commit 5081942c0d62171b765838a3075dff2ddfd76cf6
author John Stiles <johnstiles@google.com> Thu Jun 18 13:00:38 2020 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Fri Jun 19 13:25:05 2020 +0000
tree 0ce3b63985736a65484abd03ea69ad5a112ee555
parent ddca6ab54ad6754b2f21a14572f300c11dcd9f20

Optimize CPP code generation.

Previously, we were limiting our calls to appendVAList to 512-byte
chunks to avoid a potential buffer overflow. This had two problems:
1 - it did not avoid the buffer overflow :(
    see chromium:1092743
2 - every call to appendVAList is expensive; it incurs a resize of the
    code buffer (alloc new, memcpy, free old)

This CL removes the 512-byte cap as the buffer overflow issue was
resolved at http://review.skia.org/297276

This CL also includes a few more minor improvements.
- `codeAppendf` now uses a raw string so the gencode is easier to read.
- Optimized `SkStringPrintf("%s", foo)` to `SkString(foo)`.
- Optimized `strA = strB` to `strA.swap(strB)` where safe to do so.

Change-Id: Ia0909a68719848dd2ca655066a9bc6929c8fd09f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/297358
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>

src/gpu/gradients/generated/GrClampedGradientEffect.cpp

diff --git a/src/gpu/gradients/generated/GrClampedGradientEffect.cpp b/src/gpu/gradients/generated/GrClampedGradientEffect.cpp
index b657cdd..7e309c3 100644
--- a/src/gpu/gradients/generated/GrClampedGradientEffect.cpp
+++ b/src/gpu/gradients/generated/GrClampedGradientEffect.cpp
@@ -38,8 +38,14 @@
         SkString _sample1099;
         _sample1099 = this->invokeChild(_outer.gradLayout_index, args);
         fragBuilder->codeAppendf(
-                "half4 t = %s;\nif (!%s && t.y < 0.0) {\n    %s = half4(0.0);\n} else if (t.x < "
-                "0.0) {\n    %s = %s;\n} else if (t.x > 1.0) {\n    %s = %s;\n} else {",
+                R"SkSL(half4 t = %s;
+if (!%s && t.y < 0.0) {
+    %s = half4(0.0);
+} else if (t.x < 0.0) {
+    %s = %s;
+} else if (t.x > 1.0) {
+    %s = %s;
+} else {)SkSL",
                 _sample1099.c_str(),
                 (_outer.childProcessor(_outer.gradLayout_index).preservesOpaqueInput() ? "true"
                                                                                        : "false"),
@@ -49,10 +55,16 @@
         SkString _input1767("t");
         SkString _sample1767;
         _sample1767 = this->invokeChild(_outer.colorizer_index, _input1767.c_str(), args);
-        fragBuilder->codeAppendf("\n    %s = %s;\n}\n@if (%s) {\n    %s.xyz *= %s.w;\n}\n",
-                                 args.fOutputColor, _sample1767.c_str(),
-                                 (_outer.makePremul ? "true" : "false"), args.fOutputColor,
-                                 args.fOutputColor);
+        fragBuilder->codeAppendf(
+                R"SkSL(
+    %s = %s;
+}
+@if (%s) {
+    %s.xyz *= %s.w;
+}
+)SkSL",
+                args.fOutputColor, _sample1767.c_str(), (_outer.makePremul ? "true" : "false"),
+                args.fOutputColor, args.fOutputColor);
     }
 
 private: