Add Win64 -preview=in special case: by-value slices and delegates

kinke · kinke · commit 7ae93c9c9cbf · 2020-11-01T16:53:57.000+01:00
diff --git a/src/dmd/target.d b/src/dmd/target.d
@@ -790,6 +790,13 @@ extern (C++) struct Target
         {
             if (global.params.isWindows)
             {
+                // Win64 special case: by-value for slices and delegates due to
+                // high number of usages in druntime/Phobos (compiled without
+                // -preview=in but supposed to link against -preview=in code)
+                const ty = t.toBasetype().ty;
+                if (ty == Tarray || ty == Tdelegate)
+                    return false;
+
                 // If size is larger than 8 or not a power-of-2, the Win64 ABI
                 // would require a hidden reference anyway.
                 return size > 8

Original file line number	Diff line number	Diff line change
`@@ -790,6 +790,13 @@ extern (C++) struct Target`
`790`	`790`	`{`
`791`	`791`	`if (global.params.isWindows)`
`792`	`792`	`{`
	`793`	`+ // Win64 special case: by-value for slices and delegates due to`
	`794`	`+ // high number of usages in druntime/Phobos (compiled without`
	`795`	`+ // -preview=in but supposed to link against -preview=in code)`
	`796`	`+ const ty = t.toBasetype().ty;`
	`797`	`+ if (ty == Tarray \|\| ty == Tdelegate)`
	`798`	`+ return false;`
	`799`	`+`
`793`	`800`	`// If size is larger than 8 or not a power-of-2, the Win64 ABI`
`794`	`801`	`// would require a hidden reference anyway.`
`795`	`802`	`return size > 8`