I don't think this is reachable by any frontend (why would you transform
asm to asm+debug info?) but it helps tidy up some of this code, avoid
the weird special case of "emit the first CU, store the label, then emit
the rest" in MCDwarfLineTable::Emit by instead having the
DWARF-for-assembly case use the same codepath as DwarfDebug.cpp, by
registering the label of the debug_line section, thus causing it to be
emitted. (with a special case in asm output to just emit the label since
asm output uses the .loc directives, etc, rather than the debug_loc
directly)
llvm-svn: 205286
Another part of the ARM64 backend (so tests will be following soon).
This is currently used by the linker to relax adrp/ldr pairs into nops
where possible, though could well be more broadly applicable.
llvm-svn: 205084
When a label is parsed, check if there is type information available for the
label. If so, check if the symbol is a function. If the symbol is a function
and we are in thumb mode and no explicit thumb_func has been emitted, adjust the
symbol data to indicate that the function definition is a thumb function.
The application of this inferencing is improved value handling in the object
file (the required thumb bit is set on symbols which are thumb functions). It
also helps improve compatibility with binutils.
The one complication that arises from this handling is the MCAsmStreamer. The
default implementation of getOrCreateSymbolData in MCStreamer does not support
tracking the symbol data. In order to support the semantics of thumb functions,
track symbol data in assembly streamer. Although O(n) in number of labels in
the TU, this is already done in various other streamers and as such the memory
overhead is not a practical concern in this scenario.
llvm-svn: 204544
Allow object files to be tagged with a version-min load command for iOS
or MacOSX.
Teach macho-dump to understand the version-min load commands for
testcases.
rdar://11337778
llvm-svn: 204190
See r204027 for the precursor to this that applied to asm debug info.
This required some non-obvious API changes to handle the case of asm
output (we never go asm->asm so this didn't come up in r204027): the
modification of the file/directory name by MCDwarfLineTableHeader needed
to be reflected in the MCAsmStreamer caller so it could print the
appropriate .file directive, so those StringRef parameters are now
non-const ref (in/out) parameters rather than just const.
llvm-svn: 204069
The previous deduping strategy was woefully inadequate - it only
considered the most recent file used and avoided emitting a duplicate in
that case - never considering the a/b/a scenario.
It was also lacking when it came to directory paths as the previous
filename would never match the current if the filename had been split
into file and directory components.
This change builds caching functionality into the line table at the
lowest level in an optional form (a file number of 0 indicates that one
should be chosen and returned) and will eventually be reused by the
normal source level debugging DWARF emission.
llvm-svn: 204027
This compiles with no changes to clang/lld/lldb with MSVC and includes
overloads to various functions which are used by those projects and llvm
which have OwningPtr's as parameters. This should allow out of tree
projects some time to move. There are also no changes to libs/Target,
which should help out of tree targets have time to move, if necessary.
llvm-svn: 203083
Before llvm-mc would print it, but llc was assuming that it would produce
another section changing directive before one was needed. That assumption is
false with inline asm.
Fixes PR19049.
Another option would be to always create the section, but in the asm printer
avoid printing sections changes during initialization. That would work, but
* We do use the fact that llvm-mc prints it in testing. The tests can be changed
if needed.
* A quick poll on IRC suggest that most developers prefer the implicit .text to
be printed.
llvm-svn: 203001
Summary:
There should be a space before each of these two keywords to avoid
generating invalid assembly files.
NOTE: I could not find an obvious maintainers in CODE_OWNERS.TXT, but
this seems related to debug info.
Reviewers: echristo
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D2791
llvm-svn: 201359
Per the GAS documentation, .fill should permit pattern widths that
aren't a power of two. While I was in the neighborhood, I added some
sanity checking. This change was motivated by a use of this construct
in the Linux Kernel.
llvm-svn: 200606
This commit allows LLVM MC to process .cfi_startproc directives when
they are followed by an additional `simple' identifier. This signals to
elide the emission of target specific CFI instructions that would
normally occur initially.
This fixes PR16587.
Differential Revision: http://llvm-reviews.chandlerc.com/D2624
llvm-svn: 200227
This has a few advantages:
* Only targets that use a MCTargetStreamer have to worry about it.
* There is never a MCTargetStreamer without a MCStreamer, so we can use a
reference.
* A MCTargetStreamer can talk to the MCStreamer in its constructor.
llvm-svn: 200129
Also improve the implementation of EmitRawText(Twine) so it doesn't
bother using the SmallString buffer if the Twine is a simple StringRef
anyway.
llvm-svn: 193378
This patch fixes an old FIXME by creating a MCTargetStreamer interface
and moving the target specific functions for ARM, Mips and PPC to it.
The ARM streamer is still declared in a common place because it is
used from lib/CodeGen/ARMException.cpp, but the Mips and PPC are
completely hidden in the corresponding Target directories.
I will send an email to llvmdev with instructions on how to use this.
llvm-svn: 192181
When MC was first added, targets could use hasRawTextSupport to keep features
working before they were added to the MC interface.
The design goal of MC is to provide an uniform api for printing assembly and
object files. Short of relaxations and other corner cases, a object file is
just another representation of the assembly.
It was never the intention that targets would keep doing things like
if (hasRawTextSupport())
Set flags in one way.
else
Set flags in another way.
When they do that they create two code paths and the object file is no longer
just another representation of the assembly. This also then requires testing
with llc -filetype=obj, which is extremelly brittle.
This patch removes some of these hacks by replacing them with smaller ones.
The ARM flag setting is trivial, so I just moved it to the constructor. For
Mips, the patch adds two temporary hack directives that allow the assembly
to represent the same things as the object file was already able to.
The hope is that the mips developers will replace the hack directives with
the same ones that gas uses and drop the -print-hack-directives flag.
I will also try to implement a target streamer interface, so that we can
move this out of the common code.
In summary, for any new work, two rules of the thumb are
* Don't use "llc -filetype=obj" in tests.
* Don't add calls to hasRawTextSupport.
llvm-svn: 192035
The size of common symbols is now tracked correctly, so they can be listed in the arange section without needing knowledge of other following symbols.
.comm (and .lcomm) do not indicate to the system assembler any particular section to use, so we have to treat them as having no section.
Test case update to account for this.
llvm-svn: 191210
There are more than one paths to where the frame information is emitted. Place
the call to generateCompactUnwindEncodings() into the method which outputs the
frame information, thus ensuring that the encoding is there for every path. This
involved threading the MCAsmBackend object through to this method.
<rdar://problem/13623355>
llvm-svn: 190335
Currently, when an invalid attribute is encountered on processing a .s file,
clang will abort due to llvm_unreachable. Invalid user input should not cause
an abnormal termination of the compiler. Change the interface to return a
boolean to indicate the failure as a first step towards improving hanlding of
malformed user input to clang.
Signed-off-by: Saleem Abdulrasool <compnerd@compnerd.org>
llvm-svn: 188047
This is dead code since PIC16 was removed in 2010. The result was an odd mix,
where some parts would carefully pass it along and others would assert it was
zero (most of the object streamer for example).
llvm-svn: 185436
We now emit a line table for each compile unit. To reduce the prologue size
of each line table, the files and directories used by each compile unit are
stored in std::map<unsigned, std::vector< > > instead of std::vector< >.
The prologue for a lto'ed image can be as big as 93K. Duplicating 93K for each
compile unit causes a huge increase of debug info. With this patch, each
prologue will only emit the files required by the compile unit.
rdar://problem/13342023
llvm-svn: 176605
isa<> and dyn_cast<>. In several places, code is already hacking around
the absence of this, and there seem to be several interfaces that might
be lifted and/or devirtualized using this.
This change was based on a discussion with Jim Grosbach about how best
to handle testing for specific MCStreamer subclasses. He said that this
was the correct end state, and everything else was too hacky so
I decided to just make it so.
No functionality should be changed here, this is just threading the kind
through all the constructors and setting up the classof overloads.
llvm-svn: 174113
The aim of this patch is to fix the following piece of code in the
platform-independent AsmParser:
void AsmParser::CheckForValidSection() {
if (!ParsingInlineAsm && !getStreamer().getCurrentSection()) {
TokError("expected section directive before assembly directive");
Out.SwitchSection(Ctx.getMachOSection(
"__TEXT", "__text",
MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
0, SectionKind::getText()));
}
}
This was added for the "-n" option of llvm-mc.
The proposed fix adds another virtual method to MCStreamer, called
InitToTextSection. Conceptually, it's similar to the existing
InitSections which initializes all common sections and switches to
text. The new method is implemented by each platform streamer in a way
that it sees fit. So AsmParser can now do this:
void AsmParser::CheckForValidSection() {
if (!ParsingInlineAsm && !getStreamer().getCurrentSection()) {
TokError("expected section directive before assembly directive");
Out.InitToTextSection();
}
}
Which is much more reasonable.
llvm-svn: 172450
Mips16 is really a processor decoding mode (ala thumb 1) and in the same
program, mips16 and mips32 functions can exist and can call each other.
If a jal type instruction encounters an address with the lower bit set, then
the processor switches to mips16 mode (if it is not already in it). If the
lower bit is not set, then it switches to mips32 mode.
The linker knows which functions are mips16 and which are mips32.
When relocation is performed on code labels, this lower order bit is
set if the code label is a mips16 code label.
In general this works just fine, however when creating exception handling
tables and dwarf, there are cases where you don't want this lower order
bit added in.
This has been traditionally distinguished in gas assembly source by using a
different syntax for the label.
lab1: ; this will cause the lower order bit to be added
lab2=. ; this will not cause the lower order bit to be added
In some cases, it does not matter because in dwarf and debug tables
the difference of two labels is used and in that case the lower order
bits subtract each other out.
To fix this, I have added to mcstreamer the notion of a debuglabel.
The default is for label and debug label to be the same. So calling
EmitLabel and EmitDebugLabel produce the same result.
For various reasons, there is only one set of labels that needs to be
modified for the mips exceptions to work. These are the "$eh_func_beginXXX"
labels.
Mips overrides the debug label suffix from ":" to "=." .
This initial patch fixes exceptions. More changes most likely
will be needed to DwarfCFException to make all of this work
for actual debugging. These changes will be to emit debug labels in some
places where a simple label is emitted now.
Some historical discussion on this from gcc can be found at:
http://gcc.gnu.org/ml/gcc-patches/2008-08/msg00623.htmlhttp://gcc.gnu.org/ml/gcc-patches/2008-11/msg01273.html
llvm-svn: 170279
David Blaikie