Author: dgregor
Date: Wed Jul 5 13:20:15 2017
New Revision: 307197
URL: http://llvm.org/viewvc/llvm-project?rev=307197&view=rev
Log:
Cope with Range-v3's CONCEPT_REQUIRES idiom
Modified:
cfe/trunk/lib/Sema/SemaTemplate.cpp
cfe/trunk/test/SemaTemplate/overload-candidates.cpp
Modified: cfe/trunk/lib/Sema/SemaTemplate.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplate.cpp?rev=307197&r1=307196&r2=307197&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaTemplate.cpp (original)
+++ cfe/trunk/lib/Sema/SemaTemplate.cpp Wed Jul 5 13:20:15 2017
@@ -2831,10 +2831,44 @@ static void collectConjunctionTerms(Expr
Terms.push_back(Clause);
}
+// The ranges-v3 library uses an odd pattern of a top-level "||" with
+// a left-hand side that is value-dependent but never true. Identify
+// the idiom and ignore that term.
+static Expr *lookThroughRangesV3Condition(Preprocessor &PP, Expr *Cond) {
+ // Top-level '||'.
+ auto *BinOp = dyn_cast<BinaryOperator>(Cond->IgnoreParenImpCasts());
+ if (!BinOp) return Cond;
+
+ if (BinOp->getOpcode() != BO_LOr) return Cond;
+
+ // With an inner '==' that has a literal on the right-hand side.
+ Expr *LHS = BinOp->getLHS();
+ auto InnerBinOp = dyn_cast<BinaryOperator>(LHS->IgnoreParenImpCasts());
+ if (!InnerBinOp) return Cond;
+
+ if (InnerBinOp->getOpcode() != BO_EQ ||
+ !isa<IntegerLiteral>(InnerBinOp->getRHS()))
+ return Cond;
+
+ // If the inner binary operation came from a macro expansion named
+ // CONCEPT_REQUIRES or CONCEPT_REQUIRES_, return the right-hand side
+ // of the '||', which is the real, user-provided condition.
+ auto Loc = InnerBinOp->getExprLoc();
+ if (!Loc.isMacroID()) return Cond;
+
+ StringRef MacroName = PP.getImmediateMacroName(Loc);
+ if (MacroName == "CONCEPT_REQUIRES" || MacroName == "CONCEPT_REQUIRES_")
+ return BinOp->getRHS();
+
+ return Cond;
+}
+
/// Find the failed subexpression within enable_if, and describe it
/// with a string.
static std::pair<Expr *, std::string>
findFailedEnableIfCondition(Sema &S, Expr *Cond) {
+ Cond = lookThroughRangesV3Condition(S.PP, Cond);
+
// Separate out all of the terms in a conjunction.
SmallVector<Expr *, 4> Terms;
collectConjunctionTerms(Cond, Terms);
Modified: cfe/trunk/test/SemaTemplate/overload-candidates.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaTemplate/overload-candidates.cpp?rev=307197&r1=307196&r2=307197&view=diff
==============================================================================
--- cfe/trunk/test/SemaTemplate/overload-candidates.cpp (original)
+++ cfe/trunk/test/SemaTemplate/overload-candidates.cpp Wed Jul 5 13:20:15 2017
@@ -137,4 +137,30 @@ namespace PR15673 {
#endif
void wibble() {}
void wobble() { wibble<int>(); } // expected-error {{no matching function
for call to 'wibble'}}
+
+ template<typename T>
+ struct some_passing_trait : std::true_type {};
+
+#if __cplusplus <= 199711L
+ // expected-warning@+4 {{default template arguments for a function template
are a C++11 extension}}
+ // expected-warning@+4 {{default template arguments for a function template
are a C++11 extension}}
+#endif
+ template<typename T,
+ int n = 42,
+ typename std::enable_if<n == 43 || (some_passing_trait<T>::value &&
some_trait<T>::value), int>::type = 0>
+ void almost_rangesv3(); // expected-note{{candidate template ignored:
requirement '42 == 43 || (some_passing_trait<int>::value &&
some_trait<int>::value)' was not satisfied}}
+ void test_almost_rangesv3() { almost_rangesv3<int>(); } //
expected-error{{no matching function for call to 'almost_rangesv3'}}
+
+ #define CONCEPT_REQUIRES_(...) \
+ int x = 42, \
+ typename std::enable_if<(x == 43) || (__VA_ARGS__)>::type = 0
+
+#if __cplusplus <= 199711L
+ // expected-warning@+4 {{default template arguments for a function template
are a C++11 extension}}
+ // expected-warning@+4 {{default template arguments for a function template
are a C++11 extension}}
+#endif
+ template<typename T,
+ CONCEPT_REQUIRES_(some_passing_trait<T>::value &&
some_trait<T>::value)>
+ void rangesv3(); // expected-note{{candidate template ignored: requirement
'some_trait<int>::value' was not satisfied [with T = int, x = 42]}}
+ void test_rangesv3() { rangesv3<int>(); } // expected-error{{no matching
function for call to 'rangesv3'}}
}
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