FIX: Replace manual traps (nullptr access) with built-in macros

Add portable unreachable macros
Move unreachable macros to arch.h, add default compiler case
Remove unnecessary brackets in macro
Thanks @j-schultz :)
Moved macros inside the include guard of arch.h
Removed unnecessary unreachable.h include

Original merge request: xiph/rnnoise#205

Co-authored-by: j-schultz <[email protected]>
Signed-off-by: Gustavo Ramos Rehermann <[email protected]>

Author: 2 people

src/arch.h

@@ -203,4 +203,23 @@ static RENAMENOISE_INLINE int renamenoise_isnan(float x)
     #define renamenoise_stackalloc(type, id, len) type id[len]
 #endif
 
+/*
+ * Portable macros for denoting unreachable code.
+ * In such a scenario, perform an early exit ('panic').
+ */
+
+#if _MSC_VER // MSVC
+   #define renamenoise_unreachable() __assume(0)
+#elif __GNUC__ || __clang__ || __MINGW32__
+   #define renamenoise_unreachable() __builtin_unreachable()
+/*
+ * Borland case is unknown.
+ * More investigation needed.
+ */
+//--#elif __BORLANDC__
+//--#define renamenoise_unreachable() __builtin_unreachable()
+#else
+   #define renamenoise_unreachable()
+#endif
+
 #endif /* ARCH_H */

src/rnn.c

@@ -100,7 +100,7 @@ void renamenoise_compute_dense(const ReNameNoiseDenseLayer *layer, float *output
       for (i=0;i<N;i++)
          output[i] = renamenoise_relu(output[i]);
    } else {
-     *(int*)0=0;
+      renamenoise_unreachable();
    }
 }
 
@@ -146,7 +146,7 @@ void renamenoise_compute_gru(const ReNameNoiseGRULayer *gru, float *state, const
       if (gru->activation == RENAMENOISE_ACTIVATION_SIGMOID) sum = renamenoise_sigmoid_approx(RENAMENOISE_WEIGHTS_SCALE*sum);
       else if (gru->activation == RENAMENOISE_ACTIVATION_TANH) sum = renamenoise_tansig_approx(RENAMENOISE_WEIGHTS_SCALE*sum);
       else if (gru->activation == RENAMENOISE_ACTIVATION_RELU) sum = renamenoise_relu(RENAMENOISE_WEIGHTS_SCALE*sum);
-      else *(int*)0=0;
+      else renamenoise_unreachable();
       h[i] = z[i]*state[i] + (1-z[i])*sum;
    }
    for (i=0;i<N;i++)