misc-use-internal-linkage

Detects variables, functions, and classes that can be marked as static or (in C++) moved into an anonymous namespace to enforce internal linkage.

Any entity that’s only used within a single file should be given internal linkage. Doing so gives the compiler more information, allowing it to better remove dead code and perform more aggressive optimizations.

Example:

int v1; // can be marked as static

void fn1() {} // can be marked as static

// already declared as extern
extern int v2;

void fn3(); // without function body in all declaration, maybe external linkage
void fn3();

// === C++-specific ===

struct S1 {}; // can be moved into anonymous namespace

namespace {
  // already in anonymous namespace
  int v2;
  void fn2();
  struct S2 {};
}

// export declarations
export void fn4() {}
export namespace t { void fn5() {} }
export int v2;
export class C {};

Options

FixMode

Selects what kind of a fix the check should provide. The default is UseStatic.

• None Don’t fix automatically.

• UseStatic Add static for internal linkage variable and function.

AnalyzeFunctions

Whether to suggest giving functions internal linkage. Default is true.

AnalyzeVariables

Whether to suggest giving variables internal linkage. Default is true.

AnalyzeTypes

(C++ only) Whether to suggest giving user-defined types (structs, classes, unions, and enums) internal linkage. Default is true.