I am experimenting with a single split dwarf (.dwo sections in .o files).
I want to make linker to ignore .dwo sections in .o, for that I am trying to add
SHF_EXCLUDE flag ("E") for them in my asm sample.
I found that currently, it is impossible to add any flag for debug sections using llvm-mc.
That happens because we have a set of predefined unique sections created early with default flags:
https://github.com/llvm-mirror/llvm/blob/master/lib/MC/MCObjectFileInfo.cpp#L391
This patch allows a user to add any flags he wants.
I had to edit TargetLoweringObjectFileImpl.cpp to set MetaData type for debug sections.
Their kind was Data by default (so they were allocatable) and so after changes introduced by
this patch the SHF_ALLOC flag was applied for them, what does not make sense for debug sections.
One of OrcJITTests tests failed because of that.
Differential revision: https://reviews.llvm.org/D51361
llvm-svn: 340904
The format is the same as in ELF: a sequence of ULEB128-encoded
symbol indexes.
Differential Revision: https://reviews.llvm.org/D51047
llvm-svn: 340499
On Darwin we pin the DWARF line tables to version 2. Stop doing so for
DWARF v5 and later.
Differential revision: https://reviews.llvm.org/D49381
llvm-svn: 339288
This matches our behaviour for regular (i.e. relocated) references to
private symbols and therefore avoids needing to unnecessarily write
address-significant .L symbols to the object file's symbol table,
which can interfere with stack traces.
Fixes check-cfi after r339050.
llvm-svn: 339066
There are a bunch of edge cases and inconsistencies in how we're emitting sections
cause this warning to fire and it needs more work.
This reverts commit r335558.
llvm-svn: 338968
AT_NAME was being emitted before the directory paths were remapped. This
ensures that all paths are remapped before anything is emitted.
An additional test case has been added.
Note that this only works if the replacement string is an absolute path.
If not, then AT_decl_file believes the new path is a relative path, and
joins that path with the compilation directory. I do not know of a good
way to resolve this.
Patch by: Siddhartha Bagaria (starsid)
Differential revision: https://reviews.llvm.org/D49169
llvm-svn: 336793
debug compilation dir when compiling assembly files with -g.
Part of PR38050.
Patch by Siddhartha Bagaria!
Differential Revision: https://reviews.llvm.org/D48988
llvm-svn: 336680
section flags in the ELF assembler. This matches the defaults
given in the rest of MC.
Fixes PR37997 where we couldn't assemble our own assembly output
without warnings.
llvm-svn: 336072
=== Generating the CG Profile ===
The CGProfile module pass simply gets the block profile count for each BB and scans for call instructions. For each call instruction it adds an edge from the current function to the called function with the current BB block profile count as the weight.
After scanning all the functions, it generates an appending module flag containing the data. The format looks like:
```
!llvm.module.flags = !{!0}
!0 = !{i32 5, !"CG Profile", !1}
!1 = !{!2, !3, !4} ; List of edges
!2 = !{void ()* @a, void ()* @b, i64 32} ; Edge from a to b with a weight of 32
!3 = !{void (i1)* @freq, void ()* @a, i64 11}
!4 = !{void (i1)* @freq, void ()* @b, i64 20}
```
Differential Revision: https://reviews.llvm.org/D48105
llvm-svn: 335794
DWARF v5 explicitly represents file #0 in the line table. Prior
versions did not, so ".loc 0" is still an error in those cases.
Differential Revision: https://reviews.llvm.org/D48452
llvm-svn: 335350
This is the first pass in the main pipeline to use the legacy PM's
ability to run function analyses "on demand". Unfortunately, it turns
out there are bugs in that somewhat-hacky approach. At the very least,
it leaks memory and doesn't support -debug-pass=Structure. Unclear if
there are larger issues or not, but this should get the sanitizer bots
back to green by fixing the memory leaks.
llvm-svn: 335320
This patch adds support for generating a call graph profile from Branch Frequency Info.
The CGProfile module pass simply gets the block profile count for each BB and scans for call instructions. For each call instruction it adds an edge from the current function to the called function with the current BB block profile count as the weight.
After scanning all the functions, it generates an appending module flag containing the data. The format looks like:
!llvm.module.flags = !{!0}
!0 = !{i32 5, !"CG Profile", !1}
!1 = !{!2, !3, !4} ; List of edges
!2 = !{void ()* @a, void ()* @b, i64 32} ; Edge from a to b with a weight of 32
!3 = !{void (i1)* @freq, void ()* @a, i64 11}
!4 = !{void (i1)* @freq, void ()* @b, i64 20}
Differential Revision: https://reviews.llvm.org/D48105
llvm-svn: 335306
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
Summary:
This is similar to D46319 (ARM). x86-64 psABI p40 gives an example:
leaq _GLOBAL_OFFSET_TABLE(%rip), %r15 # GOTPC32 reloc
GNU as creates R_X86_64_GOTPC32. However, MC currently emits R_X86_64_PC32.
Reviewers: javed.absar, echristo
Subscribers: kristof.beyls, llvm-commits, peter.smith, grimar
Differential Revision: https://reviews.llvm.org/D47507
llvm-svn: 334515
Don't provide the assembler source as the "root file" unless the user
asked to have debug info for the assembler source (with -g).
If the source doesn't provide an explicit ".file 0" then (a) use the
compilation directory as directory #0, and (b) use the file #1 info
for file #0 also.
Differential Revision: https://reviews.llvm.org/D48055
llvm-svn: 334512
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
In order to set breakpoints on labels and list source code around
labels, we need collect debug information for labels, i.e., label
name, the function label belong, line number in the file, and the
address label located. In order to keep these information in LLVM
IR and to allow backend to generate debug information correctly.
We create a new kind of metadata for labels, DILabel. The format
of DILabel is
!DILabel(scope: !1, name: "foo", file: !2, line: 3)
We hope to keep debug information as much as possible even the
code is optimized. So, we create a new kind of intrinsic for label
metadata to avoid the metadata is eliminated with basic block.
The intrinsic will keep existing if we keep it from optimized out.
The format of the intrinsic is
llvm.dbg.label(metadata !1)
It has only one argument, that is the DILabel metadata. The
intrinsic will follow the label immediately. Backend could get the
label metadata through the intrinsic's parameter.
We also create DIBuilder API for labels to be used by Frontend.
Frontend could use createLabel() to allocate DILabel objects, and use
insertLabel() to insert llvm.dbg.label intrinsic in LLVM IR.
Differential Revision: https://reviews.llvm.org/D45024
Patch by Hsiangkai Wang.
llvm-svn: 331841
Summary:
Only allow a single unique .symver alias per symbol. This matches the
behavior of gas. I noticed that we ignored multiple mismatched symver
directives looking at https://reviews.llvm.org/D45798
Reviewers: pcc, tejohnson, espindola
Reviewed By: pcc
Subscribers: emaste, arichardson, llvm-commits, kcc
Differential Revision: https://reviews.llvm.org/D45845
llvm-svn: 331078
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
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
offsets for code models other than small/medium. For JIT application,
memory layout is less controlled and can result in truncations
otherwise.
Patch based on one by Olexa Bilaniuk!
llvm-svn: 328400
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
Extension to D12776, handle modulo by zero in the same way we handle divide by zero.
Differential Revision: https://reviews.llvm.org/D43631
llvm-svn: 325810
For instructions like call foo and jmp foo patch changes
relocation produced from R_X86_64_PC32 to R_X86_64_PLT32.
Relocation can be used as a marker for 32-bit PC-relative branches.
Linker will reduce PLT32 relocation to PC32 if function is defined locally.
Differential revision: https://reviews.llvm.org/D43383
llvm-svn: 325569
George Rimar