avoid C warnings

Author: tornaria

meson.build

@@ -1,5 +1,5 @@
 project('cysignals', 'c', 'cpp', 'cython',
-  default_options: ['warning_level=3', 'cpp_std=c++17']
+  default_options: ['warning_level=2', 'cpp_std=c++17']
 )
 
 # Python

src/cysignals/implementation.c

@@ -492,7 +492,7 @@ static void cysigs_signal_handler(int sig)
  * fact, POSIX recommends threads in
  * http://pubs.opengroup.org/onlinepubs/009695299/functions/makecontext.html
  */
-static void* _sig_on_trampoline(void* dummy)
+static void* _sig_on_trampoline(CYTHON_UNUSED void* dummy)
 {
     register int sig;
 
@@ -523,7 +523,7 @@ static void setup_trampoline(void)
     size_t trampolinestacksize = 1 << 17;
 
 #ifdef PTHREAD_STACK_MIN
-    if (trampolinestacksize < PTHREAD_STACK_MIN)
+    if (trampolinestacksize < (size_t) PTHREAD_STACK_MIN)
         trampolinestacksize = PTHREAD_STACK_MIN;
 #endif
     trampolinestack = malloc(trampolinestacksize + 4096);

src/cysignals/macros.h

@@ -112,7 +112,7 @@ extern "C" {
 /*
  * Set message, return 0 if we need to cysetjmp(), return 1 otherwise.
  */
-static inline int _sig_on_prejmp(const char* message, const char* file, int line)
+static inline int _sig_on_prejmp(const char* message, CYTHON_UNUSED const char* file, CYTHON_UNUSED int line)
 {
     cysigs.s = message;
 #if ENABLE_DEBUG_CYSIGNALS

src/cysignals/tests.pyx

@@ -58,6 +58,8 @@ cdef extern from "<pthread.h>" nogil:
 
 
 cdef extern from *:
+    # disable warning (variable might be clobbered by longjmp)
+    '#pragma GCC diagnostic ignored "-Wclobbered"'
     ctypedef int volatile_int "volatile int"
 
 
@@ -101,6 +103,9 @@ cdef void dereference_null_pointer() noexcept nogil:
     cdef volatile_int* ptr = <volatile_int*>(0)
     ptr[0] += 1
 
+# disable warning (infinite recursion in stack_overflow)
+cdef extern from *:
+    '#pragma GCC diagnostic ignored "-Winfinite-recursion"'
 
 cdef int stack_overflow(volatile_int* x=NULL) noexcept nogil:
     cdef volatile_int a = 0