[llvm-objcopy] Improve tool selection logic to recognize llvm-strip-$major as strip

Debian and some other distributions install llvm-strip as llvm-strip-$major (e.g. `/usr/bin/llvm-strip-9`)

D54193 made it work with llvm-strip-$major but did not add a test.
The behavior was regressed by D69146.

Fixes https://github.com/ClangBuiltLinux/linux/issues/940

Reviewed By: alexshap

Differential Revision: https://reviews.llvm.org/D76562

(cherry picked from commit f2f96eb605bc770e4da400dbcc7a6d2526ec1fd4)

1 files changed, 19 insertions, 5 deletions

diff --git a/llvm/tools/llvm-objcopy/llvm-objcopy.cpp b/llvm/tools/llvm-objcopy/llvm-objcopy.cpp
index e662f35f4b0..4a44a7ab087 100644
--- a/llvm/tools/llvm-objcopy/llvm-objcopy.cpp
+++ b/llvm/tools/llvm-objcopy/llvm-objcopy.cpp
@@ -322,11 +322,25 @@ enum class ToolType { Objcopy, Strip, InstallNameTool };
 int main(int argc, char **argv) {
   InitLLVM X(argc, argv);
   ToolName = argv[0];
-  ToolType Tool = StringSwitch<ToolType>(sys::path::stem(ToolName))
-                      .EndsWith("strip", ToolType::Strip)
-                      .EndsWith("install-name-tool", ToolType::InstallNameTool)
-                      .EndsWith("install_name_tool", ToolType::InstallNameTool)
-                      .Default(ToolType::Objcopy);
+
+  StringRef Stem = sys::path::stem(ToolName);
+  auto Is = [=](StringRef Tool) {
+    // We need to recognize the following filenames:
+    //
+    // llvm-objcopy -> objcopy
+    // strip-10.exe -> strip
+    // powerpc64-unknown-freebsd13-objcopy -> objcopy
+    // llvm-install-name-tool -> install-name-tool
+    auto I = Stem.rfind_lower(Tool);
+    return I != StringRef::npos &&
+           (I + Tool.size() == Stem.size() || !isAlnum(Stem[I + Tool.size()]));
+  };
+  ToolType Tool = ToolType::Objcopy;
+  if (Is("strip"))
+    Tool = ToolType::Strip;
+  else if (Is("install-name-tool") || Is("install_name_tool"))
+    Tool = ToolType::InstallNameTool;
+
   // Expand response files.
   // TODO: Move these lines, which are copied from lib/Support/CommandLine.cpp,
   // into a separate function in the CommandLine library and call that function