Re: [PATCH] gdb/testsuite: fix dw2-entry-pc.exp with ASLR

[Simon Marchi <simark@simark.ca>]

On 2026-04-14 12:48, Bratislav Filipovic wrote:
> Following Simon Marchi's fix for dw2-empty-inline-ranges.exp [1], this
> test exhibits the same failure pattern when running in an environment
> where GDB can't disable address space randomization (such as in a
> container where that capability is removed) with a toolchain generating
> position-independent executables.
> 
> The test does a first run to grab addresses of labels and function
> boundaries (foo_middle, foo_start, foo_end, and range labels).  It then
> crafts DWARF using these addresses across multiple test iterations.
> When the executable is PIE and ASLR is active, the addresses in each
> subsequent run don't match the addresses from the initial run.
> 
> The failure manifests in the 'maint info blocks' output comparisons,
> where the expected addresses (from the first run) don't match the
> actual addresses in the test runs.
> 
> The simplest fix, following Simon's approach, is to use "nopie" when
> building the binaries.  This doesn't affect the effectiveness of the
> test, which is exercising different ways DW_AT_entry_pc can be
> expressed in DWARF.
> 
> Also, with a non-PIE executable, it is no longer necessary to run the
> inferior before grabbing the addresses in the initial run, as they are
> stable.  So remove that runto_main call.
> 
> [1] https://inbox.sourceware.org/gdb-patches/20260205204257.422150-1-simon.marchi@efficios.com/
> ---
>  gdb/testsuite/gdb.dwarf2/dw2-entry-pc.exp | 8 ++------
>  1 file changed, 2 insertions(+), 6 deletions(-)
> 
> diff --git a/gdb/testsuite/gdb.dwarf2/dw2-entry-pc.exp b/gdb/testsuite/gdb.dwarf2/dw2-entry-pc.exp
> index 441aa0fde1d..f7cc7f7c067 100644
> --- a/gdb/testsuite/gdb.dwarf2/dw2-entry-pc.exp
> +++ b/gdb/testsuite/gdb.dwarf2/dw2-entry-pc.exp
> @@ -28,11 +28,7 @@ standard_testfile
>  get_func_info foo
>  
>  if { [prepare_for_testing "failed to prepare" ${testfile} \
> -	  [list ${srcfile}]] } {
> -    return -1
> -}
> -
> -if {![runto_main]} {
> +	  [list ${srcfile}] {debug nopie}]} {
>      return -1
>  }
>  
> @@ -83,7 +79,7 @@ proc get_next_suffix {} {
>  
>  proc build_and_runto_main { suffix asm_file } {
>      if {[prepare_for_testing "failed to prepare" "${::testfile}-${suffix}" \
> -	     [list $::srcfile $asm_file] {nodebug}]} {
> +	     [list $::srcfile $asm_file] {nodebug nopie}]} {
>  	return false
>      }
>  

Thanks, LGTM.

Approved-By: Simon Marchi <simon.marchi@efficios.com>

Simon