https://github.com/hnrklssn created https://github.com/llvm/llvm-project/pull/137088
Reverts llvm/llvm-project#137078
>From 30f38f86a765a24e368083ffbcac9f036e6fc221 Mon Sep 17 00:00:00 2001
From: "Henrik G. Olsson" <hnrklssn at gmail.com>
Date: Wed, 23 Apr 2025 16:48:29 -0700
Subject: [PATCH] Revert "[ConstEval] Fix crash when comparing strings past the
end (#137078)"
This reverts commit 55160e6a89820f219eaa218fa02da2006213ed2c.
---
clang/lib/AST/ExprConstant.cpp | 9 ++-------
clang/test/AST/ByteCode/cxx20.cpp | 9 ---------
clang/test/SemaCXX/constant-expression-cxx11.cpp | 2 --
3 files changed, 2 insertions(+), 18 deletions(-)
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 7c933f47bf7f0..f598ef5929aa4 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -2232,15 +2232,10 @@ static bool ArePotentiallyOverlappingStringLiterals(const EvalInfo &Info,
// within RHS. We don't need to look at the characters of one string that
// would appear before the start of the other string if they were merged.
CharUnits Offset = RHS.Offset - LHS.Offset;
- if (Offset.isNegative()) {
- if (LHSString.Bytes.size() < (size_t)-Offset.getQuantity())
- return false;
+ if (Offset.isNegative())
LHSString.Bytes = LHSString.Bytes.drop_front(-Offset.getQuantity());
- } else {
- if (RHSString.Bytes.size() < (size_t)Offset.getQuantity())
- return false;
+ else
RHSString.Bytes = RHSString.Bytes.drop_front(Offset.getQuantity());
- }
bool LHSIsLonger = LHSString.Bytes.size() > RHSString.Bytes.size();
StringRef Longer = LHSIsLonger ? LHSString.Bytes : RHSString.Bytes;
diff --git a/clang/test/AST/ByteCode/cxx20.cpp b/clang/test/AST/ByteCode/cxx20.cpp
index 4c1b1592896c9..42e6ae33e92e4 100644
--- a/clang/test/AST/ByteCode/cxx20.cpp
+++ b/clang/test/AST/ByteCode/cxx20.cpp
@@ -119,15 +119,6 @@ constexpr auto b3 = name1() == name1(); // ref-error {{must be initialized by a
constexpr auto b4 = name1() == name2();
static_assert(!b4);
-constexpr auto bar(const char *p) { return p + __builtin_strlen(p); }
-constexpr auto b5 = bar(p1) == p1;
-static_assert(!b5);
-constexpr auto b6 = bar(p1) == ""; // ref-error {{must be initialized by a constant expression}} \
- // ref-note {{comparison of addresses of potentially overlapping literals}}
-constexpr auto b7 = bar(p1) + 1 == ""; // both-error {{must be initialized by a constant expression}} \
- // ref-note {{comparison against pointer '&"test1"[6]' that points past the end of a complete object has unspecified value}} \
- // expected-note {{comparison against pointer '&"test1"[6] + 1' that points past the end of a complete object has unspecified value}}
-
namespace UninitializedFields {
class A {
public:
diff --git a/clang/test/SemaCXX/constant-expression-cxx11.cpp b/clang/test/SemaCXX/constant-expression-cxx11.cpp
index dc8f4bf1666ee..28016da925ef9 100644
--- a/clang/test/SemaCXX/constant-expression-cxx11.cpp
+++ b/clang/test/SemaCXX/constant-expression-cxx11.cpp
@@ -2203,8 +2203,6 @@ namespace BuiltinStrlen {
static_assert(__builtin_strlen("foo") == 3, "");
static_assert(__builtin_strlen("foo\0quux") == 3, "");
static_assert(__builtin_strlen("foo\0quux" + 4) == 4, "");
- static_assert(__builtin_strlen("foo") + 1 + "foo" == "foo", ""); // expected-error {{static assertion expression is not an integral constant expression}}
- // expected-note at -1 {{comparison against pointer '&"foo"[4]' that points past the end of a complete object has unspecified value}}
constexpr bool check(const char *p) {
return __builtin_strlen(p) == 3 &&