Author: gbiv
Date: Mon Dec 26 23:33:20 2016
New Revision: 290584
URL: http://llvm.org/viewvc/llvm-project?rev=290584&view=rev
Log:
Emit CCEDiags when evaluating a const variable.
This addresses post-review feedback from r290577.
Modified:
cfe/trunk/lib/AST/ExprConstant.cpp
cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp
cfe/trunk/test/SemaCXX/constant-expression-cxx1y.cpp
Modified: cfe/trunk/lib/AST/ExprConstant.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=290584&r1=290583&r2=290584&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ExprConstant.cpp (original)
+++ cfe/trunk/lib/AST/ExprConstant.cpp Mon Dec 26 23:33:20 2016
@@ -2903,7 +2903,7 @@ static CompleteObject findCompleteObject
// All the remaining cases only permit reading.
Info.FFDiag(E, diag::note_constexpr_modify_global);
return CompleteObject();
- } else if (VD->isConstexpr() || BaseType.isConstQualified()) {
+ } else if (VD->isConstexpr()) {
// OK, we can read this variable.
} else if (BaseType->isIntegralOrEnumerationType()) {
// In OpenCL if a variable is in constant address space it is a const
value.
@@ -2928,6 +2928,9 @@ static CompleteObject findCompleteObject
} else {
Info.CCEDiag(E);
}
+ } else if (BaseType.isConstQualified() && VD->hasDefinition(Info.Ctx)) {
+ Info.CCEDiag(E, diag::note_constexpr_ltor_non_constexpr) << VD;
+ // Keep evaluating to see what we can do.
} else {
// FIXME: Allow folding of values of any literal type in all languages.
if (Info.checkingPotentialConstantExpression() &&
Modified: cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp?rev=290584&r1=290583&r2=290584&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp (original)
+++ cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp Mon Dec 26 23:33:20
2016
@@ -1195,7 +1195,7 @@ struct S {
int j : f(0); // expected-error {{constant expression}} expected-note {{in
call to 'f(0)'}}
int k : g(0); // expected-error {{constant expression}} expected-note
{{temporary created here}} expected-note {{in call to 'g(0)'}}
int l : n3; // expected-error {{constant expression}} expected-note {{read
of non-const variable}}
- int m : t.n; // expected-warning{{width of bit-field 'm' (42 bits)}}
+ int m : t.n; // expected-warning{{width of bit-field 'm' (42 bits)}}
expected-warning{{expression is not an integral constant expression}}
expected-note{{read of non-constexpr variable 't' is not allowed}}
};
}
Modified: cfe/trunk/test/SemaCXX/constant-expression-cxx1y.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/constant-expression-cxx1y.cpp?rev=290584&r1=290583&r2=290584&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/constant-expression-cxx1y.cpp (original)
+++ cfe/trunk/test/SemaCXX/constant-expression-cxx1y.cpp Mon Dec 26 23:33:20
2016
@@ -959,18 +959,21 @@ namespace PR27989 {
}
namespace const_char {
-template <int M, int N>
+template <int N>
constexpr int sum(const char (&Arr)[N]) {
- static_assert(N >= M, "");
int S = 0;
- for (unsigned I = 0; I != M; ++I)
- S += Arr[I];
+ for (unsigned I = 0; I != N; ++I)
+ S += Arr[I]; // expected-note 2{{read of non-constexpr variable 'Cs' is
not allowed}}
return S;
}
// As an extension, we support evaluating some things that are `const` as
though
-// they were `constexpr`.
-const char Cs[] = {'a', 'b', 'c'};
-const int N = 2;
-static_assert(sum<N>(Cs) == 'a' + 'b', "");
+// they were `constexpr` when folding, but it should not be allowed in normal
+// constexpr evaluation.
+const char Cs[] = {'a', 'b'};
+void foo() __attribute__((enable_if(sum(Cs) == 'a' + 'b', "")));
+void run() { foo(); }
+
+static_assert(sum(Cs) == 'a' + 'b', ""); // expected-error{{not an integral
constant expression}} expected-note{{in call to 'sum(Cs)'}}
+constexpr int S = sum(Cs); // expected-error{{must be initialized by a
constant expression}} expected-note{{in call}}
}
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