Re: [PATCH] [gdb/testsuite] Add gdb.base/include-main.exp

[Tom de Vries via Gdb-patches <gdb-patches@sourceware.org>]

On 11/26/21 5:20 PM, Simon Marchi wrote:
> On 2021-11-26 4:48 a.m., Tom de Vries via Gdb-patches wrote:
>> The test-case gdb.ada/dgopt.exp uses the -gnatD switch, in combination with
>> -gnatG.
>>
>> This causes the source file $src/gdb/testsuite/gdb.ada/dgopt/x.adb to be
>> expanded into $build/gdb/testsuite/outputs/gdb.ada/dgopt/x.adb.dg, and the
>> debug information should refer to the x.adb.dg file.
>>
>> That is the case for the .debug_line part:
>> ...
>> The Directory Table is empty.
>>
>>  The File Name Table (offset 0x1c):
>>   Entry Dir     Time    Size    Name
>>   1     0       0       0       x.adb.dg
>> ...
>> but not for the .debug_info part:
>> ...
>>     <11>   DW_AT_name        : $src/gdb/testsuite/gdb.ada/dgopt/x.adb
>>     <15>   DW_AT_comp_dir    : $build/gdb/testsuite/outputs/gdb.ada/dgopt
>> ...
>>
>> Filed as PR gcc/103436.
>>
>> In C we can generate similar debug information, using a source file that does
>> not contain any code, but includes another one that does:
>> ...
>>  $ cat gdb/testsuite/gdb.base/include-main.c
>>  #include "main.c"
>> ...
>> such that in the .debug_line part we have:
>> ...
>>  The Directory Table (offset 0x1c):
>>   1     /home/vries/gdb_versions/devel/src/gdb/testsuite/gdb.base
>>
>>  The File Name Table (offset 0x57):
>>   Entry Dir     Time    Size    Name
>>   1     1       0       0       main.c
>> ...
>> and in the .debug_info part:
>> ...
>>     <11>   DW_AT_name        : $src/gdb/testsuite/gdb.base/include-main.c
>>     <15>   DW_AT_comp_dir    : $build/gdb/testsuite
>> ...
>>
>> Add a C test-case that mimics gdb.ada/dgopt.exp, that is:
>> - generate debug info as described above,
>> - issue a list of a line in include-main.c, while the corresponding
>>   CU is not expanded yet.
>>
>> Tested on x86_64-linux.
>> ---
>>  gdb/testsuite/gdb.base/include-main.c   | 18 ++++++++++
>>  gdb/testsuite/gdb.base/include-main.exp | 47 +++++++++++++++++++++++++
>>  gdb/testsuite/gdb.base/main.c           | 22 ++++++++++++
> 
> I'm not a fan of having a file with the generic name "main.c" there.

Could you explain why not?

I don't understand why we'd need to duplicate a file that can easily be
reused.  It even helps one to recognize quickly (once you known the
contents of the file) that the test-case that is being investigated does
not require a specific executable, just based on the fact it uses "main.c".

Thanks,
- Tom

> Could we name it something like "include-main-includee.c", without
> affecting the intent of the test?
> 
> Simon
>