Our assertions in WinCOFFStreamer had unexpected side effects resulting
in symbols getting unexpectedly marked as used.
This fixes PR28462.
llvm-svn: 274941
The value size was always 1 or 0, so we don't need to store it.
In a no asserts build this takes the testcase of pr26208 from 11 to 10
seconds.
llvm-svn: 258141
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
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
After r244870 flush() will only compare two null pointers and return,
doing nothing but wasting run time. The call is not required any more
as the stream and its SmallString are always in sync.
Thanks to David Blaikie for reviewing.
llvm-svn: 244928
The patch is generated using this command:
tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
llvm/lib/
Thanks to Eugene Kosov for the original patch!
llvm-svn: 240137
Use a "safeseh" string attribute to do this. You would think we chould
just accumulate the set of personalities like we do on dwarf, but this
fails to account for the LSDA-loading thunks we use for
__CxxFrameHandler3. Each of those needs to make it into .sxdata as well.
The string attribute seemed like the most straightforward approach.
llvm-svn: 239448
All flags setting/getting is now done in the class with helper methods instead
of users having to get the bits in the correct order.
Reviewed by Rafael Espíndola.
llvm-svn: 239314
This create a MCSymbolELF class and moves SymbolSize since only ELF
needs a size expression.
This reduces the size of MCSymbol from 56 to 48 bytes.
llvm-svn: 238801
.safeseh adds an entry to the .sxdata section to register all the
appropriate functions which may handle an exception. This entry is not
a relocation to the symbol but instead the symbol table index of the
function.
llvm-svn: 238641
This starts merging MCSection and MCSectionData.
There are a few issues with the current split between MCSection and
MCSectionData.
* It optimizes the the not as important case. We want the production
of .o files to be really fast, but the split puts the information used
for .o emission in a separate data structure.
* The ELF/COFF/MachO hierarchy is not represented in MCSectionData,
leading to some ad-hoc ways to represent the various flags.
* It makes it harder to remember where each item is.
The attached patch starts merging the two by moving the alignment from
MCSectionData to MCSection.
Most of the patch is actually just dropping 'const', since
MCSectionData is mutable, but MCSection was not.
llvm-svn: 237936
utils/sort_includes.py.
I clearly haven't done this in a while, so more changed than usual. This
even uncovered a missing include from the InstrProf library that I've
added. No functionality changed here, just mechanical cleanup of the
include order.
llvm-svn: 225974
Referencing one symbol from another in the same section does not
generally require a relocation. However, the MS linker has a feature
called /INCREMENTAL which enables incremental links. It achieves this
by creating thunks to the actual function and redirecting all
relocations to point to the thunk.
This breaks down with the old scheme if you have a function which
references, say, itself. On x86_64, we would use %rip relative
addressing to reference the start of the function from out current
position. This would lead to miscompiles because other references might
reference the thunk instead, breaking function pointer equality.
This fixes PR21520.
llvm-svn: 221678
COFF normally doesn't allow us to describe the alignment of COMMON
symbols.
It turns out that most linkers use the symbol size as a hint as to how
aligned the symbol should be.
However the BFD folks have added a .drectve command, which we
now support as of r219229, that allows us to specify the alignment
precisely. With this in mind, stop rounding sizes up.
llvm-svn: 219281
The GNU linker supports an -aligncomm directive that allows for power-of-2
alignment of common data. Add support to emit this directive.
llvm-svn: 219229
link.exe:
Fuzz testing has shown that COMMON symbols with size > 32 will always
have an alignment of at least 32 and all symbols with size < 32 will
have an alignment of at least the largest power of 2 less than the size
of the symbol.
binutils:
The BFD linker essentially work like the link.exe behavior but with
alignment 4 instead of 32. The BFD linker also supports an extension to
COFF which adds an -aligncomm argument to the .drectve section which
permits specifying a precise alignment for a variable but MC currently
doesn't support editing .drectve in this way.
With all of this in mind, we decide to play a little trick: we can
ensure that the alignment will be respected by bumping the size of the
global to it's alignment.
llvm-svn: 218201
Rename the routines to reflect the reality that they are more related to call
frame information than to Win64 EH. Although EH is implemented in an intertwined
manner by augmenting with an exception handler and an associated parameter, the
majority of these routines emit information required to unwind the frames. This
also helps identify that these routines are generic for most windows platforms
(they apply equally to nearly all architectures except x86) although the
encoding of the information is architecture dependent.
Unwinding data is emitted via EmitWinCFI* and exception handling information via
EmitWinEH*.
llvm-svn: 211994
In assembly the expression a=b is parsed as an assignment, so it should be
printed as one.
This remove a truly horrible hack for producing a label with "a=.". It would
be used by codegen but would never be reached by the asm parser. Sorry I
missed this when it was first committed.
llvm-svn: 211639
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.
llvm-svn: 209387
This introduces a target specific streamer, X86WinCOFFStreamer, which handles
the target specific behaviour (e.g. WinEH). This is mostly to ensure that
differences between ARM and X86 remain disjoint and do not accidentally cross
boundaries. This is the final staging change for enabling object emission for
Windows on ARM.
llvm-svn: 207344
This is in preparation for promoting WinCOFFStreamer to a base class which will
be shared by the X86 and ARM specific target COFF streamers. Also add a new
getOrCreateSymbolData interface (like MCELFStreamer) for the ARM COFF Streamer.
This makes the COFFStreamer more similar to the ELFStreamer.
llvm-svn: 207343
Stylistic changes to prepare for splitting up the COFFStreamer into target
specific streamers. Tweak some assertion messages. No functional change.
llvm-svn: 207342
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).
llvm-svn: 206355
