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7. Partial correction of the processing of "bool r = a < 1 || b > (int) 2;" type expressions.
There is an error in OpenC++ related to the processing of some expressions which are wrongly taken for templates. For example, in a string "bool r = a < 1 || b > (int) 2;" "a" variable will be taken for a template name and then a lot of troubles with syntactical analysis will follow? Full correction of this error requires great changes and is not realized by now. We offer you a temporary solution excluding the major part of errors. Further the functions are given which may be added or modified.
bool VivaParser::MaybeTypeNameOrClassTemplate(Token &token) {
if (m_env == NULL) {
return true;
}
const char *ptr = token.GetPtr();
ptrdiff_t len = token.GetLen();
Bind *bind;
bool isType = m_env->LookupType(ptr, len, bind);
return isType;
}
static bool isOperatorInTemplateArg(ptrdiff_t t) {
return t == AssignOp || t == EqualOp || t == LogOrOp ||
t == LogAndOp || t == IncOp || t == RelOp;
}
/*
template.args : '<' any* '>'
template.args must be followed by '(' or '::'
*/
bool Parser::isTemplateArgs()
{
ptrdiff_t i = 0;
ptrdiff_t t = lex->LookAhead(i++);
if(t == '<'){
ptrdiff_t n = 1;
while(n > 0){
ptrdiff_t u = lex->LookAhead(i++);
/*
TODO. :(
Fixing: bool r = a < 1 || b > (int) 2;
We'll correct not all the cases but it will be better anyway.
Editing method. If an identifier is found near the operator, it is
obviously not a template because only a type or a constant
expression may stay inside the brackets.
An example which doesn't work anyway:
r = a < fooi() || 1 > (int) b;
Unfortunately, the following expression is processed incorrectly now,
but such cases are fewer than corrected ones.
template <int z>
unsigned TFoo(unsigned a) {
return a + z;
}
enum EEnum { EE1, EE2 };
b = TFoo < EE1 && EE2 > (2);
*/
ptrdiff_t next = lex->LookAhead(i);
if (u == Identifier &&
isOperatorInTemplateArg(next))
return false;
if (isOperatorInTemplateArg(u) &&
next == Identifier)
return false;
if(u == '<')
++n;
else if(u == '>')
--n;
else if(u == '('){
ptrdiff_t m = 1;
while(m > 0){
ptrdiff_t v = lex->LookAhead(i++);
if(v == '(')
++m;
else if(v == ')')
--m;
else if(v == '\0' || v == ';' || v == '}')
return false;
}
}
else if(u == '\0' || u == ';' || u == '}')
return false;
}
t = lex->LookAhead(i);
return bool(t == Scope || t == '(');
}
return false;
}
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