Provide MSVC-friendly wrapper for this==nullptr

ppenzin · rhuanjl · commit 2a574fa591e0 · 2024-04-18T13:11:58.000+01:00
MSVC neither supports the attribute we've used, nor deletes the check.
diff --git a/lib/Common/DataStructures/ImmutableList.h b/lib/Common/DataStructures/ImmutableList.h
@@ -749,12 +749,16 @@ namespace regex
             return result;
         }
 
-       bool __attribute__((noinline)) CheckNull( void* obj ) { return obj == nullptr; }
+#ifndef _MSC_VER
+       bool __attribute__((noinline)) CheckEq(void* obj1, void *obj2) { return obj1 == obj2; }
+#else
+#define CheckEq(a, b) (a) == (b)
+#endif
 
         // Info:        Return true if the list is empty.
         bool IsEmpty()
         {
-            return CheckNull(this);
+            return CheckEq(this, Empty());
         }
 
         // Info:        Return a list containing the given single value

Original file line number	Diff line number	Diff line change
`@@ -749,12 +749,16 @@ namespace regex`
`749`	`749`	`return result;`
`750`	`750`	`}`
`751`	`751`
`752`		`- bool __attribute__((noinline)) CheckNull( void* obj ) { return obj == nullptr; }`
	`752`	`+#ifndef _MSC_VER`
	`753`	`+ bool __attribute__((noinline)) CheckEq(void* obj1, void *obj2) { return obj1 == obj2; }`
	`754`	`+#else`
	`755`	`+#define CheckEq(a, b) (a) == (b)`
	`756`	`+#endif`
`753`	`757`
`754`	`758`	`// Info: Return true if the list is empty.`
`755`	`759`	`bool IsEmpty()`
`756`	`760`	`{`
`757`		`- return CheckNull(this);`
	`761`	`+ return CheckEq(this, Empty());`
`758`	`762`	`}`
`759`	`763`
`760`	`764`	`// Info: Return a list containing the given single value`