Index: clang/lib/Driver/ToolChains/WebAssembly.cpp
===================================================================
--- clang/lib/Driver/ToolChains/WebAssembly.cpp
+++ clang/lib/Driver/ToolChains/WebAssembly.cpp
@@ -371,7 +371,11 @@
 WebAssembly::GetCXXStdlibType(const ArgList &Args) const {
   if (Arg *A = Args.getLastArg(options::OPT_stdlib_EQ)) {
     StringRef Value = A->getValue();
-    if (Value != "libc++")
+    if (Value == "libc++")
+      return ToolChain::CST_Libcxx;
+    else if (Value == "libstdc++")
+      return ToolChain::CST_Libstdcxx;
+    else
       getDriver().Diag(diag::err_drv_invalid_stdlib_name)
           << A->getAsString(Args);
   }
@@ -417,17 +421,34 @@
 
 void WebAssembly::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
                                                ArgStringList &CC1Args) const {
-  if (!DriverArgs.hasArg(options::OPT_nostdlibinc) &&
-      !DriverArgs.hasArg(options::OPT_nostdincxx)) {
-    if (getTriple().getOS() != llvm::Triple::UnknownOS) {
-      const std::string MultiarchTriple =
-          getMultiarchTriple(getDriver(), getTriple(), getDriver().SysRoot);
+
+  if (DriverArgs.hasArg(options::OPT_nostdlibinc) ||
+      DriverArgs.hasArg(options::OPT_nostdincxx))
+    return;
+
+  bool IsKnownOs = (getTriple().getOS() != llvm::Triple::UnknownOS);
+  const std::string MultiarchTriple =
+      getMultiarchTriple(getDriver(), getTriple(), getDriver().SysRoot);
+
+  switch (GetCXXStdlibType(DriverArgs)) {
+  case ToolChain::CST_Libcxx:
+    if (IsKnownOs)
       addSystemInclude(DriverArgs, CC1Args,
                        getDriver().SysRoot + "/include/" + MultiarchTriple +
                            "/c++/v1");
-    }
     addSystemInclude(DriverArgs, CC1Args,
                      getDriver().SysRoot + "/include/c++/v1");
+    break;
+  case ToolChain::CST_Libstdcxx:
+    if (IsKnownOs)
+      addSystemInclude(DriverArgs, CC1Args,
+                       getDriver().SysRoot + "/include/" + MultiarchTriple +
+                           "/c++/11");
+    addSystemInclude(DriverArgs, CC1Args,
+                     getDriver().SysRoot + "/include/c++/11");
+    break;
+  default:
+    assert(false);
   }
 }
 
@@ -440,6 +461,9 @@
     CmdArgs.push_back("-lc++abi");
     break;
   case ToolChain::CST_Libstdcxx:
+    CmdArgs.push_back("-lstdc++");
+    break;
+  default:
     llvm_unreachable("invalid stdlib name");
   }
 }
Index: clang/test/Driver/wasm-toolchain.cpp
===================================================================
--- clang/test/Driver/wasm-toolchain.cpp
+++ clang/test/Driver/wasm-toolchain.cpp
@@ -19,6 +19,11 @@
 // LINK: clang{{.*}}" "-cc1" {{.*}} "-o" "[[temp:[^"]*]]"
 // LINK: wasm-ld{{.*}}" "-L/foo/lib" "crt1.o" "[[temp]]" "-lc++" "-lc++abi" "-lc" "{{.*[/\\]}}libclang_rt.builtins-wasm32.a" "-o" "a.out"
 
+// RUN: %clangxx -### -no-canonical-prefixes -target wasm32-unknown-unknown --sysroot=/foo --stdlib=libstdc++ %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=LINK_STDCXX %s
+// LINK_STDCXX: clang{{.*}}" "-cc1" {{.*}} "-o" "[[temp:[^"]*]]"
+// LINK_STDCXX: wasm-ld{{.*}}" "-L/foo/lib" "crt1.o" "[[temp]]" "-lstdc++" "-lc" "{{.*[/\\]}}libclang_rt.builtins-wasm32.a" "-o" "a.out"
+
 // A basic C++ link command-line with optimization with unknown OS.
 
 // RUN: %clangxx -### -O2 -no-canonical-prefixes -target wasm32-unknown-unknown --sysroot=/foo %s --stdlib=c++ 2>&1 \
@@ -26,6 +31,11 @@
 // LINK_OPT: clang{{.*}}" "-cc1" {{.*}} "-o" "[[temp:[^"]*]]"
 // LINK_OPT: wasm-ld{{.*}}" "-L/foo/lib" "crt1.o" "[[temp]]" "-lc++" "-lc++abi" "-lc" "{{.*[/\\]}}libclang_rt.builtins-wasm32.a" "-o" "a.out"
 
+// RUN: %clangxx -### -O2 -no-canonical-prefixes -target wasm32-unknown-unknown --sysroot=/foo %s --stdlib=libstdc++ 2>&1 \
+// RUN:   | FileCheck -check-prefix=LINK_OPT_STDCXX %s
+// LINK_OPT_STDCXX: clang{{.*}}" "-cc1" {{.*}} "-o" "[[temp:[^"]*]]"
+// LINK_OPT_STDCXX: wasm-ld{{.*}}" "-L/foo/lib" "crt1.o" "[[temp]]" "-lstdc++" "-lc" "{{.*[/\\]}}libclang_rt.builtins-wasm32.a" "-o" "a.out"
+
 // A basic C++ link command-line with known OS.
 
 // RUN: %clangxx -### -no-canonical-prefixes -target wasm32-wasi --sysroot=/foo --stdlib=c++ %s 2>&1 \
@@ -33,6 +43,11 @@
 // LINK_KNOWN: clang{{.*}}" "-cc1" {{.*}} "-o" "[[temp:[^"]*]]"
 // LINK_KNOWN: wasm-ld{{.*}}" "-L/foo/lib/wasm32-wasi" "crt1.o" "[[temp]]" "-lc++" "-lc++abi" "-lc" "{{.*[/\\]}}libclang_rt.builtins-wasm32.a" "-o" "a.out"
 
+// RUN: %clangxx -### -no-canonical-prefixes -target wasm32-wasi --sysroot=/foo --stdlib=libstdc++ %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=LINK_KNOWN_STDCXX %s
+// LINK_KNOWN_STDCXX: clang{{.*}}" "-cc1" {{.*}} "-o" "[[temp:[^"]*]]"
+// LINK_KNOWN_STDCXX: wasm-ld{{.*}}" "-L/foo/lib/wasm32-wasi" "crt1.o" "[[temp]]" "-lstdc++" "-lc" "{{.*[/\\]}}libclang_rt.builtins-wasm32.a" "-o" "a.out"
+
 // A basic C++ link command-line with optimization with known OS.
 
 // RUN: %clangxx -### -O2 -no-canonical-prefixes -target wasm32-wasi --sysroot=/foo %s --stdlib=c++ 2>&1 \
@@ -40,6 +55,11 @@
 // LINK_OPT_KNOWN: clang{{.*}}" "-cc1" {{.*}} "-o" "[[temp:[^"]*]]"
 // LINK_OPT_KNOWN: wasm-ld{{.*}}" "-L/foo/lib/wasm32-wasi" "crt1.o" "[[temp]]" "-lc++" "-lc++abi" "-lc" "{{.*[/\\]}}libclang_rt.builtins-wasm32.a" "-o" "a.out"
 
+// RUN: %clangxx -### -O2 -no-canonical-prefixes -target wasm32-wasi --sysroot=/foo %s --stdlib=libstdc++ 2>&1 \
+// RUN:   | FileCheck -check-prefix=LINK_OPT_KNOWN_STDCXX %s
+// LINK_OPT_KNOWN_STDCXX: clang{{.*}}" "-cc1" {{.*}} "-o" "[[temp:[^"]*]]"
+// LINK_OPT_KNOWN_STDCXX: wasm-ld{{.*}}" "-L/foo/lib/wasm32-wasi" "crt1.o" "[[temp]]" "-lstdc++" "-lc" "{{.*[/\\]}}libclang_rt.builtins-wasm32.a" "-o" "a.out"
+
 // A basic C++ compile command-line with known OS.
 
 // RUN: %clangxx -### -no-canonical-prefixes -target wasm32-wasi --sysroot=/foo --stdlib=c++ %s 2>&1 \
@@ -52,3 +72,14 @@
 // COMPILE: "-internal-isystem" "[[RESOURCE_DIR]]{{(/|\\\\)}}include"
 // COMPILE: "-internal-isystem" "/foo/include/wasm32-wasi"
 // COMPILE: "-internal-isystem" "/foo/include"
+
+// RUN: %clangxx -### -no-canonical-prefixes -target wasm32-wasi --sysroot=/foo --stdlib=libstdc++ %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=COMPILE_STDCXX %s
+// COMPILE_STDCXX: clang{{.*}}" "-cc1"
+// COMPILE_STDCXX: "-resource-dir" "[[RESOURCE_DIR:[^"]*]]"
+// COMPILE_STDCXX: "-isysroot" "/foo"
+// COMPILE_STDCXX: "-internal-isystem" "/foo/include/wasm32-wasi/c++/11"
+// COMPILE_STDCXX: "-internal-isystem" "/foo/include/c++/11"
+// COMPILE_STDCXX: "-internal-isystem" "[[RESOURCE_DIR]]{{(/|\\\\)}}include"
+// COMPILE_STDCXX: "-internal-isystem" "/foo/include/wasm32-wasi"
+// COMPILE_STDCXX: "-internal-isystem" "/foo/include"