This caused the DebugInfo/Sparc/gnu-window-save.ll test to fail.
> Functions that have signed return addresses need additional dwarf support:
> - After signing the LR, and before authenticating it, the LR register is in a
> state the is unusable by a debugger or unwinder
> - To account for this a new directive, .cfi_negate_ra_state, is added
> - This directive says the signed state of the LR register has now changed,
> i.e. unsigned -> signed or signed -> unsigned
> - This directive has the same CFA code as the SPARC directive GNU_window_save
> (0x2d), adding a macro to account for multiply defined codes
> - This patch matches the gcc implementation of this support:
> https://patchwork.ozlabs.org/patch/800271/
>
> Differential Revision: https://reviews.llvm.org/D50136
llvm-svn: 343103
Functions that have signed return addresses need additional dwarf support:
- After signing the LR, and before authenticating it, the LR register is in a
state the is unusable by a debugger or unwinder
- To account for this a new directive, .cfi_negate_ra_state, is added
- This directive says the signed state of the LR register has now changed,
i.e. unsigned -> signed or signed -> unsigned
- This directive has the same CFA code as the SPARC directive GNU_window_save
(0x2d), adding a macro to account for multiply defined codes
- This patch matches the gcc implementation of this support:
https://patchwork.ozlabs.org/patch/800271/
Differential Revision: https://reviews.llvm.org/D50136
llvm-svn: 343089
Now that we create the label at the point of the directive, we don't
need to set the "current CV location", and then later when we emit the
next instruction, create a label for it and emit it.
DWARF still defers the labels used in .debug_loc until the next
instruction or value, for reasons unknown.
llvm-svn: 340883
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
The standard library functions ::isprint/std::isprint have platform-
and locale-dependent behavior which makes LLVM's output less
predictable. In particular, regression tests my fail depending on the
implementation of these functions.
Implement llvm::isPrint in StringExtras.h with a standard behavior and
replace all uses of ::isprint/std::isprint by a call it llvm::isPrint.
The function is inlined and does not look up language settings so it
should perform better than the standard library's version.
Such a replacement has already been done for isdigit, isalpha, isxdigit
in r314883. gtest does the same in gtest-printers.cc using the following
justification:
// Returns true if c is a printable ASCII character. We test the
// value of c directly instead of calling isprint(), which is buggy on
// Windows Mobile.
inline bool IsPrintableAscii(wchar_t c) {
return 0x20 <= c && c <= 0x7E;
}
Similar issues have also been encountered by Julia:
https://github.com/JuliaLang/julia/issues/7416
I noticed the problem myself when on Windows isprint('\t') started to
evaluate to true (see https://stackoverflow.com/questions/51435249) and
thus caused several unit tests to fail. The result of isprint doesn't
seem to be well-defined even for ASCII characters. Therefore I suggest
to replace isprint by a platform-independent version.
Differential Revision: https://reviews.llvm.org/D49680
llvm-svn: 338034
On darwin, all virtual sections have zerofill type, and having a
.zerofill directive in a non-virtual section is not allowed. Instead of
asserting, show a nicer error.
In order to use the equivalent of .zerofill in a non-virtual section,
the usage of .zero of .space is required.
This patch replaces the assert with an error.
Differential Revision: https://reviews.llvm.org/D48517
llvm-svn: 336127
In some cases, for example when compiling a preprocessed file, the
front-end is not able to provide an MD5 checksum for all files. When
that happens, omit the MD5 checksums from the final DWARF, because
DWARF doesn't have a way to indicate that some but not all files have
a checksum.
When assembling a .s file, and some but not all .file directives
provide an MD5 checksum, issue a warning and don't emit MD5 into the
DWARF.
Fixes PR37623.
Differential Revision: https://reviews.llvm.org/D48135
llvm-svn: 334710
On targets like Arm some relaxations may only be performed when certain
architectural features are available. As functions can be compiled with
differing levels of architectural support we must make a judgement on
whether we can relax based on the MCSubtargetInfo for the function. This
change passes through the MCSubtargetInfo for the function to
fixupNeedsRelaxation so that the decision on whether to relax can be made
per function. In this patch, only the ARM backend makes use of this
information. We must also pass the MCSubtargetInfo to applyFixup because
some fixups skip error checking on the assumption that relaxation has
occurred, to prevent code-generation errors applyFixup must see the same
MCSubtargetInfo as fixupNeedsRelaxation.
Differential Revision: https://reviews.llvm.org/D44928
llvm-svn: 334078
Summary:
Allow extended parsing of variable assembler assignment syntax and modify X86 to permit
VAR = register assignment. As we emit these as .set directives when possible, we inline
such expressions in output assembly.
Fixes PR37425.
Reviewers: rnk, void, echristo
Reviewed By: rnk
Subscribers: nickdesaulniers, llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D47545
llvm-svn: 334022
Object FIle Representation
At codegen time this is emitted into the ELF file a pair of symbol indices and a weight. In assembly it looks like:
.cg_profile a, b, 32
.cg_profile freq, a, 11
.cg_profile freq, b, 20
When writing an ELF file these are put into a SHT_LLVM_CALL_GRAPH_PROFILE (0x6fff4c02) section as (uint32_t, uint32_t, uint64_t) tuples as (from symbol index, to symbol index, weight).
Differential Revision: https://reviews.llvm.org/D44965
llvm-svn: 333823
Teach AsmParser to check with Assembler for when evaluating constant
expressions. This improves the handing of preprocessor expressions
that must be resolved at parse time. This idiom can be found as
assembling-time assertion checks in source-level assemblers. Note that
this relies on the MCStreamer to keep sufficient tabs on Section /
Fragment information which the MCAsmStreamer does not. As a result the
textual output may fail where the equivalent object generation would
pass. This can most easily be resolved by folding the MCAsmStreamer
and MCObjectStreamer together which is planned for in a separate
patch.
Currently, this feature is only enabled for assembly input, keeping IR
compilation consistent between assembly and object generation.
Reviewers: echristo, rnk, probinson, espindola, peter.smith
Reviewed By: peter.smith
Subscribers: eraman, peter.smith, arichardson, jyknight, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D45164
llvm-svn: 331218
Previously the MD5 option of the .file directive provided the checksum
as a quoted hex string; now it's a normal hex number with 0x prefix,
same as the .octa directive accepts.
Differential Revision: https://reviews.llvm.org/D45459
llvm-svn: 329820
Summary:
Some targets do not support extended format of .loc directive and
support only simple format: .loc <FileID> <Line> <Column>. Patch adds
MCAsmInfo flag and option that allows emit .loc directive without
additional flags.
Reviewers: echristo
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45184
llvm-svn: 329089
DWARF v5 specifies that the root file (also given in the DW_AT_name
attribute of the compilation unit DIE) should be emitted explicitly to
the line table's list of files. This makes the line table more
independent of the .debug_info section.
We emit the new syntax only for DWARF v5 and later.
Fixes the bug found by asan. Also XFAIL the new test for Darwin, which
is stuck on DWARF v2, and fix up other tests so they stop failing on
Windows. Last but not least, don't break "clang -g" of an assembler
file that has .file directives in it.
Differential Revision: https://reviews.llvm.org/D44054
llvm-svn: 328805
This reverts commit r328676.
Commit r328676 broke the -no-integrated-as flag necessary to build Linux kernel with Clang:
$ cat t.c
void foo() {}
$ clang -no-integrated-as -c t.c -g
/tmp/t-dcdec5.s: Assembler messages:
/tmp/t-dcdec5.s:8: Error: file number less than one
clang-7.0: error: assembler command failed with exit code 1 (use -v to see invocation)
llvm-svn: 328699
DWARF v5 specifies that the root file (also given in the DW_AT_name
attribute of the compilation unit DIE) should be emitted explicitly to
the line table's list of files. This makes the line table more
independent of the .debug_info section.
Fixes the bug found by asan. Also XFAIL the new test for Darwin, which
is stuck on DWARF v2, and fix up other tests so they stop failing on
Windows. Last but not least, don't break "clang -g" of an assembler
file that has .file directives in it.
Differential Revision: https://reviews.llvm.org/D44054
llvm-svn: 328676
On Hexagon "x = y" is a syntax used in most instructions, and is not
treated as a directive.
Differential Revision: https://reviews.llvm.org/D44256
llvm-svn: 328635
With this we only create an alias for @@@ once we know if it should
use @ or @@. This avoids last minutes renames and hacks to handle MS
names.
This only handles the ELF writer. LTO still has issues with @@@
aliases.
llvm-svn: 327160
This patch starts simplifying the handling of .symver.
For now it just moves the responsibility for creating an alias down to
the streamer. With that the asm streamer can pass a .symver unchanged,
which is nice since gas cannot parse "foo@bar = zed".
In a followup I hope to move the handling down to the writer so that
we don't need special hacks for avoiding breaking names with @@@ on
windows.
llvm-svn: 327101
Fixes the bug found by asan. Also XFAIL the new test for Darwin,
which is stuck on DWARF v2, and fix up other tests so they stop
failing on Windows.
llvm-svn: 326839
DWARF v5 specifies that the root file (also given in the DW_AT_name
attribute of the compilation unit DIE) should be emitted explicitly to
the line table's list of files. This makes the line table more
independent of the .debug_info section.
Differential Revision: https://reviews.llvm.org/D44054
llvm-svn: 326758
In DWARF v5 the Line Number Program Header is extensible, allowing values with
new content types. In this extension a content type is added,
DW_LNCT_LLVM_source, which contains the embedded source code of the file.
Add new optional attribute for !DIFile IR metadata called source which contains
source text. Use this to output the source to the DWARF line table of code
objects. Analogously extend METADATA_FILE in Bitcode and .file directive in ASM
to support optional source.
Teach llvm-dwarfdump and llvm-objdump about the new values. Update the output
format of llvm-dwarfdump to make room for the new attribute on file_names
entries, and support embedded sources for the -source option in llvm-objdump.
Differential Revision: https://reviews.llvm.org/D42765
llvm-svn: 325970
Rely on the assembler to finalize the layout of the DWARF/Itanium
exception-handling LSDA. Rather than calculate the exact size of each
thing in the LSDA, use assembler directives:
To emit the offset to the TTBase label:
.uleb128 .Lttbase0-.Lttbaseref0
.Lttbaseref0:
To emit the size of the call site table:
.uleb128 .Lcst_end0-.Lcst_begin0
.Lcst_begin0:
... call site table entries ...
.Lcst_end0:
To align the type info table:
... action table ...
.balign 4
.long _ZTIi
.long _ZTIl
.Lttbase0:
Using assembler directives simplifies the compiler and allows switching
the encoding of offsets in the call site table from udata4 to uleb128 for
a large code size savings. (This commit does not change the encoding.)
The combination of the uleb128 followed by a balign creates an unfortunate
dependency cycle that the assembler must sometimes resolve either by
padding an LEB or by inserting zero padding before the type table. See
PR35809 or GNU as bug 4029.
Patch by Ryan Prichard!
llvm-svn: 324749
The llvm assembly parser and gas both accept "@notype" in the .type
assembly directive, but we were printing it as "@no_type", which isn't
accepted by either assembler.
Differential revision: https://reviews.llvm.org/D43116
llvm-svn: 324731
Pass MD5 checksums through from IR to assembly/object files.
After this, getting Clang to compute the MD5 should be the last step
to supporting MD5 in the DWARF v5 line table header.
Differential Revision: https://reviews.llvm.org/D41926
llvm-svn: 322391
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$y for
compatibility with Microsoft's Control Flow Guard feature.
The original patch didn't have the lit.local.cfg file that restricts the new
test to x86, thus the new test was failing on the non-x86 bots.
Differential Revision: https://reviews.llvm.org/D40531
The reverts r322008, which was a revert of r322005.
This reverts commit a05b89f9aca70597dc79fe97bc49b50b51f525ba.
llvm-svn: 322136
The new test fails on the Hexagon bot. Reverting while I investigate.
This reverts https://reviews.llvm.org/rL322005
This reverts commit b7e0026b4385180c378edc658ec91a39566f2942.
llvm-svn: 322008
Adds option /guard:cf to clang-cl and -cfguard to cc1 to emit function IDs
of functions that have their address taken into a section named .gfids$y for
compatibility with Microsoft's Control Flow Guard feature.
Differential Revision: https://reviews.llvm.org/D40531
llvm-svn: 322005
Summary:
Initial changes in interfaces of MCAsmStreamer/MCTargetStreamer for
correct debug info emission for Cuda.
1. PTX foramt does not support `.ascii` directives. Added the ability to
nullify it.
2. The initial function label must follow the first debug `.loc`
directive, not be followed by.
3. DWARF sections must be enclosed in braces.
Reviewers: hfinkel, probinson, jlebar, rafael, echristo
Subscribers: sdardis, nemanjai, llvm-commits, aprantl
Differential Revision: https://reviews.llvm.org/D40033
llvm-svn: 321178
LC_BUILD_VERSION is a new load command superseding the previously used
LC_XXX_MIN_VERSION commands. This adds an assembler directive along with
encoding/streaming support.
llvm-svn: 320661
r230670 introduced a step to map EH register numbers to standard
DWARF register numbers. This failed to consider the case when a
user .cfi_* directive uses an integer literal rather than a
register name, to specify a DWARF register number that has no
corresponding LLVM register number (e.g. a special register that
the compiler and assembler have no name for).
Fixes PR34028.
Patch by Roland McGrath
Differential Revision: https://reviews.llvm.org/D36493
llvm-svn: 319586
As of today we only use .cfi_offset to specify the offset of a CSR, but
we never use .cfi_restore when the CSR is restored.
If we want to perform a more advanced type of shrink-wrapping, we need
to use .cfi_restore in order to switch the CFI state between blocks.
This patch only aims at adding support for the directive.
Differential Revision: https://reviews.llvm.org/D36114
llvm-svn: 317199
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
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
This reverts commit 6389e7aa724ea7671d096f4770f016c3d86b0d54.
There is a bug in this implementation where the string value of the
checksum is outputted, instead of the actual hex bytes. Therefore the
checksum is incorrect, and this prevent pdbs from being loaded by visual
studio. Revert this until the checksum is emitted correctly.
llvm-svn: 313431
Summary:
The checksums had already been placed in the IR, this patch allows
MCCodeView to actually write it out to an MCStreamer.
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D37157
llvm-svn: 313374
This adds support for the CFI pseudo-op return_column. This specifies
the frame table column which contains the return address.
Addresses PR33953!
llvm-svn: 309360
This makes sure we get the same redefinition rules regardless of who
is printing (asm parser, codegen) and to what (asm, obj).
This fixes an unintentional regression in r293936.
llvm-svn: 294752
Different architectures can have different meaning for flags in the
SHF_MASKPROC mask, so we should always check what the architecture use
before checking the flag.
NFC for now, but will allow fixing the value of an xmos flag.
llvm-svn: 293484
There are cases of AVX-512 instructions that have two possible encodings. This is the case with instructions that use vector registers with low indexes of 0 - 15 and do not use the zmm registers or the mask k registers.
The EVEX encoding prefix requires 4 bytes whereas the VEX prefix can take only up to 3 bytes. Consequently, using the VEX encoding for these instructions results in a code size reduction of ~2 bytes even though it is compiled with the AVX-512 features enabled.
Reviewers: Craig Topper, Zvi Rackoover, Elena Demikhovsky
Differential Revision: https://reviews.llvm.org/D27901
llvm-svn: 290663
Currently, the error messages we emit for the .org directive when the
expression is not absolute or is out of range do not include the line
number of the directive, so it can be hard to track down the problem if
a file contains many .org directives.
This patch stores the source location in the MCOrgFragment, so that it
can be used for diagnostics emitted during layout.
Since layout is an iterative process, and the errors are detected during
each iteration, it would have been possible for errors to be reported
multiple times. To prevent this, I've made the assembler bail out after
each iteration if any errors have been reported. This will still allow
multiple unrelated errors to be reported in the common case where they
are all detected in the first round of layout.
Differential Revision: https://reviews.llvm.org/D27411
llvm-svn: 289643
The relocations for `DIEEntry::EmitValue` were wrong for Win64
(emitting FK_Data_4 instead of FK_SecRel_4). This corrects that
oversight so that the DWARF data is correct in Win64 COFF files.
Fixes PR15393.
Patch by Jameson Nash <jameson@juliacomputing.com> based on a patch
by David Majnemer.
Differential Revision: https://reviews.llvm.org/D21731
llvm-svn: 289013
Move the cast<MCSymbolELF> inside emitELFSize, so that:
- it's done in one place instead of at each call
- it's more consistent with similar functions like EmitCOFFSafeSEH
- ambiguity between cast<> and dyn_cast<> is avoided (which also
eliminates an unnecessary dyn_cast call)
This also makes it easier to experiment with using ".size" directives on
non-ELF targets.
llvm-svn: 288437
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
MCContext already has many tasks, and separating CodeView out from it is
probably a good idea. The .cv_loc tracking was modelled on the DWARF
tracking which lived directly in MCContext.
Removes the inclusion of MCCodeView.h from MCContext.h, so now there are
only 10 build actions while I hack on CodeView support instead of 265.
llvm-svn: 279847
Assembler directives .dtprelword, .dtpreldword, .tprelword, and
.tpreldword generates relocations R_MIPS_TLS_DTPREL32, R_MIPS_TLS_DTPREL64,
R_MIPS_TLS_TPREL32, and R_MIPS_TLS_TPREL64 respectively.
The main motivation for this patch is to be able to write test cases
for checking correctness of the LLD linker's behaviour.
Differential Revision: https://reviews.llvm.org/D23669
llvm-svn: 279439
Add parseToken and compatriot functions to stitch error checks in
straight linear code. As part of this fix some erronous handling of
directives where the EndOfStatement token either was not checked or
Lexed on termination.
Reviewers: rnk, majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D22312
llvm-svn: 275795
Preserve assembly comments from input in output assembly and flags to
toggle property. This is on by default for inline assembly and off in
llvm-mc.
Parsed comments are emitted immediately before an EOL which generally
places them on the expected line.
Reviewers: rtrieu, dwmw2, rnk, majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D20020
llvm-svn: 275058
The truncateToSize function already has assertion to check the
lower boundary for the number bytes, but it does not check the
upper boundary which could still lead to usage errors.
Differential Revision: http://reviews.llvm.org/D20755
llvm-svn: 271773
Adds the method MCStreamer::EmitBinaryData, which is usually an alias
for EmitBytes. In the MCAsmStreamer case, it is overridden to emit hex
dump output like this:
.byte 0x0e, 0x00, 0x08, 0x10
.byte 0x03, 0x00, 0x00, 0x00
.byte 0x00, 0x00, 0x00, 0x00
.byte 0x00, 0x10, 0x00, 0x00
Also, when verbose asm comments are enabled, this patch prints the dump
output for each comment before its record, like this:
# ArgList (0x1000) {
# TypeLeafKind: LF_ARGLIST (0x1201)
# NumArgs: 0
# Arguments [
# ]
# }
.byte 0x06, 0x00, 0x01, 0x12
.byte 0x00, 0x00, 0x00, 0x00
This should make debugging easier and testing more convenient.
Reviewers: aaboud
Subscribers: majnemer, zturner, amccarth, aaboud, llvm-commits
Differential Revision: http://reviews.llvm.org/D20711
llvm-svn: 271313
This matches the behavior of GNU assembler which supports symbolic
expressions in absolute expressions used in assembly directives.
Differential Revision: http://reviews.llvm.org/D20752
llvm-svn: 271102
This matches the behavior of GNU assembler which supports symbolic
expressions in absolute expressions used in assembly directives.
Differential Revision: http://reviews.llvm.org/D20656
llvm-svn: 271028
This matches the behavior of GNU assembler which supports symbolic
expressions in absolute expressions used in assembly directives.
Differential Revision: http://reviews.llvm.org/D20337
llvm-svn: 270786
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
Removed some unused headers, replaced some headers with forward class declarations.
Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'
Patch by Eugene Kosov <claprix@yandex.ru>
Differential Revision: http://reviews.llvm.org/D19219
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
This patch adds support for the MachO .alt_entry assembly directive, and uses
it for global aliases with non-zero GEP offsets. The alt_entry flag indicates
that a symbol should be layed out immediately after the preceding symbol.
Conceptually it introduces an alternate entry point for a function or data
structure. E.g.:
safe_foo:
// check preconditions for foo
.alt_entry fast_foo
fast_foo:
// body of foo, can assume preconditions.
The .alt_entry flag is also implicitly set on assembly aliases of the form:
a = b + C
where C is a non-zero constant, since these have the same effect as an
alt_entry symbol: they introduce a label that cannot be moved relative to the
preceding one. Setting the alt_entry flag on aliases of this form fixes
http://llvm.org/PR25381.
llvm-svn: 263521
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
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
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
If a target can only emit 8-bits data, we would loop in EmitValueImpl
since it will try to split a 32-bits data in 1 chunk of 32-bits.
No test since all current targets can emit 32bits at a time.
Patch by Alexandru Guduleasa!
llvm-svn: 259399
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
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
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
For historic reasons, the behavior of .align differs between targets.
Fortunately, there are alternatives, .p2align and .balign, which make the
interpretation of the parameter explicit, and which behave consistently across
targets.
This patch teaches MC to use .p2align instead of .align, so that people reading
code for multiple architectures don't have to remember which way each platform
does its .align directive.
Differential Revision: http://reviews.llvm.org/D16549
llvm-svn: 258750
Summary:
Support for R_MIPS_NONE allows us to parse MIPS16's usage of .reloc.
R_MIPS_32 was included to be able to better test the directive.
Targets can add their relocations by overriding MCAsmBackend::getFixupKind().
Subscribers: grosbach, rafael, majnemer, dsanders, llvm-commits
Differential Revision: http://reviews.llvm.org/D13659
llvm-svn: 252888
These MachO file directives are used by linkers and other tools to provide
compatibility information, much like the existing .ios_version_min and
.macosx_version_min.
llvm-svn: 251569
When outgoing function arguments are passed using push instructions, and EH
is enabled, we may need to indicate to the stack unwinder that the stack
pointer was adjusted before the call.
This should fix the exception handling issues in PR24792.
Differential Revision: http://reviews.llvm.org/D13132
llvm-svn: 249522
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
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
Small (really small!) C++ exception handling examples work on 32-bit x86
now.
This change disables the use of .seh_* directives in WinException when
CFI is not in use. It also uses absolute symbol references in the tables
instead of imagerel32 relocations.
Also fixes a cache invalidation bug in MMI personality classification.
llvm-svn: 238575
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
formatted_raw_ostream is a wrapper over another stream to add column and line
number tracking.
It is used only for asm printing.
This patch moves the its creation down to where we know we are printing
assembly. This has the following advantages:
* Simpler lifetime management: std::unique_ptr
* We don't compute column and line number of object files :-)
llvm-svn: 234535
per-function subtarget.
Currently, code-gen passes the default or generic subtarget to the constructors
of MCInstPrinter subclasses (see LLVMTargetMachine::addPassesToEmitFile), which
enables some targets (AArch64, ARM, and X86) to change their instprinter's
behavior based on the subtarget feature bits. Since the backend can now use
different subtargets for each function, instprinter has to be changed to use the
per-function subtarget rather than the default subtarget.
This patch takes the first step towards enabling instprinter to change its
behavior based on the per-function subtarget. It adds a bit "PassSubtarget" to
AsmWriter which tells table-gen to pass a reference to MCSubtargetInfo to the
various print methods table-gen auto-generates.
I will follow up with changes to instprinters of AArch64, ARM, and X86.
llvm-svn: 233411
Now that SmallString is a first-class citizen, most SmallString::str()
calls are not required. This patch removes a whole bunch of them, yet
there are lots more.
There are two use cases where str() is really needed:
1) To use one of StringRef member functions which is not available in
SmallString.
2) To convert to std::string, as StringRef implicitly converts while
SmallString do not. We may wish to change this, but it may introduce
ambiguity.
llvm-svn: 232622
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
GCC does this for non-zero discriminators and since GCC doesn't produce
column info, that was the only place it comes up there. For LLVM, since
we can emit discriminators and/or column info, it makes more sense to
invert the condition and just test for changes in line number.
This should resolve at least some of the GDB 7.5 test suite failures
created by recent Clang changes that increase the location fidelity
(which, since Clang defaults to including column info on Linux by
default created a bunch of cases that confused GDB).
In theory we could do this better/differently by grouping actual source
statements together in a similar manner to the way lexical scopes are
handled but given that GDB isn't really in a position to consume that (&
users are probably somewhat used to different lines being different
'statements') this seems the safest and cheapest change. (I'm concerned
that doing this 'right' would bloat the debugloc data even further -
something Duncan's working hard to address)
llvm-svn: 225011
Clang's static analyzer found several potential cases of undefined
behavior, use of un-initialized values, and potentially null pointer
dereferences in tablegen, Support, MC, and ADT. This cleans them up
with specific assertions on the assumptions of the code.
llvm-svn: 224154
Summary:
".weak" symbols cannot be consumed by ptxas (PR21685). This patch makes the
weak directive in MCAsmPrinter customizable, and disables emitting ".weak"
symbols for NVPTX.
Test Plan: weak-linkage.ll
Reviewers: jholewinski
Reviewed By: jholewinski
Subscribers: majnemer, jholewinski, llvm-commits
Differential Revision: http://reviews.llvm.org/D6455
llvm-svn: 223077
When LLVM emits DWARF call frame information, it currently creates a local,
section-relative symbol in the code section, which is pointed to by a
relocation on the .eh_frame section. However, for C++ we emit some functions in
section groups, and the SysV ABI has some rules to make it easier to remove
these sections
(http://www.sco.com/developers/gabi/latest/ch4.sheader.html#section_group_rules):
A symbol table entry with STB_LOCAL binding that is defined relative to one
of a group's sections, and that is contained in a symbol table section that is
not part of the group, must be discarded if the group members are discarded.
References to this symbol table entry from outside the group are not allowed.
This means that we need to use the function symbol for the relocation, not a
temporary symbol.
There was a comment in the code claiming that the local symbol was used to
avoid creating a relocation, but a relocation must be created anyway as the
code and CFI are in different sections.
llvm-svn: 221150
Summary:
This fixes a long standing issue where we would emit many little .text
sections and only one .pdata and .xdata section. Now we generate one
.pdata / .xdata pair per .text section and associate them correctly.
Fixes PR19667.
Reviewers: majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D5181
llvm-svn: 217176
This removes the duplicate definition of GetXDataSection. This function is
available as a static method and is identical to the previous implementation.
This just cleans up the unnecessary duplication.
llvm-svn: 215289
This changes Win64EHEmitter into a utility WinEH UnwindEmitter that can be
shared across multiple architectures and a target specific bit which is
overridden (Win64::UnwindEmitter). This enables sharing the section selection
code across X86 and the intended use in ARM for emitting unwind information for
Windows on ARM.
llvm-svn: 215050
The frame information stored in this structure is driven by the requirements for
Windows NT unwinding rather than Windows 64 specifically. As a result, this
type can be shared across multiple architectures (ARM, AXP, MIPS, PPC, SH).
Rename this class in preparation for adding support for supporting unwinding
information for Windows on ARM.
Take the opportunity to constify the members as everything except the
ChainedParent is read-only. This required some adjustment to the label
handling.
llvm-svn: 214663
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.
llvm-svn: 212912
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.
llvm-svn: 212881
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
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.
llvm-svn: 211749
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
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.
llvm-svn: 210574
Luke Cheeseman