text: /*
   * Copyright 2019 Google LLC
   *
   * Use of this source code is governed by a BSD-style license that can be
   * found in the LICENSE file.
   */
  
  #include "include/core/SkM44.h"
  #include "src/sksl/SkSLByteCode.h"
  #include "src/sksl/SkSLCompiler.h"
  #include "src/sksl/SkSLExternalValue.h"
  #include "src/utils/SkJSON.h"
  
  #include "tests/Test.h"
  
  static bool nearly_equal(const float a[], const float b[], int count) {
      for (int i = 0; i < count; ++i) {
          if (!SkScalarNearlyEqual(a[i], b[i])) {
              return false;
          }
      }
      return true;
  }
  
  void test(skiatest::Reporter* r, const char* src, float* in, float* expected,
            bool exactCompare = true) {
      SkSL::Compiler compiler(/*caps=*/nullptr);
      SkSL::Program::Settings settings;
      std::unique_ptr<SkSL::Program> program = compiler.convertProgram(SkSL::Program::kGeneric_Kind,
                                                                       SkSL::String(src), settings);
      REPORTER_ASSERT(r, program);
      if (program) {
          std::unique_ptr<SkSL::ByteCode> byteCode = compiler.toByteCode(*program);
          program.reset();
          REPORTER_ASSERT(r, !compiler.errorCount());
          if (compiler.errorCount() > 0) {
              printf("%s\n%s", src, compiler.errorText().c_str());
              return;
          }
          const SkSL::ByteCodeFunction* main = byteCode->getFunction("main");
          int returnCount = main->getReturnCount();
          std::unique_ptr<float[]> out = std::unique_ptr<float[]>(new float[returnCount]);
          SkAssertResult(byteCode->run(main, in, main->getParameterCount(), out.get(), returnCount,
                                       nullptr, 0));
          bool valid = exactCompare ? !memcmp(out.get(), expected, sizeof(float) * returnCount)
                                    : nearly_equal(out.get(), expected, returnCount);
          if (!valid) {
              printf("for program: %s\n", src);
              printf("    expected (");
              const char* separator = "";
              for (int i = 0; i < returnCount; ++i) {
                  printf("%s%f", separator, expected[i]);
                  separator = ", ";
              }
              printf("), but received (");
              separator = "";
              for (int i = 0; i < returnCount; ++i) {
                  printf("%s%f", separator, out.get()[i]);
                  separator = ", ";
              }
              printf(")\n");
              main->disassemble();
          }
          REPORTER_ASSERT(r, valid);
      } else {
          printf("%s\n%s", src, compiler.errorText().c_str());
      }
  }
  
  void vec_test(skiatest::Reporter* r, const char* src) {
      SkSL::Compiler compiler(/*caps=*/nullptr);
      SkSL::Program::Settings settings;
      std::unique_ptr<SkSL::Program> program = compiler.convertProgram(SkSL::Program::kGeneric_Kind,
                                                                       SkSL::String(src), settings);
      if (!program) {
          REPORT_FAILURE(r, "!program", SkString(compiler.errorText().c_str()));
          return;
      }
  
      std::unique_ptr<SkSL::ByteCode> byteCode = compiler.toByteCode(*program);
      if (compiler.errorCount() > 0) {
          REPORT_FAILURE(r, "!toByteCode", SkString(compiler.errorText().c_str()));
          return;
      }
  
      const SkSL::ByteCodeFunction* main = byteCode->getFunction("main");
  
      // Test on four different vectors (with varying orderings to get divergent control flow)
      const float input[16] = { 1, 2, 3, 4,
                                4, 3, 2, 1,
                                7, 5, 8, 6,
                                6, 8, 5, 7 };
  
      float out_s[16], out_v[16];
      memcpy(out_s, input, sizeof(out_s));
      memcpy(out_v, input, sizeof(out_v));
  
      // First run in scalar mode to determine the expected output
      for (int i = 0; i < 4; ++i) {
          SkAssertResult(byteCode->run(main, out_s + i * 4, 4, nullptr, 0, nullptr, 0));
      }
  
      // Need to transpose input vectors for striped execution
      auto transpose = [](float* v) {
          for (int r = 0; r < 4; ++r)
          for (int c = 0; c < r; ++c)
              std::swap(v[r*4 + c], v[c*4 + r]);
      };
  
      // Need to transpose input vectors for striped execution
      transpose(out_v);
      float* args[] = { out_v, out_v + 4, out_v + 8, out_v + 12 };
  
      // Now run in parallel and compare results
      SkAssertResult(byteCode->runStriped(main, 4, args, 4, nullptr, 0, nullptr, 0));
  
      // Transpose striped outputs back
      transpose(out_v);
  
      if (0 != memcmp(out_s, out_v, sizeof(out_s))) {
          printf("for program: %s\n", src);
          for (int i = 0; i < 4; ++i) {
              printf("(%g %g %g %g) -> (%g %g %g %g), expected (%g %g %g %g)\n",
                      input[4*i + 0], input[4*i + 1], input[4*i + 2], input[4*i + 3],
                      out_v[4*i + 0], out_v[4*i + 1], out_v[4*i + 2], out_v[4*i + 3],
                      out_s[4*i + 0], out_s[4*i + 1], out_s[4*i + 2], out_s[4*i + 3]);
          }
          main->disassemble();
          REPORT_FAILURE(r, "VecInterpreter mismatch", SkString());
      }
  }
  
  void test(skiatest::Reporter* r, const char* src, float inR, float inG, float inB, float inA,
            float expectedR, float expectedG, float expectedB, float expectedA) {
      SkSL::Compiler compiler(/*caps=*/nullptr);
      SkSL::Program::Settings settings;
      std::unique_ptr<SkSL::Program> program = compiler.convertProgram(SkSL::Program::kGeneric_Kind,
                                                                       SkSL::String(src), settings);
      REPORTER_ASSERT(r, program);
      if (program) {
          std::unique_ptr<SkSL::ByteCode> byteCode = compiler.toByteCode(*program);
          program.reset();
          REPORTER_ASSERT(r, !compiler.errorCount());
          if (compiler.errorCount() > 0) {
              printf("%s\n%s", src, compiler.errorText().c_str());
              return;
          }
          const SkSL::ByteCodeFunction* main = byteCode->getFunction("main");
          float inoutColor[4] = { inR, inG, inB, inA };
          SkAssertResult(byteCode->run(main, inoutColor, 4, nullptr, 0, nullptr, 0));
          if (inoutColor[0] != expectedR || inoutColor[1] != expectedG ||
              inoutColor[2] != expectedB || inoutColor[3] != expectedA) {
              printf("for program: %s\n", src);
              printf("    expected (%f, %f, %f, %f), but received (%f, %f, %f, %f)\n", expectedR,
                     expectedG, expectedB, expectedA, inoutColor[0], inoutColor[1], inoutColor[2],
                     inoutColor[3]);
              main->disassemble();
          }
          REPORTER_ASSERT(r, inoutColor[0] == expectedR);
          REPORTER_ASSERT(r, inoutColor[1] == expectedG);
          REPORTER_ASSERT(r, inoutColor[2] == expectedB);
          REPORTER_ASSERT(r, inoutColor[3] == expectedA);
      } else {
          printf("%s\n%s", src, compiler.errorText().c_str());
      }
  
      // Do additional testing of 4x1 vs 1x4 to stress divergent control flow, etc.
      vec_test(r, src);
  }
  
  DEF_TEST(SkSLInterpreterAdd, r) {
      test(r, "void main(inout half4 color) { color.r = color.r + color.g; }", 0.25, 0.75, 0, 0, 1,
           0.75, 0, 0);
      test(r, "void main(inout half4 color) { color += half4(1, 2, 3, 4); }", 4, 3, 2, 1, 5, 5, 5, 5);
      test(r, "void main(inout half4 color) { half4 c = color; color += c; }", 0.25, 0.5, 0.75, 1,
           0.5, 1, 1.5, 2);
      test(r, "void main(inout half4 color) { color.r = int(color.r) + int(color.g); }", 1, 3, 0, 0,
           4, 3, 0, 0);
  }
  
  DEF_TEST(SkSLInterpreterSubtract, r) {
      test(r, "void main(inout half4 color) { color.r = color.r - color.g; }", 1, 0.75, 0, 0, 0.25,
           0.75, 0, 0);
      test(r, "void main(inout half4 color) { color -= half4(1, 2, 3, 4); }", 5, 5, 5, 5, 4, 3, 2, 1);
      test(r, "void main(inout half4 color) { half4 c = color; color -= c; }", 4, 3, 2, 1,
           0, 0, 0, 0);
      test(r, "void main(inout half4 color) { color.x = -color.x; }", 4, 3, 2, 1, -4, 3, 2, 1);
      test(r, "void main(inout half4 color) { color = -color; }", 4, 3, 2, 1, -4, -3, -2, -1);
      test(r, "void main(inout half4 color) { color.r = int(color.r) - int(color.g); }", 3, 1, 0, 0,
           2, 1, 0, 0);
  }
  
  DEF_TEST(SkSLInterpreterMultiply, r) {
      test(r, "void main(inout half4 color) { color.r = color.r * color.g; }", 2, 3, 0, 0, 6, 3, 0,
           0);
      test(r, "void main(inout half4 color) { color *= half4(1, 2, 3, 4); }", 2, 3, 4, 5, 2, 6, 12,
           20);
      test(r, "void main(inout half4 color) { half4 c = color; color *= c; }", 4, 3, 2, 1,
           16, 9, 4, 1);
      test(r, "void main(inout half4 color) { color.r = int(color.r) * int(color.g); }", 3, -2, 0, 0,
           -6, -2, 0, 0);
  }
  
  DEF_TEST(SkSLInterpreterDivide, r) {
      test(r, "void main(inout half4 color) { color.r = color.r / color.g; }", 1, 2, 0, 0, 0.5, 2, 0,
           0);
      test(r, "void main(inout half4 color) { color /= half4(1, 2, 3, 4); }", 12, 12, 12, 12, 12, 6,
           4, 3);
      test(r, "void main(inout half4 color) { half4 c = color; color /= c; }", 4, 3, 2, 1,
           1, 1, 1, 1);
      test(r, "void main(inout half4 color) { color.r = int(color.r) / int(color.g); }", 8, -2, 0, 0,
           -4, -2, 0, 0);
  }
  
  DEF_TEST(SkSLInterpreterRemainder, r) {
      test(r, "void main(inout half4 color) { color.r = color.r % color.g; }", 3.125, 2, 0, 0,
           1.125, 2, 0, 0);
      test(r, "void main(inout half4 color) { color %= half4(1, 2, 3, 4); }", 9.5, 9.5, 9.5, 9.5,
           0.5, 1.5, 0.5, 1.5);
      test(r, "void main(inout half4 color) { color.r = int(color.r) % int(color.g); }", 8, 3, 0, 0,
           2, 3, 0, 0);
      test(r, "void main(inout half4 color) { color.rg = half2(int2(int(color.r), int(color.g)) % "
                  "int(color.b)); }", 8, 10, 6, 0, 2, 4, 6, 0);
  }
  
  DEF_TEST(SkSLInterpreterAnd, r) {
      test(r, "void main(inout half4 color) { if (color.r > color.g && color.g > color.b) "
              "color = half4(color.a); }", 2, 1, 0, 3, 3, 3, 3, 3);
      test(r, "void main(inout half4 color) { if (color.r > color.g && color.g > color.b) "
              "color = half4(color.a); }", 1, 1, 0, 3, 1, 1, 0, 3);
      test(r, "void main(inout half4 color) { if (color.r > color.g && color.g > color.b) "
              "color = half4(color.a); }", 2, 1, 1, 3, 2, 1, 1, 3);
      test(r, "int global; bool update() { global = 123; return true; }"
              "void main(inout half4 color) { global = 0;  if (color.r > color.g && update()) "
              "color = half4(color.a); color.a = global; }", 2, 1, 1, 3, 3, 3, 3, 123);
      test(r, "int global; bool update() { global = 123; return true; }"
              "void main(inout half4 color) { global = 0;  if (color.r > color.g && update()) "
              "color = half4(color.a); color.a = global; }", 1, 1, 1, 3, 1, 1, 1, 0);
  }
  
  DEF_TEST(SkSLInterpreterOr, r) {
      test(r, "void main(inout half4 color) { if (color.r > color.g || color.g > color.b) "
              "color = half4(color.a); }", 2, 1, 0, 3, 3, 3, 3, 3);
      test(r, "void main(inout half4 color) { if (color.r > color.g || color.g > color.b) "
              "color = half4(color.a); }", 1, 1, 0, 3, 3, 3, 3, 3);
      test(r, "void main(inout half4 color) { if (color.r > color.g || color.g > color.b) "
              "color = half4(color.a); }", 1, 1, 1, 3, 1, 1, 1, 3);
      test(r, "int global; bool update() { global = 123; return true; }"
              "void main(inout half4 color) { global = 0;  if (color.r > color.g || update()) "
              "color = half4(color.a); color.a = global; }", 1, 1, 1, 3, 3, 3, 3, 123);
      test(r, "int global; bool update() { global = 123; return true; }"
              "void main(inout half4 color) { global = 0;  if (color.r > color.g || update()) "
              "color = half4(color.a); color.a = global; }", 2, 1, 1, 3, 3, 3, 3, 0);
  }
  
  DEF_TEST(SkSLInterpreterBitwise, r) {
      test(r, "void main(inout half4 color) { color.r = half(int(color.r) | 3); }",
           5, 0, 0, 0, 7, 0, 0, 0);
      test(r, "void main(inout half4 color) { color.r = half(int(color.r) & 3); }",
           6, 0, 0, 0, 2, 0, 0, 0);
      test(r, "void main(inout half4 color) { color.r = half(int(color.r) ^ 3); }",
           5, 0, 0, 0, 6, 0, 0, 0);
      test(r, "void main(inout half4 color) { color.r = half(~int(color.r) & 3); }",
           6, 0, 0, 0, 1, 0, 0, 0);
  
      test(r, "void main(inout half4 color) { color.r = half(uint(color.r) | 3); }",
           5, 0, 0, 0, 7, 0, 0, 0);
      test(r, "void main(inout half4 color) { color.r = half(uint(color.r) & 3); }",
           6, 0, 0, 0, 2, 0, 0, 0);
      test(r, "void main(inout half4 color) { color.r = half(uint(color.r) ^ 3); }",
           5, 0, 0, 0, 6, 0, 0, 0);
      test(r, "void main(inout half4 color) { color.r = half(~uint(color.r) & 3); }",
           6, 0, 0, 0, 1, 0, 0, 0);
  
      // Shift operators
      unsigned in = 0x80000011;
      unsigned out;
  
      out = 0x00000088;
      test(r, "int  main(int  x) { return x << 3; }", (float*)&in, (float*)&out);
  
      out = 0xF0000002;
      test(r, "int main(int x) { return x >> 3; }", (float*)&in, (float*)&out);
  
      out = 0x10000002;
      test(r, "uint main(uint x) { return x >> 3; }", (float*)&in, (float*)&out);
  }
  
  DEF_TEST(SkSLInterpreterMatrix, r) {
      float in[16];
      float expected[16];
  
      // Constructing matrix from scalar produces a diagonal matrix
      in[0] = 1.0f;
      expected[0] = 2.0f;
      test(r, "float main(float x) { float4x4 m = float4x4(x); return m[1][1] + m[1][2] + m[2][2]; }",
           in, expected);
  
      // With non-square matrix
      test(r, "float main(float x) { float3x2 m = float3x2(x); return m[0][0] + m[1][1] + m[2][1]; }",
           in, expected);
  
      // Constructing from a different-sized matrix fills the remaining space with the identity matrix
      test(r, "float main(float x) {"
           "float3x2 m = float3x2(x);"
           "float4x4 m2 = float4x4(m);"
           "return m2[0][0] + m2[3][3]; }",
           in, expected);
  
      // Constructing a matrix from vectors or scalars fills in values in column-major order
      in[0] = 1.0f;
      in[1] = 2.0f;
      in[2] = 4.0f;
      in[3] = 8.0f;
      expected[0] = 6.0f;
      test(r, "float main(float4 v) { float2x2 m = float2x2(v); return m[0][1] + m[1][0]; }",
           in, expected);
  
      expected[0] = 10.0f;
      test(r, "float main(float4 v) {"
           "float2x2 m = float2x2(v.x, v.y, v.w, v.z);"
           "return m[0][1] + m[1][0]; }",
           in, expected);
  
      // Initialize 16 values to be used as inputs to matrix tests
      for (int i = 0; i < 16; ++i) { in[i] = (float)i; }
  
      // M+M, M-S, S-M
      for (int i = 0; i < 16; ++i) { expected[i] = (float)(2 * i); }
      test(r, "float4x4 main(float4x4 m) { return m + m; }", in, expected);
      for (int i = 0; i < 16; ++i) { expected[i] = (float)(i + 3); }
      test(r, "float4x4 main(float4x4 m) { return m + 3.0; }", in, expected);
      test(r, "float4x4 main(float4x4 m) { return 3.0 + m; }", in, expected);
  
      // M-M, M-S, S-M
      for (int i = 0; i < 8; ++i) { expected[i] = 8.0f; }
      test(r, "float4x2 main(float4x2 m1, float4x2 m2) { return m2 - m1; }", in, expected);
      for (int i = 0; i < 16; ++i) { expected[i] = (float)(i - 3); }
      test(r, "float4x4 main(float4x4 m) { return m - 3.0; }", in, expected);
      for (int i = 0; i < 16; ++i) { expected[i] = (float)(3 - i); }
      test(r, "float4x4 main(float4x4 m) { return 3.0 - m; }", in, expected);
  
      // M*S, S*M, M/S, S/M
      for (int i = 0; i < 16; ++i) { expected[i] = (float)(i * 3); }
      test(r, "float4x4 main(float4x4 m) { return m * 3.0; }", in, expected);
      test(r, "float4x4 main(float4x4 m) { return 3.0 * m; }", in, expected);
      for (int i = 0; i < 16; ++i) { expected[i] = (float)(i) / 2.0f; }
      test(r, "float4x4 main(float4x4 m) { return m / 2.0; }", in, expected);
      for (int i = 0; i < 16; ++i) { expected[i] = 1.0f / (float)(i + 1); }
      test(r, "float4x4 main(float4x4 m) { return 1.0 / (m + 1); }", in, expected);
  
  #if 0
      // Matrix negation - legal in GLSL, not in SkSL?
      for (int i = 0; i < 16; ++i) { expected[i] = (float)(-i); }
      test(r, "float4x4 main(float4x4 m) { return -m; }", in, 16, expected);
  #endif
  
      // M*V, V*M
      for (int i = 0; i < 4; ++i) {
          expected[i] = 12.0f*i + 13.0f*(i+4) + 14.0f*(i+8);
      }
      test(r, "float4 main(float3x4 m, float3 v) { return m * v; }", in, expected);
      for (int i = 0; i < 4; ++i) {
          expected[i] = 12.0f*(3*i) + 13.0f*(3*i+1) + 14.0f*(3*i+2);
      }
      test(r, "float4 main(float4x3 m, float3 v) { return v * m; }", in, expected);
  
      // M*M
      {
          SkM44 m = SkM44::ColMajor(in);
          SkM44 m2;
          float in2[16];
          for (int i = 0; i < 16; ++i) {
              in2[i] = (i + 4) % 16;
          }
          m2 = SkM44::ColMajor(in2);
          m.setConcat(m, m2);
          // Rearrange the columns on the RHS so we detect left-hand/right-hand errors
          test(r, "float4x4 main(float4x4 m) { return m * float4x4(m[1], m[2], m[3], m[0]); }",
               in, (float*)&m);
      }
  }
  
  DEF_TEST(SkSLInterpreterTernary, r) {
      test(r, "void main(inout half4 color) { color.r = color.g > color.b ? color.g : color.b; }",
           0, 1, 2, 0, 2, 1, 2, 0);
      test(r, "void main(inout half4 color) { color.r = color.g > color.b ? color.g : color.b; }",
           0, 3, 2, 0, 3, 3, 2, 0);
  }
  
  DEF_TEST(SkSLInterpreterCast, r) {
      union Val {
          float    f;
          uint32_t u;
          int32_t  s;
      };
  
      Val input[2];
      Val expected[2];
  
      input[0].s = 3;
      input[1].s = -5;
      expected[0].f = 3.0f;
      expected[1].f = -5.0f;
      test(r, "float  main(int  x) { return float (x); }", (float*)input, (float*)expected);
      test(r, "float2 main(int2 x) { return float2(x); }", (float*)input, (float*)expected);
  
      input[0].u = 3;
      input[1].u = 5;
      expected[0].f = 3.0f;
      expected[1].f = 5.0f;
      test(r, "float  main(uint  x) { return float (x); }", (float*)input, (float*)expected);
      test(r, "float2 main(uint2 x) { return float2(x); }", (float*)input, (float*)expected);
  
      input[0].f = 3.0f;
      input[1].f = -5.0f;
      expected[0].s = 3;
      expected[1].s = -5;
      test(r, "int  main(float  x) { return int (x); }", (float*)input, (float*)expected);
      test(r, "int2 main(float2 x) { return int2(x); }", (float*)input, (float*)expected);
  
      input[0].s = 3;
      expected[0].f = 3.0f;
      expected[1].f = 3.0f;
      test(r, "float2 main(int x) { return float2(x); }", (float*)input, (float*)expected);
  }
  
  DEF_TEST(SkSLInterpreterIf, r) {
      test(r, "void main(inout half4 color) { if (color.r > color.g) color.a = 1; }", 5, 3, 0, 0,
           5, 3, 0, 1);
      test(r, "void main(inout half4 color) { if (color.r > color.g) color.a = 1; }", 5, 5, 0, 0,
           5, 5, 0, 0);
      test(r, "void main(inout half4 color) { if (color.r > color.g) color.a = 1; }", 5, 6, 0, 0,
           5, 6, 0, 0);
      test(r, "void main(inout half4 color) { if (color.r < color.g) color.a = 1; }", 3, 5, 0, 0,
           3, 5, 0, 1);
      test(r, "void main(inout half4 color) { if (color.r < color.g) color.a = 1; }", 5, 5, 0, 0,
           5, 5, 0, 0);
      test(r, "void main(inout half4 color) { if (color.r < color.g) color.a = 1; }", 6, 5, 0, 0,
           6, 5, 0, 0);
      test(r, "void main(inout half4 color) { if (color.r >= color.g) color.a = 1; }", 5, 3, 0, 0,
           5, 3, 0, 1);
      test(r, "void main(inout half4 color) { if (color.r >= color.g) color.a = 1; }", 5, 5, 0, 0,
           5, 5, 0, 1);
      test(r, "void main(inout half4 color) { if (color.r >= color.g) color.a = 1; }", 5, 6, 0, 0,
           5, 6, 0, 0);
      test(r, "void main(inout half4 color) { if (color.r <= color.g) color.a = 1; }", 3, 5, 0, 0,
           3, 5, 0, 1);
      test(r, "void main(inout half4 color) { if (color.r <= color.g) color.a = 1; }", 5, 5, 0, 0,
           5, 5, 0, 1);
      test(r, "void main(inout half4 color) { if (color.r <= color.g) color.a = 1; }", 6, 5, 0, 0,
           6, 5, 0, 0);
      test(r, "void main(inout half4 color) { if (color.r == color.g) color.a = 1; }", 2, 2, 0, 0,
           2, 2, 0, 1);
      test(r, "void main(inout half4 color) { if (color.r == color.g) color.a = 1; }", 2, -2, 0, 0,
           2, -2, 0, 0);
      test(r, "void main(inout half4 color) { if (color.r != color.g) color.a = 1; }", 2, 2, 0, 0,
           2, 2, 0, 0);
      test(r, "void main(inout half4 color) { if (color.r != color.g) color.a = 1; }", 2, -2, 0, 0,
           2, -2, 0, 1);
      test(r, "void main(inout half4 color) { if (!(color.r == color.g)) color.a = 1; }", 2, 2, 0, 0,
           2, 2, 0, 0);
      test(r, "void main(inout half4 color) { if (!(color.r == color.g)) color.a = 1; }", 2, -2, 0, 0,
           2, -2, 0, 1);
      test(r, "void main(inout half4 color) { if (color.r == color.g) color.a = 1; else "
           "color.a = 2; }", 1, 1, 0, 0, 1, 1, 0, 1);
      test(r, "void main(inout half4 color) { if (color.r == color.g) color.a = 1; else "
           "color.a = 2; }", 2, -2, 0, 0, 2, -2, 0, 2);
  }
  
  DEF_TEST(SkSLInterpreterIfVector, r) {
      test(r, "void main(inout half4 color) { if (color.rg == color.ba) color.a = 1; }",
           1, 2, 1, 2, 1, 2, 1, 1);
      test(r, "void main(inout half4 color) { if (color.rg == color.ba) color.a = 1; }",
           1, 2, 3, 2, 1, 2, 3, 2);
      test(r, "void main(inout half4 color) { if (color.rg != color.ba) color.a = 1; }",
           1, 2, 1, 2, 1, 2, 1, 2);
      test(r, "void main(inout half4 color) { if (color.rg != color.ba) color.a = 1; }",
           1, 2, 3, 2, 1, 2, 3, 1);
  }
  
  DEF_TEST(SkSLInterpreterWhile, r) {
      test(r, "void main(inout half4 color) { while (color.r < 8) { color.r++; } }",
           1, 2, 3, 4, 8, 2, 3, 4);
      test(r, "void main(inout half4 color) { while (color.r < 1) color.r += 0.25; }", 0, 0, 0, 0, 1,
           0, 0, 0);
      test(r, "void main(inout half4 color) { while (color.r > 1) color.r -= 0.25; }", 0, 0, 0, 0, 0,
           0, 0, 0);
      test(r, "void main(inout half4 color) { while (true) { color.r += 0.5; "
           "if (color.r > 5) break; } }", 0, 0, 0, 0, 5.5, 0, 0, 0);
      test(r, "void main(inout half4 color) { while (color.r < 10) { color.r += 0.5; "
              "if (color.r < 5) continue; break; } }", 0, 0, 0, 0, 5, 0, 0, 0);
      test(r,
           "void main(inout half4 color) {"
           "    while (true) {"
           "        if (color.r > 4) { break; }"
           "        while (true) { color.a = 1; break; }"
           "        break;"
           "    }"
           "}",
           6, 5, 4, 3, 6, 5, 4, 3);
  }
  
  DEF_TEST(SkSLInterpreterDo, r) {
      test(r, "void main(inout half4 color) { do color.r += 0.25; while (color.r < 1); }", 0, 0, 0, 0,
           1, 0, 0, 0);
      test(r, "void main(inout half4 color) { do color.r -= 0.25; while (color.r > 1); }", 0, 0, 0, 0,
           -0.25, 0, 0, 0);
      test(r, "void main(inout half4 color) { do { color.r += 0.5; if (color.r > 1) break; } while "
              "(true); }", 0, 0, 0, 0, 1.5, 0, 0, 0);
      test(r, "void main(inout half4 color) {do { color.r += 0.5; if (color.r < 5) "
              "continue; if (color.r >= 5) break; } while (true); }", 0, 0, 0, 0, 5, 0, 0, 0);
      test(r, "void main(inout half4 color) { do { color.r += 0.5; } while (false); }",
           0, 0, 0, 0, 0.5, 0, 0, 0);
  }
  
  DEF_TEST(SkSLInterpreterFor, r) {
      test(r, "void main(inout half4 color) { for (int i = 1; i <= 10; ++i) color.r += i; }", 0, 0, 0,
           0, 55, 0, 0, 0);
      test(r,
           "void main(inout half4 color) {"
           "    for (int i = 1; i <= 10; ++i)"
           "        for (int j = i; j <= 10; ++j)"
           "            color.r += j;"
           "}",
           0, 0, 0, 0,
           385, 0, 0, 0);
      test(r,
           "void main(inout half4 color) {"
           "    for (int i = 1; i <= 10; ++i)"
           "        for (int j = 1; ; ++j) {"
           "            if (i == j) continue;"
           "            if (j > 10) break;"
           "            color.r += j;"
           "        }"
           "}",
           0, 0, 0, 0,
           495, 0, 0, 0);
  }
  
  DEF_TEST(SkSLInterpreterPrefixPostfix, r) {
      test(r, "void main(inout half4 color) { color.r = ++color.g; }", 1, 2, 3, 4, 3, 3, 3, 4);
      test(r, "void main(inout half4 color) { color.r = color.g++; }", 1, 2, 3, 4, 2, 3, 3, 4);
  }
  
  DEF_TEST(SkSLInterpreterSwizzle, r) {
      test(r, "void main(inout half4 color) { color = color.abgr; }", 1, 2, 3, 4, 4, 3, 2, 1);
      test(r, "void main(inout half4 color) { color.rgb = half4(5, 6, 7, 8).bbg; }", 1, 2, 3, 4, 7, 7,
           6, 4);
      test(r, "void main(inout half4 color) { color.bgr = int3(5, 6, 7); }", 1, 2, 3, 4, 7, 6,
           5, 4);
  }
  
  DEF_TEST(SkSLInterpreterGlobal, r) {
      test(r, "int x; void main(inout half4 color) { x = 10; color.b = x; }", 1, 2, 3, 4, 1, 2, 10,
           4);
      test(r, "float4 x; void main(inout float4 color) { x = color * 2; color = x; }",
           1, 2, 3, 4, 2, 4, 6, 8);
      test(r, "float4 x; void main(inout float4 color) { x = float4(5, 6, 7, 8); color = x.wzyx; }",
           1, 2, 3, 4, 8, 7, 6, 5);
      test(r, "float4 x; void main(inout float4 color) { x.wzyx = float4(5, 6, 7, 8); color = x; }",
           1, 2, 3, 4, 8, 7, 6, 5);
  }
  
  DEF_TEST(SkSLInterpreterGeneric, r) {
      float value1 = 5;
      float expected1 = 25;
      test(r, "float main(float x) { return x * x; }", &value1, &expected1);
      float value2[2] = { 5, 25 };
      float expected2[2] = { 25, 625 };
      test(r, "float2 main(float x, float y) { return float2(x * x, y * y); }", value2, expected2);
  }
  
  DEF_TEST(SkSLInterpreterCompound, r) {
      struct RectAndColor { SkIRect fRect; SkColor4f fColor; };
      struct ManyRects { int fNumRects; RectAndColor fRects[4]; };
  
      const char* src =
          // Some struct definitions
          "struct Point { int x; int y; };\n"
          "struct Rect {  Point p0; Point p1; };\n"
          "struct RectAndColor { Rect r; float4 color; };\n"
  
          // Structs as globals, parameters, return values
          "RectAndColor temp;\n"
          "int rect_height(Rect r) { return r.p1.y - r.p0.y; }\n"
          "RectAndColor make_blue_rect(int w, int h) {\n"
          "  temp.r.p0.x = temp.r.p0.y = 0;\n"
          "  temp.r.p1.x = w; temp.r.p1.y = h;\n"
          "  temp.color = float4(0, 1, 0, 1);\n"
          "  return temp;\n"
          "}\n"
  
          // Initialization and assignment of types larger than 4 slots
          "RectAndColor init_big(RectAndColor r) { RectAndColor s = r; return s; }\n"
          "RectAndColor copy_big(RectAndColor r) { RectAndColor s; s = r; return s; }\n"
  
          // Same for arrays, including some non-constant indexing
          "float tempFloats[8];\n"
          "int median(int a[15]) { return a[7]; }\n"
          "float[8] sums(float a[8]) {\n"
          "  float tempFloats[8];\n"
          "  tempFloats[0] = a[0];\n"
          "  for (int i = 1; i < 8; ++i) { tempFloats[i] = tempFloats[i - 1] + a[i]; }\n"
          "  return tempFloats;\n"
          "}\n"
  
          // Uniforms, array-of-structs, dynamic indices
          "uniform Rect gRects[4];\n"
          "Rect get_rect(int i) { return gRects[i]; }\n"
  
          // Kitchen sink (swizzles, inout, SoAoS)
          "struct ManyRects { int numRects; RectAndColor rects[4]; };\n"
          "void fill_rects(inout ManyRects mr) {\n"
          "  for (int i = 0; i < mr.numRects; ++i) {\n"
          "    mr.rects[i].r = gRects[i];\n"
          "    float b = mr.rects[i].r.p1.y;\n"
          "    mr.rects[i].color = float4(b, b, b, b);\n"
          "  }\n"
          "}\n";
  
      SkSL::Compiler compiler(/*caps=*/nullptr);
      SkSL::Program::Settings settings;
      settings.fRemoveDeadFunctions = false;
      std::unique_ptr<SkSL::Program> program = compiler.convertProgram(SkSL::Program::kGeneric_Kind,
                                                                       SkSL::String(src), settings);
      REPORTER_ASSERT(r, program);
  
      std::unique_ptr<SkSL::ByteCode> byteCode = compiler.toByteCode(*program);
      REPORTER_ASSERT(r, !compiler.errorCount());
  
      auto rect_height    = byteCode->getFunction("rect_height"),
           make_blue_rect = byteCode->getFunction("make_blue_rect"),
           median         = byteCode->getFunction("median"),
           sums           = byteCode->getFunction("sums"),
           get_rect       = byteCode->getFunction("get_rect"),
           fill_rects     = byteCode->getFunction("fill_rects");
  
      SkIRect gRects[4] = { { 1,2,3,4 }, { 5,6,7,8 }, { 9,10,11,12 }, { 13,14,15,16 } };
      const float* fRects = (const float*)gRects;
  
      {
          SkIRect in = SkIRect::MakeXYWH(10, 10, 20, 30);
          int out = 0;
          SkAssertResult(byteCode->run(rect_height, (float*)&in, 4, (float*)&out, 1, fRects, 16));
          REPORTER_ASSERT(r, out == 30);
      }
  
      {
          int in[2] = { 15, 25 };
          RectAndColor out;
          SkAssertResult(byteCode->run(make_blue_rect, (float*)in, 2, (float*)&out, 8, fRects, 16));
          REPORTER_ASSERT(r, out.fRect.width() == 15);
          REPORTER_ASSERT(r, out.fRect.height() == 25);
          SkColor4f blue = { 0.0f, 1.0f, 0.0f, 1.0f };
          REPORTER_ASSERT(r, out.fColor == blue);
      }
  
      {
          int in[15] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 };
          int out = 0;
          SkAssertResult(byteCode->run(median, (float*)in, 15, (float*)&out, 1, fRects, 16));
          REPORTER_ASSERT(r, out == 8);
      }
  
      {
          float in[8] = { 1, 2, 3, 4, 5, 6, 7, 8 };
          float out[8] = { 0 };
          SkAssertResult(byteCode->run(sums, in, 8, out, 8, fRects, 16));
          for (int i = 0; i < 8; ++i) {
              REPORTER_ASSERT(r, out[i] == static_cast<float>((i + 1) * (i + 2) / 2));
          }
      }
  
      {
          int in = 2;
          SkIRect out = SkIRect::MakeEmpty();
          SkAssertResult(byteCode->run(get_rect, (float*)&in, 1, (float*)&out, 4, fRects, 16));
          REPORTER_ASSERT(r, out == gRects[2]);
      }
  
      {
          ManyRects in;
          memset(&in, 0, sizeof(in));
          in.fNumRects = 2;
          SkAssertResult(byteCode->run(fill_rects, (float*)&in, 33, nullptr, 0, fRects, 16));
          ManyRects expected;
          memset(&expected, 0, sizeof(expected));
          expected.fNumRects = 2;
          for (int i = 0; i < 2; ++i) {
              expected.fRects[i].fRect = gRects[i];
              float c = gRects[i].fBottom;
              expected.fRects[i].fColor = { c, c, c, c };
          }
          REPORTER_ASSERT(r, memcmp(&in, &expected, sizeof(in)) == 0);
      }
  }
  
  static void expect_failure(skiatest::Reporter* r, const char* src) {
      SkSL::Compiler compiler(/*caps=*/nullptr);
      SkSL::Program::Settings settings;
      auto program = compiler.convertProgram(SkSL::Program::kGeneric_Kind,
                                             SkSL::String(src), settings);
      REPORTER_ASSERT(r, program);
  
      auto byteCode = compiler.toByteCode(*program);
      REPORTER_ASSERT(r, compiler.errorCount() > 0);
      REPORTER_ASSERT(r, !byteCode);
  }
  
  static void expect_run_failure(skiatest::Reporter* r, const char* src, float* in) {
      SkSL::Compiler compiler(/*caps=*/nullptr);
      SkSL::Program::Settings settings;
      auto program = compiler.convertProgram(SkSL::Program::kGeneric_Kind,
                                             SkSL::String(src), settings);
      REPORTER_ASSERT(r, program);
  
      auto byteCode = compiler.toByteCode(*program);
      REPORTER_ASSERT(r, byteCode);
  
      auto fun = byteCode->getFunction("main");
      bool result = byteCode->run(fun, in, fun->getParameterCount(), nullptr, 0, nullptr, 0);
      REPORTER_ASSERT(r, !result);
  }
  
  DEF_TEST(SkSLInterpreterRestrictFunctionCalls, r) {
      // Ensure that simple recursion is not allowed
      expect_failure(r, "float main() { return main() + 1; }");
  
      // Ensure that calls to undefined functions are not allowed (to prevent mutual recursion)
      expect_failure(r, "float foo(); float bar() { return foo(); } float foo() { return bar(); }");
  
      // returns are not allowed inside loops
      expect_failure(r, "float main(float x) { while (x > 1) { return x; } return 0; }");
  }
  
  DEF_TEST(SkSLInterpreterEarlyReturn, r) {
      // Unlike returns in loops, returns in conditionals should work.
      const char* src = "float main(float x, float y) { if (x < y) { return x; } return y; }";
  
      SkSL::Compiler compiler(/*caps=*/nullptr);
      std::unique_ptr<SkSL::Program> program = compiler.convertProgram(SkSL::Program::kGeneric_Kind,
                                                                       SkSL::String(src),
                                                                       SkSL::Program::Settings{});
      REPORTER_ASSERT(r, program);
  
      std::unique_ptr<SkSL::ByteCode> byteCode = compiler.toByteCode(*program);
      REPORTER_ASSERT(r, byteCode);
  
      // Our function should work fine via run().
      const SkSL::ByteCodeFunction* fun = byteCode->getFunction("main");
      float in[] = { 1.0f, 2.0f };
      float ret;
      REPORTER_ASSERT(r, byteCode->run(fun, in,2, &ret,1, nullptr,0));
      REPORTER_ASSERT(r, ret == 1.0f);
  
      in[0] = 3.0f;
      REPORTER_ASSERT(r, byteCode->run(fun, in,2, &ret,1, nullptr,0));
      REPORTER_ASSERT(r, ret == 2.0f);
  
      // Now same again via runStriped(), won't quite work yet.
      float xs[] = { 1.0f, 3.0f },
            ys[] = { 2.0f, 2.0f };
      float rets[2];
      float* ins[] = { xs, ys };
      float* outs[] = { rets+0, rets+1 } ;
      REPORTER_ASSERT(r, byteCode->runStriped(fun,2, ins,2, outs,1, nullptr,0));
      REPORTER_ASSERT(r, rets[0] == 1.0f);
    //REPORTER_ASSERT(r, rets[1] == 2.0f);  // TODO: skia:10852, make striped early returns work.
  }
  
  DEF_TEST(SkSLInterpreterArrayBounds, r) {
      // Out of bounds array access at compile time
      expect_failure(r, "float main(float x[4]) { return x[-1]; }");
      expect_failure(r, "float2 main(float2 x[2]) { return x[2]; }");
  
      // Out of bounds array access at runtime is pinned, and we don't update any inout data
      float in[3] = { -1.0f, 1.0f, 2.0f };
      expect_run_failure(r, "void main(inout float data[3]) { data[int(data[0])] = 0; }", in);
      REPORTER_ASSERT(r, in[0] == -1.0f && in[1] == 1.0f && in[2] == 2.0f);
  
      in[0] = 3.0f;
      expect_run_failure(r, "void main(inout float data[3]) { data[int(data[0])] = 0; }", in);
      REPORTER_ASSERT(r, in[0] == 3.0f && in[1] == 1.0f && in[2] == 2.0f);
  }
  
  DEF_TEST(SkSLInterpreterFunctions, r) {
      const char* src =
          "float sqr(float x) { return x * x; }\n"
          "float sub(float x, float y) { return x - y; }\n"
          "float main(float x) { return sub(sqr(x), x); }\n"
  
          // Different signatures
          "float dot(float2 a, float2 b) { return a.x*b.x + a.y*b.y; }\n"
          "float dot(float3 a, float3 b) { return a.x*b.x + a.y*b.y + a.z*b.z; }\n"
          "float dot3_test(float x) { return dot(float3(x, x + 1, x + 2), float3(1, -1, 2)); }\n"
          "float dot2_test(float x) { return dot(float2(x, x + 1), float2(1, -1)); }\n";
  
      SkSL::Compiler compiler(/*caps=*/nullptr);
      SkSL::Program::Settings settings;
      settings.fRemoveDeadFunctions = false;
      std::unique_ptr<SkSL::Program> program = compiler.convertProgram(SkSL::Program::kGeneric_Kind,
                                                                       SkSL::String(src), settings);
      REPORTER_ASSERT(r, program);
  
      std::unique_ptr<SkSL::ByteCode> byteCode = compiler.toByteCode(*program);
      REPORTER_ASSERT(r, !compiler.errorCount());
  
      auto sub = byteCode->getFunction("sub");
      auto sqr = byteCode->getFunction("sqr");
      auto main = byteCode->getFunction("main");
      auto tan = byteCode->getFunction("tan");
      auto dot3 = byteCode->getFunction("dot3_test");
      auto dot2 = byteCode->getFunction("dot2_test");
  
      REPORTER_ASSERT(r, sub);
      REPORTER_ASSERT(r, sqr);
      REPORTER_ASSERT(r, main);
      REPORTER_ASSERT(r, !tan);
      REPORTER_ASSERT(r, dot3);
      REPORTER_ASSERT(r, dot2);
  
      float out = 0.0f;
      float in = 3.0f;
      SkAssertResult(byteCode->run(main, &in, 1, &out, 1, nullptr, 0));
      REPORTER_ASSERT(r, out = 6.0f);
  
      SkAssertResult(byteCode->run(dot3, &in, 1, &out, 1, nullptr, 0));
      REPORTER_ASSERT(r, out = 9.0f);
  
      SkAssertResult(byteCode->run(dot2, &in, 1, &out, 1, nullptr, 0));
      REPORTER_ASSERT(r, out = -1.0f);
  }
  
  DEF_TEST(SkSLInterpreterOutParams, r) {
      test(r,
           "void oneAlpha(inout half4 color) { color.a = 1; }"
           "void main(inout half4 color) { oneAlpha(color); }",
           0, 0, 0, 0, 0, 0, 0, 1);
      test(r,
           "half2 tricky(half x, half y, inout half2 color, half z) {"
           "    color.xy = color.yx;"
           "    return half2(x + y, z);"
           "}"
           "void main(inout half4 color) {"
           "    half2 t = tricky(1, 2, color.rb, 5);"
           "    color.ga = t;"
           "}",
           1, 2, 3, 4, 3, 3, 1, 5);
  }
  
  DEF_TEST(SkSLInterpreterSwizzleSingleLvalue, r) {
      // Add in your SkSL here.
      test(r,
           "void main(inout half4 color) { color.xywz = half4(1,2,3,4); }",
           0, 0, 0, 0, 1, 2, 4, 3);
  }
  
  DEF_TEST(SkSLInterpreterSwizzleDoubleLvalue, r) {
      // Add in your SkSL here.
      test(r,
           "void main(inout half4 color) { color.xywz.yxzw = half4(1,2,3,4); }",
           0, 0, 0, 0, 2, 1, 4, 3);
  }
  
  DEF_TEST(SkSLInterpreterMathFunctions, r) {
      float value[4], expected[4];
  
      value[0] = 0.0f; expected[0] = 0.0f;
      test(r, "float main(float x) { return sin(x); }", value, expected);
      test(r, "float main(float x) { return tan(x); }", value, expected);
  
      value[0] = 0.0f; expected[0] = 1.0f;
      test(r, "float main(float x) { return cos(x); }", value, expected);
  
      value[0] = 25.0f; expected[0] = 5.0f;
      test(r, "float main(float x) { return sqrt(x); }", value, expected);
  
      value[0] = 90.0f; expected[0] = sk_float_degrees_to_radians(value[0]);
      test(r, "float main(float x) { return radians(x); }", value, expected);
  
      value[0] = 1.0f; value[1] = -1.0f;
      expected[0] = 1.0f / SK_FloatSqrt2; expected[1] = -1.0f / SK_FloatSqrt2;
      test(r, "float2 main(float2 x) { return normalize(x); }", value, expected);
  }
  
  DEF_TEST(SkSLInterpreterVoidFunction, r) {
      test(r,
           "half x; void foo() { x = 1.0; }"
           "void main(inout half4 color) { foo(); color.r = x; }",
           0, 0, 0, 0, 1, 0, 0, 0);
  }
  
  DEF_TEST(SkSLInterpreterMix, r) {
      float value, expected;
  
      value = 0.5f; expected = 0.0f;
      test(r, "float main(float x) { return mix(-10, 10, x); }", &value, &expected);
      value = 0.75f; expected = 5.0f;
      test(r, "float main(float x) { return mix(-10, 10, x); }", &value, &expected);
      value = 2.0f; expected = 30.0f;
      test(r, "float main(float x) { return mix(-10, 10, x); }", &value, &expected);
  
      float valueVectors[]   = { 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f },
            expectedVector[] = { 3.0f, 4.0f, 5.0f, 6.0f };
      test(r, "float4 main(float4 x, float4 y) { return mix(x, y, 0.5); }", valueVectors,
           expectedVector);
  }
  
  DEF_TEST(SkSLInterpreterCross, r) {
      float args[] = { 1.0f, 4.0f, -6.0f, -2.0f, 7.0f, -3.0f };
      SkV3 cross = SkV3::Cross({args[0], args[1], args[2]},
                               {args[3], args[4], args[5]});
      float expected[] = { cross.x, cross.y, cross.z };
      test(r, "float3 main(float3 x, float3 y) { return cross(x, y); }", args, expected);
  }
  
  DEF_TEST(SkSLInterpreterInverse, r) {
      {
          SkMatrix m;
          m.setRotate(30).postScale(1, 2);
          float args[4] = { m[0], m[3], m[1], m[4] };
          SkAssertResult(m.invert(&m));
          float expt[4] = { m[0], m[3], m[1], m[4] };
          test(r, "float2x2 main(float2x2 m) { return inverse(m); }", args, expt, false);
      }
      {
          SkMatrix m;
          m.setRotate(30).postScale(1, 2).postTranslate(1, 2);
          float args[9] = { m[0], m[3], m[6], m[1], m[4], m[7], m[2], m[5], m[8] };
          SkAssertResult(m.invert(&m));
          float expt[9] = { m[0], m[3], m[6], m[1], m[4], m[7], m[2], m[5], m[8] };
          test(r, "float3x3 main(float3x3 m) { return inverse(m); }", args, expt, false);
      }
      {
          float args[16], expt[16];
          // just some crazy thing that is invertible
          SkM44 m = {1, 2, 3, 4, 1, 2, 0, 3, 1, 0, 1, 4, 1, 3, 2, 0};
          m.getColMajor(args);
          SkAssertResult(m.invert(&m));
          m.getColMajor(expt);
          test(r, "float4x4 main(float4x4 m) { return inverse(m); }", args, expt, false);
      }
  }
  
  DEF_TEST(SkSLInterpreterDot, r) {
      float args[] = { 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f };
      float expected = args[0] * args[2] +
                       args[1] * args[3];
      test(r, "float main(float2 x, float2 y) { return dot(x, y); }", args, &expected);
  
      expected = args[0] * args[3] +
                 args[1] * args[4] +
                 args[2] * args[5];
      test(r, "float main(float3 x, float3 y) { return dot(x, y); }", args, &expected);
  
      expected = args[0] * args[4] +
                 args[1] * args[5] +
                 args[2] * args[6] +
                 args[3] * args[7];
      test(r, "float main(float4 x, float4 y) { return dot(x, y); }", args, &expected);
  }
  
  static const SkSL::Type& type_of(const skjson::Value* value, SkSL::Compiler* compiler) {
      switch (value->getType()) {
          case skjson::Value::Type::kNumber: {
              float f = *value->as<skjson::NumberValue>();
              if (f == (float) (int) f) {
                  return *compiler->context().fInt_Type;
              }
              return *compiler->context().fFloat_Type;
          }
          case skjson::Value::Type::kBool:
              return *compiler->context().fBool_Type;
          default:
              return *compiler->context().fVoid_Type;
      }
  }
  
  class JSONExternalValue : public SkSL::ExternalValue {
  public:
      JSONExternalValue(const char* name, const skjson::Value* value, SkSL::Compiler* compiler)
          : INHERITED(name, type_of(value, compiler))
          , fValue(*value)
          , fCompiler(*compiler) {}
  
      bool canRead() const override {
          return type() != *fCompiler.context().fVoid_Type;
      }
  
      void read(int /*unusedIndex*/, float* target) const override {
          if (type() == *fCompiler.context().fInt_Type) {
              *(int*) target = *fValue.as<skjson::NumberValue>();
          } else if (type() == *fCompiler.context().fFloat_Type) {
              *(float*) target = *fValue.as<skjson::NumberValue>();
          } else if (type() == *fCompiler.context().fBool_Type) {
              // ByteCode "booleans" are actually bit-masks
              *(int*) target = *fValue.as<skjson::BoolValue>() ? ~0 : 0;
          } else {
              SkASSERT(false);
          }
      }
  
      SkSL::ExternalValue* getChild(const char* name) const override {
          if (fValue.getType() == skjson::Value::Type::kObject) {
              const skjson::Value& v = fValue.as<skjson::ObjectValue>()[name];
              fOwned.push_back(std::make_unique<JSONExternalValue>(name, &v, &fCompiler));
              return fOwned.back().get();
          }
          return nullptr;
      }
  
  private:
      const skjson::Value& fValue;
      SkSL::Compiler& fCompiler;
      mutable std::vector<std::unique_ptr<SkSL::ExternalValue>> fOwned;
  
      using INHERITED = SkSL::ExternalValue;
  };
  
  class PointerExternalValue : public SkSL::ExternalValue {
  public:
      PointerExternalValue(const char* name, const SkSL::Type& type, void* data, size_t size)
          : INHERITED(name, type)
          , fBytes(data)
          , fSize(size) {}
  
      bool canRead() const override {
          return true;
      }
  
      bool canWrite() const override {
          return true;
      }
  
      void read(int /*unusedIndex*/, float* target) const override {
          memcpy(target, fBytes, fSize);
      }
  
      void write(int /*unusedIndex*/, float* src) const override {
          memcpy(fBytes, src, fSize);
      }
  
  
  private:
      void* fBytes;
      size_t fSize;
  
      using INHERITED = SkSL::ExternalValue;
  };
  
  DEF_TEST(SkSLInterpreterExternalValues, r) {
      const char* json = "{ \"value1\": 12, \"child\": { \"value2\": true, \"value3\": 5.5 } }";
      skjson::DOM dom(json, strlen(json));
      SkSL::Compiler compiler(/*caps=*/nullptr);
      SkSL::Program::Settings settings;
      const char* src = "float main() {"
                        "    outValue = 152;"
                        "    return root.child.value2 ? root.value1 * root.child.value3 : -1;"
                        "}";
      int32_t outValue = -1;
      std::vector<std::unique_ptr<SkSL::ExternalValue>> externalValues;
      externalValues.push_back(std::make_unique<JSONExternalValue>("root", &dom.root(), &compiler));
      externalValues.push_back(std::make_unique<PointerExternalValue>(
              "outValue", *compiler.context().fInt_Type, &outValue, sizeof(outValue)));
      std::unique_ptr<SkSL::Program> program = compiler.convertProgram(
              SkSL::Program::kGeneric_Kind, SkSL::String(src), settings, &externalValues);
      REPORTER_ASSERT(r, program);
      if (program) {
          std::unique_ptr<SkSL::ByteCode> byteCode = compiler.toByteCode(*program);
          REPORTER_ASSERT(r, !compiler.errorCount());
          if (compiler.errorCount() > 0) {
              printf("%s\n%s", src, compiler.errorText().c_str());
              return;
          }
          const SkSL::ByteCodeFunction* main = byteCode->getFunction("main");
          float out;
          SkAssertResult(byteCode->run(main, nullptr, 0, &out, 1, nullptr, 0));
          REPORTER_ASSERT(r, out == 66.0);
          REPORTER_ASSERT(r, outValue == 152);
      } else {
          printf("%s\n%s", src, compiler.errorText().c_str());
      }
  }
  
  DEF_TEST(SkSLInterpreterExternalValuesVector, r) {
      SkSL::Compiler compiler(/*caps=*/nullptr);
      SkSL::Program::Settings settings;
      const char* src = "void main() {"
                        "    value *= 2;"
                        "}";
      int32_t value[4] = { 1, 2, 3, 4 };
      std::vector<std::unique_ptr<SkSL::ExternalValue>> externalValues;
      externalValues.push_back(std::make_unique<PointerExternalValue>(
              "value", *compiler.context().fInt4_Type, value, sizeof(value)));
      std::unique_ptr<SkSL::Program> program = compiler.convertProgram(
              SkSL::Program::kGeneric_Kind, SkSL::String(src), settings, &externalValues);
      REPORTER_ASSERT(r, program);
      if (program) {
          std::unique_ptr<SkSL::ByteCode> byteCode = compiler.toByteCode(*program);
          REPORTER_ASSERT(r, !compiler.errorCount());
          if (compiler.errorCount() > 0) {
              printf("%s\n%s", src, compiler.errorText().c_str());
              return;
          }
          const SkSL::ByteCodeFunction* main = byteCode->getFunction("main");
          SkAssertResult(byteCode->run(main, nullptr, 0, nullptr, 0, nullptr, 0));
          REPORTER_ASSERT(r, value[0] == 2);
          REPORTER_ASSERT(r, value[1] == 4);
          REPORTER_ASSERT(r, value[2] == 6);
          REPORTER_ASSERT(r, value[3] == 8);
      } else {
          printf("%s\n%s", src, compiler.errorText().c_str());
      }
  }
  
  class FunctionExternalValue : public SkSL::ExternalValue {
  public:
      FunctionExternalValue(const char* name, float(*function)(float), SkSL::Compiler& compiler)
          : INHERITED(name, *compiler.context().fFloat_Type)
          , fCompiler(compiler)
          , fFunction(function) {}
  
      bool canCall() const override {
          return true;
      }
  
      int callParameterCount() const override {
          return 1;
      }
  
      void getCallParameterTypes(const SkSL::Type** outTypes) const override {
          outTypes[0] = fCompiler.context().fFloat_Type.get();
      }
  
      void call(int /*unusedIndex*/, float* arguments, float* outReturn) const override {
          outReturn[0] = fFunction(arguments[0]);
      }
  
  private:
      SkSL::Compiler& fCompiler;
  
      float (*fFunction)(float);
  
      using INHERITED = SkSL::ExternalValue;
  };
  
  DEF_TEST(SkSLInterpreterExternalValuesCall, r) {
      SkSL::Compiler compiler(/*caps=*/nullptr);
      SkSL::Program::Settings settings;
      const char* src = "float main() {"
                        "    return external(25);"
                        "}";
      std::vector<std::unique_ptr<SkSL::ExternalValue>> externalValues;
      externalValues.push_back(std::make_unique<FunctionExternalValue>(
              "external", [](float x) { return (float)sqrt(x); }, compiler));
      std::unique_ptr<SkSL::Program> program = compiler.convertProgram(
              SkSL::Program::kGeneric_Kind, SkSL::String(src), settings, &externalValues);
      REPORTER_ASSERT(r, program);
      if (program) {
          std::unique_ptr<SkSL::ByteCode> byteCode = compiler.toByteCode(*program);
          REPORTER_ASSERT(r, !compiler.errorCount());
          if (compiler.errorCount() > 0) {
              printf("%s\n%s", src, compiler.errorText().c_str());
              return;
          }
          const SkSL::ByteCodeFunction* main = byteCode->getFunction("main");
          float out;
          SkAssertResult(byteCode->run(main, nullptr, 0, &out, 1, nullptr, 0));
          REPORTER_ASSERT(r, out == 5.0);
      } else {
          printf("%s\n%s", src, compiler.errorText().c_str());
      }
  }
  
  class VectorFunctionExternalValue : public SkSL::ExternalValue {
  public:
      VectorFunctionExternalValue(const char* name, void(*function)(float[4], float[4]),
                                  SkSL::Compiler& compiler)
          : INHERITED(name, *compiler.context().fFloat4_Type)
          , fCompiler(compiler)
          , fFunction(function) {}
  
      bool canCall() const override {
          return true;
      }
  
      int callParameterCount() const override {
          return 1;
      }
  
      void getCallParameterTypes(const SkSL::Type** outTypes) const override {
          outTypes[0] = fCompiler.context().fFloat4_Type.get();
      }
  
      void call(int /*unusedIndex*/, float* arguments, float* outReturn) const override {
          fFunction(arguments, outReturn);
      }
  
  private:
      SkSL::Compiler& fCompiler;
  
      void (*fFunction)(float[4], float[4]);
  
      using INHERITED = SkSL::ExternalValue;
  };
  
  
  DEF_TEST(SkSLInterpreterExternalValuesVectorCall, r) {
      SkSL::Compiler compiler(/*caps=*/nullptr);
      SkSL::Program::Settings settings;
      const char* src =
              "float4 main() {"
              "    return external(float4(1, 4, 9, 16));"
              "}";
      std::vector<std::unique_ptr<SkSL::ExternalValue>> externalValues;
      externalValues.push_back(std::make_unique<VectorFunctionExternalValue>(
              "external",
              [](float in[4], float out[4]) {
                  out[0] = sqrt(in[0]);
                  out[1] = sqrt(in[1]);
                  out[2] = sqrt(in[2]);
                  out[3] = sqrt(in[3]);
              },
              compiler));
      std::unique_ptr<SkSL::Program> program = compiler.convertProgram(
              SkSL::Program::kGeneric_Kind, SkSL::String(src), settings, &externalValues);
      REPORTER_ASSERT(r, program);
      if (program) {
          std::unique_ptr<SkSL::ByteCode> byteCode = compiler.toByteCode(*program);
          REPORTER_ASSERT(r, !compiler.errorCount());
          if (compiler.errorCount() > 0) {
              printf("%s\n%s", src, compiler.errorText().c_str());
              return;
          }
          const SkSL::ByteCodeFunction* main = byteCode->getFunction("main");
          float out[4];
          SkAssertResult(byteCode->run(main, nullptr, 0, out, 4, nullptr, 0));
          REPORTER_ASSERT(r, out[0] == 1.0);
          REPORTER_ASSERT(r, out[1] == 2.0);
          REPORTER_ASSERT(r, out[2] == 3.0);
          REPORTER_ASSERT(r, out[3] == 4.0);
      } else {
          printf("%s\n%s", src, compiler.errorText().c_str());
      }
  }
  