MONGOCRYPT-783 address -Wformat warnings

[eramongodb]

Related to MONGOCRYPT-783.

The -Wformat-nonliteral warning warns when the provided format string cannot be checked at compile-time for correctness or security issues. Currently, there are 2 warnings for GCC and 6 warnings for Clang. Addressing these initial warnings reveal an additional 6 for GCC and 1 for Clang. Addressing these warnings converts all format strings in the codebase into string literals which can be checked at compile-time. These new compile-time checks enabled the following warnings:

• Clang:
  • -Wformat-security: 28 unique, 38 total.
  • -Wformat-extra-args: 1 unique, 1 total.
  • -Wformat: 74 unique, 197 total.
• GCC:
  • -Wformat-security: 29 unique, 39 total.
  • -Wformat-extra-args: 1 unique, 1 total.
  • -Wformat=: 2 unique, 2 total.

To address -Wformat warnings for enumerators (e.g. bson_type_t), arguments are cast to int along with %d specifiers, as most enumerators are expected/assumed to be representable by int.

Aside from straightforward format specifier fixes, functions that accept a format string are given format(__printf__) attributes (addressing most -Wformat-nonliteral warnings). This motivated the addition of *_from_str equivalents of *_from_json test utilities that do not have the formatting requirement (addressing most -Wformat-security warnings).

Note

This PR introduces new -Wformat= GCC warnings due to use of %z in kms_request.c. These new warnings are resolved by #969.

[kevinAlbs]

The warning fixes are much appreciated.

[kevinAlbs]

Consider using TMP_BSONF to avoid need to disable/re-enable clang-format:

#define PLACEHOLDER_TEMPLATE                                                                                           \
    RAW_STRING({                                                                                                       \
        "t" : {"$numberInt" : "1"},                                                                                    \
        "a" : {"$numberInt" : "4"},                                                                                    \
        "ki" : {"$binary" : {"base64" : "EjRWeBI0mHYSNBI0VniQEg==", "subType" : "04"}},                                \
        "ku" : {"$binary" : {"base64" : "q83vqxI0mHYSNBI0VniQEg==", "subType" : "04"}},                                \
        "v" : MC_STR,                                                                                                  \
        "cm" : {"$numberLong" : "7"}                                                                                   \
    })

    bson_t *const as_bson = TMP_BSONF(PLACEHOLDER_TEMPLATE, spec_json_in);

Though notably TMP_BSONF is a printf-like function but does not benefit from the same warnings. I expect it is OK for testing.

[eramongodb]

Needed to use MC_BSON with TMP_BSON_STR instead of MC_STR due to MC_STR being substituted as "<str>", whereas spec_json_in is a JSON string, so the expanded JSON looks like: "v": "{ ... }" when it should be "v": { ... }.