gn: add support for clang for MIPS

build/config/compiler/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/android/config.gni")
 import("//build/config/chrome_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/nacl/config.gni")
 import("//build/toolchain/ccache.gni")
 
@@ skipping 407 matching lines @@
             # Clang doesn't support this option.
             cflags += [ "-mthumb-interwork" ]
           }
         }
       }
       if (arm_tune != "") {
         cflags += [ "-mtune=$arm_tune" ]
       }
     } else if (current_cpu == "mipsel") {
       if (mips_arch_variant == "r6") {
-        cflags += [
-          "-mips32r6",
-          "-Wa,-mips32r6",
-        ]
-        if (is_android) {
+        if (is_clang) {
+          cflags += [
+            "-target",
+            "mipsel-linux-gnu",
+            "-march=mips32r6",
+          ]
           ldflags += [
+            "-target",
+            "mipsel-linux-gnu",
+          ]
+        } else {
+          cflags += [
             "-mips32r6",
-            "-Wl,-melf32ltsmip",
+            "-Wa,-mips32r6",
+          ]
+          if (is_android) {
+            ldflags += [
+              "-mips32r6",
+              "-Wl,-melf32ltsmip",
+            ]
+          }
+        }
+      } else if (mips_arch_variant == "r2") {
+        if (is_clang) {
+          if (is_android) {
+            cflags += [
+              "-target",
+              "mipsel-linux-android",
+              "-march=mipsel",
+              "-mcpu=mips32r2",
+            ]
+            ldflags += [
+              "-target",
+              "mipsel-linux-android",
+            ]
+          } else {
+            cflags += [
+              "-target",
+              "mipsel-linux-gnu",
+              "-march=mipsel",
+              "-mcpu=mips32r2",
+            ]
+            ldflags += [
+              "-target",
+              "mipsel-linux-gnu",
+            ]
+          }
+        } else {
+          cflags += [
+            "-mips32r2",
+            "-Wa,-mips32r2",
+          ]
+          if (mips_float_abi == "hard" && mips_fpu_mode != "") {
+            cflags += [ "-m$mips_fpu_mode" ]
+          }
+        }
+      } else if (mips_arch_variant == "r1") {
+        if (is_clang) {
+          if (is_android) {
+            cflags += [
+              "-target",
+              "mipsel-linux-android",
+              "-march=mipsel",
+              "-mcpu=mips32",
+            ]
+            ldflags += [
+              "-target",
+              "mipsel-linux-android",
+            ]
+          } else {
+            cflags += [
+              "-target",
+              "mipsel-linux-gnu",
+              "-march=mipsel",
+              "-mcpu=mips32",
+            ]
+            ldflags += [
+              "-target",
+              "mipsel-linux-gnu",
+            ]
+          }
+        } else {
+          cflags += [
+            "-mips32",
+            "-Wa,-mips32",
           ]
         }
-      } else if (mips_arch_variant == "r2") {
-        cflags += [
-          "-mips32r2",
-          "-Wa,-mips32r2",
-        ]
-        if (mips_float_abi == "hard" && mips_fpu_mode != "") {
-          cflags += [ "-m$mips_fpu_mode" ]
-        }
-      } else if (mips_arch_variant == "r1") {
-        cflags += [
-          "-mips32",
-          "-Wa,-mips32",
-        ]
       }
 
       if (mips_dsp_rev == 1) {
         cflags += [ "-mdsp" ]
       } else if (mips_dsp_rev == 2) {
         cflags += [ "-mdspr2" ]
       }
 
       cflags += [ "-m${mips_float_abi}-float" ]
     } else if (current_cpu == "mips64el") {
@@ skipping 789 matching lines @@
   if (symbol_level == 0) {
     configs = [ ":no_symbols" ]
   } else if (symbol_level == 1) {
     configs = [ ":minimal_symbols" ]
   } else if (symbol_level == 2) {
     configs = [ ":symbols" ]
   } else {
     assert(false)
   }
 }