commit 18432bea764863d1c42fd569bd3846673ee4e802
Author: Christopher Di Bella <cjdb@google.com>
Date:   Wed Oct 14 10:13:32 2020 -0700

    [Driver]: fix compiler-rt path when printing libgcc for baremetal
    
    clang --target arm-none-eabi --print-libgcc-file-name --rtlib=compiler-rt
    used to print `/path/to/lib/clang/version/lib/libclang_rt.builtins-arm.a`
    but should print `/path/to/lib/clang/version/lib/baremetal/libclang_rt.builtins-arm.a`.
    Similarly, --target armv7m-none-eabi should print libclang_rt.builtins-armv7m.a
    This matches the compiler-rt file name used at link time in the
    baremetal driver.
    
    Reviewed By: manojgupta
    
    Differential Revision: https://reviews.llvm.org/D89327

diff --git a/clang/include/clang/Driver/ToolChain.h b/clang/include/clang/Driver/ToolChain.h
index 7495e08fe6e..4704308f045 100644
--- a/clang/include/clang/Driver/ToolChain.h
+++ b/clang/include/clang/Driver/ToolChain.h
@@ -419,10 +419,10 @@ public:
   getCompilerRTArgString(const llvm::opt::ArgList &Args, StringRef Component,
                          FileType Type = ToolChain::FT_Static) const;
 
-  std::string getCompilerRTBasename(const llvm::opt::ArgList &Args,
-                                    StringRef Component,
-                                    FileType Type = ToolChain::FT_Static,
-                                    bool AddArch = true) const;
+  virtual std::string
+  getCompilerRTBasename(const llvm::opt::ArgList &Args, StringRef Component,
+                        FileType Type = ToolChain::FT_Static,
+                        bool AddArch = true) const;
 
   // Returns target specific runtime path if it exists.
   virtual Optional<std::string> getRuntimePath() const;
@@ -435,7 +435,7 @@ public:
   std::string getArchSpecificLibPath() const;
 
   // Returns <OSname> part of above.
-  StringRef getOSLibName() const;
+  virtual StringRef getOSLibName() const;
 
   /// needsProfileRT - returns true if instrumentation profile is on.
   static bool needsProfileRT(const llvm::opt::ArgList &Args);
diff --git a/clang/lib/Driver/ToolChains/BareMetal.cpp b/clang/lib/Driver/ToolChains/BareMetal.cpp
index 6ed81c1e34a..9df42061e12 100644
--- a/clang/lib/Driver/ToolChains/BareMetal.cpp
+++ b/clang/lib/Driver/ToolChains/BareMetal.cpp
@@ -35,8 +35,6 @@ BareMetal::BareMetal(const Driver &D, const llvm::Triple &Triple,
     getProgramPaths().push_back(getDriver().Dir);
 }
 
-BareMetal::~BareMetal() {}
-
 /// Is the triple {arm,thumb}-none-none-{eabi,eabihf} ?
 static bool isARMBareMetal(const llvm::Triple &Triple) {
   if (Triple.getArch() != llvm::Triple::arm &&
@@ -64,6 +62,13 @@ Tool *BareMetal::buildLinker() const {
   return new tools::baremetal::Linker(*this);
 }
 
+std::string BareMetal::getCompilerRTPath() const { return getRuntimesDir(); }
+
+std::string BareMetal::getCompilerRTBasename(const llvm::opt::ArgList &,
+                                             StringRef, FileType, bool) const {
+  return ("libclang_rt.builtins-" + getTriple().getArchName() + ".a").str();
+}
+
 std::string BareMetal::getRuntimesDir() const {
   SmallString<128> Dir(getDriver().ResourceDir);
   llvm::sys::path::append(Dir, "lib", "baremetal");
diff --git a/clang/lib/Driver/ToolChains/BareMetal.h b/clang/lib/Driver/ToolChains/BareMetal.h
index 4c0c739307b..0be9377134c 100644
--- a/clang/lib/Driver/ToolChains/BareMetal.h
+++ b/clang/lib/Driver/ToolChains/BareMetal.h
@@ -23,7 +23,7 @@ class LLVM_LIBRARY_VISIBILITY BareMetal : public ToolChain {
 public:
   BareMetal(const Driver &D, const llvm::Triple &Triple,
             const llvm::opt::ArgList &Args);
-  ~BareMetal() override;
+  ~BareMetal() override = default;
 
   static bool handlesTarget(const llvm::Triple &Triple);
 protected:
@@ -37,6 +37,14 @@ public:
   bool isPICDefaultForced() const override { return false; }
   bool SupportsProfiling() const override { return false; }
 
+  StringRef getOSLibName() const override { return "baremetal"; }
+
+  std::string getCompilerRTPath() const override;
+  std::string getCompilerRTBasename(const llvm::opt::ArgList &Args,
+                                    StringRef Component,
+                                    FileType Type = ToolChain::FT_Static,
+                                    bool AddArch = true) const override;
+
   RuntimeLibType GetDefaultRuntimeLibType() const override {
     return ToolChain::RLT_CompilerRT;
   }
diff --git a/clang/test/Driver/print-libgcc-file-name-clangrt.c b/clang/test/Driver/print-libgcc-file-name-clangrt.c
index 74a88e565bb..ac921ec38b1 100644
--- a/clang/test/Driver/print-libgcc-file-name-clangrt.c
+++ b/clang/test/Driver/print-libgcc-file-name-clangrt.c
@@ -42,3 +42,9 @@
 // RUN:     -resource-dir=%S/Inputs/resource_dir_with_arch_subdir \
 // RUN:   | FileCheck --check-prefix=CHECK-CLANGRT-ARM-ABI %s
 // CHECK-CLANGRT-ARM-ABI: libclang_rt.builtins-armhf.a
+
+// RUN: %clang -rtlib=compiler-rt -print-libgcc-file-name 2>&1 \
+// RUN:     --target=armv7m-none-eabi \
+// RUN:     -resource-dir=%S/Inputs/resource_dir_with_arch_subdir \
+// RUN:   | FileCheck --check-prefix=CHECK-CLANGRT-ARM-BAREMETAL %s
+// CHECK-CLANGRT-ARM-BAREMETAL: libclang_rt.builtins-armv7m.a