On Nov 20, 2008, at 12:27 AM, Chris Lattner wrote:
On Nov 18, 2008, at 8:13 AM, Douglas Gregor wrote:
+ DiagnosticInfo &operator<<(const SourceRange &R) {
+ assert((unsigned)DiagObj->NumDiagArgs <
+ sizeof(DiagObj->DiagRanges)/sizeof(DiagObj-
DiagRanges[0]) &&
+ "Too many arguments to diagnostic!");
+ DiagObj->DiagRanges[DiagObj->NumDiagRanges++] = &R;
+ return *this;
+ }
+
};
These operator<<'s should be free functions, because we will
certainly
have other operator<<'s for DiagnosticInfo elsewhere in the compiler
that must be free functions, e.g.,
DiagnosticInfo& operator<<(DiagnosticInfo& DI, QualType Ty); // in
clang/AST/Type.h
and we don't want non-member and member operator<<'s overloaded
because the available conversions on the first argument differ, and
that causes overloading weirdness.
Yes, I totally agree. Okay, I'm to the point where I want to do
this. However, this is not my day. Please take a look at this patch:
<operators.patch>
I just move the operators out of the class in a straightforward
way. With this patch, I get build errors like these:
Lexer.cpp: In function ‘char DecodeTrigraphChar(const char*,
clang::Lexer*)’:
Lexer.cpp:352: error: no match for ‘operator<<’ in
‘clang::Lexer::Diag(const char*, unsigned int) const((CP - 2u), 9u)
<< std::operator+(const std::basic_string<_CharT, _Traits, _Alloc>&,
_CharT) [with _Char
T = char, _Traits = std::char_traits<char>, _Alloc =
std::allocator<char>](((int)Res))’
/Users/sabre/llvm/tools/clang/lib/Lex/../../include/clang/Basic/
Diagnostic.h:366: note: candidates are: clang::DiagnosticInfo&
clang::operator<<(clang::DiagnosticInfo&, const std::string&)
/Users/sabre/llvm/tools/clang/lib/Lex/../../include/clang/Basic/
Diagnostic.h:371: note: clang::DiagnosticInfo&
clang::operator<<(clang::DiagnosticInfo&, const char*)
/Users/sabre/llvm/tools/clang/lib/Lex/../../include/clang/Basic/
Diagnostic.h:376: note: clang::DiagnosticInfo&
clang::operator<<(clang::DiagnosticInfo&, int)
/Users/sabre/llvm/tools/clang/lib/Lex/../../include/clang/Basic/
Diagnostic.h:381: note: clang::DiagnosticInfo&
clang::operator<<(clang::DiagnosticInfo&, unsigned int)
/Users/sabre/llvm/tools/clang/lib/Lex/../../include/clang/Basic/
Diagnostic.h:386: note: clang::DiagnosticInfo&
clang::operator<<(clang::DiagnosticInfo&, const
clang::IdentifierInfo*)
/Users/sabre/llvm/tools/clang/lib/Lex/../../include/clang/Basic/
Diagnostic.h:392: note: clang::DiagnosticInfo&
clang::operator<<(clang::DiagnosticInfo&, const clang::SourceRange&)
This is the source line:
Lexer *L; char Res;
...
L->Diag(CP-2, diag::trigraph_converted) << std::string()+Res;
The basic problem is that Diag() is returning a temporary, but a non-
const (lvalue) reference can't bind to a temporary. I suggest making
the first parameter to these operator<<'s either a const
DiagnosticInfo& or a DiagnosticInfo. (The former will require a bunch
of other member functions to be const, but so what?)
This is a good point where we can step back and look at the amazing
awfulness of this diagnostic. It's 'pretty' printing out the
expression in question, in a horribly mangled form. Then it dumps
out a candidate list, but manages to not tell me the types that it
actually *has* on the LHS/RHS of the <<.
We should use this kind of thing as a test case for our diagnostics,
to see how clear we can make them.
- Doug
_______________________________________________
cfe-commits mailing list
[email protected]
http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
