Re: [committed][gdb/testsuite] Fix gdb.ada/access_tagged_param.exp for aarch64

[Luis Machado <luis.machado@arm.com>]

On 9/7/22 10:30, Tom de Vries wrote:
> Hi,
> 
> On aarch64-linux, I run into:
> ...
> Breakpoint 2, pck.inspect (obj=0x430eb0 \
>    <system.pool_global.global_pool_object>, <objL>=0) at pck.adb:17^M
> 17         procedure Inspect (Obj: access Top_T'Class) is^M
> (gdb) FAIL: gdb.ada/access_tagged_param.exp: continue
> ...
> while on x86_64-linux, I see:
> ...
> Breakpoint 2, pck.inspect (obj=0x62b2a0, <objL>=2) at pck.adb:19^M
> 19            null;^M
> (gdb) PASS: gdb.ada/access_tagged_param.exp: continue
> ...
> Note the different line numbers, 17 vs 19.
> 
> The difference comes from the gdbarch_skip_prologue implementation.
> 
> The amd64_skip_prologue implementation doesn't use gcc line numbers, and falls
> back to the architecture-specific prologue analyzer, which correctly skips
> past the prologue, to address 0x4022f7:
> ...
> 00000000004022ec <pck__inspect>:
>    4022ec:       55                      push   %rbp
>    4022ed:       48 89 e5                mov    %rsp,%rbp
>    4022f0:       48 89 7d f8             mov    %rdi,-0x8(%rbp)
>    4022f4:       89 75 f4                mov    %esi,-0xc(%rbp)
>    4022f7:       90                      nop
>    4022f8:       90                      nop
>    4022f9:       5d                      pop    %rbp
>    4022fa:       c3                      ret
> ...
> 
> The aarch64_skip_prologue implementation does use gcc line numbers, which are:
> ...
> File name                    Line number    Starting address    View    Stmt
> pck.adb                               17            0x402580               x
> pck.adb                               17            0x402580       1       x
> pck.adb                               19            0x40258c               x
> pck.adb                               20            0x402590               x
> ...
> and which are represented like this internally in gdb:
> ...
> INDEX  LINE   ADDRESS            IS-STMT PROLOGUE-END
> 0      17     0x0000000000402580 Y
> 1      17     0x0000000000402580 Y
> 2      19     0x000000000040258c Y
> 3      20     0x0000000000402590 Y
> 4      END    0x00000000004025a0 Y
> ...
> 
> The second entry is interpreted as end-of-prologue, so 0x402580 is used, while
> the actual end of the prologue is at 0x40258c:
> ...
> 0000000000402580 <pck__inspect>:
>    402580:       d10043ff        sub     sp, sp, #0x10
>    402584:       f90007e0        str     x0, [sp, #8]
>    402588:       b90007e1        str     w1, [sp, #4]
>    40258c:       d503201f        nop
>    402590:       d503201f        nop
>    402594:       910043ff        add     sp, sp, #0x10
>    402598:       d65f03c0        ret
>    40259c:       d503201f        nop
> ...
> 
> Note that the architecture-specific prologue analyzer would have gotten this
> right:
> ...
> (gdb) p /x aarch64_analyze_prologue (gdbarch, pc, pc + 128, 0)
> $2 = 0x40258c
> ...
> 
> Fix the FAIL by making the test-case more robust against problems in prologue
> skipping, by setting the breakpoint on line 19 instead.
> 
> Likewise in a few similar test-cases.
> 
> Tested on x86_64-linux and aarch64-linux.
> 
> Committed to trunk.
> 
> Thanks,
> - Tom
> 
> [gdb/testsuite] Fix gdb.ada/access_tagged_param.exp for aarch64
> 
> ---
>   gdb/testsuite/gdb.ada/access_tagged_param.exp | 2 +-
>   gdb/testsuite/gdb.ada/ptype_tagged_param.exp  | 2 +-
>   gdb/testsuite/gdb.ada/ref_param.exp           | 2 +-
>   3 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/gdb/testsuite/gdb.ada/access_tagged_param.exp b/gdb/testsuite/gdb.ada/access_tagged_param.exp
> index 2b8e8ef172f..931c7fb12a9 100644
> --- a/gdb/testsuite/gdb.ada/access_tagged_param.exp
> +++ b/gdb/testsuite/gdb.ada/access_tagged_param.exp
> @@ -33,7 +33,7 @@ if ![runto "foo"] then {
>     return
>   }
>   
> -gdb_breakpoint "pck.inspect"
> +gdb_breakpoint "pck.adb:19"
>   
>   # Continue until we reach the breakpoint, and verify that we can print
>   # the value of all the parameters.
> diff --git a/gdb/testsuite/gdb.ada/ptype_tagged_param.exp b/gdb/testsuite/gdb.ada/ptype_tagged_param.exp
> index 0972e02a636..3a4a84a22ce 100644
> --- a/gdb/testsuite/gdb.ada/ptype_tagged_param.exp
> +++ b/gdb/testsuite/gdb.ada/ptype_tagged_param.exp
> @@ -27,7 +27,7 @@ set has_runtime_debug_info [gnat_runtime_has_debug_info]
>   
>   clean_restart ${testfile}
>   
> -if ![runto "position_x" ] then {
> +if ![runto "pck.adb:20" ] then {
>     return -1
>   }
>   
> diff --git a/gdb/testsuite/gdb.ada/ref_param.exp b/gdb/testsuite/gdb.ada/ref_param.exp
> index cbe0c065d34..56347932564 100644
> --- a/gdb/testsuite/gdb.ada/ref_param.exp
> +++ b/gdb/testsuite/gdb.ada/ref_param.exp
> @@ -25,7 +25,7 @@ if {[gdb_compile_ada "${srcfile}" "${binfile}" executable [list debug ]] != "" }
>   
>   clean_restart ${testfile}
>   
> -if ![runto call_me] then {
> +if ![runto pck.adb:20] then {
>     perror "Couldn't run ${testfile}"
>     return
>   }

Great! Thanks for the fixing this Tom.