RE: [PATCH] Fix gdb.cp/no-dmgl-verbose.exp test

[Carl Love <cel@us.ibm.com>]

On Fri, 2022-04-29 at 09:14 +0000, Lancelot SIX wrote:

<snip>

> > Fix gdb.cp/no-dmgl-verbose.exp test
> > 
> > The test tries to check that setting a break point on f
> > (std::string) fails
> > since the function is not defined.  The test is not syntactically
> > correct.
> > The test fails on both PowerPC and Intel.
> > 
> > This patch fixes the test to set the breakpoint and verify that it
> > fails
> > since the function is not defined.
> > 
> > The test now runs correctly on Power 10 and Intel x86_64.
> > ---
> >  gdb/testsuite/gdb.cp/no-dmgl-verbose.exp | 5 +----
> >  1 file changed, 1 insertion(+), 4 deletions(-)
> > 
> > diff --git a/gdb/testsuite/gdb.cp/no-dmgl-verbose.exp
> > b/gdb/testsuite/gdb.cp/no-dmgl-verbose.exp
> > index 14f11ddcf04..d4ec88f3b6d 100644
> > --- a/gdb/testsuite/gdb.cp/no-dmgl-verbose.exp
> > +++ b/gdb/testsuite/gdb.cp/no-dmgl-verbose.exp
> > @@ -28,8 +28,5 @@ clean_restart ${testfile}.o
> >  
> >  gdb_test_no_output "set breakpoint pending off"
> >  
> > -gdb_breakpoint {'f(std::string)'}
> > -
> > -gdb_test {break 'f(std::basic_string<char, std::char_traits<char>,
> > std::allocator<char> >)'} \
> > -	 {Function ".*" not defined\.} \
> > +gdb_test "break 'f(std::string)'" ".*Function.*not defined." \
>                                                              ^
> 
> I guess here the last . should be escaped (\.) otherwise has a
> special
> meaning for a regex.
True, as written I believe the period will match any character.
> 
> >  	 "DMGL_VERBOSE-demangled f(std::string) is not defined"
> 
> Also looks like that the test was testing that we can break on
> "f(std::string)", not "f($what_string_really_is)".  This is not GDB's
> behaviour, as far as I can tell.  To me GDB does the opposite.  One
> can
> break using the full name of std::string, not "std::string".
> 
> Also, on my system, std::string is in reality
> "std::__cxx11::basic_string<char, std::char_traits<char>,
> std::allocator<char> >",
> not what is used in the test.

Yes, on PowerPC I also see the same type

File /usr/include/c++/11/bits/stringfwd.h:
79:     typedef std::__cxx11::basic_string<char,
std::char_traits<char>, std::allocator<char> > std::string;
> 
> I can test such behaviour with something like:
> 
>     gdb_test "break 'f(std::string)'" ".*Function.*not defined\." \
>         "f(std::string) is not defined"
> 
>     set realtype ""
>     gdb_test_multiple "info types ^std::string$" "" {
>         -re -wrap "typedef (\[^;\]*) std::string;" {
>             set realtype $expect_out(1,string)
>             pass $gdb_test_name
>         }
>     }
> 
>     if { $realtype != "" } {
>         gdb_breakpoint "f($realtype)"
>     }
> 
> That being said, it would be nice to be able to place a breakpoint
> using
> "f(std::string)"…

OK, I added the new test.  It works as expected on PowerPC and on my
Intel system.

(gdb) PASS: gdb.cp/no-dmgl-verbose.exp: info types ^std::string$
break f(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >)

Breakpoint 1 at 0x10: file /home/carll/GDB/build-current/gdb/testsuite/../../../binutils-gdb-current/gdb/testsuite/gdb.cp/no-dmgl-verbose.cc, line 23.

The additional test is good to have.

The above suggested changes were tested on both PowerPC and Intel and
pass as expected.

Please let me know if the updated patch looks ok.  Thanks.

                        Carl Love
-----------------------------------------------------------
Fix gdb.cp/no-dmgl-verbose.exp test

The test tries to check that setting a break point on f (std::string) fails
since the function is not defined as given.  The test was chaged to verify
f(std::string) is not defined.  An additional test was added to test setting
a breakpoint using the actual string type.

The test now runs correctly on Power 10 and Intel x86_64.
---
 gdb/testsuite/gdb.cp/no-dmgl-verbose.exp | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/gdb/testsuite/gdb.cp/no-dmgl-verbose.exp b/gdb/testsuite/gdb.cp/no-dmgl-verbose.exp
index 14f11ddcf04..a18ab81318c 100644
--- a/gdb/testsuite/gdb.cp/no-dmgl-verbose.exp
+++ b/gdb/testsuite/gdb.cp/no-dmgl-verbose.exp
@@ -28,8 +28,17 @@ clean_restart ${testfile}.o
 
 gdb_test_no_output "set breakpoint pending off"
 
-gdb_breakpoint {'f(std::string)'}
+gdb_test "break 'f(std::string)'" ".*Function.*not defined\." \
+    "f(std::string) is not defined"
+
+set realtype ""
+gdb_test_multiple "info types ^std::string$" "" {
+    -re -wrap "typedef (\[^;\]*) std::string;" {
+	set realtype $expect_out(1,string)
+	pass $gdb_test_name
+    }
+}
 
-gdb_test {break 'f(std::basic_string<char, std::char_traits<char>, std::allocator<char> >)'} \
-	 {Function ".*" not defined\.} \
-	 "DMGL_VERBOSE-demangled f(std::string) is not defined"
+if { $realtype != "" } {
+    gdb_breakpoint "f($realtype)"
+}
-- 
2.31.1