[Bug c++/43790] New: In lambda express, calling member function of non-captured class gives internal compiler error

[darlingm at gmail dot com]

The below at the bottom of this comment gives:

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/home/mdarling/code.gccerror/testing/gccError/gccError.cpp: In lambda function:
/home/mdarling/code.gccerror/testing/gccError/gccError.cpp:25:14: error:
'classInstance' is not captured
/home/mdarling/code.gccerror/testing/gccError/gccError.cpp:26:4: internal
compiler error: tree check: expected class 'type', have 'exceptional'
(error_mark) in cv_unqualified, at cp/tree.c:937
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See <http://gcc.gnu.org/bugs.html> for instructions.



The original internal compiler error was of course in a much larger project,
and had a bunch of other code errors on it being the first compile attempt.  I
got tunnel visioned at the first sight of an internal compiler error and spent
hours re-checking out the svn gcc source and recompiling, in case my svn
version from a week ago had a fixed bug in it.

After removing irrelevant portions of the program to get down to a small test
case, it appears that calling a member function of a non-captured class gives
an internal compiler error.  Properly changing the lambda expression line to
"function<string ()> lambdaExpression = [&classInstance] () {" prevents the
internal compiler error.

I know it's invalid c++0x code that's causing the internal compiler error, but
removing the internal compiler error and only showing the message "error:
'classInstance' is not captured" might save someone else a few hours who gets
tunnel visioned on the one error.  :)


==========
#include <iostream>
#include <string>
#include <functional>
using namespace std;

class theClass {
   public:
      theClass();
      string getA();
   private:
      string a;
};

theClass::theClass() 
: a("theData") {
}

string theClass::getA() {
   return a;
}

int main() {
   theClass classInstance;
   function<string ()> lambdaExpression = [] () {
      return classInstance.getA();
   }; 
   cout << lambdaExpression() << endl;
}


-- 
           Summary: In lambda express, calling member function of non-
                    captured class gives internal compiler error
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: darlingm at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43790