compiler: implement clear builtin for maps

4 files changed, 22 insertions, 0 deletions

diff --git a/compiler/compiler.go b/compiler/compiler.go
index 6af6debe8..6dd43935a 100644
--- a/compiler/compiler.go
+++ b/compiler/compiler.go
@@ -1632,6 +1632,10 @@ func (b *builder) createBuiltin(argTypes []types.Type, argValues []llvm.Value, c
 			call.AddCallSiteAttribute(1, b.ctx.CreateEnumAttribute(llvm.AttributeKindID("align"), uint64(elementAlign)))
 
 			return llvm.Value{}, nil
+		case *types.Map:
+			m := argValues[0]
+			b.createMapClear(m)
+			return llvm.Value{}, nil
 		default:
 			return llvm.Value{}, b.makeError(pos, "unsupported type in clear builtin: "+typ.String())
 		}
diff --git a/compiler/map.go b/compiler/map.go
index c3d428902..21f0ee4a6 100644
--- a/compiler/map.go
+++ b/compiler/map.go
@@ -185,6 +185,11 @@ func (b *builder) createMapDelete(keyType types.Type, m, key llvm.Value, pos tok
 	}
 }
 
+// Clear the given map.
+func (b *builder) createMapClear(m llvm.Value) {
+	b.createRuntimeCall("hashmapClear", []llvm.Value{m}, "")
+}
+
 // createMapIteratorNext lowers the *ssa.Next instruction for iterating over a
 // map. It returns a tuple of {bool, key, value} with the result of the
 // iteration.
diff --git a/compiler/testdata/go1.21.go b/compiler/testdata/go1.21.go
index 3d92b69b1..589486d02 100644
--- a/compiler/testdata/go1.21.go
+++ b/compiler/testdata/go1.21.go
@@ -59,3 +59,7 @@ func clearSlice(s []int) {
 func clearZeroSizedSlice(s []struct{}) {
 	clear(s)
 }
+
+func clearMap(m map[string]int) {
+	clear(m)
+}
diff --git a/compiler/testdata/go1.21.ll b/compiler/testdata/go1.21.ll
index 73a368383..d65c75f4f 100644
--- a/compiler/testdata/go1.21.ll
+++ b/compiler/testdata/go1.21.ll
@@ -147,6 +147,15 @@ entry:
   ret void
 }
 
+; Function Attrs: nounwind
+define hidden void @main.clearMap(ptr dereferenceable_or_null(40) %m, ptr %context) unnamed_addr #2 {
+entry:
+  call void @runtime.hashmapClear(ptr %m, ptr undef) #5
+  ret void
+}
+
+declare void @runtime.hashmapClear(ptr dereferenceable_or_null(40), ptr) #1
+
 ; Function Attrs: nocallback nofree nosync nounwind readnone speculatable willreturn
 declare i32 @llvm.smin.i32(i32, i32) #4