The problem is printing the wrong value for dynamic local variables
when using the "info locals" command. Consider the following code:
procedure Print (I1 : Positive; I2 : Positive) is
type My_String is array (I1 .. I2) of Character;
I : My_String := (others => 'A');
S : String (1 .. I2 + 3) := (others => ' ');
begin
S (I1 .. I2) := String (I); -- BREAK
Put_Line (S);
end Print;
After the debugger stopped at BREAK, we try printing all local variables.
Here is what we get:
(gdb) info locals
i = "["00"]["00"]"
s = "["00"]["00"]["00"]["00"]["00"]["00"]["00"]["00"]"
Curiously, printing their value using the "print" command works:
(gdb) print i
$1 = "AA"
(gdb) print s
$2 = " "
We traced the problem to trying to get the contents of a variable
(call to value_contents) before "fix'ing" it. For those not familiar
with the Ada language support, "fixing" a value consists of swapping
the value's dynamic type with a static version that is appropriate
for our actual value. As a result, the dynamic type was used to
determine the value size, which is zero, and thus the value contents
was empty.
gdb/ChangeLog:
* valprint.c (common_val_print): Fix the value before extracting
its contents.
* ada-lang.c (ada_to_fixed_value): Make this function extern.
* ada-lang.h (ada_to_fixed_value): New function declaration.
* ada-valprint.c (ada_value_print): Use ada_to_fixed_value
to avoid code duplication and fix a bug in the handling of
fixed types contents.
gdb/testsuite/ChangeLog:
* gdb.ada/dyn_loc: New testcase.
Joel Brobecker