Re: [PATCHv2 3/3] gdb: allow 'until' to work in outermost frame

[Pedro Alves <pedro@palves.net>]

On 2026-06-11 22:59, Andrew Burgess wrote:

> +# Use 'bt 1' to get the name of the current function.  Returns the
> +# name of the current function, or the empty string if the current
> +# function name cannot be established.

Nit: I'd think "frame" would be more natural than "bt 1".

> +proc current_function_name { testname } {
> +    set func_name ""
> +    gdb_test_multiple "bt 1" $testname {
> +	-re -wrap "#0\\s+\[^\r\n\]*\\s+in (\[^( \]+) \\(.*" {
> +	    set func_name $expect_out(1,string)
> +	}
> +    }
> +
> +    return $func_name
> +}
> +
> +# Start the inferior with 'starti', then use 'until' within the
> +# outermost frame.  This is the real outermost frame, not 'main'.
> +#
> +# PAST_ENTRY should be 'on' or 'off' and is used in a 'set backtrace
> +# past-entry ...' command.
> +proc run_test { use_stepi past_entry testfile } {
> +    clean_restart $testfile
> +
> +    if { [gdb_starti_cmd] < 0 } {
> +	untested starti
> +	return
> +    }
> +
> +    gdb_test "" "Program stopped\\..*" "starti"

On Windows when you get to the entry address there's already more than one thread, so the above will
fail.  E.g.:

 (gdb) starti
 Starting program: C:/msys2/home/alves/gdb/build-testsuite/outputs/gdb.base/patch/patch.exe
 [New Thread 12888.0x3260]

 Thread 1 stopped.
 0x00007ff9abd3d78e in ntdll!RtlGetReturnAddressHijackTarget ()
    from C:/WINDOWS/SYSTEM32/ntdll.dll
 (gdb) info thr
   Id   Target Id           Frame
 * 1    Thread 12888.0x404c 0x00007ff9abd3d78e in ntdll!RtlGetReturnAddressHijackTarget () from C:/WINDOWS/SYSTEM32/ntdll.dll
   2    Thread 12888.0x3260 0x00007ff9abd83d24 in ntdll!ZwWaitForWorkViaWorkerFactory () from C:/WINDOWS/SYSTEM32/ntdll.dll
 (gdb)

> +    # Find an address to use in the 'until' command.
> +    set until_address ""
> +    set capture_address false
> +    gdb_test_multiple "disassemble" "find address for until" {
> +	-re "^=> $::hex \[^\r\n\]+\r\n" {
> +	    set capture_address true
> +	    exp_continue
> +	}
> +
> +	-re "^\\s+($::hex) \[^\r\n\]+\r\n" {
> +	    if { $capture_address } {
> +		set until_address $expect_out(1,string)
> +		set capture_address false
> +	    }
> +
> +	    exp_continue
> +	}
> +
> +	-re "^$::gdb_prompt $" {
> +	    set found_address [expr { $until_address ne "" }]
> +	    if { !$found_address } {
> +		unsupported "$gdb_test_name (no instruction found)"
> +		return
> +	    }
> +	    pass $gdb_test_name
> +	}
> +
> +	-re "^\[^\r\n\]*\r\n" {
> +	    exp_continue
> +	}

Could use -lbl ?