Re-land sksl fragment processor support

This reverts commit ed50200682e0de72c3abecaa4d5324ebcd1ed9f9.

Bug: skia:
Change-Id: I9caa7454b391450620d6989dc472abb3cf7a2cab
Reviewed-on: https://skia-review.googlesource.com/20965
Reviewed-by: Ben Wagner <benjaminwagner@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>

1 files changed, 111 insertions, 0 deletions

diff --git a/src/sksl/SkSLSectionAndParameterHelper.h b/src/sksl/SkSLSectionAndParameterHelper.h
new file mode 100644
index 0000000000..81e5f3b192
--- /dev/null
+++ b/src/sksl/SkSLSectionAndParameterHelper.h
@@ -0,0 +1,111 @@
+/*
+ * Copyright 2017 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SKSL_SECTIONANDPARAMETERHELPER
+#define SKSL_SECTIONANDPARAMETERHELPER
+
+#include "SkSLErrorReporter.h"
+#include "ir/SkSLProgram.h"
+#include "ir/SkSLSection.h"
+#include "ir/SkSLVarDeclarations.h"
+#include <unordered_map>
+#include <vector>
+
+namespace SkSL {
+
+#define CLASS_SECTION              "class"
+#define CPP_SECTION                "cpp"
+#define HEADER_SECTION             "header"
+#define CONSTRUCTOR_PARAMS_SECTION "constructorParams"
+#define CONSTRUCTOR_SECTION        "constructor"
+#define CONSTRUCTOR_CODE_SECTION   "constructorCode"
+#define INITIALIZERS_SECTION       "initializers"
+#define EMIT_CODE_SECTION          "emitCode"
+#define FIELDS_SECTION             "fields"
+#define MAKE_SECTION               "make"
+#define OPTIMIZATION_FLAGS_SECTION "optimizationFlags"
+#define SET_DATA_SECTION           "setData"
+#define TEST_CODE_SECTION          "test"
+
+class SectionAndParameterHelper {
+public:
+    SectionAndParameterHelper(const Program& program, ErrorReporter& errors) {
+        for (const auto& p : program.fElements) {
+            switch (p->fKind) {
+                case ProgramElement::kVar_Kind: {
+                    const VarDeclarations* decls = (const VarDeclarations*) p.get();
+                    for (const auto& raw : decls->fVars) {
+                        const VarDeclaration& decl = (VarDeclaration&) *raw;
+                        if (IsParameter(*decl.fVar)) {
+                            fParameters.push_back(decl.fVar);
+                        }
+                    }
+                    break;
+                }
+                case ProgramElement::kSection_Kind: {
+                    const Section* s = (const Section*) p.get();
+                    if (IsSupportedSection(s->fName.c_str())) {
+                        if (SectionAcceptsArgument(s->fName.c_str())) {
+                            if (!s->fArgument.size()) {
+                                errors.error(s->fPosition,
+                                             ("section '@" + s->fName +
+                                              "' requires one parameter").c_str());
+                            }
+                        } else if (s->fArgument.size()) {
+                            errors.error(s->fPosition,
+                                         ("section '@" + s->fName + "' has no parameters").c_str());
+                        }
+                    } else {
+                        errors.error(s->fPosition,
+                                     ("unsupported section '@" + s->fName + "'").c_str());
+                    }
+                    if (fSections.find(s->fName) != fSections.end()) {
+                        errors.error(s->fPosition,
+                                     ("duplicate section '@" + s->fName + "'").c_str());
+                    }
+                    fSections[s->fName] = s;
+                    break;
+                }
+                default:
+                    break;
+            }
+        }
+    }
+
+    static bool IsParameter(const Variable& var) {
+        return (var.fModifiers.fFlags & Modifiers::kIn_Flag) &&
+               -1 == var.fModifiers.fLayout.fBuiltin;
+    }
+
+    static bool IsSupportedSection(const char* name) {
+        return !strcmp(name, CLASS_SECTION) ||
+               !strcmp(name, CPP_SECTION) ||
+               !strcmp(name, HEADER_SECTION) ||
+               !strcmp(name, CONSTRUCTOR_SECTION) ||
+               !strcmp(name, CONSTRUCTOR_CODE_SECTION) ||
+               !strcmp(name, CONSTRUCTOR_PARAMS_SECTION) ||
+               !strcmp(name, EMIT_CODE_SECTION) ||
+               !strcmp(name, FIELDS_SECTION) ||
+               !strcmp(name, INITIALIZERS_SECTION) ||
+               !strcmp(name, MAKE_SECTION) ||
+               !strcmp(name, OPTIMIZATION_FLAGS_SECTION) ||
+               !strcmp(name, SET_DATA_SECTION) ||
+               !strcmp(name, TEST_CODE_SECTION);
+    }
+
+    static bool SectionAcceptsArgument(const char* name) {
+        return !strcmp(name, SET_DATA_SECTION) ||
+               !strcmp(name, TEST_CODE_SECTION);
+    }
+
+    std::vector<const Variable*> fParameters;
+    std::unordered_map<String, const Section*> fSections;
+};
+
+} // namespace SkSL
+
+#endif