https://github.com/katzdm updated https://github.com/llvm/llvm-project/pull/89565
>From a3f8a8648e2002273d47d7886b29fb02c728b5b7 Mon Sep 17 00:00:00 2001 From: Dan Katz <kat...@gmail.com> Date: Tue, 16 Apr 2024 17:14:50 -0400 Subject: [PATCH 1/5] Fix bug with constexpr initialization. --- clang/lib/Parse/ParseDecl.cpp | 12 ++++++- clang/test/CXX/expr/expr.const/p6-2a.cpp | 7 ++-- clang/test/SemaCXX/builtin_vectorelements.cpp | 4 +-- clang/test/SemaCXX/cxx2a-consteval.cpp | 32 ++++++++++++------- clang/unittests/Support/TimeProfilerTest.cpp | 1 - 5 files changed, 36 insertions(+), 20 deletions(-) diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp index 583232f2d610d0..0ea6fccaa7eb34 100644 --- a/clang/lib/Parse/ParseDecl.cpp +++ b/clang/lib/Parse/ParseDecl.cpp @@ -2554,6 +2554,13 @@ Decl *Parser::ParseDeclarationAfterDeclarator( return ParseDeclarationAfterDeclaratorAndAttributes(D, TemplateInfo); } +static bool isConstexprVariable(const Decl *D) { + if (const VarDecl *Var = dyn_cast_or_null<VarDecl>(D)) + return Var->isConstexpr(); + + return false; +} + Decl *Parser::ParseDeclarationAfterDeclaratorAndAttributes( Declarator &D, const ParsedTemplateInfo &TemplateInfo, ForRangeInit *FRI) { // RAII type used to track whether we're inside an initializer. @@ -2561,9 +2568,12 @@ Decl *Parser::ParseDeclarationAfterDeclaratorAndAttributes( Parser &P; Declarator &D; Decl *ThisDecl; + llvm::SaveAndRestore<bool> ConstantContext; InitializerScopeRAII(Parser &P, Declarator &D, Decl *ThisDecl) - : P(P), D(D), ThisDecl(ThisDecl) { + : P(P), D(D), ThisDecl(ThisDecl), + ConstantContext(P.Actions.isConstantEvaluatedOverride, + isConstexprVariable(ThisDecl)) { if (ThisDecl && P.getLangOpts().CPlusPlus) { Scope *S = nullptr; if (D.getCXXScopeSpec().isSet()) { diff --git a/clang/test/CXX/expr/expr.const/p6-2a.cpp b/clang/test/CXX/expr/expr.const/p6-2a.cpp index a937474d53b221..8b940b2ee9fb2a 100644 --- a/clang/test/CXX/expr/expr.const/p6-2a.cpp +++ b/clang/test/CXX/expr/expr.const/p6-2a.cpp @@ -43,12 +43,11 @@ struct Temporary { constexpr Temporary t = {3}; // expected-error {{must have constant destruction}} expected-note {{created here}} expected-note {{in call}} namespace P1073R3 { -consteval int f() { return 42; } // expected-note 2 {{declared here}} +consteval int f() { return 42; } // expected-note {{declared here}} consteval auto g() { return f; } consteval int h(int (*p)() = g()) { return p(); } constexpr int r = h(); -constexpr auto e = g(); // expected-error {{call to consteval function 'P1073R3::g' is not a constant expression}} \ - expected-error {{constexpr variable 'e' must be initialized by a constant expression}} \ - expected-note 2 {{pointer to a consteval declaration is not a constant expression}} +constexpr auto e = g(); // expected-error {{constexpr variable 'e' must be initialized by a constant expression}} \ + expected-note {{pointer to a consteval declaration is not a constant expression}} static_assert(r == 42); } // namespace P1073R3 diff --git a/clang/test/SemaCXX/builtin_vectorelements.cpp b/clang/test/SemaCXX/builtin_vectorelements.cpp index 59ff09ac72e42d..12f2cbe57bd47d 100644 --- a/clang/test/SemaCXX/builtin_vectorelements.cpp +++ b/clang/test/SemaCXX/builtin_vectorelements.cpp @@ -42,11 +42,11 @@ void test_builtin_vectorelements() { #include <arm_sve.h> consteval int consteval_elements() { // expected-error {{consteval function never produces a constant expression}} - return __builtin_vectorelements(svuint64_t); // expected-note {{cannot determine number of elements for sizeless vectors in a constant expression}} // expected-note {{cannot determine number of elements for sizeless vectors in a constant expression}} // expected-note {{cannot determine number of elements for sizeless vectors in a constant expression}} + return __builtin_vectorelements(svuint64_t); // expected-note {{cannot determine number of elements for sizeless vectors in a constant expression}} // expected-note {{cannot determine number of elements for sizeless vectors in a constant expression}} } void test_bad_constexpr() { - constexpr int eval = consteval_elements(); // expected-error {{initialized by a constant expression}} // expected-error {{not a constant expression}} // expected-note {{in call}} // expected-note {{in call}} + constexpr int eval = consteval_elements(); // expected-error {{initialized by a constant expression}} // expected-note {{in call}} constexpr int i32 = __builtin_vectorelements(svuint32_t); // expected-error {{initialized by a constant expression}} // expected-note {{cannot determine number of elements for sizeless vectors in a constant expression}} constexpr int i16p8 = __builtin_vectorelements(svuint16_t) + 16; // expected-error {{initialized by a constant expression}} // expected-note {{cannot determine number of elements for sizeless vectors in a constant expression}} constexpr int lambda = [] { return __builtin_vectorelements(svuint16_t); }(); // expected-error {{initialized by a constant expression}} // expected-note {{cannot determine number of elements for sizeless vectors in a constant expression}} // expected-note {{in call}} diff --git a/clang/test/SemaCXX/cxx2a-consteval.cpp b/clang/test/SemaCXX/cxx2a-consteval.cpp index 192621225a543c..d1f3b094f8afd5 100644 --- a/clang/test/SemaCXX/cxx2a-consteval.cpp +++ b/clang/test/SemaCXX/cxx2a-consteval.cpp @@ -260,6 +260,18 @@ int(*test)(int) = l1; } +namespace lvalue_to_rvalue_init_from_heap { + +struct S { + int *value; + constexpr S(int v) : value(new int {v}) {} + constexpr ~S() { delete value; } +}; +consteval S fn() { return S(5); } + +constexpr int a = *fn().value; +} + namespace std { template <typename T> struct remove_reference { using type = T; }; @@ -713,7 +725,7 @@ constexpr derp d; struct test { consteval int operator[](int i) const { return {}; } consteval const derp * operator->() const { return &d; } - consteval int f() const { return 12; } // expected-note 2{{declared here}} + consteval int f() const { return 12; } // expected-note {{declared here}} }; constexpr test a; @@ -726,8 +738,7 @@ constexpr int s = a.operator[](1); constexpr int t = a[1]; constexpr int u = a.operator->()->b; constexpr int v = a->b; -// FIXME: I believe this case should work, but we currently reject. -constexpr int w = (a.*&test::f)(); // expected-error {{cannot take address of consteval function 'f' outside of an immediate invocation}} +constexpr int w = (a.*&test::f)(); constexpr int x = a.f(); // Show that we reject when not in an immediate context. @@ -1032,17 +1043,15 @@ int f() { namespace GH57682 { void test() { - constexpr auto l1 = []() consteval { // expected-error {{cannot take address of consteval call operator of '(lambda at}} \ - // expected-note 2{{declared here}} + constexpr auto l1 = []() consteval { // expected-note {{declared here}} return 3; }; constexpr int (*f1)(void) = l1; // expected-error {{constexpr variable 'f1' must be initialized by a constant expression}} \ // expected-note {{pointer to a consteval declaration is not a constant expression}} - constexpr auto lstatic = []() static consteval { // expected-error {{cannot take address of consteval call operator of '(lambda at}} \ - // expected-note 2{{declared here}} \ - // expected-warning {{extension}} + constexpr auto lstatic = []() static consteval { // expected-note {{declared here}} \ + // expected-warning {{extension}} return 3; }; constexpr int (*f2)(void) = lstatic; // expected-error {{constexpr variable 'f2' must be initialized by a constant expression}} \ @@ -1073,7 +1082,7 @@ struct tester { consteval const char* make_name(const char* name) { return name;} consteval const char* pad(int P) { return "thestring"; } -int bad = 10; // expected-note 6{{declared here}} +int bad = 10; // expected-note 5{{declared here}} tester glob1(make_name("glob1")); tester glob2(make_name("glob2")); @@ -1082,9 +1091,8 @@ tester paddedglob(make_name(pad(bad))); // expected-error {{call to consteval fu // expected-note {{read of non-const variable 'bad' is not allowed in a constant expression}} constexpr tester glob3 = { make_name("glob3") }; -constexpr tester glob4 = { make_name(pad(bad)) }; // expected-error {{call to consteval function 'GH58207::make_name' is not a constant expression}} \ - // expected-error {{constexpr variable 'glob4' must be initialized by a constant expression}} \ - // expected-note 2{{read of non-const variable 'bad' is not allowed in a constant expression}} +constexpr tester glob4 = { make_name(pad(bad)) }; // expected-error {{constexpr variable 'glob4' must be initialized by a constant expression}} \ + // expected-note 1{{read of non-const variable 'bad' is not allowed in a constant expression}} auto V = make_name(pad(3)); auto V1 = make_name(pad(bad)); // expected-error {{call to consteval function 'GH58207::make_name' is not a constant expression}} \ diff --git a/clang/unittests/Support/TimeProfilerTest.cpp b/clang/unittests/Support/TimeProfilerTest.cpp index 97fdbb7232b135..9c1a955743f1ee 100644 --- a/clang/unittests/Support/TimeProfilerTest.cpp +++ b/clang/unittests/Support/TimeProfilerTest.cpp @@ -193,7 +193,6 @@ Frontend | ParseDeclarationOrFunctionDefinition (test.cc:16:1) | | ParseFunctionDefinition (slow_test) | | | EvaluateAsInitializer (slow_value) -| | | EvaluateAsConstantExpr (<test.cc:17:33, col:59>) | | | EvaluateAsConstantExpr (<test.cc:18:11, col:37>) | ParseDeclarationOrFunctionDefinition (test.cc:22:1) | | EvaluateAsConstantExpr (<test.cc:23:31, col:57>) >From c9eaffe0538dd9435fe6824253fd9bef0b1eff3b Mon Sep 17 00:00:00 2001 From: "Daniel M. Katz" <kat...@gmail.com> Date: Mon, 22 Apr 2024 08:59:55 -0400 Subject: [PATCH 2/5] Use dyn_cast without checking for null Co-authored-by: cor3ntin <corentinja...@gmail.com> --- clang/lib/Parse/ParseDecl.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp index 0ea6fccaa7eb34..c8c876bf1fffea 100644 --- a/clang/lib/Parse/ParseDecl.cpp +++ b/clang/lib/Parse/ParseDecl.cpp @@ -2555,7 +2555,7 @@ Decl *Parser::ParseDeclarationAfterDeclarator( } static bool isConstexprVariable(const Decl *D) { - if (const VarDecl *Var = dyn_cast_or_null<VarDecl>(D)) + if (const VarDecl *Var = dyn_cast<VarDecl>(D)) return Var->isConstexpr(); return false; >From 3b7187244bf8ab6be7a80d79e1abc92458bd2bcd Mon Sep 17 00:00:00 2001 From: Dan Katz <kat...@gmail.com> Date: Mon, 22 Apr 2024 09:01:48 -0400 Subject: [PATCH 3/5] Add release notes. --- clang/docs/ReleaseNotes.rst | 2 ++ 1 file changed, 2 insertions(+) diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 45a9a79739a4eb..0dd9896cbb3cd0 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -536,6 +536,8 @@ Bug Fixes to C++ Support - Clang now correctly tracks type dependence of by-value captures in lambdas with an explicit object parameter. Fixes (#GH70604), (#GH79754), (#GH84163), (#GH84425), (#GH86054), (#GH86398), and (#GH86399). +- Fix a bug in which valid constexpr variable initializers containing immediate function calls were + sometimes diagnosed as not constant expressions. Bug Fixes to AST Handling ^^^^^^^^^^^^^^^^^^^^^^^^^ >From 41fe69c5ac581c8ae325f2a13a9157fbd9c2d9a7 Mon Sep 17 00:00:00 2001 From: Dan Katz <kat...@gmail.com> Date: Mon, 22 Apr 2024 12:38:11 -0400 Subject: [PATCH 4/5] Re-introduce null check. Use EvaluationContext instead of override. --- clang/lib/Parse/ParseDecl.cpp | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp index c8c876bf1fffea..1d92a8c57f16ec 100644 --- a/clang/lib/Parse/ParseDecl.cpp +++ b/clang/lib/Parse/ParseDecl.cpp @@ -2555,7 +2555,7 @@ Decl *Parser::ParseDeclarationAfterDeclarator( } static bool isConstexprVariable(const Decl *D) { - if (const VarDecl *Var = dyn_cast<VarDecl>(D)) + if (const VarDecl *Var = dyn_cast_if_present<VarDecl>(D)) return Var->isConstexpr(); return false; @@ -2568,12 +2568,13 @@ Decl *Parser::ParseDeclarationAfterDeclaratorAndAttributes( Parser &P; Declarator &D; Decl *ThisDecl; - llvm::SaveAndRestore<bool> ConstantContext; + EnterExpressionEvaluationContext EC; InitializerScopeRAII(Parser &P, Declarator &D, Decl *ThisDecl) : P(P), D(D), ThisDecl(ThisDecl), - ConstantContext(P.Actions.isConstantEvaluatedOverride, - isConstexprVariable(ThisDecl)) { + EC(P.Actions, Sema::ExpressionEvaluationContext::ConstantEvaluated, + ThisDecl, Sema::ExpressionEvaluationContextRecord::EK_Other, + isConstexprVariable(ThisDecl)) { if (ThisDecl && P.getLangOpts().CPlusPlus) { Scope *S = nullptr; if (D.getCXXScopeSpec().isSet()) { >From cf4ecf035cc82fedceecc9c31e35f81722b867a4 Mon Sep 17 00:00:00 2001 From: Dan Katz <kat...@gmail.com> Date: Mon, 22 Apr 2024 13:28:03 -0400 Subject: [PATCH 5/5] Adjust other tests newly failing from change. --- clang/test/AST/Interp/intap.cpp | 3 +-- clang/test/CXX/expr/expr.const/p2-0x.cpp | 4 ++-- clang/test/Parser/pragma-fenv_access.c | 3 --- clang/test/SemaCXX/constant-expression-cxx11.cpp | 2 +- clang/test/SemaCXX/cxx2a-consteval.cpp | 14 ++++++++------ clang/test/SemaCXX/ext-int.cpp | 2 +- 6 files changed, 13 insertions(+), 15 deletions(-) diff --git a/clang/test/AST/Interp/intap.cpp b/clang/test/AST/Interp/intap.cpp index d4440124856915..1b8ec2dfdab79e 100644 --- a/clang/test/AST/Interp/intap.cpp +++ b/clang/test/AST/Interp/intap.cpp @@ -9,8 +9,7 @@ using MaxBitInt = _BitInt(128); constexpr _BitInt(2) A = 0; constexpr _BitInt(2) B = A + 1; -constexpr _BitInt(2) C = B + 1; // expected-warning {{from 2 to -2}} \ - // ref-warning {{from 2 to -2}} +constexpr _BitInt(2) C = B + 1; static_assert(C == -2, ""); static_assert(C - B == A, ""); // expected-error {{not an integral constant expression}} \ // expected-note {{value -3 is outside the range of representable values}} \ diff --git a/clang/test/CXX/expr/expr.const/p2-0x.cpp b/clang/test/CXX/expr/expr.const/p2-0x.cpp index e3cd057baba75f..86b9b066d6867f 100644 --- a/clang/test/CXX/expr/expr.const/p2-0x.cpp +++ b/clang/test/CXX/expr/expr.const/p2-0x.cpp @@ -244,8 +244,8 @@ namespace UndefinedBehavior { constexpr int n13 = n5 + n5; // expected-error {{constant expression}} expected-note {{value -4294967296 is outside the range of }} constexpr int n14 = n3 - n5; // expected-error {{constant expression}} expected-note {{value 4294967295 is outside the range of }} constexpr int n15 = n5 * n5; // expected-error {{constant expression}} expected-note {{value 4611686018427387904 is outside the range of }} - constexpr signed char c1 = 100 * 2; // ok expected-warning{{changes value}} - constexpr signed char c2 = '\x64' * '\2'; // also ok expected-warning{{changes value}} + constexpr signed char c1 = 100 * 2; // ok - no error from changing value because initializer is constexpr. + constexpr signed char c2 = '\x64' * '\2'; // also ok - no error from changing value because initializer is constexpr. constexpr long long ll1 = 0x7fffffffffffffff; // ok constexpr long long ll2 = ll1 + 1; // expected-error {{constant}} expected-note {{ 9223372036854775808 }} constexpr long long ll3 = -ll1 - 1; // ok diff --git a/clang/test/Parser/pragma-fenv_access.c b/clang/test/Parser/pragma-fenv_access.c index 76256cff1b49b5..86d40bbab4be93 100644 --- a/clang/test/Parser/pragma-fenv_access.c +++ b/clang/test/Parser/pragma-fenv_access.c @@ -32,9 +32,6 @@ int main(void) { CONST int not_too_big = 255; CONST float fnot_too_big = not_too_big; CONST int too_big = 0x7ffffff0; -#if defined(CPP) -//expected-warning@+2{{implicit conversion}} -#endif CONST float fbig = too_big; // inexact #if !defined(CPP) #define static_assert _Static_assert diff --git a/clang/test/SemaCXX/constant-expression-cxx11.cpp b/clang/test/SemaCXX/constant-expression-cxx11.cpp index efb391ba0922d8..815d2e1651d4ac 100644 --- a/clang/test/SemaCXX/constant-expression-cxx11.cpp +++ b/clang/test/SemaCXX/constant-expression-cxx11.cpp @@ -1961,7 +1961,7 @@ namespace ConstexprConstructorRecovery { namespace Lifetime { void f() { - constexpr int &n = n; // expected-error {{constant expression}} expected-note {{use of reference outside its lifetime}} expected-warning {{not yet bound to a value}} + constexpr int &n = n; // expected-error {{constant expression}} expected-note {{use of reference outside its lifetime}} constexpr int m = m; // expected-error {{constant expression}} expected-note {{read of object outside its lifetime}} } diff --git a/clang/test/SemaCXX/cxx2a-consteval.cpp b/clang/test/SemaCXX/cxx2a-consteval.cpp index d1f3b094f8afd5..bfe27547b67cc2 100644 --- a/clang/test/SemaCXX/cxx2a-consteval.cpp +++ b/clang/test/SemaCXX/cxx2a-consteval.cpp @@ -1043,21 +1043,23 @@ int f() { namespace GH57682 { void test() { - constexpr auto l1 = []() consteval { // expected-note {{declared here}} + constexpr auto l1 = []() consteval { // expected-error {{cannot take address of consteval call operator of '(lambda at}} \ + // expected-note 2 {{declared here}} return 3; }; - constexpr int (*f1)(void) = l1; // expected-error {{constexpr variable 'f1' must be initialized by a constant expression}} \ - // expected-note {{pointer to a consteval declaration is not a constant expression}} + int (*f1)(void) = l1; + + constexpr int (*f2)(void) = l1; // expected-error {{constexpr variable 'f2' must be initialized by a constant expression}} \ + // expected-note {{pointer to a consteval declaration is not a constant expression}} constexpr auto lstatic = []() static consteval { // expected-note {{declared here}} \ // expected-warning {{extension}} return 3; }; - constexpr int (*f2)(void) = lstatic; // expected-error {{constexpr variable 'f2' must be initialized by a constant expression}} \ + constexpr int (*f3)(void) = lstatic; // expected-error {{constexpr variable 'f3' must be initialized by a constant expression}} \ // expected-note {{pointer to a consteval declaration is not a constant expression}} - -} + }; } namespace GH60286 { diff --git a/clang/test/SemaCXX/ext-int.cpp b/clang/test/SemaCXX/ext-int.cpp index 000b871ccd3433..931842b7e3c53b 100644 --- a/clang/test/SemaCXX/ext-int.cpp +++ b/clang/test/SemaCXX/ext-int.cpp @@ -25,7 +25,7 @@ _BitInt(33) Declarations(_BitInt(48) &Param) { // Useable in params and returns. unsigned _BitInt(1) l; signed _BitInt(1) m; // expected-error{{signed _BitInt must have a bit size of at least 2}} - constexpr _BitInt(6) n = 33; // expected-warning{{implicit conversion from 'int' to 'const _BitInt(6)' changes value from 33 to -31}} + constexpr _BitInt(6) n = 33; constexpr _BitInt(7) o = 33; // Check imposed max size. _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits