https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78909
Bug ID: 78909
Summary: local variables unavailable in constructor under
Oracle dbx
Product: gcc
Version: 6.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: debug
Assignee: unassigned at gcc dot gnu.org
Reporter: ivan.soleimanipour at oracle dot com
Target Milestone: ---
Consider this code:
---------------------------------------------
#include <stdio.h>
class Widget {
public:
Widget(int i) {
int x = i;
while (!x);
}
void method(int j) {
int y = j;
while (!y);
}
int id;
};
class AnotherClass {
};
class MyClass : public AnotherClass {
public:
static void callback(Widget *b, MyClass *ptr) {
ptr->callback(b);
}
void callback(Widget *b) {
printf("callback\n");
}
};
int
main()
{
Widget *b = new Widget(4);
b->method(5);
MyClass mc;
MyClass::callback(b, &mc);
}
----------------------------------------------
Using Oracle Solaris/Developer Studio dbx if you stop in Widget() you cannot
see
'x' but if you stop in method() you can see 'y'.
There are two contributing causes:
1) See bug https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55541
While it has been fixed in the 5.x series it seems that constructors
still suffer from it. I.e. if you look at the dwarfdump for the above
program Widget() still has a TAG_lexical_block enclosing 'x'.
2) ... and that TAG_lexical_block is missing the attributes AT_low_pc and
AT_high_pc. Nor is there an AT_ranges. Because no extent can be
established for the lexical block dbx won't create a Scope in it's symbol
table and there's nowhere to hang 'x' off of so it gets ignored.
