RFR: 8354920: SA core file support on Linux only prints error messages when debug logging is enabled [v2]

[Kevin Walls]

On Tue, 22 Apr 2025 09:28:52 GMT, Kevin Walls <kevinw at openjdk.org> wrote:

>> Daniel Jeliński has updated the pull request incrementally with eight additional commits since the last revision:
>> 
>>  - Update copyright
>>  - Add more error messages
>>  - Add more error messages
>>  - Add more error messages
>>  - Add more error messages
>>  - Add more error messages
>>  - Add more error messages
>>  - Add more error messages
>
> src/jdk.hotspot.agent/linux/native/libsaproc/ps_proc.c line 450:
> 
>> 448:   if ( (ph = (struct ps_prochandle*) calloc(1, sizeof(struct ps_prochandle))) == NULL) {
>> 449:     snprintf(err_buf, err_buf_len, "can't allocate memory for ps_prochandle");
>> 450:     print_error("%s\n", err_buf);
> 
> This might be one that would print it twice - the caller in LinuxDebuggerLocal.cpp will print what's in err_buf.

Looks like here in Pgrab the intent is to snprintf an error message in err_buf, and the caller prints it.  So Pgrab should not need the print_error calls.

Some functions which are called, like read_lib_info, may print their own specific error message, then Pgrab stores an error that "failed to read lib info".. These are reporting the same thing but I don't see that as a problem or duplication, it could be really useful to track where things fail.

Yes it's a little annoying that Pgrab_core is different, it doesn't take an error_buf so needs to print_error about any problems.

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PR Review Comment: https://git.openjdk.org/jdk/pull/24722#discussion_r2053763445