Warnings in compilation for C89 (ANSI C)

[felipemarkson]

If you try to compile picohttpparser.c using C89 you get a couple of warnings:

gcc -std=c89 -pedantic -c picohttpparser.c

OUTPUT

picohttpparser.c: In function ‘parse_headers’:
picohttpparser.c:336:9: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  336 |         const char *value;
      |         ^~~~~
picohttpparser.c:342:9: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  342 |         const char *value_end = value + value_len;
      |         ^~~~~

As picohttpparser does not allocate memory, it is great to use with micro-controllers which may not support C99.

This issue is to solve these warning.

[kazuho]

Thank you for opening the issue and filing a PR.

In our coding style, we intentionally allow use of some C99 dialects; see https://github.com/h2o/h2o/wiki/Coding-Style.

Would it be possible for you to solve the issue by changing the compiler options?

[oerdnj]

Just to chime in as a user of the library. C99 is now 25 years old. Lack of tooling for fringe platforms should not be an argument to compromise on the code clarity and all features listed in #2188 greatly improve the code style.

As a matter of fact, I am big fan of all C code should gradually move to at least C11/C17, but that’s another story ;)

[felipemarkson]

In our coding style, we intentionally allow use of some C99 dialects; see https://github.com/h2o/h2o/wiki/Coding-Style.

@kazuho Oh! I hadn't realized that. Since the warning is caused by only three lines of code, I thought this library supported ANSI C. PR #80 should be rejected then and I will close this issue if you prefer.

Thanks.