llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Henrik G. Olsson (hnrklssn) <details> <summary>Changes</summary> Relands #<!-- -->137078 after updating clang/test/AST/ByteCode/cxx20.cpp to account for diagnostic outputs that differ between Linux and macOS. --- Full diff: https://github.com/llvm/llvm-project/pull/137091.diff 3 Files Affected: - (modified) clang/lib/AST/ExprConstant.cpp (+7-2) - (modified) clang/test/AST/ByteCode/cxx20.cpp (+8) - (modified) clang/test/SemaCXX/constant-expression-cxx11.cpp (+2) ``````````diff diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp index f598ef5929aa4..7c933f47bf7f0 100644 --- a/clang/lib/AST/ExprConstant.cpp +++ b/clang/lib/AST/ExprConstant.cpp @@ -2232,10 +2232,15 @@ 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 (Offset.isNegative()) { + if (LHSString.Bytes.size() < (size_t)-Offset.getQuantity()) + return false; LHSString.Bytes = LHSString.Bytes.drop_front(-Offset.getQuantity()); - else + } else { + if (RHSString.Bytes.size() < (size_t)Offset.getQuantity()) + return false; 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 42e6ae33e92e4..69a53a567fa41 100644 --- a/clang/test/AST/ByteCode/cxx20.cpp +++ b/clang/test/AST/ByteCode/cxx20.cpp @@ -119,6 +119,14 @@ 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}} \ + // both-note-re {{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 28016da925ef9..dc8f4bf1666ee 100644 --- a/clang/test/SemaCXX/constant-expression-cxx11.cpp +++ b/clang/test/SemaCXX/constant-expression-cxx11.cpp @@ -2203,6 +2203,8 @@ 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@-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 && `````````` </details> https://github.com/llvm/llvm-project/pull/137091 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
