https://github.com/boomanaiden154 created https://github.com/llvm/llvm-project/pull/184160
This is necessary to support build environments where the compiler/associated tools are actually just symlinks into a CAS. Without this, we try and resolve binaries relative to the real path of clang-linker-wrapper, which is usually in a directory prefixed with the first couple characters of a SHA digest and named with a SHA digest. We also need to ensure that we propagate --no-canonical-prefixes to sub clang invocations so that clang is able to resolve lld in such environments. >From 97c771d81570661cce67b57db5aaeebd7ff50437 Mon Sep 17 00:00:00 2001 From: Aiden Grossman <[email protected]> Date: Mon, 2 Mar 2026 15:52:01 +0000 Subject: [PATCH] =?UTF-8?q?[=F0=9D=98=80=F0=9D=97=BD=F0=9D=97=BF]=20initia?= =?UTF-8?q?l=20version?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Created using spr 1.3.7 --- .../linker-wrapper-canonical-prefixes.c | 25 +++++++++++++++++++ .../ClangLinkerWrapper.cpp | 9 +++++++ .../clang-linker-wrapper/LinkerWrapperOpts.td | 4 +++ 3 files changed, 38 insertions(+) create mode 100644 clang/test/Driver/linker-wrapper-canonical-prefixes.c diff --git a/clang/test/Driver/linker-wrapper-canonical-prefixes.c b/clang/test/Driver/linker-wrapper-canonical-prefixes.c new file mode 100644 index 0000000000000..79152cc69c078 --- /dev/null +++ b/clang/test/Driver/linker-wrapper-canonical-prefixes.c @@ -0,0 +1,25 @@ +// UNSUPPORTED: system-windows +// REQUIRES: x86-registered-target +// REQUIRES: amdgpu-registered-target + +// An externally visible variable so static libraries extract. +__attribute__((visibility("protected"), used)) int x; + +// RUN: rm -rf %t.test_dir && mkdir -p %t.test_dir +// RUN: touch %t.test_dir/clang +// RUN: chmod +x %t.test_dir/clang +// RUN: ln -s clang-linker-wrapper %t.test_dir/clang-linker-wrapper + +// RUN: %clang -cc1 %s -triple x86_64-unknown-linux-gnu -emit-obj -o %t.elf.o +// RUN: %clang -cc1 %s -triple amdgcn-amd-amdhsa -emit-llvm-bc -o %t.amdgpu.bc + +// RUN: llvm-offload-binary -o %t.out \ +// RUN: --image=file=%t.elf.o,kind=openmp,triple=amdgcn-amd-amdhsa,arch=gfx908 \ +// RUN: --image=file=%t.elf.o,kind=openmp,triple=amdgcn-amd-amdhsa,arch=gfx908 +// RUN: %clang -cc1 %s -triple x86_64-unknown-linux-gnu -emit-obj -o %t.o -fembed-offload-object=%t.out +// RUN: %t.test_dir/clang-linker-wrapper --host-triple=x86_64-unknown-linux-gnu --dry-run \ +// RUN: --linker-path=/usr/bin/ld %t.o -o a.out --no-canonical-prefixes 2>&1 | FileCheck %s + +// Check that we resolve clang to the symlink rather than the bin/ directory +// and that the sub-clang invocation was passed -no-canonical-prefixes. +// CHECK: test_dir/clang" {{.*}} -no-canonical-prefixes diff --git a/clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp b/clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp index c49ce44432e5a..b2b6910cd7e0b 100644 --- a/clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp +++ b/clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp @@ -140,6 +140,9 @@ static std::list<SmallString<128>> TempFiles; /// Codegen flags for LTO backend. static codegen::RegisterCodeGenFlags CodeGenFlags; +/// Whether or not to look through symlinks when resolving binaries. +static bool CanonicalPrefixes = true; + using OffloadingImage = OffloadBinary::OffloadingImage; namespace llvm { @@ -219,6 +222,8 @@ void printCommands(ArrayRef<StringRef> CmdArgs) { } std::string getMainExecutable(const char *Name) { + if (!CanonicalPrefixes) + return sys::path::parent_path(LinkerExecutable).str(); void *Ptr = (void *)(intptr_t)&getMainExecutable; auto COWPath = sys::fs::getMainExecutable(Name, Ptr); return sys::path::parent_path(COWPath).str(); @@ -539,6 +544,9 @@ Expected<StringRef> clang(ArrayRef<StringRef> InputFiles, const ArgList &Args, Args.MakeArgString("--target=" + Triple.getTriple()), }; + if (!CanonicalPrefixes) + CmdArgs.push_back("-no-canonical-prefixes"); + if (!Arch.empty()) Triple.isAMDGPU() ? CmdArgs.push_back(Args.MakeArgString("-mcpu=" + Arch)) : CmdArgs.push_back(Args.MakeArgString("-march=" + Arch)); @@ -1350,6 +1358,7 @@ int main(int Argc, char **Argv) { DryRun = Args.hasArg(OPT_dry_run); SaveTemps = Args.hasArg(OPT_save_temps); CudaBinaryPath = Args.getLastArgValue(OPT_cuda_path_EQ).str(); + CanonicalPrefixes = !Args.hasArg(OPT_no_canonical_prefixes); llvm::Triple Triple( Args.getLastArgValue(OPT_host_triple_EQ, sys::getDefaultTargetTriple())); diff --git a/clang/tools/clang-linker-wrapper/LinkerWrapperOpts.td b/clang/tools/clang-linker-wrapper/LinkerWrapperOpts.td index ef3a16b2f58bb..973e5bb51a507 100644 --- a/clang/tools/clang-linker-wrapper/LinkerWrapperOpts.td +++ b/clang/tools/clang-linker-wrapper/LinkerWrapperOpts.td @@ -69,6 +69,10 @@ def emit_fatbin_only Flags<[WrapperOnlyOption]>, HelpText<"Emit fat binary directly without wrapping or host linking">; +def no_canonical_prefixes : Flag<["--"], "no-canonical-prefixes">, + Flags<[WrapperOnlyOption]>, + HelpText<"Do not resolve symbolic links, turn relative paths into absolute ones, or do anything else to identify the executable">; + // Flags passed to the device linker. def arch_EQ : Joined<["--"], "arch=">, Flags<[DeviceOnlyOption, HelpHidden]>, MetaVarName<"<arch>">, _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
