Add static asserts around assumed-static skia enum values

Protects assumptions around enums value built into LUTs

Change-Id: Ica0692e4309d50b4d3897e0f3f47809d14f786fe

2 files changed, 28 insertions, 1 deletions

diff --git a/libs/hwui/SkiaShader.cpp b/libs/hwui/SkiaShader.cpp
index 1f959469fb56..6c105cfc7b00 100644
--- a/libs/hwui/SkiaShader.cpp
+++ b/libs/hwui/SkiaShader.cpp
@@ -32,12 +32,19 @@ namespace uirenderer {
 // Support
 ///////////////////////////////////////////////////////////////////////////////
 
-static const GLenum gTileModes[] = {
+static constexpr GLenum gTileModes[] = {
         GL_CLAMP_TO_EDGE,   // == SkShader::kClamp_TileMode
         GL_REPEAT,          // == SkShader::kRepeat_Mode
         GL_MIRRORED_REPEAT  // == SkShader::kMirror_TileMode
 };
 
+static_assert(gTileModes[SkShader::kClamp_TileMode] == GL_CLAMP_TO_EDGE,
+        "SkShader TileModes have changed");
+static_assert(gTileModes[SkShader::kRepeat_TileMode] == GL_REPEAT,
+        "SkShader TileModes have changed");
+static_assert(gTileModes[SkShader::kMirror_TileMode] == GL_MIRRORED_REPEAT,
+        "SkShader TileModes have changed");
+
 /**
  * This function does not work for n == 0.
  */
diff --git a/libs/hwui/renderstate/Blend.cpp b/libs/hwui/renderstate/Blend.cpp
index 29927ed8667b..b21e15e8fad9 100644
--- a/libs/hwui/renderstate/Blend.cpp
+++ b/libs/hwui/renderstate/Blend.cpp
@@ -30,6 +30,26 @@ struct Blender {
     GLenum dst;
 };
 
+// assumptions made by lookup tables in either this file or ProgramCache
+static_assert(0 == SkXfermode::kClear_Mode, "SkXfermode enums have changed");
+static_assert(1 == SkXfermode::kSrc_Mode, "SkXfermode enums have changed");
+static_assert(2 == SkXfermode::kDst_Mode, "SkXfermode enums have changed");
+static_assert(3 == SkXfermode::kSrcOver_Mode, "SkXfermode enums have changed");
+static_assert(4 == SkXfermode::kDstOver_Mode, "SkXfermode enums have changed");
+static_assert(5 == SkXfermode::kSrcIn_Mode, "SkXfermode enums have changed");
+static_assert(6 == SkXfermode::kDstIn_Mode, "SkXfermode enums have changed");
+static_assert(7 == SkXfermode::kSrcOut_Mode, "SkXfermode enums have changed");
+static_assert(8 == SkXfermode::kDstOut_Mode, "SkXfermode enums have changed");
+static_assert(9 == SkXfermode::kSrcATop_Mode, "SkXfermode enums have changed");
+static_assert(10 == SkXfermode::kDstATop_Mode, "SkXfermode enums have changed");
+static_assert(11 == SkXfermode::kXor_Mode, "SkXfermode enums have changed");
+static_assert(12 == SkXfermode::kPlus_Mode, "SkXfermode enums have changed");
+static_assert(13 == SkXfermode::kModulate_Mode, "SkXfermode enums have changed");
+static_assert(14 == SkXfermode::kScreen_Mode, "SkXfermode enums have changed");
+static_assert(15 == SkXfermode::kOverlay_Mode, "SkXfermode enums have changed");
+static_assert(16 == SkXfermode::kDarken_Mode, "SkXfermode enums have changed");
+static_assert(17 == SkXfermode::kLighten_Mode, "SkXfermode enums have changed");
+
 // In this array, the index of each Blender equals the value of the first
 // entry. For instance, gBlends[1] == gBlends[SkXfermode::kSrc_Mode]
 const Blender kBlends[] = {