[cfe-commits] r99561 - in /cfe/trunk: include/clang/Basic/DiagnosticSemaKinds.td lib/Sema/SemaTemplate.cpp test/CXX/temp/temp.fct.spec/temp.deduct/p9.cpp test/SemaTemplate/temp_arg_nontype.cpp
Douglas Gregor
dgregor at apple.com
Thu Mar 25 15:21:04 PDT 2010
Author: dgregor
Date: Thu Mar 25 17:21:04 2010
New Revision: 99561
URL: http://llvm.org/viewvc/llvm-project?rev=99561&view=rev
Log:
Warn when the conversion of an integral non-type template argument to
the type of its corresponding non-type template parameter changes the
value. Previously, we were diagnosing this as an error, which was
wrong. We give reasonably nice warnings like:
test/SemaTemplate/temp_arg_nontype.cpp:100:10: warning: non-type template
argument value '256' truncated to '0' for template parameter of type
'unsigned char'
Overflow<256> *overflow3; // expected-warning{{non-type template ...
^~~
test/SemaTemplate/temp_arg_nontype.cpp:96:24: note: template parameter is
declared here
template<unsigned char C> struct Overflow;
^
Added:
cfe/trunk/test/CXX/temp/temp.fct.spec/temp.deduct/p9.cpp
Modified:
cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
cfe/trunk/lib/Sema/SemaTemplate.cpp
cfe/trunk/test/SemaTemplate/temp_arg_nontype.cpp
Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=99561&r1=99560&r2=99561&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Thu Mar 25 17:21:04 2010
@@ -1207,12 +1207,12 @@
def err_template_arg_not_convertible : Error<
"non-type template argument of type %0 cannot be converted to a value "
"of type %1">;
-def err_template_arg_negative : Error<
- "non-type template argument provides negative value '%0' for unsigned "
- "template parameter of type %1">;
-def err_template_arg_too_large : Error<
- "non-type template argument value '%0' is too large for template "
- "parameter of type %1">;
+def warn_template_arg_negative : Warning<
+ "non-type template argument with value '%0' converted to '%1' for unsigned "
+ "template parameter of type %2">;
+def warn_template_arg_too_large : Warning<
+ "non-type template argument value '%0' truncated to '%1' for "
+ "template parameter of type %2">;
def err_template_arg_no_ref_bind : Error<
"non-type template parameter of reference type %0 cannot bind to template "
"argument of type %1">;
@@ -1379,7 +1379,7 @@
"for '%0' required here">;
def note_explicit_template_arg_substitution_here : Note<
"while substituting explicitly-specified template arguments into function "
- "template %f, here">;
+ "template %0, here">;
def note_function_template_deduction_instantiation_here : Note<
"while substituting deduced template arguments into function template %0, "
"here">;
Modified: cfe/trunk/lib/Sema/SemaTemplate.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplate.cpp?rev=99561&r1=99560&r2=99561&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaTemplate.cpp (original)
+++ cfe/trunk/lib/Sema/SemaTemplate.cpp Thu Mar 25 17:21:04 2010
@@ -2554,38 +2554,39 @@
IntegerType = Context.getCanonicalType(Enum->getDecl()->getIntegerType());
if (!Arg->isValueDependent()) {
- // Check that an unsigned parameter does not receive a negative
- // value.
+ llvm::APSInt OldValue = Value;
+
+ // Coerce the template argument's value to the value it will have
+ // based on the template parameter's type.
+ unsigned AllowedBits = Context.getTypeSize(IntegerType);
+ Value.setIsSigned(IntegerType->isSignedIntegerType());
+ if (Value.getBitWidth() != AllowedBits)
+ Value.extOrTrunc(AllowedBits);
+
+ // Complain if an unsigned parameter received a negative value.
if (IntegerType->isUnsignedIntegerType()
- && (Value.isSigned() && Value.isNegative())) {
- Diag(Arg->getSourceRange().getBegin(), diag::err_template_arg_negative)
- << Value.toString(10) << Param->getType()
+ && (OldValue.isSigned() && OldValue.isNegative())) {
+ Diag(Arg->getSourceRange().getBegin(), diag::warn_template_arg_negative)
+ << OldValue.toString(10) << Value.toString(10) << Param->getType()
<< Arg->getSourceRange();
Diag(Param->getLocation(), diag::note_template_param_here);
- return true;
}
- // Check that we don't overflow the template parameter type.
- unsigned AllowedBits = Context.getTypeSize(IntegerType);
+ // Complain if we overflowed the template parameter's type.
unsigned RequiredBits;
if (IntegerType->isUnsignedIntegerType())
- RequiredBits = Value.getActiveBits();
- else if (Value.isUnsigned())
- RequiredBits = Value.getActiveBits() + 1;
+ RequiredBits = OldValue.getActiveBits();
+ else if (OldValue.isUnsigned())
+ RequiredBits = OldValue.getActiveBits() + 1;
else
- RequiredBits = Value.getMinSignedBits();
+ RequiredBits = OldValue.getMinSignedBits();
if (RequiredBits > AllowedBits) {
Diag(Arg->getSourceRange().getBegin(),
- diag::err_template_arg_too_large)
- << Value.toString(10) << Param->getType()
+ diag::warn_template_arg_too_large)
+ << OldValue.toString(10) << Value.toString(10) << Param->getType()
<< Arg->getSourceRange();
Diag(Param->getLocation(), diag::note_template_param_here);
- return true;
}
-
- if (Value.getBitWidth() != AllowedBits)
- Value.extOrTrunc(AllowedBits);
- Value.setIsSigned(IntegerType->isSignedIntegerType());
}
// Add the value of this argument to the list of converted
Added: cfe/trunk/test/CXX/temp/temp.fct.spec/temp.deduct/p9.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/temp/temp.fct.spec/temp.deduct/p9.cpp?rev=99561&view=auto
==============================================================================
--- cfe/trunk/test/CXX/temp/temp.fct.spec/temp.deduct/p9.cpp (added)
+++ cfe/trunk/test/CXX/temp/temp.fct.spec/temp.deduct/p9.cpp Thu Mar 25 17:21:04 2010
@@ -0,0 +1,6 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+
+template <int> int f(int); // expected-note 2{{candidate}}
+template <signed char> int f(int); // expected-note 2{{candidate}}
+int i1 = f<1>(0); // expected-error{{ambiguous}}
+int i2 = f<1000>(0); // expected-error{{ambiguous}}
Modified: cfe/trunk/test/SemaTemplate/temp_arg_nontype.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaTemplate/temp_arg_nontype.cpp?rev=99561&r1=99560&r2=99561&view=diff
==============================================================================
--- cfe/trunk/test/SemaTemplate/temp_arg_nontype.cpp (original)
+++ cfe/trunk/test/SemaTemplate/temp_arg_nontype.cpp Thu Mar 25 17:21:04 2010
@@ -97,21 +97,21 @@
Overflow<5> *overflow1; // okay
Overflow<255> *overflow2; // okay
-Overflow<256> *overflow3; // expected-error{{non-type template argument value '256' is too large for template parameter of type 'unsigned char'}}
+Overflow<256> *overflow3; // expected-warning{{non-type template argument value '256' truncated to '0' for template parameter of type 'unsigned char'}}
template<unsigned> struct Signedness; // expected-note{{template parameter is declared here}}
Signedness<10> *signedness1; // okay
-Signedness<-10> *signedness2; // expected-error{{non-type template argument provides negative value '-10' for unsigned template parameter of type 'unsigned int'}}
+Signedness<-10> *signedness2; // expected-warning{{non-type template argument with value '-10' converted to '4294967286' for unsigned template parameter of type 'unsigned int'}}
template<signed char C> struct SignedOverflow; // expected-note 3 {{template parameter is declared here}}
SignedOverflow<1> *signedoverflow1;
SignedOverflow<-1> *signedoverflow2;
SignedOverflow<-128> *signedoverflow3;
-SignedOverflow<-129> *signedoverflow4; // expected-error{{non-type template argument value '-129' is too large for template parameter of type 'signed char'}}
+SignedOverflow<-129> *signedoverflow4; // expected-warning{{non-type template argument value '-129' truncated to '127' for template parameter of type 'signed char'}}
SignedOverflow<127> *signedoverflow5;
-SignedOverflow<128> *signedoverflow6; // expected-error{{non-type template argument value '128' is too large for template parameter of type 'signed char'}}
-SignedOverflow<(unsigned char)128> *signedoverflow7; // expected-error{{non-type template argument value '128' is too large for template parameter of type 'signed char'}}
+SignedOverflow<128> *signedoverflow6; // expected-warning{{non-type template argument value '128' truncated to '-128' for template parameter of type 'signed char'}}
+SignedOverflow<(unsigned char)128> *signedoverflow7; // expected-warning{{non-type template argument value '128' truncated to '-128' for template parameter of type 'signed char'}}
// Check canonicalization of template arguments.
template<int (*)(int, int)> struct FuncPtr0;
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