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
Currently, llvm always emits a DWARF CIE with a version of 1, even when emitting
DWARF 3 or 4, which both support CIE version 3. This patch makes it emit the
newer CIE version when we are emitting DWARF 3 or 4. This will not reduce
compatibility, as we already emit other DWARF3/4 features, and is worth doing as
the DWARF3 spec removed some ambiguities in the interpretation of call frame
information.
It also fixes a minor bug where the "return address" field of the CIE was
encoded as a ULEB128, which is only valid when the CIE version is 3. There are
no test changes for this, because (as far as I can tell) none of the platforms
that we test have a return address register with a DWARF register number >127.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211272 91177308-0d34-0410-b5e6-96231b3b80d8
used by all of the MC level tools and codegen. Fix up all uses
in the compiler to use this and set it on the context accordingly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211257 91177308-0d34-0410-b5e6-96231b3b80d8
We would get confused by '@' characters in symbol names, we would
mistake the text following them for the variant kind.
When an identifier a string, the variant kind will never show up inside
of it. Instead, check to see if there is a variant following the
string.
This fixes PR19965.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211249 91177308-0d34-0410-b5e6-96231b3b80d8
ARMTargetStreamer implements ConstantPool and AssmeblerConstantPools
to keep track of assembler-generated constant pools that are used for
ldr-pseudo.
When implementing ldr-pseudo for AArch64, these two classes can be reused.
So this patch factors them out from ARM target to the general MC lib.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211198 91177308-0d34-0410-b5e6-96231b3b80d8
Most Windows platforms use auxiliary data for unwinding. This information is
stored in the .pdata section. The encoding format for the data differs between
architectures and Windows variants. Windows MIPS and Alpha use identical
formats; Alpha64 is the same with different widths. Windows x86_64 and Itanium
share the representation. All Windows CE entries are identical irrespective of
the architecture. ARMv7 (Windows [NT] on ARM) has its own format.
This enumeration will become the differentiator once the windows EH emission
infrastructure is generalised, allowing us to emit the necessary unwinding
information for Windows on ARM.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210634 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r206683.
The code was confusing SEH register numbers with DWARF register numbers.
The test case it was committed with was obviously incorrect. The
disassembler was roundtripping '.seh_pushreg %rsi' as '.seh_pushreg
%rbp', and other exciting things.
Noticed by Vadim Chugunov.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210574 91177308-0d34-0410-b5e6-96231b3b80d8
I saw at least a memory leak or two from inspection (on probably
untested error paths) and r206991, which was the original inspiration
for this change.
I ran this idea by Jim Grosbach a few weeks ago & he was OK with it.
Since it's a basically mechanical patch that seemed sufficient - usual
post-commit review, revert, etc, as needed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210427 91177308-0d34-0410-b5e6-96231b3b80d8
link.exe requires that the text section has the IMAGE_SCN_MEM_16BIT flag set.
Otherwise, it will treat the function as ARM. If this occurs, then jumps to the
function will fail, switching from thumb to ARM mode execution.
With this change, it is possible to link using the MSVC linker as well.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210415 91177308-0d34-0410-b5e6-96231b3b80d8
GAS documents the .type directive as having an optional comma following the key
symbol name when using the STT_<TYPE_IN_UPPER_CASE> form. However, it treats
the comma as optional in all cases. This makes the IAS support both forms of
inputs. Furthermore, the prefixed forms take either the upper case name or the
lower case alias.
The tests are split into two separate sets as the hash character serves as a
comment character on x86, which is tested in the second set by using arm-elf
which uses the at symbol as a comment character.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210407 91177308-0d34-0410-b5e6-96231b3b80d8
This adjusts the section setup for the windows-itanium environment. This
environment does not report to be a known windows msvc environment, even though
it is (nearly) identical to the MSVC environment for C code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210406 91177308-0d34-0410-b5e6-96231b3b80d8
Add some whitespace, combine two sequential conditionals into a single one.
Reformat some section definitions to maintain uniformity in the function.
NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210405 91177308-0d34-0410-b5e6-96231b3b80d8
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
