Index: clang/lib/Driver/ToolChains/Gnu.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Gnu.cpp
+++ clang/lib/Driver/ToolChains/Gnu.cpp
@@ -972,19 +972,27 @@
   CmdArgs.push_back("-o");
   CmdArgs.push_back(Output.getFilename());
 
-  for (const auto &II : Inputs)
-    CmdArgs.push_back(II.getFilename());
-
-  if (Arg *A = Args.getLastArg(options::OPT_g_Flag, options::OPT_gN_Group,
-                               options::OPT_gdwarf_2, options::OPT_gdwarf_3,
-                               options::OPT_gdwarf_4, options::OPT_gdwarf_5,
-                               options::OPT_gdwarf))
-    if (!A->getOption().matches(options::OPT_g0)) {
-      Args.AddLastArg(CmdArgs, options::OPT_g_Flag);
 
-      unsigned DwarfVersion = getDwarfVersion(getToolChain(), Args);
-      CmdArgs.push_back(Args.MakeArgString("-gdwarf-" + Twine(DwarfVersion)));
-    }
+  bool IsInputTyAsm = false;
+  for (const auto &II : Inputs) {
+    CmdArgs.push_back(II.getFilename());
+    StringRef BaseInput = StringRef(II.getBaseInput());
+    types::ID InputType = types::lookupTypeForExtension(
+        llvm::sys::path::extension(BaseInput).drop_front());
+    if (InputType == types::TY_Asm || InputType == types::TY_PP_Asm)
+      IsInputTyAsm = true;
+  }
+
+  if (IsInputTyAsm)
+    if (Arg *A = Args.getLastArg(options::OPT_g_Flag, options::OPT_gN_Group,
+                                 options::OPT_gdwarf_2, options::OPT_gdwarf_3,
+                                 options::OPT_gdwarf_4, options::OPT_gdwarf_5,
+                                 options::OPT_gdwarf))
+      if (!A->getOption().matches(options::OPT_g0)) {
+        Args.AddLastArg(CmdArgs, options::OPT_g_Flag);
+        unsigned DwarfVersion = getDwarfVersion(getToolChain(), Args);
+        CmdArgs.push_back(Args.MakeArgString("-gdwarf-" + Twine(DwarfVersion)));
+      }
 
   const char *Exec =
       Args.MakeArgString(getToolChain().GetProgramPath(DefaultAssembler));
Index: clang/test/Driver/as-options.cpp
===================================================================
--- /dev/null
+++ clang/test/Driver/as-options.cpp
@@ -0,0 +1,11 @@
+// Test that -g and -gdwarf-* are not passed through to GAS.
+// RUN: %clang --target=arm-linux-gnueabi -fno-integrated-as -g -c %s -### 2>&1 | \
+// RUN:   FileCheck --check-prefix=DEBUG %s
+// RUN: %clang --target=arm-linux-gnueabi -fno-integrated-as -gdwarf-4 -c %s -### 2>&1 | \
+// RUN:   FileCheck --check-prefix=DEBUG %s
+// RUN: %clang --target=arm-linux-gnueabi -fno-integrated-as -gdwarf-4 -g -c %s -### 2>&1 | \
+// RUN:   FileCheck --check-prefix=DEBUG %s
+// RUN: %clang --target=arm-linux-gnueabi -fno-integrated-as -g \
+// RUN:   -fdebug-default-version=4 -c %s -### 2>&1 | FileCheck --check-prefix=DEBUG %s
+// DEBUG-NOT: "-g"
+// DEBUG-NOT: "-gdwarf-4"
\ No newline at end of file
Index: clang/test/Driver/gcc_forward.c
===================================================================
--- clang/test/Driver/gcc_forward.c
+++ clang/test/Driver/gcc_forward.c
@@ -34,3 +34,15 @@
 // CHECK-NOT: "-Wall"
 // CHECK-NOT: "-Wdocumentation"
 // CHECK: "-o" "a.out"
+//
+// Test that -g and -gdwarf-* are not passed through to GAS.
+// RUN: %clang --target=arm-linux-gnueabi -fno-integrated-as -g -c %s -### 2>&1 | \
+// RUN:   FileCheck --check-prefix=DEBUG %s
+// RUN: %clang --target=arm-linux-gnueabi -fno-integrated-as -gdwarf-4 -c %s -### 2>&1 | \
+// RUN:   FileCheck --check-prefix=DEBUG %s
+// RUN: %clang --target=arm-linux-gnueabi -fno-integrated-as -gdwarf-4 -g -c %s -### 2>&1 | \
+// RUN:   FileCheck --check-prefix=DEBUG %s
+// RUN: %clang --target=arm-linux-gnueabi -fno-integrated-as -g \
+// RUN:   -fdebug-default-version=4 -c %s -### 2>&1 | FileCheck --check-prefix=DEBUG %s
+// DEBUG-NOT: "-g"
+// DEBUG-NOT: "-gdwarf-4"
\ No newline at end of file