Re: Heap Corruption

[Adrian Vogelsgesang]

Hi Jot,

skimming over your code, I couldn’t find anything particularly wrong or 
suspicious…

If you could post a self-contained repro that would me to follow your steps and 
maybe debug this in more depth.
In case it requires more than a few files, maybe you could upload your code to 
Github and share the link here.

Heap corruption is always mean to debug…
It could be that your heap was already corrupted way earlier, but only the 
“delete” notices that corruption which occurred for a totally independent 
reason.
In general, I would recommend to enable address sanitizer in your compile 
(“-fsanitize=address” flag in both gcc & clang; see 
https://clang.llvm.org/docs/AddressSanitizer.html) which should point you to 
the exact line of code which causes the corruption.

Furthermore, I would in general recommend to always use 
`std::unique_ptr`/`std::make_unique` over “new” and “delete”.

Cheers,
Adrian


From: help-bison <help-bison-bounces+avogelsgesang=tableau.com@gnu.org>
Date: Thursday, 10. December 2020 at 03:23
To: help-bison@gnu.org <help-bison@gnu.org>
Subject: Heap Corruption
I'm at a loss.

I have set up a c++ scanner/parser to run on the command line (windows).
The parser corrupts the heap. I have no clue at all what I am doing wrong.

I think I have set everything up correctly and everything compiles without
any issue. I have defined a parser class, a lexer class, and my own driver
class. This driver class is passed to the lexer and parser. My .l and .y
files are copies of what I have already set up in a DLL - which does not
have this issue.

I am not sure what to post (unnecessary clutter?) but below is what I
believe is a confirmation of my issue.

Note: I simply construct the parser and delete it immediately - and get a
heap corruption error.Tracing thru the code, it looks like it is simply
establishing the stack (when creating the Parser).

Anyone have a similar issue? Any ideas are welcome.
I'll post anything anybody wants to look at.

Thanks

//----------------
class Driver
{
protected:
        gen::Parser* pParser;
        gen::Scanner* pScanner;
        ParseResults* pResult;

public:
    Driver()
    {
        pResult = new ParseResults;              // Test ok
        delete pResult;                         // Test ok
        pResult = new ParseResults;
        pScanner = new gen::Scanner(this);      // Test ok
        delete pScanner;                        // Test ok
        pScanner = new gen::Scanner(this);
        pParser = new gen::Parser(this);        // Test ok
        delete pParser;                         // Test <= FAIL: Heap Corruption
        pParser = new gen::Parser(this);
    }

    virtual ~Driver()
    {
        delete pScanner;
        delete pParser;
        delete pResult;
    }

    gen::Parser* getParser() const { return pParser; }
    gen::Scanner* getScanner() const { return pScanner; }
    ParseResults* getResult() const { return pResult; }
};