Turned on SkSL->GLSL compiler

src/sksl/SkSLMain.cpp

Index: src/sksl/SkSLMain.cpp
diff --git a/src/sksl/SkSLMain.cpp b/src/sksl/SkSLMain.cpp
index 24fbb6c260fa7921dd9502173cf1f263f3d4d800..de1b9819d55a5bc7f59c909de451b49cb392cd40 100644
--- a/src/sksl/SkSLMain.cpp
+++ b/src/sksl/SkSLMain.cpp
@@ -9,6 +9,24 @@
 #include <fstream>
 #include "SkSLCompiler.h"
 
+bool endsWith(const std::string& s, const std::string& ending) {
+    if (s.length() >= ending.length()) {
+        return (0 == s.compare(s.length() - ending.length(), ending.length(), ending));
+    }
+    return false;
+}
+
+static SkSL::GLCaps default_caps() {
+    return { 
+             400, 
+             SkSL::GLCaps::kGL_Standard,
+             false, // isCoreProfile
+             false, // usesPrecisionModifiers;
+             false, // mustDeclareFragmentShaderOutput
+             true   // canUseMinAndAbsTogether
+           };
+}
+
 /**
  * Very simple standalone executable to facilitate testing.
  */
@@ -35,14 +53,30 @@ int main(int argc, const char** argv) {
         printf("error reading '%s'\n", argv[1]);
         exit(2);
     }
-    std::ofstream out(argv[2], std::ofstream::binary);
-    SkSL::Compiler compiler;
-    if (!compiler.toSPIRV(kind, text, out)) {
-        printf("%s", compiler.errorText().c_str());
-        exit(3);
-    }
-    if (out.rdstate()) {
-        printf("error writing '%s'\n", argv[2]);
-        exit(4);
+    std::string name(argv[2]);
+    if (endsWith(name, ".spirv")) {
+        std::ofstream out(argv[2], std::ofstream::binary);
+        SkSL::Compiler compiler;
+        if (!compiler.toSPIRV(kind, text, out)) {
+            printf("%s", compiler.errorText().c_str());
+            exit(3);
+        }
+        if (out.rdstate()) {
+            printf("error writing '%s'\n", argv[2]);
+            exit(4);
+        }
+    } else if (endsWith(name, ".glsl")) {
+        std::ofstream out(argv[2], std::ofstream::binary);
+        SkSL::Compiler compiler;
+        if (!compiler.toGLSL(kind, text, default_caps(), out)) {
+            printf("%s", compiler.errorText().c_str());
+            exit(3);
+        }
+        if (out.rdstate()) {
+            printf("error writing '%s'\n", argv[2]);
+            exit(4);
+        }
+    } else {
+        printf("expected output filename to end with '.spirv' or '.glsl'");
     }
 }