[AST] Refine the condition for element-dependent array fillers
This patch fixes clang to not consider braced initializers for
aggregate elements of arrays to be potentially dependent on the
indices of the initialized elements. Resolves bug 18978:
initialize a large static array = clang oom?
https://bugs.llvm.org/show_bug.cgi?id=18978
Differential Revision: https://reviews.llvm.org/D43187
llvm-svn: 325120
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 61bd1e5..e56569d 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -48,6 +48,8 @@
#include <cstring>
#include <functional>
+#define DEBUG_TYPE "exprconstant"
+
using namespace clang;
using llvm::APSInt;
using llvm::APFloat;
@@ -6780,6 +6782,22 @@
return ArrayExprEvaluator(Info, This, Result).Visit(E);
}
+// Return true iff the given array filler may depend on the element index.
+static bool MaybeElementDependentArrayFiller(const Expr *FillerExpr) {
+ // For now, just whitelist non-class value-initialization and initialization
+ // lists comprised of them.
+ if (isa<ImplicitValueInitExpr>(FillerExpr))
+ return false;
+ if (const InitListExpr *ILE = dyn_cast<InitListExpr>(FillerExpr)) {
+ for (unsigned I = 0, E = ILE->getNumInits(); I != E; ++I) {
+ if (MaybeElementDependentArrayFiller(ILE->getInit(I)))
+ return true;
+ }
+ return false;
+ }
+ return true;
+}
+
bool ArrayExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(E->getType());
if (!CAT)
@@ -6809,10 +6827,13 @@
const Expr *FillerExpr = E->hasArrayFiller() ? E->getArrayFiller() : nullptr;
// If the initializer might depend on the array index, run it for each
- // array element. For now, just whitelist non-class value-initialization.
- if (NumEltsToInit != NumElts && !isa<ImplicitValueInitExpr>(FillerExpr))
+ // array element.
+ if (NumEltsToInit != NumElts && MaybeElementDependentArrayFiller(FillerExpr))
NumEltsToInit = NumElts;
+ DEBUG(llvm::dbgs() << "The number of elements to initialize: " <<
+ NumEltsToInit << ".\n");
+
Result = APValue(APValue::UninitArray(), NumEltsToInit, NumElts);
// If the array was previously zero-initialized, preserve the