uint32_t
AppleObjCTypeEncodingParser::ReadNumber(lldb_utility::StringLexer &type) {
uint32_t total = 0;
while (type.HasAtLeast(1) && isdigit(type.Peek()))
total = 10 * total + (type.Next() - '0');
return total;
}
std::string
AppleObjCTypeEncodingParser::ReadStructName(lldb_utility::StringLexer &type) {
StreamString buffer;
while (type.HasAtLeast(1) && type.Peek() != '=')
buffer.Printf("%c", type.Next());
return buffer.GetString();
}
std::string
AppleObjCTypeEncodingParser::ReadQuotedString(lldb_utility::StringLexer& type)
{
StreamString buffer;
while (type.HasAtLeast(1) && type.Peek() != '"')
buffer.Printf("%c",type.Next());
StringLexer::Character next = type.Next();
assert (next == '"');
return buffer.GetString();
}
// the runtime can emit these in the form of @"SomeType", giving more specifics
// this would be interesting for expression parser interop, but since we actually try
// to avoid exposing the ivar info to the expression evaluator, consume but ignore the type info
// and always return an 'id'; if anything, dynamic typing will resolve things for us anyway
clang::QualType
AppleObjCTypeEncodingParser::BuildObjCObjectPointerType (clang::ASTContext &ast_ctx, lldb_utility::StringLexer& type, bool for_expression)
{
if (!type.NextIf('@'))
return clang::QualType();
std::string name;
if (type.NextIf('"'))
{
// We have to be careful here. We're used to seeing
// @"NSString"
// but in records it is possible that the string following an @ is the name of the next field and @ means "id".
// This is the case if anything unquoted except for "}", the end of the type, or another name follows the quoted string.
//
// E.g.
// - @"NSString"@ means "id, followed by a field named NSString of type id"
// - @"NSString"} means "a pointer to NSString and the end of the struct"
// - @"NSString""nextField" means "a pointer to NSString and a field named nextField"
// - @"NSString" followed by the end of the string means "a pointer to NSString"
//
// As a result, the rule is: If we see @ followed by a quoted string, we peek.
// - If we see }, ), ], the end of the string, or a quote ("), the quoted string is a class name.
// - If we see anything else, the quoted string is a field name and we push it back onto type.
name = ReadQuotedString(type);
if (type.HasAtLeast(1))
{
switch (type.Peek())
{
default:
// roll back
type.PutBack(name.length() + 2); // undo our consumption of the string and of the quotes
name.clear();
break;
case '}':
case ')':
case ']':
case '"':
// the quoted string is a class name – see the rule
break;
}
}
else
{
// the quoted string is a class name – see the rule
}
}
if (for_expression && !name.empty())
{
size_t less_than_pos = name.find_first_of('<');
if (less_than_pos != std::string::npos)
{
if (less_than_pos == 0)
return ast_ctx.getObjCIdType();
else
name.erase(less_than_pos);
}
DeclVendor *decl_vendor = m_runtime.GetDeclVendor();
assert (decl_vendor); // how are we parsing type encodings for expressions if a type vendor isn't in play?
const bool append = false;
const uint32_t max_matches = 1;
std::vector<clang::NamedDecl *> decls;
uint32_t num_types = decl_vendor->FindDecls(ConstString(name),
append,
max_matches,
decls);
// The user can forward-declare something that has no definition. The runtime doesn't prohibit this at all.
// This is a rare and very weird case. We keep this assert in debug builds so we catch other weird cases.
#ifdef LLDB_CONFIGURATION_DEBUG
assert(num_types);
#else
if (!num_types)
return ast_ctx.getObjCIdType();
#endif
return ClangASTContext::GetTypeForDecl(decls[0]).GetPointerType().GetQualType();
}
else
{
// We're going to resolve this dynamically anyway, so just smile and wave.
return ast_ctx.getObjCIdType();
}
}