[Bug gdb/10309] New: gdb wide char support fails with typedefs in C

[Bug gdb/10309] New: gdb wide char support fails with typedefs in C

[holger dot hopp at sap dot com]

I noticed that the gdb in development (gdb-weekly-6.8.50.20090616.tar.bz2)
now includes support for printing wide character (wchar_t, char16_t,
char32_t) types. That's great!

Unfortunately this does not work correctly with typedefs in C.
With typedefs in C++ this works properly.

Reproduce:
Compile the attached example program with gcc-4.4 oder gcc-4.5 (trunk):
$ gcc --std=gnu99 -O0 -g tst.c -o tst-c
$ g++ --std=c++0x -O0 -g tst.c -o tst-c++
And then single-step tst-c and tst-c++ in gdb.

With tst-c++ you will get

[...]
(gdb) 
main () at tst.c:60
60	  ignore_mw (mwstr);
(gdb) 
ignore_mw (str=0x4009a0 L"Hello World 8") at tst.c:45
45	void ignore_mw  (const my_wchar_t  *str) { ignore ((void*)str); }
(gdb) 
ignore (anything=0x4009a0) at tst.c:36
36	{ }
[...]

gdb prints  L"Hello World 8"  and that's what I expect.

With tst-c you will get

[...]
(gdb) 
main () at tst.c:60
60	  ignore_mw (mwstr);
(gdb) 
ignore_mw (str=0x4008a0) at tst.c:45
45	void ignore_mw  (const my_wchar_t  *str) { ignore ((void*)str); }
(gdb) 
ignore (anything=0x4008a0) at tst.c:36
36	{ }
(gdb) 
[...]

gdb does not detect wchar_t string type in C, if the type is a typedef.



Probable reason:
In C there is not base type wchar_t [char16_t, char32_t] as in C++.
There is only a typedef (with gcc via __WCHAR_TYPE__, __CHAR16_TYPE__,
and __CHAR32_TYPE__). But the function 'classify_type' in gdb/c-lang.c
does not pass all typedefs. The comment says
  /* We do one or two passes -- one on ELTTYPE, and then maybe a
     second one on a typedef target.  */
I think some modifications in 'classify_type' are needed. The two-pass
solution is not sufficient.

-- 
           Summary: gdb wide char support fails with typedefs in C
           Product: gdb
           Version: 6.8
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: gdb
        AssignedTo: unassigned at sourceware dot org
        ReportedBy: holger dot hopp at sap dot com
                CC: gdb-prs at sourceware dot org
 GCC build triplet: x86_64-unknown-linux-gnu
  GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: x86_64-unknown-linux-gnu


http://sourceware.org/bugzilla/show_bug.cgi?id=10309

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[Bug gdb/10309] gdb wide char support fails with typedefs in C

[holger dot hopp at sap dot com]

------- Additional Comments From holger dot hopp at sap dot com  2009-06-22 14:41 -------
Created an attachment (id=4012)
 --> (http://sourceware.org/bugzilla/attachment.cgi?id=4012&action=view)
test case


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[Bug gdb/10309] gdb wide char support fails with typedefs in C

[tromey at redhat dot com]

------- Additional Comments From tromey at redhat dot com  2009-06-22 18:33 -------
I'll handle this.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at sourceware dot|tromey at redhat dot com
                   |org                         |
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2009-06-22 18:33:54
               date|                            |


http://sourceware.org/bugzilla/show_bug.cgi?id=10309

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[Bug gdb/10309] gdb wide char support fails with typedefs in C

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2009-06-23 16:26 -------
Subject: Bug 10309

CVSROOT:	/cvs/src
Module name:	src
Changes by:	tromey@sourceware.org	2009-06-23 16:26:05

Modified files:
	gdb            : ChangeLog c-lang.c c-valprint.c 
	gdb/testsuite  : ChangeLog 
	gdb/testsuite/gdb.base: charset.c charset.exp 

Log message:
	gdb
	PR gdb/10309:
	* c-lang.c (classify_type): Iterate over typedefs.
	* c-valprint.c (textual_element_type): Iterate over typedefs.
	gdb/testsuite
	* gdb.base/charset.exp (test_combination): Regression test.
	* gdb.base/charset.c (my_wchar_t): New typedef.
	(myvar): New global.
	(main): Set myvar.

Patches:
http://sources.redhat.com/cgi-bin/cvsweb.cgi/src/gdb/ChangeLog.diff?cvsroot=src&r1=1.10620&r2=1.10621
http://sources.redhat.com/cgi-bin/cvsweb.cgi/src/gdb/c-lang.c.diff?cvsroot=src&r1=1.71&r2=1.72
http://sources.redhat.com/cgi-bin/cvsweb.cgi/src/gdb/c-valprint.c.diff?cvsroot=src&r1=1.57&r2=1.58
http://sources.redhat.com/cgi-bin/cvsweb.cgi/src/gdb/testsuite/ChangeLog.diff?cvsroot=src&r1=1.1891&r2=1.1892
http://sources.redhat.com/cgi-bin/cvsweb.cgi/src/gdb/testsuite/gdb.base/charset.c.diff?cvsroot=src&r1=1.9&r2=1.10
http://sources.redhat.com/cgi-bin/cvsweb.cgi/src/gdb/testsuite/gdb.base/charset.exp.diff?cvsroot=src&r1=1.14&r2=1.15



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[Bug gdb/10309] gdb wide char support fails with typedefs in C

[tromey at redhat dot com]

------- Additional Comments From tromey at redhat dot com  2009-06-23 16:28 -------
I've checked in the fix.
Thanks for finding this.


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|6.8                         |6.9


http://sourceware.org/bugzilla/show_bug.cgi?id=10309

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