fix(readability/casting): ignore calling-convention function pointers - #448

cpplint.py (2)

6689-6689: 🎯 Functional Correctness | 🔵 Trivial | ⚡ Quick win

Consider supporting arrays of function pointers.

Using \w* for the function pointer name restricts it to word characters. This means the regex will fail to match arrays of function pointers, such as (CALLCONV* FuncArray[3])(void), because \w* does not match the [ and ] characters.

To seamlessly handle these valid cases while avoiding spaces and parentheses, consider replacing \w* with [^() ]*. This mirrors the logic used in the adjacent pointer-to-member regex (line 6688).

🛠 Proposed fix

-                    or re.match(r"\((?:\w+\s*)?\*\s*\w*\)\s*\(", matched_funcptr)
+                    or re.match(r"\((?:\w+\s*)?\*\s*[^() ]*\)\s*\(", matched_funcptr)

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@cpplint.py` at line 6689, Update the function-pointer regex alternative near
the adjacent pointer-to-member pattern to allow array declarators in names such
as FuncArray[3]. Replace the restrictive word-character name match with a
character class that excludes parentheses and spaces, preserving the existing
surrounding function-pointer matching behavior.

---

6831-6836: 🎯 Functional Correctness | 🔵 Trivial | 💤 Low value

Consider edge cases like function parameters and trailing return types.

The typedef and using check perfectly addresses the alias cases mentioned in the issue. However, be aware that this same false positive can still occur if the function-pointer type is used directly as a function parameter or trailing return type, for example:
void Register(int32_t(CALLCONV *)(void));

Since (CALLCONV *) is followed by (void), it will still be flagged as a C-style cast here because the line lacks typedef or using.

While fully addressing this might be out of scope for this specific PR, it's worth keeping in mind or adding a TODO for future improvement.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@cpplint.py` around lines 6831 - 6836, Extend the false-positive guard near
the existing typedef/using check to recognize function-pointer type syntax used
directly in function parameters or trailing return types, including patterns
such as `(CALLCONV *)` followed by `(void)`. Preserve the current alias handling
and add a focused TODO if complete support is out of scope.

cpplint_unittest.py (1)

1119-1133: 🎯 Functional Correctness | 🔵 Trivial | ⚡ Quick win

Add a positive control for the new suppression.

These tests verify only that function-pointer declarations produce no warning. Add a nearby case that must still report a real cast with similar tokens. This will detect overmatching in the new typedef and using suppression.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@cpplint_unittest.py` around lines 1119 - 1133, Add a nearby positive-control
test in the relevant cpplint unittest alongside the existing function-pointer
cases, using similar calling-convention/function-pointer tokens but an actual
C-style cast that must produce the expected warning. Keep the current no-warning
assertions unchanged and use TestLint’s expected-output argument to verify the
suppression does not overmatch.