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Re: C99 compliance for src/port/snprintf.c

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: David Steele <david@pgmasters.net>
Cc: pgsql-hackers@lists.postgresql.org
Date: 2018-08-15T19:57:43Z
Lists: pgsql-hackers 
David Steele <david@pgmasters.net> writes:
> On 8/15/18 3:18 PM, Tom Lane wrote:
>> I do dearly miss the ability to easily limit the scope of a loop's
>> control variable to just the loop, eg
>> 	for (int i = 0; ...) { ... }
>> But AFAIK that's C++ not C99.

> This works in C99 -- and I'm a really big fan.

It does?  [ checks standard... ]  Oh wow:

       6.8.5  Iteration statements

       Syntax

               iteration-statement:
                       while ( expression ) statement
                       do statement while ( expression ) ;
                       for ( expr-opt ; expr-opt ; expr-opt ) statement
                       for ( declaration ; expr-opt ; expr-opt ) statement

I'd always thought this was only in C++.  This alone might be a sufficient
reason to drop C89 compiler support ...

			regards, tom lane

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Remove test for VA_ARGS, implied by C99.

  2. Introduce minimal C99 usage to verify compiler support.

  3. Require C99 (and thus MSCV 2013 upwards).

  4. Require a C99-compliant snprintf(), and remove related workarounds.

  5. Try to enable C99 in configure, but do not rely on it (yet).

  6. Make snprintf.c follow the C99 standard for snprintf's result value.

  7. Clean up assorted misuses of snprintf()'s result value.