[PROTON-2772] [c] Add parameter safety annotations for printf format strings

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: proton-c-0.39.0
• Fix Version/s: proton-c-0.40.0
• Component/s: proton-c
• Assignee: Jiri Daněk
• Reporter: Jiri Daněk
• Created: 14/Oct/23 11:58
• Updated: 2 days ago 16:03
• Resolved: 10/Jan/24 13:38

Description

There seem to be various mismatched printf format arguments. This is best resolved by annotating the string format parameters so that regular compilation warns on the mismatches as they happen.

Proton already has some of this, but it is incomplete.

```
/home/jdanek/repos/qpid/qpid-proton/c/src/core/logger.c: In function ‘pni_logger_log_raw’:
/home/jdanek/repos/qpid/qpid-proton/c/src/core/logger.c:204:41: error: format ‘%x’ expects argument of type ‘unsigned int’, but argument 4 has type ‘size_t’ {aka ‘long unsigned int’} [-Werror=format=]
  204 |     pn_fixed_string_addf(&out, "%04x/%04x: ", i, size);
      |                                      ~~~^        ~~~~
      |                                         |        |
      |                                         |        size_t {aka long unsigned int}
      |                                         unsigned int
      |                                      %04lx
cc1: all warnings being treated as errors
```

On windows, we want to enable these optional warning flags

"/analyzer"
"/we6328" # Size mismatch: 'unsigned __int64' passed as _Param_(4) when 'int' is required in call to 'ssl_log'.
"/we6340" # Mismatch on sign: 'unsigned __int64' passed as _Param_(4) when some signed type is required in call to 'ssl_log'.