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-rw-r--r--include/clang/Sema/Sema.h6
-rw-r--r--lib/Sema/SemaDeclCXX.cpp13
-rw-r--r--lib/Sema/SemaExpr.cpp51
-rw-r--r--test/SemaCXX/constant-expression-cxx11.cpp22
-rw-r--r--test/SemaCXX/static-assert.cpp5
5 files changed, 56 insertions, 41 deletions
diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h
index 34e5174f41..88b3f595b2 100644
--- a/include/clang/Sema/Sema.h
+++ b/include/clang/Sema/Sema.h
@@ -6002,10 +6002,12 @@ public:
/// in the global scope.
bool CheckObjCDeclScope(Decl *D);
- /// VerifyIntegerConstantExpression - verifies that an expression is an ICE,
+ /// VerifyIntegerConstantExpression - Verifies that an expression is an ICE,
/// and reports the appropriate diagnostics. Returns false on success.
/// Can optionally return the value of the expression.
- bool VerifyIntegerConstantExpression(const Expr *E, llvm::APSInt *Result = 0);
+ bool VerifyIntegerConstantExpression(const Expr *E, llvm::APSInt *Result = 0,
+ unsigned DiagId = 0,
+ bool AllowFold = true);
/// VerifyBitField - verifies that a bit field expression is an ICE and has
/// the correct width, and that the field type is valid.
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index fb0307fb28..2176afa92d 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -9636,18 +9636,15 @@ Decl *Sema::ActOnStaticAssertDeclaration(SourceLocation StaticAssertLoc,
StringLiteral *AssertMessage = cast<StringLiteral>(AssertMessageExpr_);
if (!AssertExpr->isTypeDependent() && !AssertExpr->isValueDependent()) {
- llvm::APSInt Value(32);
- if (!AssertExpr->isIntegerConstantExpr(Value, Context)) {
- Diag(StaticAssertLoc,
- diag::err_static_assert_expression_is_not_constant) <<
- AssertExpr->getSourceRange();
+ llvm::APSInt Cond;
+ if (VerifyIntegerConstantExpression(AssertExpr, &Cond,
+ diag::err_static_assert_expression_is_not_constant,
+ /*AllowFold=*/false))
return 0;
- }
- if (Value == 0) {
+ if (!Cond)
Diag(StaticAssertLoc, diag::err_static_assert_failed)
<< AssertMessage->getString() << AssertExpr->getSourceRange();
- }
}
if (DiagnoseUnexpandedParameterPack(AssertExpr, UPPC_StaticAssertExpression))
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index d9626369d9..8231cda75e 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -9232,30 +9232,45 @@ bool Sema::DiagnoseAssignmentResult(AssignConvertType ConvTy,
return isInvalid;
}
-bool Sema::VerifyIntegerConstantExpression(const Expr *E, llvm::APSInt *Result){
- // FIXME: In C++11, this evaluates the expression even if it's not an ICE.
- // Don't evaluate it a second time below just to get the diagnostics.
- llvm::APSInt ICEResult;
- if (E->isIntegerConstantExpr(ICEResult, Context)) {
- if (Result)
- *Result = ICEResult;
- return false;
+bool Sema::VerifyIntegerConstantExpression(const Expr *E, llvm::APSInt *Result,
+ unsigned DiagID, bool AllowFold) {
+ // Circumvent ICE checking in C++11 to avoid evaluating the expression twice
+ // in the non-ICE case.
+ if (!getLangOptions().CPlusPlus0x) {
+ if (E->isIntegerConstantExpr(Context)) {
+ if (Result)
+ *Result = E->EvaluateKnownConstInt(Context);
+ return false;
+ }
}
Expr::EvalResult EvalResult;
llvm::SmallVector<PartialDiagnosticAt, 8> Notes;
EvalResult.Diag = &Notes;
- if (!E->EvaluateAsRValue(EvalResult, Context) || !EvalResult.Val.isInt() ||
- EvalResult.HasSideEffects) {
- Diag(E->getExprLoc(), diag::err_expr_not_ice) << E->getSourceRange();
+ // Try to evaluate the expression, and produce diagnostics explaining why it's
+ // not a constant expression as a side-effect.
+ bool Folded = E->EvaluateAsRValue(EvalResult, Context) &&
+ EvalResult.Val.isInt() && !EvalResult.HasSideEffects;
+
+ // In C++11, we can rely on diagnostics being produced for any expression
+ // which is not a constant expression. If no diagnostics were produced, then
+ // this is a constant expression.
+ if (Folded && getLangOptions().CPlusPlus0x && Notes.empty()) {
+ if (Result)
+ *Result = EvalResult.Val.getInt();
+ return false;
+ }
+
+ if (!Folded || !AllowFold) {
+ Diag(E->getSourceRange().getBegin(),
+ DiagID ? DiagID : diag::err_expr_not_ice) << E->getSourceRange();
// We only show the notes if they're not the usual "invalid subexpression"
// or if they are actually in a subexpression.
- if (!Notes.empty() &&
- (Notes.size() != 1 ||
- Notes[0].second.getDiagID() != diag::note_invalid_subexpr_in_const_expr
- || Notes[0].first != E->IgnoreParens()->getExprLoc())) {
+ if (Notes.size() != 1 ||
+ Notes[0].second.getDiagID() != diag::note_invalid_subexpr_in_const_expr
+ || Notes[0].first != E->IgnoreParens()->getExprLoc()) {
for (unsigned I = 0, N = Notes.size(); I != N; ++I)
Diag(Notes[I].first, Notes[I].second);
}
@@ -9263,10 +9278,10 @@ bool Sema::VerifyIntegerConstantExpression(const Expr *E, llvm::APSInt *Result){
return true;
}
- Diag(E->getExprLoc(), diag::ext_expr_not_ice) << E->getSourceRange();
+ Diag(E->getSourceRange().getBegin(), diag::ext_expr_not_ice)
+ << E->getSourceRange();
- if (Notes.size() &&
- Diags.getDiagnosticLevel(diag::ext_expr_not_ice, E->getExprLoc())
+ if (Diags.getDiagnosticLevel(diag::ext_expr_not_ice, E->getExprLoc())
!= DiagnosticsEngine::Ignored)
for (unsigned I = 0, N = Notes.size(); I != N; ++I)
Diag(Notes[I].first, Notes[I].second);
diff --git a/test/SemaCXX/constant-expression-cxx11.cpp b/test/SemaCXX/constant-expression-cxx11.cpp
index f284bd6133..4b59157ea6 100644
--- a/test/SemaCXX/constant-expression-cxx11.cpp
+++ b/test/SemaCXX/constant-expression-cxx11.cpp
@@ -141,7 +141,7 @@ static_assert(F(1, 0) == 1, "");
static_assert(F(2, "test") == 2, "");
static_assert(F(3, &F) == 3, "");
int k = 0;
-static_assert(F(4, k) == 3, ""); // expected-error {{constant expression}}
+static_assert(F(4, k) == 3, ""); // expected-error {{constant expression}} expected-note {{subexpression}}
}
@@ -414,7 +414,9 @@ static_assert(sum_xs == 15, "");
constexpr int ZipFoldR(int (*F)(int x, int y, int c), int n,
const int *xs, const int *ys, int c) {
- return n ? F(*xs, *ys, ZipFoldR(F, n-1, xs+1, ys+1, c)) : c;
+ return n ? F(
+ *xs, // expected-note {{subexpression not valid}}
+ *ys, ZipFoldR(F, n-1, xs+1, ys+1, c)) : c;
}
constexpr int MulAdd(int x, int y, int c) { return x * y + c; }
constexpr int InnerProduct = ZipFoldR(MulAdd, 5, xs, ys, 0);
@@ -434,7 +436,7 @@ constexpr int xs_1 = p[-4]; // expected-error {{constant expression}}
constexpr int zs[2][2][2][2] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
static_assert(zs[0][0][0][0] == 1, "");
static_assert(zs[1][1][1][1] == 16, "");
-static_assert(zs[0][0][0][2] == 3, ""); // expected-error {{constant expression}}
+static_assert(zs[0][0][0][2] == 3, ""); // expected-error {{constant expression}} expected-note {{subexpression}}
static_assert((&zs[0][0][0][2])[-1] == 2, "");
static_assert(**(**(zs + 1) + 1) == 11, "");
static_assert(*(&(&(*(*&(&zs[2] - 1)[0] + 2 - 2))[2])[-1][-1] + 1) == 11, "");
@@ -505,7 +507,7 @@ constexpr const E &e1 = E(); // expected-error {{constant expression}}
// We notice this when evaluating an expression which uses it, but not when
// checking its initializer.
constexpr E e2 = E(); // unexpected-error {{constant expression}}
-static_assert(e2.p == &e2.p, ""); // unexpected-error {{constant expression}}
+static_assert(e2.p == &e2.p, ""); // unexpected-error {{constant expression}} unexpected-note {{subexpression}}
// FIXME: We don't pass through the fact that 'this' is ::e3 when checking the
// initializer of this declaration.
constexpr E e3; // unexpected-error {{constant expression}}
@@ -533,10 +535,10 @@ struct G {
constexpr G() : t(&t) {}
} constexpr g;
-static_assert(g.t.u1.a == 42, ""); // expected-error {{constant expression}}
+static_assert(g.t.u1.a == 42, ""); // expected-error {{constant expression}} expected-note {{subexpression}}
static_assert(g.t.u1.b == 42, "");
static_assert(g.t.u2.c == 42, "");
-static_assert(g.t.u2.d == 42, ""); // expected-error {{constant expression}}
+static_assert(g.t.u2.d == 42, ""); // expected-error {{constant expression}} expected-note {{subexpression}}
struct S {
int a, b;
@@ -580,10 +582,10 @@ constexpr AggregateInit agg1 = { "hello"[0] };
static_assert(strcmp_ce(&agg1.c, "hello") == 0, "");
static_assert(agg1.n == 0, "");
static_assert(agg1.d == 0.0, "");
-static_assert(agg1.arr[-1] == 0, ""); // expected-error {{constant expression}}
+static_assert(agg1.arr[-1] == 0, ""); // expected-error {{constant expression}} expected-note {{subexpression}}
static_assert(agg1.arr[0] == 0, "");
static_assert(agg1.arr[4] == 0, "");
-static_assert(agg1.arr[5] == 0, ""); // expected-error {{constant expression}}
+static_assert(agg1.arr[5] == 0, ""); // expected-error {{constant expression}} expected-note {{subexpression}}
static_assert(agg1.p == nullptr, "");
namespace SimpleDerivedClass {
@@ -706,8 +708,8 @@ constexpr U u[4] = { { .a = 0 }, { .b = 1 }, { .a = 2 }, { .b = 3 } }; // expect
static_assert(u[0].a == 0, "");
static_assert(u[0].b, ""); // expected-error {{constant expression}}
static_assert(u[1].b == 1, "");
-static_assert((&u[1].b)[1] == 2, ""); // expected-error {{constant expression}}
-static_assert(*(&(u[1].b) + 1 + 1) == 3, ""); // expected-error {{constant expression}}
+static_assert((&u[1].b)[1] == 2, ""); // expected-error {{constant expression}} expected-note {{subexpression}}
+static_assert(*(&(u[1].b) + 1 + 1) == 3, ""); // expected-error {{constant expression}} expected-note {{subexpression}}
static_assert((&(u[1]) + 1 + 1)->b == 3, "");
}
diff --git a/test/SemaCXX/static-assert.cpp b/test/SemaCXX/static-assert.cpp
index 0991a5f89c..2b44e81d3e 100644
--- a/test/SemaCXX/static-assert.cpp
+++ b/test/SemaCXX/static-assert.cpp
@@ -1,8 +1,8 @@
// RUN: %clang_cc1 -fsyntax-only -verify %s -std=c++11
-int f();
+int f(); // expected-note {{declared here}}
-static_assert(f(), "f"); // expected-error {{static_assert expression is not an integral constant expression}}
+static_assert(f(), "f"); // expected-error {{static_assert expression is not an integral constant expression}} expected-note {{non-constexpr function 'f' cannot be used in a constant expression}}
static_assert(true, "true is not false");
static_assert(false, "false is false"); // expected-error {{static_assert failed "false is false"}}
@@ -27,4 +27,3 @@ template<typename T> struct S {
S<char> s1; // expected-note {{in instantiation of template class 'S<char>' requested here}}
S<int> s2;
-
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2025-08-02 07:59:55 +0000