DCL41-C. Do not refer to a static object in an external inline function

C11, 6.7.4 (Function Specifiers), p3 says:

An inline definition of a function with external linkage shall not contain a definition of a modifiable object with static or thread storage duration, and shall not contain a reference to an identifier with internal linkage.

Noncompliant Code Example

This code refers to a static constant inside an external inline function:

static const double C = -0x16c087e80f1e27.0p-62;  /* -0.00138867637746099294692 */

extern inline void func(double a) {
  double b;
  b = a * C; // GCC flagged this line
}

Compliant Solution

This compliant solution does not declare the constant to be {[static}}.

const double C = -0x16c087e80f1e27.0p-62;  /* -0.00138867637746099294692 */

extern inline void func(double a) {
  double b;
  b = a * C; // GCC flagged this line
}