pycparser visit else only of an if-else statement

Question

I'm using pycparser to parse some C code. Specifically, I need certain portions of the code, included in pycparser are some visitors like visit_If to visit "If" sections of the code. However, I'm having problem visiting 'else' part of an if-else statement.

Example 1:

if (x == 0)
{
    // some statements
}
else
{
    // some statements -> I only need all codes under else
}

Example 2:

if (x == 0)
    // a statement
else
    // a statement -> I only need all codes under else

How is this possible in pycparser?

score 0 · Accepted Answer · answered Sep 17 '18 at 12:56

0

The If node has an iffalse child node which is the else clause from the original code. For example, see the C code generator (part of pycparser):

def visit_If(self, n):
    s = 'if ('
    if n.cond: s += self.visit(n.cond)
    s += ')\n'
    s += self._generate_stmt(n.iftrue, add_indent=True)
    if n.iffalse:
        s += self._make_indent() + 'else\n'
        s += self._generate_stmt(n.iffalse, add_indent=True)
    return s

This is a good example of visiting an If node and accessing all its child nodes.

answered Sep 17 '18 at 12:56

Eli Bendersky

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I would also like to ask know how to get the line number of "else" line. I know its in coord.line but iffalse coord.line of example 1 points to "{". Is there a way? – Thor Sep 18 '18 at 19:00
@Thor, It should point to the right place. This could be a bug so please open a Github issue with a minimal reproducer – Eli Bendersky Sep 20 '18 at 12:32
Accepted answer. I added a github issue – Thor Sep 29 '18 at 21:11

pycparser visit else only of an if-else statement

1 Answers1