: 229375
2015-02-16 11:57:17 +00:00
David Majnemer 3df3c61e91 MC, COFF: Align section contents to a four byte boundary
llvm-svn: 228879
2015-02-11 22:22:30 +00:00
David Majnemer 1de3094d78 MC: Calculate intra-section symbol differences correctly for COFF
This fixes PR22060.

llvm-svn: 228565
2015-02-09 06:31:31 +00:00
David Majnemer 5614ea9aae MC: Emit COFF section flags in the "proper" order
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
2015-02-07 08:26:40 +00:00
Rafael Espindola 12ca34f53f Bring r226038 back.
No change in this commit, but clang was changed to also produce trivial comdats when
needed.

Original message:

Don't create new comdats in CodeGen.

This patch stops the implicit creation of comdats during codegen.

Clang now sets the comdat explicitly when it is required. With this patch clang and gcc
now produce the same result in pr19848.

llvm-svn: 226467
2015-01-19 15:16:06 +00:00
Timur Iskhodzhanov 60b721363c Revert r226242 - Revert Revert Don't create new comdats in CodeGen
This breaks AddressSanitizer (ninja check-asan) on Windows

llvm-svn: 226251
2015-01-16 08:38:45 +00:00
Rafael Espindola 67a79e72f5 Revert "Revert Don't create new comdats in CodeGen"
This reverts commit r226173, adding r226038 back.

No change in this commit, but clang was changed to also produce trivial comdats for
costructors, destructors and vtables when needed.

Original message:

Don't create new comdats in CodeGen.

This patch stops the implicit creation of comdats during codegen.

Clang now sets the comdat explicitly when it is required. With this patch clang and gcc
now produce the same result in pr19848.

llvm-svn: 226242
2015-01-16 02:22:55 +00:00
Timur Iskhodzhanov f5adf13fac Revert Don't create new comdats in CodeGen
It breaks AddressSanitizer on Windows.

llvm-svn: 226173
2015-01-15 16:14:34 +00:00
Rafael Espindola fad1639a12 Don't create new comdats in CodeGen.
This patch stops the implicit creation of comdats during codegen.

Clang now sets the comdat explicitly when it is required. With this patch clang and gcc
now produce the same result in pr19848.

llvm-svn: 226038
2015-01-14 20:55:48 +00:00
Michael Kuperstein c43b063358 [COFF] Don't try to add quotes to already quoted linker directives
If a linker directive is already quoted, don't try to quote it again, otherwise it creates a mess.
This pops up in places like:
#pragma comment(linker,"\"/foo bar'\"")

Differential Revision: http://reviews.llvm.org/D6792

llvm-svn: 224998
2014-12-30 19:23:48 +00:00