Currently both True/False counts were folded. It lost the information,
"It is True or False before folding." It prevented recalling branch
counts in merging template instantiations.
In `llvm-cov`, a folded branch is shown as:
- `[True: n, Folded]`
- `[Folded, False n]`
In the case If `n` is zero, a branch is reported as "uncovered". This is
distinguished from "folded" branch. When folded branches are merged,
`Folded` may be dissolved.
In the coverage map, either `Counter` is `Zero`. Currently both were
`Zero`.
Since "partial fold" has been introduced, either case in `switch` is
omitted as `Folded`.
Each `case:` in `switch` is reported as `[True: n, Folded]`, since
`False` count doesn't show meaningful value.
When `switch` doesn't have `default:`, `switch (Cond)` is reported as
`[Folded, False: n]`, since `True` count was just the sum of `case`(s).
`switch` with `default` can be considered as "the statement that doesn't
have any `False`(s)".
With `system-headers-coverage=false`, functions defined in system
headers were not instrumented but corresponding covmaps were emitted. It
caused wasting covmap and profraw.
This change improves:
- Reduce object size (due to reduced covmap)
- Reduce size of profraw (uninstrumented system headers occupied
counters)
- Smarter view of coverage report. Stubs of uninstrumented system
headers will be no longer seen.
By storing possible test vectors instead of combinations of conditions,
the restriction is dramatically relaxed.
This introduces two options to `cc1`:
* `-fmcdc-max-conditions=32767`
* `-fmcdc-max-test-vectors=2147483646`
This change makes coverage mapping, profraw, and profdata incompatible
with Clang-18.
- Bitmap semantics changed. It is incompatible with previous format.
- `BitmapIdx` in `Decision` points to the end of the bitmap.
- Bitmap is packed per function.
- `llvm-cov` can understand `profdata` generated by `llvm-profdata-18`.
RFC:
https://discourse.llvm.org/t/rfc-coverage-new-algorithm-and-file-format-for-mc-dc/76798
--
Change(s) since llvmorg-19-init-14288-g7ead2d8c7e91
- Update compiler-rt/test/profile/ContinuousSyncMode/image-with-mcdc.c
This broke the lit tests on Mac:
https://green.lab.llvm.org/job/llvm.org/job/clang-stage1-RA/1096/
> By storing possible test vectors instead of combinations of conditions,
> the restriction is dramatically relaxed.
>
> This introduces two options to `cc1`:
>
> * `-fmcdc-max-conditions=32767`
> * `-fmcdc-max-test-vectors=2147483646`
>
> This change makes coverage mapping, profraw, and profdata incompatible
> with Clang-18.
>
> - Bitmap semantics changed. It is incompatible with previous format.
> - `BitmapIdx` in `Decision` points to the end of the bitmap.
> - Bitmap is packed per function.
> - `llvm-cov` can understand `profdata` generated by `llvm-profdata-18`.
>
> RFC:
> https://discourse.llvm.org/t/rfc-coverage-new-algorithm-and-file-format-for-mc-dc/76798
This reverts commit 7ead2d8c7e9114b3f23666209a1654939987cb30.
By storing possible test vectors instead of combinations of conditions,
the restriction is dramatically relaxed.
This introduces two options to `cc1`:
* `-fmcdc-max-conditions=32767`
* `-fmcdc-max-test-vectors=2147483646`
This change makes coverage mapping, profraw, and profdata incompatible
with Clang-18.
- Bitmap semantics changed. It is incompatible with previous format.
- `BitmapIdx` in `Decision` points to the end of the bitmap.
- Bitmap is packed per function.
- `llvm-cov` can understand `profdata` generated by `llvm-profdata-18`.
RFC:
https://discourse.llvm.org/t/rfc-coverage-new-algorithm-and-file-format-for-mc-dc/76798
Introduced in #78041, originally reported as #79957 and fixed partially
in #80050.
`OpaqueValueExpr` used with `TemplateArgument::StructuralValue` has no
corresponding source expression.
A test case with subobject-referring NTTP added.
The problematic program is as follows:
```shell
#define pre_a 0
#define PRE(x) pre_##x
void f(void) {
PRE(a) && 0;
}
int main(void) { return 0; }
```
in which after token concatenation (`##`), there's another nested macro
`pre_a`.
Currently only the outer expansion region will be produced. ([compiler
explorer
link](https://godbolt.org/#g:!((g:!((g:!((h:codeEditor,i:(filename:'1',fontScale:14,fontUsePx:'0',j:1,lang:___c,selection:(endColumn:29,endLineNumber:8,positionColumn:29,positionLineNumber:8,selectionStartColumn:29,selectionStartLineNumber:8,startColumn:29,startLineNumber:8),source:'%23define+pre_a+0%0A%23define+PRE(x)+pre_%23%23x%0A%0Avoid+f(void)+%7B%0A++++PRE(a)+%26%26+0%3B%0A%7D%0A%0Aint+main(void)+%7B+return+0%3B+%7D'),l:'5',n:'0',o:'C+source+%231',t:'0')),k:51.69491525423727,l:'4',n:'0',o:'',s:0,t:'0'),(g:!((g:!((h:compiler,i:(compiler:cclang_assertions_trunk,filters:(b:'0',binary:'1',binaryObject:'1',commentOnly:'0',debugCalls:'1',demangle:'0',directives:'0',execute:'0',intel:'0',libraryCode:'1',trim:'1',verboseDemangling:'0'),flagsViewOpen:'1',fontScale:14,fontUsePx:'0',j:2,lang:___c,libs:!(),options:'-fprofile-instr-generate+-fcoverage-mapping+-fcoverage-mcdc+-Xclang+-dump-coverage-mapping+',overrides:!(),selection:(endColumn:1,endLineNumber:1,positionColumn:1,positionLineNumber:1,selectionStartColumn:1,selectionStartLineNumber:1,startColumn:1,startLineNumber:1),source:1),l:'5',n:'0',o:'+x86-64+clang+(assertions+trunk)+(Editor+%231)',t:'0')),k:34.5741843594503,l:'4',m:28.903654485049834,n:'0',o:'',s:0,t:'0'),(g:!((h:output,i:(compilerName:'x86-64+clang+(trunk)',editorid:1,fontScale:14,fontUsePx:'0',j:2,wrap:'1'),l:'5',n:'0',o:'Output+of+x86-64+clang+(assertions+trunk)+(Compiler+%232)',t:'0')),header:(),l:'4',m:71.09634551495017,n:'0',o:'',s:0,t:'0')),k:48.30508474576271,l:'3',n:'0',o:'',t:'0')),l:'2',m:100,n:'0',o:'',t:'0')),version:4))
```text
f:
File 0, 4:14 -> 6:2 = #0
Decision,File 0, 5:5 -> 5:16 = M:0, C:2
Expansion,File 0, 5:5 -> 5:8 = #0 (Expanded file = 1)
File 0, 5:15 -> 5:16 = #1
Branch,File 0, 5:15 -> 5:16 = 0, 0 [2,0,0]
File 1, 2:16 -> 2:23 = #0
File 2, 1:15 -> 1:16 = #0
File 2, 1:15 -> 1:16 = #0
Branch,File 2, 1:15 -> 1:16 = 0, 0 [1,2,0]
```
The inner expansion region isn't produced because:
1. In the range-based for loop quoted below, each sloc is processed and
possibly emit a corresponding expansion region.
2. For our sloc in question, its direct parent returned by
`getIncludeOrExpansionLoc()` is a `<scratch space>`, because that's how
`##` is processed.
88b6186af3/clang/lib/CodeGen/CoverageMappingGen.cpp (L518-L520)
3. This `<scratch space>` cannot be found in the FileID mapping so
`ParentFileID` will be assigned an `std::nullopt`
88b6186af3/clang/lib/CodeGen/CoverageMappingGen.cpp (L521-L526)
4. As a result this iteration of for loop finishes early and no
expansion region is added for the sloc.
This problem gets worse with MC/DC: as the example shows, there's a
branch from File 2 but File 2 itself is missing. This will trigger
assertion failures.
The fix is more or less a workaround and takes a similar approach as
#89573.
~~Depends on #89573.~~ This includes #89573. Kudos to @chapuni!
This and #89573 together fix#87000: I tested locally, both the reduced
program and my original use case (fwiw, Linux kernel) can run
successfully.
---------
Co-authored-by: NAKAMURA Takumi <geek4civic@gmail.com>
`emitSourceRegions()` has bugs to emit malformed MC/DC coverage
mappings. They were detected in `llvm-cov` as the crash.
Detect inconsistencies earlier in `clang` with assertions.
* mcdc-scratch-space.c covers #87000.
- Introduce `LeafExprSet`,
- Suppress traversing LAnd and LOr expr under system headers.
- Handle LAnd and LOr as instrumented leaves to override
`!isInstrumentedCondition(C)`.
- Replace Loc with FileLoc if it is expanded with system headers.
Fixes#78920
`ArrayInitLoopExpr` AST node has two occurences of its as-written
initializing expression in its subexpressions through a non-unique
`OpaqueValueExpr`. It causes double-visiting of the initializing
expression if not handled explicitly, as discussed in #85837.
This avoids visiting `co_await` or `co_yield` operand 5 times (it is
repeated under transformed awaiter subexpression, and under
`await_ready`, `await_suspend`, and `await_resume` generated call
subexpressions).
This patch inserts 1-byte counters instead of an 8-byte counters into
llvm profiles for source-based code coverage. The origial idea was
proposed as block-cov for PGO, and this patch repurposes that idea for
coverage: https://groups.google.com/g/llvm-dev/c/r03Z6JoN7d4
The current 8-byte counters mechanism add counters to minimal regions,
and infer the counters in the remaining regions via adding or
subtracting counters. For example, it infers the counter in the if.else
region by subtracting the counters between if.entry and if.then regions
in an if statement. Whenever there is a control-flow merge, it adds the
counters from all the incoming regions. However, we are not going to be
able to infer counters by subtracting two execution counts when using
single-byte counters. Therefore, this patch conservatively inserts
additional counters for the cases where we need to add or subtract
counters.
RFC:
https://discourse.llvm.org/t/rfc-single-byte-counters-for-source-based-code-coverage/75685
Fix an issue that produces a wrong coverage mapping when using binary
conditional operators as show in the example below.
Before this patch:
1| 1|int binary_cond(int x) {
2| 1| x = x ?: 4;
3| 1| int y = 0;
4| 0| return x; <-- Not covered
5| 1|}
After this patch:
1| 1|int binary_cond(int x) {
2| 1| x = x ?: 4;
3| 1| int y = 0;
4| 1| return x; <-- Covered
5| 1|}
`if constexpr` and `if consteval` conditional statements code coverage
should behave more like a preprocesor `#if`-s than normal
ConditionalStmt. This PR should fix that.
---------
Co-authored-by: cor3ntin <corentinjabot@gmail.com>
Clean-up of the algorithm that assigns MC/DC True/False control-flow
condition IDs when constructing an MC/DC decision region. This patch
creates a common API for setting/getting the condition IDs, making the
binary logical operator visitor functions much cleaner.
This patch also fixes issue
https://github.com/llvm/llvm-project/issues/77873 in which a record's
control flow map can be malformed due to an incorrect calculation of the
True/False condition IDs.
During the ISO C++ Committee meeting plenary session the C++23 Standard
has been voted as technical complete.
This updates the reference to c++2b to c++23 and updates the __cplusplus
macro.
Drive-by fixes c++1z -> c++17 and c++2a -> c++20 when seen.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D149553
This patch prefixes omp outlined helpers and reduction funcs
with the original function's name.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D140722
This patch attempts to prefix omp outlined helpers and reduction funcs
with the original function's name.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D140722
marked as 'not executed'.
In the current coverage mapping implementation, we terminate the current region
and start a zero region when we hit a nonreturn function. However, for logical OR,
the second operand is not executed if the first operand evaluates to true. If the
nonreturn function is called in the right side of logical OR and the left side of
logical OR is TRUE, we should not start a zero `GapRegionCounter`. This will also
apply to `VisitAbstractConditionalOperator`.
Fixes https://github.com/llvm/llvm-project/issues/59030
Reviewed By: zequanwu
Differential Revision: https://reviews.llvm.org/D144371
Since we decided to remove the support for `-fcoroutines-ts` in
clang/llvm17 and the clang16/llvm16 is branched. So we're going to
remove the `-fcoroutines-ts` option.
Originally, the following commit removed mapping coverage regions for system headers:
93205af066
It might be viable and useful to collect coverage from system headers in some systems.
This patch adds --system-headers-coverage option (disabled by default) to enable
collecting coverage from system headers.
Differential Revision: https://reviews.llvm.org/D143304
This is a reland of https://reviews.llvm.org/D122336.
Original patch caused a problem in collecting coverage in
Fuchsia because it was returning early without putting unused
function names into __llvm_prf_names section. This patch
fixes that issue.
The original commit message is as the following:
CoverageMappingModuleGen generates a coverage mapping record
even for unused functions with internal linkage, e.g.
static int foo() { return 100; }
Clang frontend eliminates such functions, but InstrProfiling pass
still emits runtime hook since there is a coverage record.
Fuchsia uses runtime counter relocation, and pulling in profile
runtime for unused functions causes a linker error:
undefined hidden symbol: __llvm_profile_counter_bias.
Since https://reviews.llvm.org/D98061, we do not hook profile
runtime for the binaries that none of its translation units
have been instrumented in Fuchsia. This patch extends that for
the instrumented binaries that consist of only unused functions.
Reviewed By: phosek
Differential Revision: https://reviews.llvm.org/D122336
Clang crashes when encountering an `if consteval` statement.
This is the minimum fix not to crash.
The fix is consistent with the current behavior of if constexpr,
which does generate coverage data for the discarded branches.
This is of course not correct and a better solution is
needed for both if constexpr and if consteval.
See https://github.com/llvm/llvm-project/issues/54419.
Fixes#57377
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D132723
I noticed these two tests emit a warning about a missing
unhandled_exception. That's irrelevant to what is being tested, but
is unnecessary noise.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D125535
CoverageMappingModuleGen generates a coverage mapping record
even for unused functions with internal linkage, e.g.
static int foo() { return 100; }
Clang frontend eliminates such functions, but InstrProfiling pass
still pulls in profile runtime since there is a coverage record.
Fuchsia uses runtime counter relocation, and pulling in profile
runtime for unused functions causes a linker error:
undefined hidden symbol: __llvm_profile_counter_bias.
Since 389dc94d4be7, we do not hook profile runtime for the binaries
that none of its translation units have been instrumented in Fuchsia.
This patch extends that for the instrumented binaries that
consist of only unused functions.
Differential Revision: https://reviews.llvm.org/D122336
A significant number of our tests in C accidentally use functions
without prototypes. This patch converts the function signatures to have
a prototype for the situations where the test is not specific to K&R C
declarations. e.g.,
void func();
becomes
void func(void);
This is the fifth batch of tests being updated (there are a significant
number of other tests left to be updated).
Note, the behavior of -ast-print is broken. It prints functions with a
prototype (void) as if they have no prototype () in C. Some tests need
to disable strict prototype checking when recompiling the results of an
-ast-print invocation.
Now in libcxx and clang, all the coroutine components are defined in
std::experimental namespace.
And now the coroutine TS is merged into C++20. So in the working draft
like N4892, we could find the coroutine components is defined in std
namespace instead of std::experimental namespace.
And the coroutine support in clang seems to be relatively stable. So I
think it may be suitable to move the coroutine component into the
experiment namespace now.
This patch would make clang lookup coroutine_traits in std namespace
first. For the compatibility consideration, clang would lookup in
std::experimental namespace if it can't find definitions in std
namespace. So the existing codes wouldn't be break after update
compiler.
And in case the compiler found std::coroutine_traits and
std::experimental::coroutine_traits at the same time, it would emit an
error for it.
The support for looking up std::experimental::coroutine_traits would be
removed in Clang16.
Reviewed By: lxfind, Quuxplusone
Differential Revision: https://reviews.llvm.org/D108696
This reverts commit 2fbd254aa46b, which broke the libc++ CI. I'm reverting
to get things stable again until we've figured out a way forward.
Differential Revision: https://reviews.llvm.org/D108696
Summary: Now in libcxx and clang, all the coroutine components are
defined in std::experimental namespace.
And now the coroutine TS is merged into C++20. So in the working draft
like N4892, we could find the coroutine components is defined in std
namespace instead of std::experimental namespace.
And the coroutine support in clang seems to be relatively stable. So I
think it may be suitable to move the coroutine component into the
experiment namespace now.
But move the coroutine component into the std namespace may be an break
change. So I planned to split this change into two patch. One in clang
and other in libcxx.
This patch would make clang lookup coroutine_traits in std namespace
first. For the compatibility consideration, clang would lookup in
std::experimental namespace if it can't find definitions in std
namespace and emit a warning in this case. So the existing codes
wouldn't be break after update compiler.
Test Plan: check-clang, check-libcxx
Reviewed By: lxfind
Differential Revision: https://reviews.llvm.org/D108696
