COFF lacks a feature that other object file formats support: mergeable
sections.
To work around this, MSVC sticks constant pool entries in special COMDAT
sections so that each constant is in it's own section. This permits
unused constants to be dropped and it also allows duplicate constants in
different translation units to get merged together.
This fixes PR20262.
Differential Revision: http://reviews.llvm.org/D4482
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213006 91177308-0d34-0410-b5e6-96231b3b80d8
This is the first of a number of changes designed to generalise
MCWin64EHInstruction to support different target architectures. An ordered set
(vector) of these instructions is saved per frame to permit the emission of
information for Windows NT style unwinding. The only bit of information which
is actually target specific here is the Opcode for the unwinding bytecode. The
remainder of the information is simply generic information that is relevant to
the Windows NT unwinding model.
Remove the accessors for the fields, making them const and public instead. Sink
the knowledge of the alias'ed name into the single source and sink a single-use
check method into the use.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212914 91177308-0d34-0410-b5e6-96231b3b80d8
Rename member variables and functions for the MCStreamer for DWARF-like
unwinding management. Rename the Windows ones as well and make the naming and
handling similar across the two. No functional change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212912 91177308-0d34-0410-b5e6-96231b3b80d8
MC was aping a binutils bug where aliases would default their linkage to
private instead of internal.
I've sent a patch to the binutils maintainers and they've recently
applied it to the GNU assembler sources.
This fixes PR20152.
Differential Revision: http://reviews.llvm.org/D4395
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212899 91177308-0d34-0410-b5e6-96231b3b80d8
Due to the fact that the windows unwinding has the concept of chained frames, we
maintain a current frame info pointer that is adjusted on any push and pop of a
unwinding context. This just removes an unnecessary variable that was used to
mirror the DWARF unwinding code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212882 91177308-0d34-0410-b5e6-96231b3b80d8
This structure contains information related to the call frame used to generate
unwinding information. Rename this to reflect the future use to represent the
shared state between various architectures for WinCFI information.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212881 91177308-0d34-0410-b5e6-96231b3b80d8
These two routines didn't take a "const MCSymbolData &SD"
like the other MCELF::Get routines for some reason ...
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212834 91177308-0d34-0410-b5e6-96231b3b80d8
This adds a utility method to access the WinCFI information in bulk and uses
that to iterate rather than requesting the count and individually iterating
them. This is in preparation for restructuring WinCFI handling to enable more
clear sharing across architectures to enable unwind information emission for
Windows on ARM.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212683 91177308-0d34-0410-b5e6-96231b3b80d8
Use 0 for the invalid buffer instead of -1/~0 and switch to unsigned
representation to enable more idiomatic usage.
Also introduce a trivial SourceMgr::getMainFileID() instead of hard-coding 0/1
to identify the main file.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212398 91177308-0d34-0410-b5e6-96231b3b80d8
Now that we have a lib/MC/MCAnalysis, the dependency was there just because
of two helper classes. Move the two over to MC.
This will allow IRObjectFile to parse inline assembly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212248 91177308-0d34-0410-b5e6-96231b3b80d8
The new library is 150KB on a Release+Asserts build, so it is quiet a bit of
code that regular users of MC don't need to link with now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212209 91177308-0d34-0410-b5e6-96231b3b80d8
This is a small targeted fix for pr20119. The code needs quiet a bit of
refactoring and I added some FIXMEs about it, but I want to get the testcase
passing first.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212101 91177308-0d34-0410-b5e6-96231b3b80d8
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*.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211994 91177308-0d34-0410-b5e6-96231b3b80d8
COFF sections in MC were represented by a tuple of section-name and
COMDAT-name. This is not sufficient to represent a .text section
associated with another .text section; we need a way to distinguish
between the key section and the one marked associative.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211913 91177308-0d34-0410-b5e6-96231b3b80d8
string_ostream is a safe and efficient string builder that combines opaque
stack storage with a built-in ostream interface.
small_string_ostream<bytes> additionally permits an explicit stack storage size
other than the default 128 bytes to be provided. Beyond that, storage is
transferred to the heap.
This convenient class can be used in most places an
std::string+raw_string_ostream pair or SmallString<>+raw_svector_ostream pair
would previously have been used, in order to guarantee consistent access
without byte truncation.
The patch also converts much of LLVM to use the new facility. These changes
include several probable bug fixes for truncated output, a programming error
that's no longer possible with the new interface.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211749 91177308-0d34-0410-b5e6-96231b3b80d8
--
This patch enables LLVM to emit Win64-native unwind info rather than
DWARF CFI. It handles all corner cases (I hope), including stack
realignment.
Because the unwind info is not flexible enough to describe stack frames
with a gap of unknown size in the middle, such as the one caused by
stack realignment, I modified register spilling code to place all spills
into the fixed frame slots, so that they can be accessed relative to the
frame pointer.
Patch by Vadim Chugunov!
Reviewed By: rnk
Differential Revision: http://reviews.llvm.org/D4081
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211691 91177308-0d34-0410-b5e6-96231b3b80d8
The method was empty in the null streamer but I mistakenly replaced it with
the aborting one in MCStreamer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211666 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211639 91177308-0d34-0410-b5e6-96231b3b80d8
Utilize range based for-loops to simplify some code.
Use insert() instead of a loop for simplicity/efficiency.
No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211486 91177308-0d34-0410-b5e6-96231b3b80d8
Correct the section flags for code built for Windows on ARM with
`-ffunction-sections`. Windows on ARM uses solely Thumb-2 instructions, and
indicates that the function is thumb by placing it in a text section that has
IMAGE_SCN_MEM_16BIT flag set.
When we encounter a .section directive, a new section is constructed. This may
be a text segment. In order to identify that we need the additional flag,
expose the target triple through the ObjectFileInfo as this information is lost
otherwise.
Since any modern ARM targeting environment on Windows would be Thumb-2 (Windows
ARM NT or Windows Embedded Compact), introducing a new flag to indicate the
section attribute seems to be a bit overkill. Simply depend on the target
triple. Since there is one location that this information is currently needed,
creating a target specific assembly parser and delegating the parsing of section
switches also feels a bit heavy handed. If it turns out that this information
ends up changing additional behaviour, then it may be worth considering that
alternative.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211481 91177308-0d34-0410-b5e6-96231b3b80d8
User may initialize a var with non-zero value and specify .bss section.
E.g. : int a __attribute__((section(".bss"))) = 2;
This patch converts an assertion to error report for better user
experience.
Differential Revision: http://reviews.llvm.org/D4199
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211455 91177308-0d34-0410-b5e6-96231b3b80d8
This patch enables LLVM to emit Win64-native unwind info rather than
DWARF CFI. It handles all corner cases (I hope), including stack
realignment.
Because the unwind info is not flexible enough to describe stack frames
with a gap of unknown size in the middle, such as the one caused by
stack realignment, I modified register spilling code to place all spills
into the fixed frame slots, so that they can be accessed relative to the
frame pointer.
Patch by Vadim Chugunov!
Reviewed By: rnk
Differential Revision: http://reviews.llvm.org/D4081
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211399 91177308-0d34-0410-b5e6-96231b3b80d8
Use the MCStreamer base implementations for file ID tracking instead of
overriding them as no-ops.
Avoids assertions when streaming Dwarf debug info, and fixes ASM parsing of loc
and file directives.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211282 91177308-0d34-0410-b5e6-96231b3b80d8
Currently, when using llvm as an assembler, DWARF debug information is only
generated for the .text section. This patch modifies this so that DWARF info
is emitted for all executable sections.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211273 91177308-0d34-0410-b5e6-96231b3b80d8
