[Flang] Search flang_rt in clang_rt path #151954
Conversation
| get_toolchain_arch_dirname(arch_dirname) | ||
| set(outval "${outval}/${arch_dirname}") |
There was a problem hiding this comment.
On my machine, both compiler-rt and flang-rt libraries are installed into <install_dir>/lib/clang/22/lib/darwin.
IIUC, this change would make flang-rt libraries be installed in a new directory, <install_dir>/lib/clang/22/lib/<target>, right?
Wouldn't it be better to make flang look for its libraries in the same path as compiler-rt?
There was a problem hiding this comment.
On my machine, both compiler-rt and flang-rt libraries are installed into
<install_dir>/lib/clang/22/lib/darwin.
That was the original intention/idea.
IIUC, this change would make flang-rt libraries be installed in a new directory,
<install_dir>/lib/clang/22/lib/<target>, right? Wouldn't it be better to make flang look for its libraries in the same path as compiler-rt?
ToolChain::addFlangRTLibPath calls ToolChain::getArchSpecificLibPaths() which is overridable by the MachO ToolChain (but not actually overridden). The x86_64 is added here:
llvm-project/clang/lib/Driver/ToolChain.cpp
Line 1041 in 852cc92
It felt best to avoid platform-specific exceptions making the problem more managable.
Turns out ToolChain::getArchSpecificLibPaths() is only used when using RPath. ToolChain::addFlangRTLibPath is called to fill getFilePaths. On non-MachO platforms seem that getRuntimePath() covers it, but is skipped on MachO1:
llvm-project/clang/lib/Driver/ToolChain.cpp
Lines 1010 to 1011 in 852cc92
Trying another version soon
Footnotes
|
This patch didn't change the behavior for me, unfortunately. |
|
This did not resolve the problem because the new location is not in the linker's search path. |
Meinersbur
changed the title
|
For reference. compiler-rt special Apple code: flang-rt special Apple code: |
|
Testing with the two new commits still fails to locate Again with FWIW: |
|
@PHHargrove Thanks for the details. There is something weird about your setup.
|
llvmbot
added
clang
|
@llvm/pr-subscribers-clang-driver @llvm/pr-subscribers-clang Author: Michael Kruse (Meinersbur) Changesclang_rt has two separate systems for find its location (simplified):
To simplify the search path, Flang-RT normally assumes only Fixes #151031 Full diff: https://github.com/llvm/llvm-project/pull/151954.diff 1 Files Affected:
diff --git a/clang/lib/Driver/ToolChain.cpp b/clang/lib/Driver/ToolChain.cpp
index 25c6b5a486fd5..7667dbddb0ca2 100644
--- a/clang/lib/Driver/ToolChain.cpp
+++ b/clang/lib/Driver/ToolChain.cpp
@@ -855,17 +855,30 @@ void ToolChain::addFortranRuntimeLibs(const ArgList &Args,
void ToolChain::addFortranRuntimeLibraryPath(const llvm::opt::ArgList &Args,
ArgStringList &CmdArgs) const {
- // Default to the <driver-path>/../lib directory. This works fine on the
- // platforms that we have tested so far. We will probably have to re-fine
- // this in the future. In particular, on some platforms, we may need to use
- // lib64 instead of lib.
+ auto AddLibSearchPathIfExists = [&](const Twine &Path) {
+ // Linker may emit warnings about non-existing directories
+ if (!llvm::sys::fs::is_directory(Path))
+ return;
+
+ if (getTriple().isKnownWindowsMSVCEnvironment())
+ CmdArgs.push_back(Args.MakeArgString("-libpath:" + Path));
+ else
+ CmdArgs.push_back(Args.MakeArgString("-L" + Path));
+ };
+
+ // Search for flang_rt.* at the same location as clang_rt.* with
+ // LLVM_ENABLE_PER_TARGET_RUNTIME_DIR=0. On most platforms, flang_rt is
+ // located at the path returned by getRuntimePath() which is already added to
+ // the library search path. This exception is for Apple-Darwin.
+ AddLibSearchPathIfExists(getCompilerRTPath());
+
+ // Fall back to the non-resource directory <driver-path>/../lib. We will
+ // probably have to refine this in the future. In particular, on some
+ // platforms, we may need to use lib64 instead of lib.
SmallString<256> DefaultLibPath =
llvm::sys::path::parent_path(getDriver().Dir);
llvm::sys::path::append(DefaultLibPath, "lib");
- if (getTriple().isKnownWindowsMSVCEnvironment())
- CmdArgs.push_back(Args.MakeArgString("-libpath:" + DefaultLibPath));
- else
- CmdArgs.push_back(Args.MakeArgString("-L" + DefaultLibPath));
+ AddLibSearchPathIfExists(DefaultLibPath);
}
void ToolChain::addFlangRTLibPath(const ArgList &Args,
|
|
LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/59/builds/22209 Here is the relevant piece of the build log for the reference |
Regarding item 2: My I cannot account for the difference, but have determined that Homebrew's Regarding item 1: unexpected library directory. I removed both the build and installation directories, checked out the merge commit which closed this PR (8de4819), reran The flang runtime is installed in TL;DR: I cannot account for either of the "something weird" items, but with a fresh build I no longer reproduce #151031. cmake commoand: Verbose compile and run: |
|
/cherry-pick 8de4819 |
Error: Command failed due to missing milestone. |
|
/pull-request #152458 |
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 llvm#151031 (cherry picked from commit 8de4819)
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 whenLLVM_ENABLE_PER_TARGET_RUNTIME_DIR=0getRuntimePath(), e.g.../lib/clang/22/lib/x86_64-pc-windows-msvc, used whenLLVM_ENABLE_PER_TARGET_RUNTIME_DIR=1To simplify the search path, Flang-RT normally assumes only
getRuntimePath(), i.e. ignoringLLVM_ENABLE_PER_TARGET_RUNTIME_DIRand always using theLLVM_ENABLE_PER_TARGET_RUNTIME_DIR=1mechanism. There is an exception for Apple Darwin triples wheregetRuntimePath()returns nothing. The flang-rt/compiler-rt CMake code for library location also ignoresLLVM_ENABLE_PER_TARGET_RUNTIME_DIRbut uses theLLVM_ENABLE_PER_TARGET_RUNTIME_DIR=0path instead. Since onlygetRuntimePath()is automatically added to the linker command line, this patch explicitly addsgetCompilerRTPath()to the search path when linking flang_rt.Fixes #151031