generator: improve error handling

[jbowler]

This ensures that printf() in the generator does not get file buffered (and therefore delayed relative to stderr) when piping output to a file and provides ReportHandler "context" for ReportHandler warnings.

[mrbean-bremen]

LGTM

[mrbean-bremen]

Not sure what happens with the Windows build - it run into an STATUS_STACK_BUFFER_OVERRUN error...

[jbowler]

Not sure what happens with the Windows build - it run into an STATUS_STACK_BUFFER_OVERRUN error...

That sounds like infinite recursion. I'll pushed a no-op change to force the builds to run again.

[jbowler]

Ok, this time it succeeded. Maybe setvbuf(stdout,nullptr,_IOLBF,0) is calling something recursively. I'll try commenting it out. Passing "nullptr" may be a problem; it's a C API not a C++ one. "0" is safer.

[jbowler]

It works without setvbuf so apparently there is some setvbuf bug with MSVC, or maybe the header files manage to do something weird. I've re-pushed it with nullptr replaced by 0, which is the maximally C compliant approach and avoids using macros apart from _IOLBF which might be #defined to something else.

[jbowler]

The MSVC documentation is here:

https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/setvbuf?view=msvc-170

This is not consistent with the ANSI-C documentation (ANSI X3.159-1989, identical to ISO C-90) wihch states in 4.9.5.6 that, "[t]he argument size specifies the size of the array." So in C-90 size should logically be 0 if the buffer pointer is NULL. In MSVC the documentation says that a size of less than 2 (i.e. 0 or 1) invokes the "invalid parameter handler" which may well the causing an infinite loop.

The only other possibility is that there is a debug/release msvcrt.dll mismatch on the test system. That pretty much always causes crashes when the CRT is used from a mismatched debug/release executable or library. If the change I just pushed doesn't fix the MSVC build I'll just #define the setting out on VC.

[jbowler]

Good to go. I passed 128 as the size parameter to setvbuf on MSVC and 0 for everything else. Note the description of the (non-standard) setlinebuf function in the Linux and other man pages. I double checked and setvbuf is giving me 0 as the result on Linux+glibc.