Add support for the GNU C style __attribute__((error(""))) and
__attribute__((warning(""))). These attributes are meant to be put on
declarations of functions whom should not be called.
They are frequently used to provide compile time diagnostics similar to
_Static_assert, but which may rely on non-ICE conditions (ie. relying on
compiler optimizations). This is also similar to diagnose_if function
attribute, but can diagnose after optimizations have been run.
While users may instead simply call undefined functions in such cases to
get a linkage failure from the linker, these provide a much more
ergonomic and actionable diagnostic to users and do so at compile time
rather than at link time. Users instead may be able use inline asm .err
directives.
These are used throughout the Linux kernel in its implementation of
BUILD_BUG and BUILD_BUG_ON macros. These macros generally cannot be
converted to use _Static_assert because many of the parameters are not
ICEs. The Linux kernel still needs to be modified to make use of these
when building with Clang; I have a patch that does so I will send once
this feature is landed.
To do so, we create a new IR level Function attribute, "dontcall" (both
error and warning boil down to one IR Fn Attr). Then, similar to calls
to inline asm, we attach a !srcloc Metadata node to call sites of such
attributed callees.
The backend diagnoses these during instruction selection, while we still
know that a call is a call (vs say a JMP that's a tail call) in an arch
agnostic manner.
The frontend then reconstructs the SourceLocation from that Metadata,
and determines whether to emit an error or warning based on the callee's
attribute.
Link: https://bugs.llvm.org/show_bug.cgi?id=16428
Link: https://github.com/ClangBuiltLinux/linux/issues/1173
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D106030
Some Clang diagnostics could only report OpenCL C version. Because
C++ for OpenCL can be used as an alternative to OpenCL C, the text
for diagnostics should reflect that.
Desrciptions modified for these diagnostics:
`err_opencl_unknown_type_specifier`
`warn_option_invalid_ocl_version`
`err_attribute_requires_opencl_version`
`warn_opencl_attr_deprecated_ignored`
`ext_opencl_ext_vector_type_rgba_selector`
Differential Revision: https://reviews.llvm.org/D107648
Clang diagnostics refer to identifier names in quotes.
This patch makes inline remarks conform to the convention.
New behavior:
```
% clang -O2 -Rpass=inline -Rpass-missed=inline -S a.c
a.c:4:25: remark: 'foo' inlined into 'bar' with (cost=-30, threshold=337) at callsite bar:0:25; [-Rpass=inline]
int bar(int a) { return foo(a); }
^
```
Reviewed By: hoy
Differential Revision: https://reviews.llvm.org/D107791
Clang diagnostics should not start with a capital letter or use
trailing punctuation (https://clang.llvm.org/docs/InternalsManual.html#the-format-string),
but quite a few driver diagnostics were not following this advice. This
corrects the grammar and punctuation to improve consistency, but does
not change the circumstances under which the diagnostics are produced.
Support -Wno-frame-larger-than (with no =) and make it properly
interoperate with -Wframe-larger-than. Reject -Wframe-larger-than with
no argument.
We continue to support Clang's old spelling, -Wframe-larger-than=, for
compatibility with existing users of that facility.
In passing, stop the driver from accepting and ignoring
-fwarn-stack-size and make it a cc1-only flag as intended.
-Wframe-larger-than= is an interesting warning; we can't know the frame
size until PrologueEpilogueInsertion (PEI); very late in the compilation
pipeline.
-Wframe-larger-than= was propagated through CC1 as an -mllvm flag, then
was a cl::opt in LLVM's PEI pass; this meant it was dropped during LTO
and needed to be re-specified via -plugin-opt.
Instead, make it part of the IR proper as a module level attribute,
similar to D103048. Introduce -fwarn-stack-size CC1 option.
Reviewed By: rsmith, qcolombet
Differential Revision: https://reviews.llvm.org/D103928
This patch removes duplicates also encountered in the output of clang-scan-deps when one same header file is encountered with different casing and/or different separators ('/' vs '\').
The case of separators can appear when the same file is included externally by
`#include <folder/file.h>`
whereas a file from the same folder does
`#include "file.h"`
Under Windows, clang computes the paths using '/' from the include directive, the `\` from the -I options, and the concatenations use the native `\`, leading to internal paths containing a mix of both separators.
Differential Revision: https://reviews.llvm.org/D102339
This was reverted to mitigate mitigate miscompiles caused by
the logical and/or to bitwise and/or fold. Reapply it now that
the underlying issue has been fixed by D101191.
-----
This patch folds more operations to poison.
Alive2 proof: https://alive2.llvm.org/ce/z/mxcb9G (it does not contain tests about div/rem because they fold to poison when raising UB)
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D92270
This attempts to move driver tests out of Frontend and to Driver, separates
RUNs that should fail from RUNs that should succeed, and prevent creating
output files or dumping output.
Differential Revision: https://reviews.llvm.org/D101867
This implements the flag proposed in RFC
http://lists.llvm.org/pipermail/cfe-dev/2020-August/066437.html.
The goal is to add a way to override the default target C++ ABI through a
compiler flag. This makes it easier to test and transition between different
C++ ABIs through compile flags rather than build flags.
In this patch:
- Store -fc++-abi= in a LangOpt. This isn't stored in a CodeGenOpt because
there are instances outside of codegen where Clang needs to know what the
ABI is (particularly through ASTContext::createCXXABI), and we should be
able to override the target default if the flag is provided at that point.
- Expose the existing ABIs in TargetCXXABI as values that can be passed
through this flag.
- Create a .def file for these ABIs to make it easier to check flag values.
- Add an error for diagnosing bad ABI flag values.
Differential Revision: https://reviews.llvm.org/D85802
FileCheck now gives an error when there's a check for an undefined
variable, which this test does in one of its NOT checks. Fix this by
being a bit looser in what the test checks.
Consider the following set of files:
a.cc:
#include "a.h"
a.h:
#ifndef A_H
#define A_H
#include "b.h"
#include "c.h" // This gets "skipped".
#endif
b.h:
#ifndef B_H
#define B_H
#include "c.h"
#endif
c.h:
#ifndef C_H
#define C_H
void c();
#endif
And the output of the -H option:
$ clang -c -H a.cc
. ./a.h
.. ./b.h
... ./c.h
Note that the include of c.h in a.h is not shown in the output (GCC does the
same). This is because of the include guard optimization: clang knows c.h is
covered by an include guard which is already defined, so when it sees the
include in a.h, it skips it. The same would have happened if #pragma once were
used instead of include guards.
However, a.h *does* include c.h, and it may be useful to show that in the -H
output. This patch adds a flag for doing that.
Differential revision: https://reviews.llvm.org/D100480
After c773d0f973 the remark is only emitted if the loop is profitable
to vectorize, but cannot be vectorized. Hence, it depends on
X86-specific cost-modeling.
SYCL compilations initiated by the driver will spawn off one or more
frontend compilation jobs (one for device and one for host). This patch
reworks the driver options to make upstreaming this from the downstream
SYCL fork easier.
This patch introduces a language option to identify host executions
(SYCLIsHost) and a -cc1 frontend option to enable this mode. -fsycl and
-fno-sycl become driver-only options that are rejected when passed to
-cc1. This is because the frontend and beyond should be looking at
whether the user is doing a device or host compilation specifically.
Because the frontend should only ever be in one mode or the other,
-fsycl-is-device and -fsycl-is-host are mutually exclusive options.
This seems to be more of a Clang thing rather than a generic LLVM thing,
so this moves it out of LLVM pipelines and as Clang extension hooks into
LLVM pipelines.
Move the post-inline EEInstrumentation out of the backend pipeline and
into a late pass, similar to other sanitizer passes. It doesn't fit
into the codegen pipeline.
Also fix up EntryExitInstrumentation not running at -O0 under the new
PM. PR49143
Reviewed By: hans
Differential Revision: https://reviews.llvm.org/D97608
Finally, this patch moves from round-tripping one `CompilerInvocation` at a time to round-tripping the invocation as a whole.
This patch includes only the code required to make round-tripping the whole invocation work. More cleanups will be done in a follow-up patch.
Depends on D96847, D97041 & D97042.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D96280
Displaying the problem range could crash if the begin and end of a
range is in different files or macros. After the change such range
is displayed only as the beginning location.
There is a bug for this problem:
https://bugs.llvm.org/show_bug.cgi?id=46540
Reviewed By: steakhal
Differential Revision: https://reviews.llvm.org/D95860
This patch implements generation of remaining header search arguments.
It's done manually in C++ as opposed to TableGen, because we need the flexibility and don't anticipate reuse.
This patch also tests the generation of header search options via a round-trip. This way, the code gets exercised whenever Clang is built and tested in asserts mode. All `check-clang` tests pass.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D94472
On z/OS, the following error message is not matched correctly in lit tests.
```
EDC5129I No such file or directory.
```
This patch uses a lit config substitution to check for platform specific error messages.
Reviewed By: muiez, jhenderson
Differential Revision: https://reviews.llvm.org/D95246
On z/OS, the following error message is not matched correctly in lit tests. This patch updates the CHECK expression to match the end period successfully.
```
EDC5129I No such file or directory.
```
Differential Revision: https://reviews.llvm.org/D94239
This patch moves the parsing of `{Lang,CodeGen}Options` from `parseSimpleArgs` to the original `Parse{Lang,CodeGen}Args` functions.
This ensures all marshalled `LangOptions` are being parsed **after** the call `setLangDefaults`, which in turn enables us to marshall `LangOptions` that somehow depend on the defaults. (In a future patch.)
Now, `CodeGenOptions` need to be parsed **after** `LangOptions`, because `-cl-mad-enable` (a `CodeGenOpt`) depends on the value of `-cl-fast-relaxed-math` and `-cl-unsafe-math-optimizations` (`LangOpts`).
Unfortunately, this removes the nice property that marshalled options get parsed in the exact order they appear in the `.td` file. Now we cannot be sure that a TableGen record referenced in `ImpliedByAnyOf` has already been parsed. This might cause an ordering issues (i.e. reading value of uninitialized variable). I plan to mitigate this by moving each `XxxOpt` group from `parseSimpleArgs` back to their original parsing function. With this setup, if an option from group `A` references option from group `B` in TableGen, the compiler will require us to make the `CompilerInvocation` member for `B` visible in the parsing function for `A`. That's where we notice that `B` didn't get parsed yet.
Reviewed By: Bigcheese
Differential Revision: https://reviews.llvm.org/D94682
On z/OS, the following error message is not matched correctly in lit tests. This patch updates the CHECK expression to match successfully.
```
EDC5129I No such file or directory.
```
Reviewed By: muiez
Differential Revision: https://reviews.llvm.org/D94239
Expanding from D94808 - we ensure the same InlineAdvisor is used by both
InlinerPass instances. The notion of mandatory inlining is moved into
the core InlineAdvisor: advisors anyway have to handle that case, so
this change also factors out that a bit better.
Differential Revision: https://reviews.llvm.org/D94825
This change modifies the source location formatting from:
LineNumber.Discriminator
to:
LineNumber:ColumnNumber.Discriminator
The motivation here is to enhance location information for inline replay that currently exists for the SampleProfile inliner. This will be leveraged further in inline replay for the CGSCC inliner in the related diff.
The ReplayInlineAdvisor is also modified to read the new format and now takes into account the callee for greater accuracy.
Testing:
ninja check-llvm
Reviewed By: mtrofin
Differential Revision: https://reviews.llvm.org/D94333
The patch adds the required methods to FixedPointBuilder
for converting between fixed-point and floating point,
and uses them from Clang.
This depends on D54749.
Reviewed By: leonardchan
Differential Revision: https://reviews.llvm.org/D86632
For a default visibility external linkage definition, dso_local is set for ELF
-fno-pic/-fpie and COFF and Mach-O. Since default clang -cc1 for ELF is similar
to -fpic ("PIC Level" is not set), this nuance causes unneeded binary format differences.
To make emitted IR similar, ELF -cc1 -fpic will default to -fno-semantic-interposition,
which sets dso_local for default visibility external linkage definitions.
To make this flip smooth and enable future (dso_local as definition default),
this patch replaces (function) `define ` with `define{{.*}} `,
(variable/constant/alias) `= ` with `={{.*}} `, or inserts appropriate `{{.*}} `.
This patch enables marshalling of the exception model options while enforcing their mutual exclusivity. The clang driver interface remains the same, this only affects the cc1 command line.
Depends on D93215.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D93216
Committing on behalf of thejh (Jann Horn).
As part of this change, one existing test case has to be adjusted
because it accidentally stripped the NoDeref attribute without
getting caught.
Depends on D92140
Differential Review: https://reviews.llvm.org/D92141
Committing on behalf of thejh (Jann Horn).
Given an attribute((noderef)) pointer "p" to the struct
struct s { int a[2]; };
ensure that the following expressions are treated the same way by the
noderef logic:
p->a
(*p).a
Until now, the first expression would be treated correctly (nothing is
added to PossibleDerefs because CheckMemberAccessOfNoDeref() bails out
on array members), but the second expression would incorrectly warn
because "*p" creates a PossibleDerefs entry.
Handle this case the same way as for the AddrOf operator.
Differential Revision: https://reviews.llvm.org/D92140
This is the #2 of 2 changes that make remarks hotness threshold option
available in more tools. The changes also allow the threshold to sync with
hotness threshold from profile summary with special value 'auto'.
This change expands remarks hotness threshold option
-fdiagnostics-hotness-threshold in clang and *-remarks-hotness-threshold in
other tools to utilize hotness threshold from profile summary.
Remarks hotness filtering relies on several driver options. Table below lists
how different options are correlated and affect final remarks outputs:
| profile | hotness | threshold | remarks printed |
|---------|---------|-----------|-----------------|
| No | No | No | All |
| No | No | Yes | None |
| No | Yes | No | All |
| No | Yes | Yes | None |
| Yes | No | No | All |
| Yes | No | Yes | None |
| Yes | Yes | No | All |
| Yes | Yes | Yes | >=threshold |
In the presence of profile summary, it is often more desirable to directly use
the hotness threshold from profile summary. The new argument value 'auto'
indicates threshold will be synced with hotness threshold from profile summary
during compilation. The "auto" threshold relies on the availability of profile
summary. In case of missing such information, no remarks will be generated.
Differential Revision: https://reviews.llvm.org/D85808
Enable performing mandatory inlinings upfront, by reusing the same logic
as the full inliner, instead of the AlwaysInliner. This has the
following benefits:
- reduce code duplication - one inliner codebase
- open the opportunity to help the full inliner by performing additional
function passes after the mandatory inlinings, but before th full
inliner. Performing the mandatory inlinings first simplifies the problem
the full inliner needs to solve: less call sites, more contextualization, and,
depending on the additional function optimization passes run between the
2 inliners, higher accuracy of cost models / decision policies.
Note that this patch does not yet enable much in terms of post-always
inline function optimization.
Differential Revision: https://reviews.llvm.org/D91567
Nick Desaulniers