get rid of using __builtin_unreachable directly [Bug #17787]

nobu · XrXr · commit 105ecd953fa6 · 2021-04-14T15:03:46.000-04:00
As it is an independent feature from `clz`, `ctz` and `popcount`,
it might be unavailable even if the latters are built in.
diff --git a/internal/bits.h b/internal/bits.h
@@ -284,7 +284,7 @@ nlz_int64(uint64_t x)
     }
     else {
         /* :FIXME: Is there a way to make this branch a compile-time error? */
-        __builtin_unreachable();
+        UNREACHABLE_RETURN(~0);
     }
 
 #else
@@ -419,7 +419,7 @@ rb_popcount64(uint64_t x)
     }
     else {
         /* :FIXME: Is there a way to make this branch a compile-time error? */
-        __builtin_unreachable();
+        UNREACHABLE_RETURN(~0);
     }
 
 #else
@@ -492,7 +492,7 @@ ntz_int64(uint64_t x)
     }
     else {
         /* :FIXME: Is there a way to make this branch a compile-time error? */
-        __builtin_unreachable();
+        UNREACHABLE_RETURN(~0);
     }
 
 #else

Original file line number	Diff line number	Diff line change
`@@ -284,7 +284,7 @@ nlz_int64(uint64_t x)`
`284`	`284`	`}`
`285`	`285`	`else {`
`286`	`286`	`/* :FIXME: Is there a way to make this branch a compile-time error? */`
`287`		`- __builtin_unreachable();`
	`287`	`+ UNREACHABLE_RETURN(~0);`
`288`	`288`	`}`
`289`	`289`
`290`	`290`	`#else`
`@@ -419,7 +419,7 @@ rb_popcount64(uint64_t x)`
`419`	`419`	`}`
`420`	`420`	`else {`
`421`	`421`	`/* :FIXME: Is there a way to make this branch a compile-time error? */`
`422`		`- __builtin_unreachable();`
	`422`	`+ UNREACHABLE_RETURN(~0);`
`423`	`423`	`}`
`424`	`424`
`425`	`425`	`#else`
`@@ -492,7 +492,7 @@ ntz_int64(uint64_t x)`
`492`	`492`	`}`
`493`	`493`	`else {`
`494`	`494`	`/* :FIXME: Is there a way to make this branch a compile-time error? */`
`495`		`- __builtin_unreachable();`
	`495`	`+ UNREACHABLE_RETURN(~0);`
`496`	`496`	`}`
`497`	`497`
`498`	`498`	`#else`