Update assumption in template diffing about integer template arguments.

Fix for PR22017.  Integer template arguments are automatically bit extended to
the size of the integer type.  In template diffing, evaluated expressions were
not having their results extending, leading to comparing two APSInt's with
different widths.  Apply the proper bit extending when evaluating template
arguments.  This mainly affected bool template arguments.

llvm-svn: 230603
This commit is contained in:
Richard Trieu 2015-02-26 02:40:48 +00:00
parent 99b0a9cdd7
commit 555c9673fd
2 changed files with 27 additions and 6 deletions

View File

@ -1003,9 +1003,11 @@ class TemplateDiff {
Tree.SetDefault(FromIter.isEnd() && FromExpr, ToIter.isEnd() && ToExpr);
if (FromDefaultNonTypeDecl->getType()->isIntegralOrEnumerationType()) {
if (FromExpr)
HasFromInt = GetInt(Context, FromIter, FromExpr, FromInt);
HasFromInt = GetInt(Context, FromIter, FromExpr, FromInt,
FromDefaultNonTypeDecl->getType());
if (ToExpr)
HasToInt = GetInt(Context, ToIter, ToExpr, ToInt);
HasToInt = GetInt(Context, ToIter, ToExpr, ToInt,
ToDefaultNonTypeDecl->getType());
}
if (HasFromInt && HasToInt) {
Tree.SetNode(FromInt, ToInt, HasFromInt, HasToInt);
@ -1026,9 +1028,11 @@ class TemplateDiff {
if (HasFromInt || HasToInt) {
if (!HasFromInt && FromExpr)
HasFromInt = GetInt(Context, FromIter, FromExpr, FromInt);
HasFromInt = GetInt(Context, FromIter, FromExpr, FromInt,
FromDefaultNonTypeDecl->getType());
if (!HasToInt && ToExpr)
HasToInt = GetInt(Context, ToIter, ToExpr, ToInt);
HasToInt = GetInt(Context, ToIter, ToExpr, ToInt,
ToDefaultNonTypeDecl->getType());
Tree.SetNode(FromInt, ToInt, HasFromInt, HasToInt);
if (HasFromInt && HasToInt) {
Tree.SetSame(FromInt == ToInt);
@ -1210,9 +1214,11 @@ class TemplateDiff {
}
/// GetInt - Retrieves the template integer argument, including evaluating
/// default arguments.
/// default arguments. If the value comes from an expression, extend the
/// APSInt to size of IntegerType to match the behavior in
/// Sema::CheckTemplateArgument
static bool GetInt(ASTContext &Context, const TSTiterator &Iter,
Expr *ArgExpr, llvm::APSInt &Int) {
Expr *ArgExpr, llvm::APSInt &Int, QualType IntegerType) {
// Default, value-depenedent expressions require fetching
// from the desugared TemplateArgument, otherwise expression needs to
// be evaluatable.
@ -1224,12 +1230,14 @@ class TemplateDiff {
case TemplateArgument::Expression:
ArgExpr = Iter.getDesugar().getAsExpr();
Int = ArgExpr->EvaluateKnownConstInt(Context);
Int = Int.extOrTrunc(Context.getTypeSize(IntegerType));
return true;
default:
llvm_unreachable("Unexpected template argument kind");
}
} else if (ArgExpr->isEvaluatable(Context)) {
Int = ArgExpr->EvaluateKnownConstInt(Context);
Int = Int.extOrTrunc(Context.getTypeSize(IntegerType));
return true;
}

View File

@ -1261,6 +1261,19 @@ void foo(const T &t) {
// CHECK-ELIDE-NOTREE: binding of reference to type 'condition<[...]>' to a value of type 'const condition<[...]>' drops qualifiers
}
namespace BoolArgumentBitExtended {
template <bool B> struct BoolT {};
template <typename T> void foo(T) {}
void test() {
BoolT<false> X;
foo<BoolT<true>>(X);
}
// CHECK-ELIDE-NOTREE: no matching function for call to 'foo'
// CHECK-ELIDE-NOTREE: candidate function [with T = BoolArgumentBitExtended::BoolT<true>] not viable: no known conversion from 'BoolT<0>' to 'BoolT<1>' for 1st argument
}
// CHECK-ELIDE-NOTREE: {{[0-9]*}} errors generated.
// CHECK-NOELIDE-NOTREE: {{[0-9]*}} errors generated.
// CHECK-ELIDE-TREE: {{[0-9]*}} errors generated.