This revision was not accepted when it landed; it landed in state "Needs
Review".
This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rG6d09aaecdfe5: Revert "[clang] Add early exit when
checking for const init of arrays." (authored by adamcz).
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D113599/new/
https://reviews.llvm.org/D113599
Files:
clang/lib/AST/ExprConstant.cpp
clang/test/SemaCXX/PR51712-large-array-constexpr-check-oom.cpp
Index: clang/test/SemaCXX/PR51712-large-array-constexpr-check-oom.cpp
===================================================================
--- clang/test/SemaCXX/PR51712-large-array-constexpr-check-oom.cpp
+++ /dev/null
@@ -1,11 +0,0 @@
-// REQUIRES: shell
-// UNSUPPORTED: win32
-// RUN: ulimit -v 1048576
-// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify -triple=x86_64 %s
-// expected-no-diagnostics
-
-// This used to require too much memory and crash with OOM.
-struct {
- int a, b, c, d;
-} arr[1<<30];
-
Index: clang/lib/AST/ExprConstant.cpp
===================================================================
--- clang/lib/AST/ExprConstant.cpp
+++ clang/lib/AST/ExprConstant.cpp
@@ -10596,55 +10596,28 @@
bool HadZeroInit = Value->hasValue();
if (const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(Type)) {
- unsigned FinalSize = CAT->getSize().getZExtValue();
+ unsigned N = CAT->getSize().getZExtValue();
// Preserve the array filler if we had prior zero-initialization.
APValue Filler =
HadZeroInit && Value->hasArrayFiller() ? Value->getArrayFiller()
: APValue();
- *Value = APValue(APValue::UninitArray(), 0, FinalSize);
- if (FinalSize == 0)
- return true;
+ *Value = APValue(APValue::UninitArray(), N, N);
+
+ if (HadZeroInit)
+ for (unsigned I = 0; I != N; ++I)
+ Value->getArrayInitializedElt(I) = Filler;
+ // Initialize the elements.
LValue ArrayElt = Subobject;
ArrayElt.addArray(Info, E, CAT);
- // We do the whole initialization in two passes, first for just one
element,
- // then for the whole array. It's possible we may find out we can't do
const
- // init in the first pass, in which case we avoid allocating a potentially
- // large array. We don't do more passes because expanding array requires
- // copying the data, which is wasteful.
- for (const unsigned N : {1u, FinalSize}) {
- unsigned OldElts = Value->getArrayInitializedElts();
- if (OldElts == N)
- break;
-
- // Expand the array to appropriate size.
- APValue NewValue(APValue::UninitArray(), N, FinalSize);
- for (unsigned I = 0; I < OldElts; ++I)
- NewValue.getArrayInitializedElt(I).swap(
- Value->getArrayInitializedElt(I));
- Value->swap(NewValue);
-
- if (HadZeroInit)
- for (unsigned I = OldElts; I < N; ++I)
- Value->getArrayInitializedElt(I) = Filler;
-
- // Initialize the elements.
- for (unsigned I = OldElts; I < N; ++I) {
- if (!VisitCXXConstructExpr(E, ArrayElt,
- &Value->getArrayInitializedElt(I),
- CAT->getElementType()) ||
- !HandleLValueArrayAdjustment(Info, E, ArrayElt,
- CAT->getElementType(), 1))
- return false;
- // When checking for const initilization any diagnostic is considered
- // an error.
- if (Info.EvalStatus.Diag && !Info.EvalStatus.Diag->empty() &&
- !Info.keepEvaluatingAfterFailure())
- return false;
- }
- }
+ for (unsigned I = 0; I != N; ++I)
+ if (!VisitCXXConstructExpr(E, ArrayElt,
&Value->getArrayInitializedElt(I),
+ CAT->getElementType()) ||
+ !HandleLValueArrayAdjustment(Info, E, ArrayElt,
CAT->getElementType(),
+ 1))
+ return false;
return true;
}
Index: clang/test/SemaCXX/PR51712-large-array-constexpr-check-oom.cpp
===================================================================
--- clang/test/SemaCXX/PR51712-large-array-constexpr-check-oom.cpp
+++ /dev/null
@@ -1,11 +0,0 @@
-// REQUIRES: shell
-// UNSUPPORTED: win32
-// RUN: ulimit -v 1048576
-// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify -triple=x86_64 %s
-// expected-no-diagnostics
-
-// This used to require too much memory and crash with OOM.
-struct {
- int a, b, c, d;
-} arr[1<<30];
-
Index: clang/lib/AST/ExprConstant.cpp
===================================================================
--- clang/lib/AST/ExprConstant.cpp
+++ clang/lib/AST/ExprConstant.cpp
@@ -10596,55 +10596,28 @@
bool HadZeroInit = Value->hasValue();
if (const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(Type)) {
- unsigned FinalSize = CAT->getSize().getZExtValue();
+ unsigned N = CAT->getSize().getZExtValue();
// Preserve the array filler if we had prior zero-initialization.
APValue Filler =
HadZeroInit && Value->hasArrayFiller() ? Value->getArrayFiller()
: APValue();
- *Value = APValue(APValue::UninitArray(), 0, FinalSize);
- if (FinalSize == 0)
- return true;
+ *Value = APValue(APValue::UninitArray(), N, N);
+
+ if (HadZeroInit)
+ for (unsigned I = 0; I != N; ++I)
+ Value->getArrayInitializedElt(I) = Filler;
+ // Initialize the elements.
LValue ArrayElt = Subobject;
ArrayElt.addArray(Info, E, CAT);
- // We do the whole initialization in two passes, first for just one element,
- // then for the whole array. It's possible we may find out we can't do const
- // init in the first pass, in which case we avoid allocating a potentially
- // large array. We don't do more passes because expanding array requires
- // copying the data, which is wasteful.
- for (const unsigned N : {1u, FinalSize}) {
- unsigned OldElts = Value->getArrayInitializedElts();
- if (OldElts == N)
- break;
-
- // Expand the array to appropriate size.
- APValue NewValue(APValue::UninitArray(), N, FinalSize);
- for (unsigned I = 0; I < OldElts; ++I)
- NewValue.getArrayInitializedElt(I).swap(
- Value->getArrayInitializedElt(I));
- Value->swap(NewValue);
-
- if (HadZeroInit)
- for (unsigned I = OldElts; I < N; ++I)
- Value->getArrayInitializedElt(I) = Filler;
-
- // Initialize the elements.
- for (unsigned I = OldElts; I < N; ++I) {
- if (!VisitCXXConstructExpr(E, ArrayElt,
- &Value->getArrayInitializedElt(I),
- CAT->getElementType()) ||
- !HandleLValueArrayAdjustment(Info, E, ArrayElt,
- CAT->getElementType(), 1))
- return false;
- // When checking for const initilization any diagnostic is considered
- // an error.
- if (Info.EvalStatus.Diag && !Info.EvalStatus.Diag->empty() &&
- !Info.keepEvaluatingAfterFailure())
- return false;
- }
- }
+ for (unsigned I = 0; I != N; ++I)
+ if (!VisitCXXConstructExpr(E, ArrayElt, &Value->getArrayInitializedElt(I),
+ CAT->getElementType()) ||
+ !HandleLValueArrayAdjustment(Info, E, ArrayElt, CAT->getElementType(),
+ 1))
+ return false;
return true;
}
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