commit aaea0d98fb64268b2f685ae2a36602920f129b36
author John Stiles <johnstiles@google.com> Mon Oct 26 13:09:37 2020 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Mon Oct 26 17:45:35 2020 +0000
tree c9833ac3e9ffa79d9f389c27eba7f2d6cda2d346
parent faa16931331468c6f9ae8412106c1d8e6d6e444b

Update `nameVariable` to return the variable name directly.

Previously, the generated name was passed back in a SkString-pointer
output parameter. Directly returning the SkString simplified nearly
every call site, and made none of them worse.

Change-Id: Ied57adcf8fb087a301641adad437d8a68f8d3297
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/329622
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>

src/gpu/glsl/GrGLSLProgramBuilder.cpp

diff --git a/src/gpu/glsl/GrGLSLProgramBuilder.cpp b/src/gpu/glsl/GrGLSLProgramBuilder.cpp
index 31e5408..87b5c2e 100644
--- a/src/gpu/glsl/GrGLSLProgramBuilder.cpp
+++ b/src/gpu/glsl/GrGLSLProgramBuilder.cpp
@@ -288,19 +288,20 @@
 }
 #endif
 
-void GrGLSLProgramBuilder::nameVariable(SkString* out, char prefix, const char* name, bool mangle) {
+SkString GrGLSLProgramBuilder::nameVariable(char prefix, const char* name, bool mangle) {
+    SkString out;
     if ('\0' == prefix) {
-        *out = name;
+        out = name;
     } else {
-        out->printf("%c%s", prefix, name);
+        out.printf("%c%s", prefix, name);
     }
     if (mangle) {
-        if (out->endsWith('_')) {
-            // Names containing "__" are reserved.
-            out->append("x");
-        }
-        out->appendf("_Stage%d%s", fStageIndex, fFS.getMangleString().c_str());
+        // Names containing "__" are reserved; add "x" if needed to avoid consecutive underscores.
+        const char *underscoreSplitter = out.endsWith('_') ? "x" : "";
+
+        out.appendf("%s_Stage%d%s", underscoreSplitter, fStageIndex, fFS.getMangleString().c_str());
     }
+    return out;
 }
 
 void GrGLSLProgramBuilder::nameExpression(SkString* output, const char* baseName) {
@@ -311,7 +312,7 @@
     if (output->size()) {
         outName = output->c_str();
     } else {
-        this->nameVariable(&outName, '\0', baseName);
+        outName = this->nameVariable(/*prefix=*/'\0', baseName);
     }
     fFS.codeAppendf("half4 %s;", outName.c_str());
     *output = outName;