test library statically.

src/funcs.c

@@ -0,0 +1,9 @@
+#include "funcs.h"
+
+void doSomething(int32_t a, int32_t b) {
+  someNotImplementedFunction(a, b);
+}
+
+void addNumbers(int32_t l, int32_t r) {
+  doSomething(l + r, 32);
+}

src/funcs.h

@@ -0,0 +1,11 @@
+typedef int int32_t;
+
+void doSomething(int32_t a, int32_t b);
+
+void someNotImplementedFunction(int32_t x, int32_t y);
+
+void addNumbers(int32_t l, int32_t r);
+
+void someHeaderImplementedFunction(int32_t a, int32_t b) {
+  doSomething(a, b);
+}