Turned on SkSL->GLSL compiler

src/gpu/gl/builders/GrGLShaderStringBuilder.cpp

Index: src/gpu/gl/builders/GrGLShaderStringBuilder.cpp
diff --git a/src/gpu/gl/builders/GrGLShaderStringBuilder.cpp b/src/gpu/gl/builders/GrGLShaderStringBuilder.cpp
index d2e49a5cfb0b5716b988aa4d3aaec1d4a5451050..2f1860aa5017d6933cb13a07afe56e49263e70f3 100644
--- a/src/gpu/gl/builders/GrGLShaderStringBuilder.cpp
+++ b/src/gpu/gl/builders/GrGLShaderStringBuilder.cpp
@@ -9,6 +9,8 @@
 #include "gl/GrGLGpu.h"
 #include "gl/GrGLSLPrettyPrint.h"
 #include "SkTraceEvent.h"
+#include "SkSLCompiler.h"
+#include "ir/SkSLProgram.h"
 
 #define GL_CALL(X) GR_GL_CALL(gpu->glInterface(), X)
 #define GL_CALL_RET(R, X) GR_GL_CALL_RET(gpu->glInterface(), R, X)
@@ -18,6 +20,74 @@ static const bool c_PrintShaders{false};
 
 static void print_shader_source(const char** strings, int* lengths, int count);
 
+static SkSL::GLCaps skslcaps_for_context(const GrGLContext& context) {
+    GrGLStandard standard = context.standard();
+    const GrGLCaps* caps = context.caps();
+    const GrGLSLCaps* glslCaps = caps->glslCaps();
+    SkSL::GLCaps result;
+    switch (standard) {
+        case kGL_GrGLStandard:
+            result.fStandard = SkSL::GLCaps::kGL_Standard;
+            break;
+        case kGLES_GrGLStandard:
+            result.fStandard = SkSL::GLCaps::kGLES_Standard;
+            break;
+        default:
+            SkASSERT(false);
+            result.fStandard = SkSL::GLCaps::kGL_Standard;
+    }
+
+    switch (glslCaps->generation()) {
+        case k110_GrGLSLGeneration:
+            if (kGLES_GrGLStandard == standard) {
+                // ES2's shader language is based on GLSL 1.20 but is version 1.00 of the ES 
+                // language
+                result.fVersion = 100;
+            } else {
+                SkASSERT(kGL_GrGLStandard == standard);
+                result.fVersion = 110;
+            }
+            break;
+        case k130_GrGLSLGeneration:
+            SkASSERT(kGL_GrGLStandard == standard);
+            result.fVersion = 130;
+            break;
+        case k140_GrGLSLGeneration:
+            SkASSERT(kGL_GrGLStandard == standard);
+            result.fVersion = 140;
+            break;
+        case k150_GrGLSLGeneration:
+            SkASSERT(kGL_GrGLStandard == standard);
+            result.fVersion = 150;
+            break;
+        case k330_GrGLSLGeneration:
+            if (kGLES_GrGLStandard == standard) {
+                result.fVersion = 300;
+            } else {
+                SkASSERT(kGL_GrGLStandard == standard);
+                result.fVersion = 330;
+            }
+            break;
+        case k400_GrGLSLGeneration:
+            SkASSERT(kGL_GrGLStandard == standard);
+            result.fVersion = 400;
+            break;
+        case k310es_GrGLSLGeneration:
+            SkASSERT(kGLES_GrGLStandard == standard);
+            result.fVersion = 310;
+            break;
+        case k320es_GrGLSLGeneration:
+            SkASSERT(kGLES_GrGLStandard == standard);
+            result.fVersion = 320;
+            break;
+    }
+    result.fIsCoreProfile = caps->isCoreProfile();
+    result.fUsesPrecisionModifiers = glslCaps->usesPrecisionModifiers();
+    result.fMustDeclareFragmentShaderOutput = glslCaps->mustDeclareFragmentShaderOutput();
+    result.fCanUseMinAndAbsTogether = glslCaps->canUseMinAndAbsTogether();
+    return result;
+}
+
 GrGLuint GrGLCompileAndAttachShader(const GrGLContext& glCtx,
                                     GrGLuint programId,
                                     GrGLenum type,
@@ -33,15 +103,31 @@ GrGLuint GrGLCompileAndAttachShader(const GrGLContext& glCtx,
         return 0;
     }
 
+    std::string sksl;
 #ifdef SK_DEBUG
     SkString prettySource = GrGLSLPrettyPrint::PrettyPrintGLSL(strings, lengths, count, false);
-    const GrGLchar* sourceStr = prettySource.c_str();
-    GrGLint sourceLength = static_cast<GrGLint>(prettySource.size());
-    GR_GL_CALL(gli, ShaderSource(shaderId, 1, &sourceStr, &sourceLength));
+    sksl = std::string(prettySource.c_str());
 #else
-    GR_GL_CALL(gli, ShaderSource(shaderId, count, strings, lengths));
+    for (int i = 0; i < count; i++) {
+        sksl.append(strings[i], lengths[i]);
+    }
 #endif
 
+    std::string glsl;
+    // creating Compiler is expensive, and we are single-threaded anyway, so just reuse a static one
+    static SkSL::Compiler compiler;

[bsalomon, 2016/09/08 19:51:37]

We only allow a single GrContext to be used on one thread (at a time). But there
can be multiple GrContexts running simultaneously on different threads.

[ethannicholas, 2016/09/09 16:34:54]

I moved the compiler instance into GrGLContext to avoid this problem. To
minimize the impact of this change (GrGLContext is used in *a lot* of places), I
use a raw pointer to SkSL::Compiler to avoid having to import SkSLCompiler.h
from GrGLContext.h. This may not be the best way to fix this -- thoughts?

[bsalomon, 2016/09/12 13:48:57]

I don't have a problem with including SkSLCompiler.h in GrGLContext.h. Though,
can't std::unique_ptr be used with just a forward decl?

[ethannicholas, 2016/09/12 14:53:26]

error: invalid application of ‘sizeof’ to incomplete type ‘SkSL::Compiler’

:-(

+    SkSL::GLCaps caps = skslcaps_for_context(glCtx);
+    SkASSERT(type == GR_GL_VERTEX_SHADER || type == GR_GL_FRAGMENT_SHADER);
+    bool result = compiler.toGLSL(type == GR_GL_VERTEX_SHADER ? SkSL::Program::kVertex_Kind
+                                                              : SkSL::Program::kFragment_Kind,
+                                  std::string(sksl.c_str()),
+                                  caps,
+                                  &glsl);
+    SkASSERTF(result, "SkSL errors:\n%s", compiler.errorText().c_str());
+    const char* glslChars = glsl.c_str();
+    GrGLint  glslLength = (GrGLint) glsl.length();
+    GR_GL_CALL(gli, ShaderSource(shaderId, 1, &glslChars, &glslLength));
+
     // If tracing is enabled in chrome then we pretty print
     bool traceShader;
     TRACE_EVENT_CATEGORY_GROUP_ENABLED(TRACE_DISABLED_BY_DEFAULT("skia.gpu"), &traceShader);