maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

When we run into a template parameter that should have a default 

argument but doesn't (because previous template parameters had default
arguments), clear out all of the default arguments so that we maintain
the invariant that a template parameter has a default argument only if
subsequence template parameters also have default arguments.
Fixes a crash-on-invalid <rdar://problem/8913649>.

llvm-svn: 124345
This commit is contained in:
Douglas Gregor 2011-01-27 01:40:17 +00:00
parent dff0be70ba
commit 0693defea9
2 changed files with 25 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
clang/lib/Sema/SemaTemplate.cpp
View File

@ -1149,6 +1149,7 @@ bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams,
if (OldParams)
OldParam = OldParams->begin();
bool RemoveDefaultArguments = false;
for (TemplateParameterList::iterator NewParam = NewParams->begin(),
NewParamEnd = NewParams->end();
NewParam != NewParamEnd; ++NewParam) {
@ -1317,13 +1318,14 @@ bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams,
} else if (MissingDefaultArg) {
// C++ [temp.param]p11:
// If a template-parameter of a class template has a default
// template-argument, each subsequent template- parameter shall either
// template-argument, each subsequent template-parameter shall either
// have a default template-argument supplied or be a template parameter
// pack.
Diag((*NewParam)->getLocation(),
diag::err_template_param_default_arg_missing);
Diag(PreviousDefaultArgLoc, diag::note_template_param_prev_default_arg);
Invalid = true;
RemoveDefaultArguments = true;
}
// If we have an old template parameter list that we're merging
@ -1332,6 +1334,22 @@ bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams,
++OldParam;
}
// We were missing some default arguments at the end of the list, so remove
// all of the default arguments.
if (RemoveDefaultArguments) {
for (TemplateParameterList::iterator NewParam = NewParams->begin(),
NewParamEnd = NewParams->end();
NewParam != NewParamEnd; ++NewParam) {
if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*NewParam))
TTP->removeDefaultArgument();
else if (NonTypeTemplateParmDecl *NTTP
= dyn_cast<NonTypeTemplateParmDecl>(*NewParam))
NTTP->removeDefaultArgument();
else
cast<TemplateTemplateParmDecl>(*NewParam)->removeDefaultArgument();
}
}
return Invalid;
}

6
clang/test/CXX/temp/temp.param/p1.cpp
View File

@ -4,3 +4,9 @@
template<template<> class C> class D; // expected-error{{template template parameter must have its own template parameters}}
struct A {};
template<class M,
class T = A, // expected-note{{previous default template argument defined here}}
class C> // expected-error{{template parameter missing a default argument}}
class X0 {}; // expected-note{{template is declared here}}
X0<int> x0; // expected-error{{too few template arguments for class template 'X0'}}