c++ compilation

karan101 · 03-08-2006, 06:33 PM

I get this compilation error when i try to compile this line code under g++ 4.0.1 :

Code:

analyze.cpp: In member function ‘void Analyzer::incScope(TreeNode*)’:
analyze.cpp:321: error: cast from ‘TreeNode*’ to ‘int’ loses precision

and my code is this:

Code:

symobTable->incScope( int(t));

t is tree node which looks like this:

Code:

class TreeNode {
public:

static const int MAXCHILDREN = 3;
TreeNode * child[MAXCHILDREN];
TreeNode * sibling;
int lineno;
NodeKind nodekind;
union {
DeclKind decl;
StmtKind stmt;
ExpKind exp;
} kind;

union {
TokenType op;
int val;
char * name;
} attr;

ExpType type;

int scope;
};

this code compiles under g++ 2.95 but not with 4.01 anybody knows what kind of casting I should be using or any way to get around this...
thanks

jonaskoelker · 03-08-2006, 07:11 PM

Firstly, post you code in code tags instead of quote tags (please edit your post). Secondly, [i]don't[i] add any characters to your code or the compiler output. Be verbatim! (edit that out too).

I assume you have added stars in pairs (baaad idea--use italics, bold or something similar to emphasize stuff you think it's needed).

So that raises the question: why do you want to cast the node to an int? What you might mean is to take the address of t (one spells that "&t").

hth --Jonas

cppkid · 03-09-2006, 04:02 AM

I didn't get it. If the function takes TreeNode as the parameter and the parameter you are passing is also TreeNode, then why you are casting that variable to int???
Just pass the variable 't' into the function, i don't think you should cast it.

jonaskoelker · 03-09-2006, 10:38 AM

cppkid: actually, we're both wrong--you thought it was (TreeNode, TreeNode), I thought it was (TreeNode, TreeNode*). In fact (read the OP), it's (TreeNode*, TreeNode*).

To OP: don't cast it to an int. Just pass in t.

cppkid · 03-09-2006, 10:59 AM

Yes i noticed that, i just just wanted to put your attention that you didn't have to cast to someother datastructure... Anyway my fault that i didn't mentioned properly... Sorry for inconvinence...

All the best.

jonaskoelker · 03-09-2006, 11:02 AM

np. I just wanted to point it out so the OP didn't get more confused than necessary.

karan101 · 03-12-2006, 05:23 AM

thnx guys for the commens. I don't understand it myself why the author is casting that. Its just a complicated c code that we have to modify it for our project.... I tryed to understand it but its just to messy anyways the interesting thing is that it compiles at school with g++ 2.95 but not on my laptop's 4.01 ... is there anything i can do to compile it without changing the code...
thanks