1 files changed, 14 insertions, 0 deletions
diff --git a/contrib/llvm-project/clang/lib/CodeGen/CGDecl.cpp b/contrib/llvm-project/clang/lib/CodeGen/CGDecl.cpp
index a5da0aa2965a..bbe14ef4c172 100644
--- a/contrib/llvm-project/clang/lib/CodeGen/CGDecl.cpp
+++ b/contrib/llvm-project/clang/lib/CodeGen/CGDecl.cpp
@@ -1759,20 +1759,34 @@ void CodeGenFunction::emitZeroOrPatternForAutoVarInit(QualType type,
                                                       const VarDecl &D,
                                                       Address Loc) {
   auto trivialAutoVarInit = getContext().getLangOpts().getTrivialAutoVarInit();
+  auto trivialAutoVarInitMaxSize =
+      getContext().getLangOpts().TrivialAutoVarInitMaxSize;
   CharUnits Size = getContext().getTypeSizeInChars(type);
   bool isVolatile = type.isVolatileQualified();
   if (!Size.isZero()) {
+    // We skip auto-init variables by their alloc size. Take this as an example:
+    // "struct Foo {int x; char buff[1024];}" Assume the max-size flag is 1023.
+    // All Foo type variables will be skipped. Ideally, we only skip the buff
+    // array and still auto-init X in this example.
+    // TODO: Improve the size filtering to by member size.
+    auto allocSize = CGM.getDataLayout().getTypeAllocSize(Loc.getElementType());
     switch (trivialAutoVarInit) {
     case LangOptions::TrivialAutoVarInitKind::Uninitialized:
       llvm_unreachable("Uninitialized handled by caller");
     case LangOptions::TrivialAutoVarInitKind::Zero:
       if (CGM.stopAutoInit())
         return;
+      if (trivialAutoVarInitMaxSize > 0 &&
+          allocSize > trivialAutoVarInitMaxSize)
+        return;
       emitStoresForZeroInit(CGM, D, Loc, isVolatile, Builder);
       break;
     case LangOptions::TrivialAutoVarInitKind::Pattern:
       if (CGM.stopAutoInit())
         return;
+      if (trivialAutoVarInitMaxSize > 0 &&
+          allocSize > trivialAutoVarInitMaxSize)
+        return;
       emitStoresForPatternInit(CGM, D, Loc, isVolatile, Builder);
       break;
     }