tdep/2075: incorrect return value when bool functions are printed on amd64

larue@cadence.com larue@cadence.com
Fri Jan 27 21:48:00 GMT 2006


>Number:         2075
>Category:       tdep
>Synopsis:       incorrect return value when bool functions are printed on amd64
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Jan 27 21:48:01 GMT 2006
>Closed-Date:
>Last-Modified:
>Originator:     Woody LaRue
>Release:        gdb-6.3
>Organization:
>Environment:
amd64 / linux
>Description:
printing a function that returns a bool value always returns false.

>How-To-Repeat:
cat test.cpp
bool test()
{
  return true;
}

main(int, char**)
{
while(1);
}
sdvopt05{larue 60}:!g++
g++ -g test.cpp
sdvopt05{larue 61}:gdb a.out
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This GDB was configured as "x86_64-linux-gnu"...Using host libthread_db library "/lib64/tls/libthread_db.so.1".

(gdb) run
Starting program: /home/larue/a.out 

Interrupt


Program received signal SIGINT, Interrupt.
main () at test.cpp:8
8       while(1);
(gdb) print test()
$1 = false
(gdb) 
>Fix:
I have a fix to the function amd64_classify function (add TYPE_CODE_BOOL to the test clause)

static void
amd64_classify (struct type *type, enum amd64_reg_class class[2])
{
  enum type_code code = TYPE_CODE (type);
  int len = TYPE_LENGTH (type);

  class[0] = class[1] = AMD64_NO_CLASS;

  /* Arguments of types (signed and unsigned) _Bool, char, short, int,
     long, long long, and pointers are in the INTEGER class.  Similarly,
     range types, used by languages such as Ada, are also in the INTEGER
     class.  */

 /* Adding TYPE_CODE_BOOL to the following test. Without this printing a boolean 
    valued function is incorrectly returning false.

    larue@cadence.com 1/27/06  */
  if ((code == TYPE_CODE_INT || code == TYPE_CODE_ENUM
       || code == TYPE_CODE_RANGE
       || code == TYPE_CODE_PTR || code == TYPE_CODE_REF || TYPE_CODE_BOOL)
/* ADD BOOLEAN TO CLAUSE */
      && (len == 1 || len == 2 || len == 4 || len == 8))
    class[0] = AMD64_INTEGER;

>Release-Note:
>Audit-Trail:
>Unformatted:



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