Encoded show_help text causing compiler warnings

[jsquyres]

With older GCC (e.g., 8), we get warnings when compiling the new very-long strings from #13144:

 "The user is responsible for free'ing the returned string session ID." },
 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
show_help_content.c:2723:1: warning: unknown escape sequence: '\;'
 "delimiters - e.g., \"my\;weird.nspace:5\"." },
 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
show_help_content.c:3948:1: warning: string length '4136' is greater than the length '4095' ISO C99 compilers are required to support [-Woverlength-strings]
 "Provide all output in XML format" },
 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
show_help_content.c:4964:1: warning: string length '5598' is greater than the length '4095' ISO C99 compilers are required to support [-Woverlength-strings]
 "CR_Pack_Nodes configuration parameter." },
 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
show_help_content.c:5061:1: warning: string length '5488' is greater than the length '4095' ISO C99 compilers are required to support [-Woverlength-strings]
 "Show help message for cpu_bind" },
 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
show_help_content.c:5312:13: warning: no previous prototype for 'opal_show_help_get_content' [-Wmissing-prototypes]
 const char *opal_show_help_get_content(const char *filename, const char* topic)
             ^~~~~~~~~~~~~~~~~~~~~~~~~~

[rhc54]

Do you know when those limits were raised, and to what size? The tools are going to soar past that limit for their "usage" topic.

[jsquyres]

No. I was just going to split up the strings to be argv-style lists, each of which are <4095 bytes. The rendered results will be the same, but we'll be able to handle older compilers.

[rhc54]

FWIW: I fixed this in my version of your script - you can see it here: openpmix/openpmix#3577

It was a pretty simple fix. I also printed out the array in a more human-readable fashion for my convenience.

[rhc54]

Also note that I've had a lot of trouble getting thru the old CI based on Josh's docker images due to Python conflicts. Those old images do have Python 3 in them, but apparently before they supported all those cute formatting directives. So I've had to remove a bunch of them, replacing them with string concatenations. Might be a warning about compatibility with older Python 3 releases.

[jsquyres]

@rhc54 Thanks for the pointers!

If you care, I filed #13178 with the fixes here. It actually ended up simplifying things.

[rhc54]

I'll take a look at it and see what I can steal. My show-help is more complicated because of the hierarchical support (i.e., you can ask "--help foo" to get help on an option). I also added a bunch of checking in it to ensure we were using all the topics, weren't missing topics, the executables have all their options in their "--help" output, etc.

Figured if I'm going to spend a month pulling it all into memory, I might as well make sure it is all correct too! This way, it becomes a CI tool to double-check someone committing a new option or a new tool.