Re: [PATCH] [gdb/testsuite] Fix gdb.cp/typeid.exp with m32 PIE

[Simon Marchi <simark@simark.ca>]

On 2025-12-16 08:42, Tom de Vries wrote:
> On x86_64-linux, if I run test-case gdb.cp/typeid.exp with target boards:
> - unix/-m64
> - unix/-m32
> - unix/-fPIE/-pie/-m64
> - unix/-fPIE/-pie/-m32
> for only target board unix/-fPIE/-pie/-m32 I get:
> ...
> (gdb) print &typeid(i)^M
> could not find typeinfo symbol for 'int'^M
> (gdb) FAIL: gdb.cp/typeid.exp: before starting: print &typeid(i)
> print &typeid(i) == &typeid(typeof(i))^M
> could not find typeinfo symbol for 'int'^M
> (gdb) FAIL: gdb.cp/typeid.exp: before starting: print &typeid(i) == &typeid(typeof(i))
> print &typeid(cp)^M
> could not find typeinfo symbol for 'char*'^M
> (gdb) FAIL: gdb.cp/typeid.exp: before starting: print &typeid(cp)
> print &typeid(cp) == &typeid(typeof(cp))^M
> could not find typeinfo symbol for 'char*'^M
> (gdb) FAIL: gdb.cp/typeid.exp: before starting: print &typeid(cp) == &typeid(typeof(cp))
> print &typeid(ccp)^M
> could not find typeinfo symbol for 'char const*'^M
> (gdb) FAIL: gdb.cp/typeid.exp: before starting: print &typeid(ccp)
> print &typeid(ccp) == &typeid(typeof(ccp))^M
> could not find typeinfo symbol for 'char const*'^M
> (gdb) FAIL: gdb.cp/typeid.exp: before starting: print &typeid(ccp) == &typeid(typeof(ccp))
> ...
> 
> This is yet another configuration for which these tests don't work.
> 
> We're already allowing this for clang and istarget "powerpc*-*-*".
> 
> I don't think there is value in trying to detect yet another configuration.
> 
> Instead, just allow it in general.

I don't know the history of this test.  Why is the type info for these base
types missing before running?  Is it a compiler bug or feature?

> diff --git a/gdb/testsuite/gdb.cp/typeid.exp b/gdb/testsuite/gdb.cp/typeid.exp
> index e12b032f32b..58f0a928a63 100644
> --- a/gdb/testsuite/gdb.cp/typeid.exp
> +++ b/gdb/testsuite/gdb.cp/typeid.exp
> @@ -27,29 +27,35 @@ proc do_typeid_tests {started} {
>      # We might see the standard type or gdb's internal type.
>      set type_re "(std::type_info|gdb_gnu_v3_type_info)"
>  
> -    set var {ca b}
> -    set have_base_types 1
> -    if {!$started} {
> -       if {[test_compiler_info clang-*-* c++]} {
> -	   # Note that we test pointer equality rather than object
> -	   # Clang doesn't place type information for the base types in
> -	   # the executable, and relies on this being linked in from the
> -	   # standard library.  As a result, type information for these
> -	   # variables is only available once the inferior is started.
> -	   set have_base_types 0
> -       } elseif {[istarget "powerpc*-*-*"]} {
> -	   # On PowerPC, RTTI typeinfo for base types (i, cp, ccp) may not be
> -	   # emitted until the inferior is started.
> -	   set have_base_types 0
> -       }
> -    }
> -    if { $have_base_types } {
> -	lappend var i cp ccp
> -    }
> +    # The typeinfo for some of these variables may or may not be present
> +    # before the inferior has started.  Mark these by listing them in
> +    # maybe_missing_var.
> +    set maybe_missing_var {i cp ccp}
> +    set var [concat {ca b} $maybe_missing_var]
>  
>      foreach simple_var $var {
> -	gdb_test "print &typeid($simple_var)" \
> -	    " = \\($type_re \\*\\) $hex.*"
> +	set maybe_missing \
> +	    [expr {[lsearch -exact $maybe_missing_var $simple_var] != -1}]

From the comment, it sounds like the type info for these should be
available once the inferior is started.  So, should maybe_missing stay
false if $started is true?

> +
> +	set missing 0
> +	set re [subst_vars { = \($type_re \*\) $hex.*}]
> +	gdb_test_multiple "print &typeid($simple_var)" "" {
> +	    -re -wrap $re {
> +		pass $gdb_test_name
> +	    }
> +	    -re -wrap "could not find typeinfo symbol for '.*'" {
> +		if { $maybe_missing } {
> +		    unsupported $gdb_test_name

unsupported or xfail?

Simon