[clang] [clang] Fix a crash from nested ArrayInitLoopExpr (PR #67722)
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Fri Sep 29 05:52:02 PDT 2023
https://github.com/isuckatcs updated https://github.com/llvm/llvm-project/pull/67722
>From a6d3c27ea0b35e32198e1652fe3f6d647bc8cec4 Mon Sep 17 00:00:00 2001
From: isuckatcs <65320245+isuckatcs at users.noreply.github.com>
Date: Thu, 28 Sep 2023 20:43:23 +0200
Subject: [PATCH 1/5] [clang] Fix a crash from nested ArrayInitLoopExpr
When visiting an ArrayInitLoopExpr, clang creates a temporary
variable for the source array, however in a nested AILE this
variable is created multiple times, in every iteration as they
have the same AST node and clang is unable to differentiate them.
Fixes #57135
---
clang/lib/AST/ExprConstant.cpp | 11 ++++++-----
.../nested-array-init-loop-in-lambda-capture.cpp | 13 +++++++++++++
2 files changed, 19 insertions(+), 5 deletions(-)
create mode 100644 clang/test/AST/nested-array-init-loop-in-lambda-capture.cpp
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index fea06b97259fe31..a1f5c262ca10be3 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -10967,19 +10967,20 @@ bool ArrayExprEvaluator::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E) {
LValue Subobject = This;
Subobject.addArray(Info, E, CAT);
- bool Success = true;
for (EvalInfo::ArrayInitLoopIndex Index(Info); Index != Elements; ++Index) {
if (!EvaluateInPlace(Result.getArrayInitializedElt(Index),
Info, Subobject, E->getSubExpr()) ||
!HandleLValueArrayAdjustment(Info, E, Subobject,
CAT->getElementType(), 1)) {
- if (!Info.noteFailure())
- return false;
- Success = false;
+
+ // There's no need to try and evaluate the rest, as those are the exact
+ // same expressions.
+ std::ignore = Info.noteFailure();
+ return false;
}
}
- return Success;
+ return true;
}
bool ArrayExprEvaluator::VisitCXXConstructExpr(const CXXConstructExpr *E) {
diff --git a/clang/test/AST/nested-array-init-loop-in-lambda-capture.cpp b/clang/test/AST/nested-array-init-loop-in-lambda-capture.cpp
new file mode 100644
index 000000000000000..82d27380b637d03
--- /dev/null
+++ b/clang/test/AST/nested-array-init-loop-in-lambda-capture.cpp
@@ -0,0 +1,13 @@
+// RUN: %clang_cc1 -fexperimental-new-constant-interpreter -std=c++17 -verify %s
+// RUN: %clang_cc1 -std=c++17 -verify=ref %s
+
+// ref-no-diagnostics
+// expected-no-diagnostics
+
+void used_to_crash() {
+ int s[2][2];
+
+ int arr[4];
+
+ arr[0] = [s] { return s[0][0]; }();
+}
>From 8f8f2b9ce187a5479b7c6bced51bff97c38f36bc Mon Sep 17 00:00:00 2001
From: isuckatcs <65320245+isuckatcs at users.noreply.github.com>
Date: Thu, 28 Sep 2023 21:26:40 +0200
Subject: [PATCH 2/5] wrapping the temporary into a scope
---
clang/lib/AST/ExprConstant.cpp | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index a1f5c262ca10be3..12b4d6b22c2c2bc 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -10950,6 +10950,9 @@ bool ArrayExprEvaluator::VisitCXXParenListOrInitListExpr(
}
bool ArrayExprEvaluator::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E) {
+
+ FullExpressionRAII Scope(Info);
+
LValue CommonLV;
if (E->getCommonExpr() &&
!Evaluate(Info.CurrentCall->createTemporary(
@@ -10967,20 +10970,19 @@ bool ArrayExprEvaluator::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E) {
LValue Subobject = This;
Subobject.addArray(Info, E, CAT);
+ bool Success = true;
for (EvalInfo::ArrayInitLoopIndex Index(Info); Index != Elements; ++Index) {
if (!EvaluateInPlace(Result.getArrayInitializedElt(Index),
Info, Subobject, E->getSubExpr()) ||
!HandleLValueArrayAdjustment(Info, E, Subobject,
CAT->getElementType(), 1)) {
-
- // There's no need to try and evaluate the rest, as those are the exact
- // same expressions.
- std::ignore = Info.noteFailure();
- return false;
+ if (!Info.noteFailure())
+ return false;
+ Success = false;
}
}
- return true;
+ return Success;
}
bool ArrayExprEvaluator::VisitCXXConstructExpr(const CXXConstructExpr *E) {
>From fb659cb7620d396882964ab628319643212a75b8 Mon Sep 17 00:00:00 2001
From: isuckatcs <65320245+isuckatcs at users.noreply.github.com>
Date: Fri, 29 Sep 2023 07:30:12 +0200
Subject: [PATCH 3/5] addressed comments
---
clang/lib/AST/ExprConstant.cpp | 16 +++++++++++---
clang/test/AST/Interp/cxx20.cpp | 37 +++++++++++++++++++++++++++++++--
2 files changed, 48 insertions(+), 5 deletions(-)
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 12b4d6b22c2c2bc..1c0fa3ad2b6fb3e 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -10950,9 +10950,6 @@ bool ArrayExprEvaluator::VisitCXXParenListOrInitListExpr(
}
bool ArrayExprEvaluator::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E) {
-
- FullExpressionRAII Scope(Info);
-
LValue CommonLV;
if (E->getCommonExpr() &&
!Evaluate(Info.CurrentCall->createTemporary(
@@ -10972,6 +10969,16 @@ bool ArrayExprEvaluator::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E) {
bool Success = true;
for (EvalInfo::ArrayInitLoopIndex Index(Info); Index != Elements; ++Index) {
+ // C++ [class.temporary]/5
+ // There are four contexts in which temporaries are destroyed at a different
+ // point than the end of the full-expression. [...] The second context is
+ // when a copy constructor is called to copy an element of an array while
+ // the entire array is copied [...]. In either case, if the constructor has
+ // one or more default arguments, the destruction of every temporary created
+ // in a default argument is sequenced before the construction of the next
+ // array element, if any.
+ FullExpressionRAII Scope(Info);
+
if (!EvaluateInPlace(Result.getArrayInitializedElt(Index),
Info, Subobject, E->getSubExpr()) ||
!HandleLValueArrayAdjustment(Info, E, Subobject,
@@ -10980,6 +10987,9 @@ bool ArrayExprEvaluator::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E) {
return false;
Success = false;
}
+
+ // Make sure we run the destructors too.
+ Scope.destroy();
}
return Success;
diff --git a/clang/test/AST/Interp/cxx20.cpp b/clang/test/AST/Interp/cxx20.cpp
index 0b13f41270a95b8..197090b0a37d9df 100644
--- a/clang/test/AST/Interp/cxx20.cpp
+++ b/clang/test/AST/Interp/cxx20.cpp
@@ -1,5 +1,5 @@
-// RUN: %clang_cc1 -fexperimental-new-constant-interpreter -std=c++20 -verify %s
-// RUN: %clang_cc1 -std=c++20 -verify=ref %s
+// RUN: %clang_cc1 -fcxx-exceptions -fexperimental-new-constant-interpreter -std=c++20 -verify %s
+// RUN: %clang_cc1 -fcxx-exceptions -std=c++20 -verify=ref %s
void test_alignas_operand() {
alignas(8) char dummy;
@@ -700,3 +700,36 @@ namespace ThreeWayCmp {
static_assert(pa1 <=> pa2 == -1, "");
static_assert(pa2 <=> pa1 == 1, "");
}
+
+// FIXME: Interp should also be able to evaluate this snippet properly.
+namespace ConstexprArrayInitLoopExprDestructors
+{
+ struct Highlander {
+ int *p = 0;
+ constexpr Highlander() {}
+ constexpr void set(int *p) { this->p = p; ++*p; if (*p != 1) throw "there can be only one"; } // expected-note {{not valid in a constant expression}}
+ constexpr ~Highlander() { --*p; }
+ };
+
+ struct X {
+ int *p;
+ constexpr X(int *p) : p(p) {}
+ constexpr X(const X &x, Highlander &&h = Highlander()) : p(x.p) {
+ h.set(p); // expected-note {{in call to '&Highlander()->set(&n)'}}
+ }
+ };
+
+ constexpr int f() {
+ int n = 0;
+ X x[3] = {&n, &n, &n};
+ auto [a, b, c] = x; // expected-note {{in call to 'X(x[0], Highlander())'}}
+ return n;
+ }
+
+ static_assert(f() == 0); // expected-error {{not an integral constant expression}} \
+ // expected-note {{in call to 'f()'}}
+
+ int main() {
+ return f();
+ }
+}
>From bedfe40d2bab344d8f2720a2ac47dfc991b2f403 Mon Sep 17 00:00:00 2001
From: isuckatcs <65320245+isuckatcs at users.noreply.github.com>
Date: Fri, 29 Sep 2023 13:25:25 +0200
Subject: [PATCH 4/5] addressed comments
---
clang/docs/ReleaseNotes.rst | 5 +++++
clang/test/AST/Interp/arrays.cpp | 7 +------
2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 09302040a3510b6..47d409eadf5b30e 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -269,6 +269,8 @@ Bug Fixes in This Version
- Fixes crash when trying to obtain the common sugared type of
`decltype(instantiation-dependent-expr)`.
Fixes (`#67603 <https://github.com/llvm/llvm-project/issues/67603>`_)
+- Fixes a crash caused by a multidimensional array being captured by a lambda
+ (`#67722 <https://github.com/llvm/llvm-project/issues/67722>`_).
Bug Fixes to Compiler Builtins
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -370,6 +372,9 @@ Bug Fixes to C++ Support
argument. Fixes:
(`#67395 <https://github.com/llvm/llvm-project/issues/67395>`_)
+- Fix a bug when destructors in a ``constexpr`` structured binding were
+ called at the wrong place.
+
Bug Fixes to AST Handling
^^^^^^^^^^^^^^^^^^^^^^^^^
- Fixed an import failure of recursive friend class template.
diff --git a/clang/test/AST/Interp/arrays.cpp b/clang/test/AST/Interp/arrays.cpp
index 5640f57f6aeb826..303ad6839208e43 100644
--- a/clang/test/AST/Interp/arrays.cpp
+++ b/clang/test/AST/Interp/arrays.cpp
@@ -1,5 +1,5 @@
// RUN: %clang_cc1 -fexperimental-new-constant-interpreter -verify %s
-// RUN: %clang_cc1 -verify=ref -DCUR_INTERP %s
+// RUN: %clang_cc1 -verify=ref %s
constexpr int m = 3;
constexpr const int *foo[][5] = {
@@ -352,10 +352,6 @@ namespace ZeroInit {
}
namespace ArrayInitLoop {
- /// FIXME: The ArrayInitLoop for the decomposition initializer in g() has
- /// f(n) as its CommonExpr. We need to evaluate that exactly once and not
- /// N times as we do right now.
-#ifndef CUR_INTERP
struct X {
int arr[3];
};
@@ -369,5 +365,4 @@ namespace ArrayInitLoop {
}
static_assert(g() == 6); // expected-error {{failed}} \
// expected-note {{15 == 6}}
-#endif
}
>From 4382ca06317df3b3efe150a0396bf431e544238d Mon Sep 17 00:00:00 2001
From: isuckatcs <65320245+isuckatcs at users.noreply.github.com>
Date: Fri, 29 Sep 2023 14:51:46 +0200
Subject: [PATCH 5/5] addressed comments
---
clang/docs/ReleaseNotes.rst | 4 ++--
clang/test/AST/Interp/arrays.cpp | 3 +++
2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 47d409eadf5b30e..942168b2c014a5b 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -372,8 +372,8 @@ Bug Fixes to C++ Support
argument. Fixes:
(`#67395 <https://github.com/llvm/llvm-project/issues/67395>`_)
-- Fix a bug when destructors in a ``constexpr`` structured binding were
- called at the wrong place.
+- Fixed a bug causing destructors of constant-evaluated structured bindings
+ initialized by array elements to be called in the wrong evaluation context.
Bug Fixes to AST Handling
^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/test/AST/Interp/arrays.cpp b/clang/test/AST/Interp/arrays.cpp
index 303ad6839208e43..7985f6841658e56 100644
--- a/clang/test/AST/Interp/arrays.cpp
+++ b/clang/test/AST/Interp/arrays.cpp
@@ -352,6 +352,9 @@ namespace ZeroInit {
}
namespace ArrayInitLoop {
+ /// FIXME: The ArrayInitLoop for the decomposition initializer in g() has
+ /// f(n) as its CommonExpr. We need to evaluate that exactly once and not
+ /// N times as we do right now.
struct X {
int arr[3];
};
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