This reverts commit fd4808887e.
This patch causes gcc to issue a lot of warnings like:
warning: base class ‘class llvm::MCParsedAsmOperand’ should be
explicitly initialized in the copy constructor [-Wextra]
Renamed the option for llvm-cov and changed variable names to use more
inclusive terms. Also changed the binary for the test.
Reviewed By: alanphipps
Differential Revision: https://reviews.llvm.org/D112816
Commit 9f2967bcfe introduced support for
branch coverage including export to the LCOV format.
This commit corrects the LCOV field name for branches from BFH to BRH.
The mistake seems to have slipped in as typo because the correct field
name BRH is used in the comment section at the beginning of the file.
Differential Revision: https://reviews.llvm.org/D108358
This is a mechanical change. This actually also renames the
similarly named methods in the SmallString class, however these
methods don't seem to be used outside of the llvm subproject, so
this doesn't break building of the rest of the monorepo.
When making compilation relocatable, for example in distributed
compilation scenarios, we want to set compilation dir to a relative
value like `.` but this presents a problem when generating reports
because if the file path is relative as well, for example `..`, you
may end up writing files outside of the output directory.
This change introduces a flag that allows overriding the compilation
directory that's stored inside the profile with a different value that
is absolute.
Differential Revision: https://reviews.llvm.org/D100232
Originally landed in: 6400905a61
Reverted in: 668dccc396
Fix branch coverage merging in FunctionCoverageSummary::get() for instantiation
groups.
This change corrects the implementation for the branch coverage summary to do
the same thing for branches that is done for lines and regions. That is,
across function instantiations in an instantiation group, the maximum branch
coverage found in any of those instantiations is returned, with the total
number of branches being the same across instantiations.
Differential Revision: https://reviews.llvm.org/D102193
groups.
This change corrects the implementation for the branch coverage
summary to do the same thing for branches that is done for lines and regions.
That is, across function instantiations in an instantiation group, the maximum
branch coverage found in any of those instantiations is returned, with the
total number of branches being the same across instantiations.
Differential Revision: https://reviews.llvm.org/D102193
CommandLine.h is indirectly included in ~50% of TUs when building
clang, and VirtualFileSystem.h is large.
(Already remarked by jhenderson on D70769.)
No behavior change.
Differential Revision: https://reviews.llvm.org/D100957
In future patches I will be setting the IsText parameter frequently so I will refactor the args to be in the following order. I have removed the FileSize parameter because it is never used.
```
static ErrorOr<std::unique_ptr<MemoryBuffer>>
getFile(const Twine &Filename, bool IsText = false,
bool RequiresNullTerminator = true, bool IsVolatile = false);
static ErrorOr<std::unique_ptr<MemoryBuffer>>
getFileOrSTDIN(const Twine &Filename, bool IsText = false,
bool RequiresNullTerminator = true);
static ErrorOr<std::unique_ptr<MB>>
getFileAux(const Twine &Filename, uint64_t MapSize, uint64_t Offset,
bool IsText, bool RequiresNullTerminator, bool IsVolatile);
static ErrorOr<std::unique_ptr<WritableMemoryBuffer>>
getFile(const Twine &Filename, bool IsVolatile = false);
```
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D99182
Currently, getSourceFile accesses file system to check if two paths are
the same file with a thread lock, which is a huge performance bottleneck
in some cases. Currently, it's accessing file system size(files) * size(files) times.
Thus, cache file status information, which reduces file system access to size(files) times.
When I tested it with two binaries and 16 cpu cores,
it saved over 70% of time.
Binary 1: 56 secs -> 3 secs
Binary 2: 17 hours -> 4 hours
Differential Revision: https://reviews.llvm.org/D97061
This is an enhancement to LLVM Source-Based Code Coverage in clang to track how
many times individual branch-generating conditions are taken (evaluate to TRUE)
and not taken (evaluate to FALSE). Individual conditions may comprise larger
boolean expressions using boolean logical operators. This functionality is
very similar to what is supported by GCOV except that it is very closely
anchored to the ASTs.
Differential Revision: https://reviews.llvm.org/D84467
No longer rely on an external tool to build the llvm component layout.
Instead, leverage the existing `add_llvm_componentlibrary` cmake function and
introduce `add_llvm_component_group` to accurately describe component behavior.
These function store extra properties in the created targets. These properties
are processed once all components are defined to resolve library dependencies
and produce the header expected by llvm-config.
Differential Revision: https://reviews.llvm.org/D90848
When all provided source files are filtered out either due to `--ignore-filename-regex` or not part of binary, don't generate coverage reults for all source files. Because if users want to generate coverage results for all source files, they don't even need to provid selected source files or `--ignore-filename-regex`.
Differential Revision: https://reviews.llvm.org/D89359
This reverts commit c2bd20ef652 and the follow up fix 16605bba6fb.
The tools/llvm-cov/warnings.h continues to fail on Windows platforms even
after the follow up, for example on the llvm-clang-win-x-armv7l builder:
http://lab.llvm.org:8011/#/builders/60/builds/94
When all provided source files are filtered out either due to `--ignore-filename-regex` or not part of binary, don't generate coverage reults for all source files. Because if users want to generate coverage results for all source files, they don't even need to provid selected source files or `--ignore-filename-regex`.
Differential Revision: https://reviews.llvm.org/D89359
Currently, -object takes a comma separated list of objects as an
argument, which prevents it working with path names that contain a
comma. Drop comma-separated support, which requires to set pass the
-object flag multiple times to set multiple objects.
Patch by Andrew Gallagher!
Differential Revision: https://reviews.llvm.org/D87003
The current organization of FileInfo and its referenced utility functions of
(GCOVFile, GCOVFunction, GCOVBlock) is messy. Some members of FileInfo are just
copied from GCOVFile. FileInfo::print (.gcov output and --intermediate output)
is interleaved with branch statistics and computation of line execution counts.
--intermediate has to do redundant .gcov output to gather branch statistics.
This patch deletes lots of code and introduces a clearer work flow:
```
fn collectFunction
for each block b
for each line lineNum
let line be LineInfo of the file on lineNum
line.exists = 1
increment function's lines & linesExec if necessary
increment line.count
line.blocks.push_back(&b)
fn collectSourceLine
compute cycle counts
count = incoming_counts + cycle_counts
if line.exists
++summary->lines
if line.count
++summary->linesExec
fn collectSource
for each line
call collectSourceLine
fn main
for each function
call collectFunction
print function summary
for each source file
call collectSource
print file summary
annotate the source file with line execution counts
if -i
print intermediate file
```
The output order of functions and files now follows the original order in
.gcno files.
.gcno, .gcda and source files can be modified while we are reading them. If the
concurrent modification of a file being read nullifies the NUL terminator
assumption, llvm-cov can trip over an assertion failure in MemoryBuffer::init.
This is not so rare - the source files can be in an editor and .gcda can be
written by an running process (if the process forks, when .gcda gets written is
probably more unpredictable).
There is no accompanying test because an assertion failure requires data
races with some involved setting.
If .gcda is corrupted, gcov continues to produce a .gcov and just
assumes execution counts are zeros. This is reasonable, because the
program can corrupt its .gcda output. The code path should be similar to
the code path without .gcda.
Between gcov 4.9~8, `gcov -i $file` prints coverage information to
$file.gcov in an intermediate text format (single file, instead of
$source.gcov for each source file).
lcov newer than 2019-05-24 detects -i support and uses it to increase
processing speed. gcov 9 (GCC r265587) removed --intermediate-format
and -i was changed to mean --json-format. However, we consider this
format still useful and support it. geninfo (part of lcov) supports this
format even if we announce that we are compatible with gcov 9.0.0
gcov by default prints to a .gcov file. With --stdout, stdout is used.
Some summary information is omitted. There is no separator for multiple
source files.
GCDAProfiling.c unnecessarily writes function names to .gcda files.
GCC 4.2 gcc/libgcov.c (now renamed to libgcc/libgcov*) did not write function
names. gcov-7 (compatible) crashes on .gcda produced by libclang_rt.profile
rL176173 realized the problem and introduced a mode to remove function
names.
llvm-cov code apparently takes GCDAProfiling.c output format as truth
and tries to decode function names. Additionally, llvm-cov tries to
decode tags in certain order which does not match libgcov emitted .gcda
files.
This patch fixes the .gcda decoder and makes it work with GCC 8 and 9
(10 is compatible with 9). Note, line statistics are broken and not
fixed by this patch.
Add test/tools/llvm-cov/gcov-{4.7,8,9}.c to test compatibility.
As reported here: https://reviews.llvm.org/D75153#1987272
Before, each instance of llvm-cov was creating one thread per hardware core, which wasn't needed probably because the number of inputs were small. This was probably causing a thread rlimit issue on large core count systems.
After this patch, the previous behavior is restored (to what was before rG8404aeb5):
If --num-threads is not specified, we create one thread per input, up to num.cores.
When specified, --num-threads indicates any number of threads, with no upper limit.
Differential Revision: https://reviews.llvm.org/D78408
I got a report recently that a user was having trouble interpreting the
meaning of the error message. Hopefully this is more readable; produces
something like the following:
error: No such file or directory: Could not read profile data!
Differential Revision: https://reviews.llvm.org/D76796
The goal of this patch is to maximize CPU utilization on multi-socket or high core count systems, so that parallel computations such as LLD/ThinLTO can use all hardware threads in the system. Before this patch, on Windows, a maximum of 64 hardware threads could be used at most, in some cases dispatched only on one CPU socket.
== Background ==
Windows doesn't have a flat cpu_set_t like Linux. Instead, it projects hardware CPUs (or NUMA nodes) to applications through a concept of "processor groups". A "processor" is the smallest unit of execution on a CPU, that is, an hyper-thread if SMT is active; a core otherwise. There's a limit of 32-bit processors on older 32-bit versions of Windows, which later was raised to 64-processors with 64-bit versions of Windows. This limit comes from the affinity mask, which historically is represented by the sizeof(void*). Consequently, the concept of "processor groups" was introduced for dealing with systems with more than 64 hyper-threads.
By default, the Windows OS assigns only one "processor group" to each starting application, in a round-robin manner. If the application wants to use more processors, it needs to programmatically enable it, by assigning threads to other "processor groups". This also means that affinity cannot cross "processor group" boundaries; one can only specify a "preferred" group on start-up, but the application is free to allocate more groups if it wants to.
This creates a peculiar situation, where newer CPUs like the AMD EPYC 7702P (64-cores, 128-hyperthreads) are projected by the OS as two (2) "processor groups". This means that by default, an application can only use half of the cores. This situation could only get worse in the years to come, as dies with more cores will appear on the market.
== The problem ==
The heavyweight_hardware_concurrency() API was introduced so that only *one hardware thread per core* was used. Once that API returns, that original intention is lost, only the number of threads is retained. Consider a situation, on Windows, where the system has 2 CPU sockets, 18 cores each, each core having 2 hyper-threads, for a total of 72 hyper-threads. Both heavyweight_hardware_concurrency() and hardware_concurrency() currently return 36, because on Windows they are simply wrappers over std:🧵:hardware_concurrency() -- which can only return processors from the current "processor group".
== The changes in this patch ==
To solve this situation, we capture (and retain) the initial intention until the point of usage, through a new ThreadPoolStrategy class. The number of threads to use is deferred as late as possible, until the moment where the std::threads are created (ThreadPool in the case of ThinLTO).
When using hardware_concurrency(), setting ThreadCount to 0 now means to use all the possible hardware CPU (SMT) threads. Providing a ThreadCount above to the maximum number of threads will have no effect, the maximum will be used instead.
The heavyweight_hardware_concurrency() is similar to hardware_concurrency(), except that only one thread per hardware *core* will be used.
When LLVM_ENABLE_THREADS is OFF, the threading APIs will always return 1, to ensure any caller loops will be exercised at least once.
Differential Revision: https://reviews.llvm.org/D71775
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
Kazu Hirata