gn: add support for clang for MIPS

build/config/compiler/BUILD.gn

Index: build/config/compiler/BUILD.gn
diff --git a/build/config/compiler/BUILD.gn b/build/config/compiler/BUILD.gn
index bd1067f8fc37e5fb42b2ef8abd05e2f624bd66b1..6923a32f1dd4c5f8e7a02b236df2251ebcd57615 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -425,29 +425,93 @@ config("compiler_cpu_abi") {
       }
     } 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") {
-        cflags += [
-          "-mips32r2",
-          "-Wa,-mips32r2",
-        ]
-        if (mips_float_abi == "hard" && mips_fpu_mode != "") {
-          cflags += [ "-m$mips_fpu_mode" ]
+        if (is_clang) {
+          if (is_android) {
+            cflags += [
+              "-target",
+              "mipsel-linux-android",
+              "-march=mipsel",
+              "-mcpu=mips32r2",
+            ]
+            ldflags += [
+              "-target",
+              "mipsel-linux-android",
+            ]
+          } else {
+            cflags += [
+              "-target",
+              "mipsel-linux-gnu",
+              "-march=mipsel",
+              "-mcpu=mips32r2",
+            ]
+            ldflags += [
+              "-target",
+              "mipsel-linux-gnu",
+            ]
+          }
+        } else {
+          cflags += [
+            "-mips32r2",
+            "-Wa,-mips32r2",
+          ]
+          if (mips_float_abi == "hard" && mips_fpu_mode != "") {
+            cflags += [ "-m$mips_fpu_mode" ]
+          }
         }
       } else if (mips_arch_variant == "r1") {
-        cflags += [
-          "-mips32",
-          "-Wa,-mips32",
-        ]
+        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",
+          ]
+        }
       }
 
       if (mips_dsp_rev == 1) {