[clang] 31142c4 - [clang] Make --ld-path= work with -fuse-ld=lld

[Nico Weber via cfe-commits]

Author: Nico Weber
Date: 2022-09-23T09:04:19-04:00
New Revision: 31142c4290533eeb771a0fc66af4918bd74bc162

URL: https://github.com/llvm/llvm-project/commit/31142c4290533eeb771a0fc66af4918bd74bc162
DIFF: https://github.com/llvm/llvm-project/commit/31142c4290533eeb771a0fc66af4918bd74bc162.diff

LOG: [clang] Make --ld-path= work with -fuse-ld=lld

This allows using --ld-path= to set a custom linker path, while
still informing clang that the binary at that path is an lld built
at the same revision as clang, so that clang can make assumptions
about the flags it supports, its output format, etc.

This currently only has an observable effect on Darwin.

Differential Revision: https://reviews.llvm.org/D134063

Added: 
    

Modified: 
    clang/lib/Driver/ToolChain.cpp
    clang/test/Driver/darwin-ld-demangle-lld.c

Removed: 
    


################################################################################
diff  --git a/clang/lib/Driver/ToolChain.cpp b/clang/lib/Driver/ToolChain.cpp
index 5547f28d6351..fdbe7270bddd 100644
--- a/clang/lib/Driver/ToolChain.cpp
+++ b/clang/lib/Driver/ToolChain.cpp
@@ -621,13 +621,18 @@ std::string ToolChain::GetLinkerPath(bool *LinkerIsLLD) const {
   // --ld-path= takes precedence over -fuse-ld= and specifies the executable
   // name. -B, COMPILER_PATH and PATH and consulted if the value does not
   // contain a path component separator.
+  // -fuse-ld=lld can be used with --ld-path= to inform clang that the binary
+  // that --ld-path= points to is lld.
   if (const Arg *A = Args.getLastArg(options::OPT_ld_path_EQ)) {
     std::string Path(A->getValue());
     if (!Path.empty()) {
       if (llvm::sys::path::parent_path(Path).empty())
         Path = GetProgramPath(A->getValue());
-      if (llvm::sys::fs::can_execute(Path))
+      if (llvm::sys::fs::can_execute(Path)) {
+        if (LinkerIsLLD)
+          *LinkerIsLLD = UseLinker == "lld";
         return std::string(Path);
+      }
     }
     getDriver().Diag(diag::err_drv_invalid_linker_name) << A->getAsString(Args);
     return GetProgramPath(getDefaultLinker());

diff  --git a/clang/test/Driver/darwin-ld-demangle-lld.c b/clang/test/Driver/darwin-ld-demangle-lld.c
index 3d44c3d432f2..12fd8502ce7a 100644
--- a/clang/test/Driver/darwin-ld-demangle-lld.c
+++ b/clang/test/Driver/darwin-ld-demangle-lld.c
@@ -1,8 +1,12 @@
 // With -fuse-ld=lld, -demangle is always passed to the linker on Darwin.
 // REQUIRES: shell
 
-// RUN: %clang --target=x86_64-apple-darwin -### \
-// RUN:   -fuse-ld=lld -B%S/Inputs/lld -mlinker-version=0 %s 2>&1 \
+// RUN: %clang --target=x86_64-apple-darwin -### -fuse-ld=lld \
+// RUN:   -B%S/Inputs/lld -mlinker-version=0 %s 2>&1 \
+// RUN:   | FileCheck %s
+
+// RUN: %clang --target=x86_64-apple-darwin -### -fuse-ld=lld \
+// RUN:   --ld-path=%S/Inputs/lld/ld64.lld -mlinker-version=0 %s 2>&1 \
 // RUN:   | FileCheck %s
 
 // CHECK: "-demangle"