The Generic_GCC::GCCInstallationDetector class picks the GCC
installation directory with the largest version number. Since the
location of the libstdc++ include directories is tied to the GCC
version, this can break C++ compilation if the libstdc++ headers for
this particular GCC version are not available. Linux distributions tend
to package the libstdc++ headers separately from GCC. This frequently
leads to situations in which a newer version of GCC gets installed as a
dependency of another package without installing the corresponding
libstdc++ package. Clang then fails to compile C++ code because it
cannot find the libstdc++ headers. Since libstdc++ headers are in fact
installed on the system, the GCC installation continues to work, the
user may not be aware of the details of the GCC detection, and the
compiler does not recognize the situation and emit a warning, this
behavior can be hard to understand - as witnessed by many related bug
reports over the years.
The goal of this work is to change the GCC detection to prefer GCC
installations that contain libstdc++ include directories over those
which do not. This should happen regardless of the input language since
picking different GCC installations for a build that mixes C and C++
might lead to incompatibilities.
Any change to the GCC installation detection will probably have a
negative impact on some users. For instance, for a C user who relies on
using the GCC installation with the largest version number, it might
become necessary to use the --gcc-install-dir option to ensure that this
GCC version is selected.
This seems like an acceptable trade-off given that the situation for
users who do not have any special demands on the particular GCC
installation directory would be improved significantly.
This patch does not yet change the automatic GCC installation directory
choice. Instead, it does introduce a warning that informs the user about
the future change if the chosen GCC installation directory differs from
the one that would be chosen if the libstdc++ headers are taken into
account.
See also this related Discourse discussion:
https://discourse.llvm.org/t/rfc-take-libstdc-into-account-during-gcc-detection/86992.
The clang/flang driver has two separate systems for find the location of
clang_rt (simplified):
* `getCompilerRTPath()`, e.g. `../lib/clang/22/lib/windows`,
used when `LLVM_ENABLE_PER_TARGET_RUNTIME_DIR=0`
* `getRuntimePath()`, e.g. `../lib/clang/22/lib/x86_64-pc-windows-msvc`,
used when `LLVM_ENABLE_PER_TARGET_RUNTIME_DIR=1`
To simplify the search path, Flang-RT normally assumes only
`getRuntimePath()`, i.e. ignoring `LLVM_ENABLE_PER_TARGET_RUNTIME_DIR`
and always using the `LLVM_ENABLE_PER_TARGET_RUNTIME_DIR=1` mechanism.
There is an exception for Apple Darwin triples where `getRuntimePath()`
returns nothing. The flang-rt/compiler-rt CMake code for library
location also ignores `LLVM_ENABLE_PER_TARGET_RUNTIME_DIR` but uses the
`LLVM_ENABLE_PER_TARGET_RUNTIME_DIR=0` path instead. Since only
`getRuntimePath()` is automatically added to the linker command line,
this patch explicitly adds `getCompilerRTPath()` to the path when
linking flang_rt.
Fixes#151031
The Cygwin target is generally very similar to the MinGW target. The
default auto-import behavior, the default calling convention, the
`.dll.a` import library extension, the `__GXX_TYPEINFO_EQUALITY_INLINE`
pre-define by `g++`, and the long double configuration.
Co-authored-by: Mateusz Mikuła <oss@mateuszmikula.dev>
If a user passed an invalid value to `-march`, an assertion failure
happened in the AArch64 multilib logic.
But an invalid `-march` value is an expected case that should be handled
via error messages.
This patch removes the requirement that the `-march` value must be
valid.
This patch provides a single point for handling the logic behind
choosing common bitcode libraries. The intention is that the users of
ROCm installation detector will not have to rewrite options handling
code each time the bitcode libraries are queried. This is not too
distant from detectors for other architecture that encapsulate the
similar decision making process, providing cleaner interface. The only
flag left in `getCommonBitcodeLibs` (main point of entry) is
`NeedsASanRT`, this is deliberate, as in order to calculate it we need
to consult `ToolChain`.
Summary:
This patch reworks how we create offloading toolchains. Previously we
would handle this separately for all the different kinds. This patch
instead changes this to use the target triple and the offloading kind to
determine the proper toolchain. In the old case where the user only
passes `--offload-arch` we instead infer the triple from the passed
arguments. This is a pretty major overhaul but currently passes all the
clang tests with only minor changes to error messages.
If a multilib collection contains libraries built for different methods
of accessing global data (via absolute address, or via a GOT in -fPIC
style, or as an offset from a fixed register in Arm -frwpi style), then
`multilib.yaml` will need to know which relocation model an application
is using in order to select the right library.
Even if a multilib collection only supports one relocation model, it's
still useful for `multilib.yaml` to be able to tell if the user has
selected the right one, so as to give a useful error message if they
haven't, instead of silently selecting a library that won't work.
In this commit we determine the PIC / ROPI / RWPI status using the
existing logic in `ParsePICArgs`, and translate it back into a canonical
set of multilib selection flags.
Summary:
This patch is mostly an NFC that renames the existing `-fopenmp-targets`
into `--offload-targets`. Doing this early to simplify a follow-up patch
that will hopefully allow this syntax to be used more generically over
the existing `--offload` syntax (which I think is mostly unmaintained
now.). Following in the well-trodden path of trying to pull language
specific offload options into generic ones, but right now this is still
just OpenMP specific.
This patch moves the CommonArgs utilities into a location visible by the
Frontend Drivers, so that the Frontend Drivers may share option parsing
code with the Compiler Driver. This is useful when the Frontend Drivers
would like to verify that their incoming options are well-formed and
also not reinvent the option parsing wheel.
We already see code in the Clang/Flang Drivers that is parsing and
verifying its incoming options. E.g. OPT_ffp_contract. This option is
parsed in the Compiler Driver, Clang Driver, and Flang Driver, all with
slightly different parsing code. It would be nice if the Frontend
Drivers were not required to duplicate this Compiler Driver code. That
way there is no/low maintenance burden on keeping all these parsing
functions in sync.
Along those lines, the Frontend Drivers will now have a useful mechanism
to verify their incoming options are well-formed. Currently, the
Frontend Drivers trust that the Compiler Driver is not passing back junk
in some cases. The Language Drivers may even accept junk with no error
at all. E.g.:
`clang -cc1 -mprefer-vector-width=junk test.c'
With this patch, we'll now be able to tighten up incomming options to
the Frontend drivers in a lightweight way.
---------
Co-authored-by: Cameron McInally <cmcinally@nvidia.com>
Co-authored-by: Shafik Yaghmour <shafik.yaghmour@intel.com>
If the runtime path is not found (by getTargetSubDirPath()), since per
target runtime directory is enabled on AIX, we should fall back to the
target subdirectory rather than the OS subdirectory.
Previously, when the triple is `powerpc-ibm-aix-unknown`, the driver
fails to find subdirectory `lib/powerpc-ibm-aix`.
This ensures the correct runtime path is found if the triple has the
-unknown environment component attached.
This PR addressed issue #140748 to support XRay instrumentation on the
host side when using offloading.
It makes the following changes:
- Initializes `XRayArgs` using the processed toolchain arguments instead
of the raw input.
- Removes the current caching mechanism of `XRayArgs` in the `ToolChain`
class, as this is error-prone and potential benefits are questionable.
For reference, `SanitizierArgs`, which is constructed in a similar
manner but is much more complex, does not use any caching.
- Adds driver tests to verify that XRay flags are set correctly with
offloading and `-Xarch_host`.
lookupTarget takes StringRef and internally creates an instance of
std::string with the StringRef as part of constructing Triple, so we
don't need to create temporary instances of std::string on our own.
Move the Darwin framework search path logic from
InitHeaderSearch::AddDefaultIncludePaths to
DarwinClang::AddClangSystemIncludeArgs. Add a new -internal-iframework
cc1 argument to support the tool chain adding these paths.
Now that the tool chain is adding search paths via cc1 flag, they're
only added if they exist, so the Preprocessor/cuda-macos-includes.cu
test is no longer relevant.
Change Driver/driverkit-path.c and Driver/darwin-subframeworks.c to do
-### style testing similar to the darwin-header-search and
darwin-embedded-search-paths tests. Rename darwin-subframeworks.c to
darwin-framework-search-paths.c and have it test all framework search
paths, not just SubFrameworks.
Add a unit test to validate that the myriad of search path flags result
in the expected search path list.
Fixes https://github.com/llvm/llvm-project/issues/75638
The PR is to generalize the re-use of the `compilerRT` code of adding
the path of `libflang_rt.runtime.a (so)` from AIX and LoP only to all
platforms via a new function `addFlangRTLibPath`.
It also added `-static-libflangrt` and `-shared-libflangrt` compiler
options to allow users choosing which `flang-rt` to link to. It defaults
to shared `flang-rt`, which is consistent with the linker behavior,
except on AIX, it defaults to static.
Also, PR #134320 exposed an issue in PR #131041 that the the overriding
`addFortranRuntimeLibs` is missing the link to `libquadmath`. This PR
also fixed that and restored the test case that PR #131041 broke.
This PR is to improve the driver code to build `flang-rt` path by
re-using the logic and code of `compiler-rt`.
1. Moved `addFortranRuntimeLibraryPath` and `addFortranRuntimeLibs` to
`ToolChain.h` and made them virtual so that they can be overridden if
customization is needed. The current implementation of those two
procedures is moved to `ToolChain.cpp` as the base implementation to
default to.
2. Both AIX and PPCLinux now override `addFortranRuntimeLibs`.
The overriding function of `addFortranRuntimeLibs` for both AIX and
PPCLinux calls `getCompilerRTArgString` => `getCompilerRT` =>
`buildCompilerRTBasename` to get the path to `flang-rt`. This code
handles `LLVM_ENABLE_PER_TARGET_RUNTIME_DIR` setting. As shown in
`PPCLinux.cpp`, `FT_static` is the default. If not found, it will search
and build for `FT_shared`. To differentiate `flang-rt` from `clang-rt`,
a boolean flag `IsFortran` is passed to the chain of functions in order
to reach `buildCompilerRTBasename`.
Previously, alignment option was passed to multilib selection logic only
when -mno-unaligned-access was explicitly specified on the command line.
Now this change ensure both -mno-unaligned-access and -munaligned-access
are passed to the multilib selection logic, which now also considers the
target architecture when determining alignment access policy.
In the wake of discussion in PR #131200 and internal discussion after,
we will add support for `LLVM_ENABLE_PER_TARGET_RUNTIME=ON` for AIX
instead of disable it. I already reverted the change in PR #131200.
The default value of the option is still OFF on AIX.
Add an option similar to the -qtarget option in XL to allow the user to
say they want to be able to run the generated program on an older
version of the LE environment. This option will do two things:
- set the `__TARGET_LIBS` macro so the system headers exclude newer
interfaces when targeting older environments
- set the arch level to match the minimum arch level for that older
version of LE. It doesn't happen right now since all of the supported LE
versions have a the same minimum ach level. So the option doesn't change
this yet.
The user can specify three different kinds of arguments:
1. -mzos-target=zosv*V*r*R* - where V & R are the version and release
2. -mzos-target=0x4vrrmmmm - v, r, m, p are the hex values for the
version, release, and modlevel
3. -mzos-target=current - uses the latest version of LE the system
headers have support for
Summary:
Currently the `-Xarch` argument needs to re-parse the option, which goes
through every single registered argument. This causes errors when trying
to pass `-O1` through it because it thinks it's a DXC option. This patch
changes the behavior to only allow `clang` options. Concievably we could
detect the driver mode to make this more robust, but I don't know if
there are other users for this.
Fixes: https://github.com/llvm/llvm-project/issues/110325
Summary:
Currently, `-Xarch_` is handled specially between different toolchains,
(i.e. Mach-O).
This patch unifies the handling so that it can be used generically.
The main benefit here is that we now have a more generic version of
`-Xopenmp-target=`, which should probably just be deprecated.
Additionally, it allows us to specially pass arguments to different
architectures for offloading.
This patch is done in preparation for making selecting offloading
toolchains more generic, this will be helpful while people are moving
toward compile jobs that include multiple toolchains (SPIR-V, AMDGCN,
NVPTX).
In the discussion around #116792, @rjmccall mentioned that ARCMigrate
has been obsoleted and that we could go ahead and remove it from Clang,
so this patch does just that.
This patch is the second step to extend the current multilib system to
support the selection of library variants which do not correspond to
existing command-line options.
Proposal can be found in
https://discourse.llvm.org/t/rfc-multilib-custom-flags/81058
The multilib mechanism supports libraries that target code generation or
language options such as --target, -mcpu, -mfpu, -mbranch-protection.
However, some library variants are particular to features that do not
correspond to any command-line options. Examples include variants for
multithreading and semihosting.
This work introduces a way to instruct the multilib system to consider
these features in library selection.
The driver must be informed about the multilib custom flags with a new
command-line option.
```
-fmultilib-flag=C
```
Where the grammar for C is:
```
C -> option
option -> multithreaded | no-multithreaded | io-none | io-semihosting | io-linux-syscalls | ...
```
There must be one option instance for each flag specified:
```
-fmultilib-flag=multithreaded -fmultilib-flag=io-semihosting
```
Contradictory options are untied by *last one wins*.
These options are to be used exclusively by the multilib mechanism in
the Clang driver. Hence they are not forwarded to the compiler frontend.
Introduces the SYCL based toolchain and initial toolchain construction
when using the '-fsycl' option. This option will enable SYCL based
offloading, creating a SPIR-V based IR file packaged into the compiled
host object.
This includes early support for creating the host/device object using
the new offloading model. The device object is created using the
spir64-unknown-unknown target triple.
New/Updated Options:
-fsycl Enables SYCL offloading for host and device
-fsycl-device-only
Enables device only compilation for SYCL
-fsycl-host-only
Enables host only compilation for SYCL
RFC Reference:
https://discourse.llvm.org/t/rfc-sycl-driver-enhancements/74092
This is a reland of: https://github.com/llvm/llvm-project/pull/107493
Introduces the SYCL based toolchain and initial toolchain construction
when using the '-fsycl' option. This option will enable SYCL based
offloading, creating a SPIR-V based IR file packaged into the compiled
host object.
This includes early support for creating the host/device object using
the new offloading model. The device object is created using the
spir64-unknown-unknown target triple.
New/Updated Options:
-fsycl Enables SYCL offloading for host and device
-fsycl-device-only
Enables device only compilation for SYCL
-fsycl-host-only
Enables host only compilation for SYCL
RFC Reference:
https://discourse.llvm.org/t/rfc-sycl-driver-enhancements/74092
This removes the temporary ban on mixing AMDGCN flavoured SPIR-V and
concrete targets (e.g. `gfx900`) in the same HIPAMD compilation. This is
done primarily by tweaking the effective / observable triple when the
target is `amdgcnspirv`, which seamlessly composes with the existing
infra. The test is stolen from #75357.
In https://github.com/llvm/llvm-project/pull/109837, it sets a global
variable(`PGOInstrumentColdFunctionOnly`) in PassBuilderPipelines.cpp
which introduced a data race detected by TSan. To fix this, I decouple
the flag setting, the flags are now set
separately(`instrument-cold-function-only-path` is required to be used
with `--pgo-instrument-cold-function-only`).
PR https://github.com/llvm/llvm-project/pull/111976 was enabling the
tests updated in the PR to run on all systems. We found a few didn't run
on z/OS. I tracked the problem down to:
1. the ExecuteToolChainProgram() function wasn't passing the executable
name as the first arg. That was causing exec on z/OS to fail.
2. the temp file needs to be a text file so codepage conversion happens.
This patch adds support for cold function coverage instrumentation based
on sampling PGO counts. The major motivation is to detect dead functions
for the services that are optimized with sampling PGO. If a function is
covered by sampling profile count (e.g., those with an entry count > 0),
we choose to skip instrumenting those functions, which significantly
reduces the instrumentation overhead.
More details about the implementation and flags:
- Added a flag `--pgo-instrument-cold-function-only` in
`PGOInstrumentation.cpp` as the main switch to control skipping the
instrumentation.
- Built the extra instrumentation passes(a bundle of passes in
`addPGOInstrPasses`) under sampling PGO pipeline. This is controlled by
`--instrument-cold-function-only-path` flag.
- Added a driver flag `-fprofile-generate-cold-function-coverage`:
- 1) Config the flags in one place, i,e. adding
`--instrument-cold-function-only-path=<...>` and
`--pgo-function-entry-coverage`. Note that the instrumentation file path
is passed through `--instrument-sample-cold-function-path`, because we
cannot use the `PGOOptions.ProfileFile` as it's already used by
`-fprofile-sample-use=<...>`.
- 2) makes linker to link `compiler_rt.profile` lib(see
[ToolChain.cpp#L1125-L1131](https://github.com/llvm/llvm-project/blob/main/clang/lib/Driver/ToolChain.cpp#L1125-L1131)
).
- Added a flag(`--pgo-cold-instrument-entry-threshold`) to config entry
count to determine cold function.
Overall, the full command is like:
```
clang++ -O2 -fprofile-generate-cold-function-coverage=<...> -fprofile-sample-use=<...> code.cc -o code
```
This does a global rename from `flang-new` to `flang`. I also
removed/changed any TODOs that I found related to making this change.
---------
Co-authored-by: H. Vetinari <h.vetinari@gmx.com>
Co-authored-by: Andrzej Warzynski <andrzej.warzynski@arm.com>
PR #102521, which landed as 1ea0865dd6fa, implemented
`CLANG_TOOLCHAIN_PROGRAM_TIMEOUT`, but the logic is obviously wrong.
If the user-specified value is negative, it should become zero to mean
infinite. Otherwise, it should be left as is. Thus, use `std::max`
not `std::min`. This obvious fixup doesn't seem worth another pull
request.
This change modifies -ffp-model=fast to select options that more closely
match -funsafe-math-optimizations, and introduces a new model,
-ffp-model=aggressive which matches the existing behavior (except for a
minor change in the fp-contract behavior).
The primary motivation for this change is to make -ffp-model=fast more
user friendly, particularly in light of LLVM's aggressive optimizations
when -fno-honor-nans and -fno-honor-infinites are used.
This was previously proposed here:
https://discourse.llvm.org/t/making-ffp-model-fast-more-user-friendly/78402
This changes the bare-metal driver logic such that it _always_ tries
multilib.yaml if it exists, and it falls back to the hardwired/default
RISC-V multilib selection only if a multilib.yaml doesn't exist. In
contrast, the current behavior is that RISC-V can never use
multilib.yaml, but other targets will try it if it exists.
The flags `-march=` and `-mabi=` are exposed for multilib.yaml to match
on. There is no attempt to help YAML file creators to duplicate the
existing hard-wired multilib reuse logic -- they will have to implement
it using `Mappings`.
This should be backwards-compatible with existing sysroots, as
multilib.yaml was previously never used for RISC-V, and the behavior
doesn't change after this PR if the file doesn't exist.
When working on very busy systems, check-offload frequently fails many
tests with this diagnostic:
```
clang: error: cannot determine amdgcn architecture: /tmp/llvm/build/bin/amdgpu-arch: Child timed out: ; consider passing it via '-march'
```
This patch accepts the environment variable
`CLANG_TOOLCHAIN_PROGRAM_TIMEOUT` to set the timeout. It also increases
the timeout from 10 to 60 seconds.
Support for this was added back in 2016
(https://reviews.llvm.org/D27499), but never enabled in the driver.
Since then, it's been possible to enable this with an arm triple and the
-mthumb option, but not with a thumb triple.
This also caused -fsanitise=cfi to enable cfi-icall for arm triple but
not thumb triples, which caused spurious sanitiser failures if mixing
the two ISAs in one program.
