[Clang] Search for 'offload-arch' only next to the clang driver

[jhuber6]

Summary:
Previously, querying for the offload architecture tool would invoke the
user's PATH, which is bad when potentially using the driver from a
direct path. This patch change this to only consider the
offload-arch that's supposed to live next to the driver executable.
Now we will no longer pick up a potentially conflicting version of this
tool and it should always be found (Since it's a clang tool that's
installazed alongside the driver)

[llvmbot]

@llvm/pr-subscribers-clang

@llvm/pr-subscribers-clang-driver

Author: Joseph Huber (jhuber6)

Changes

Summary:
Previously, querying for the offload architecture tool would invoke the
user's PATH, which is bad when potentially using the driver from a
direct path. This patch change this to only consider the
offload-arch that's supposed to live next to the driver executable.
Now we will no longer pick up a potentially conflicting version of this
tool and it should always be found (Since it's a clang tool that's
installazed alongside the driver)

---

Full diff: https://github.com/llvm/llvm-project/pull/150965.diff

1 Files Affected:

• (modified) clang/lib/Driver/Driver.cpp (+1-1)

diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index 853f694850ba8..b90bd1d9ea17b 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -910,7 +910,7 @@ getSystemOffloadArchs(Compilation &C, Action::OffloadKind Kind) {
 
   SmallVector<std::string> GPUArchs;
   if (llvm::ErrorOr<std::string> Executable =
-          llvm::sys::findProgramByName(Program)) {
+          llvm::sys::findProgramByName(Program, {C.getDriver().Dir})) {
     llvm::SmallVector<StringRef> Args{*Executable};
     if (Kind == Action::OFK_HIP)
       Args.push_back("--only=amdgpu");

[shiltian]

Is clang tools always installed?

[jhuber6]

Is clang tools always installed?

Yes, but if they somehow weren't this would just become an error for native detection, nothing catastrophic.