interp: support llvm.lifetime.* calls

This fixes a bug found when updating a map with string keys.
Originally reported here:
https://github.com/hybridgroup/gdg-2019/issues/6

interp/frame.go

@@ -433,6 +433,8 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 				fr.locals[inst] = &LocalValue{fr.Eval, llvm.ConstInt(fr.Mod.Context().Int64Type(), 0, false)}
 			case callee.Name() == "llvm.dbg.value":
 				// do nothing
+			case strings.HasPrefix(callee.Name(), "llvm.lifetime."):
+				// do nothing
 			case callee.Name() == "runtime.trackPointer":
 				// do nothing
 			case strings.HasPrefix(callee.Name(), "runtime.print") || callee.Name() == "runtime._panic":

interp/interp_test.go

@@ -14,6 +14,7 @@ func TestInterp(t *testing.T) {
 		"basic",
 		"slice-copy",
 		"consteval",
+		"map",
 	} {
 		name := name // make tc local to this closure
 		t.Run(name, func(t *testing.T) {

interp/scan.go

@@ -1,6 +1,8 @@
 package interp
 
 import (
+	"strings"
+
 	"tinygo.org/x/go-llvm"
 )
 
@@ -39,22 +41,25 @@ type sideEffectResult struct {
 // returns whether this function has side effects and if it does, which globals
 // it mentions anywhere in this function or any called functions.
 func (e *evalPackage) hasSideEffects(fn llvm.Value) (*sideEffectResult, error) {
-	switch fn.Name() {
-	case "runtime.alloc":
+	name := fn.Name()
+	switch {
+	case name == "runtime.alloc":
 		// Cannot be scanned but can be interpreted.
 		return &sideEffectResult{severity: sideEffectNone}, nil
-	case "runtime.nanotime":
+	case name == "runtime.nanotime":
 		// Fixed value at compile time.
 		return &sideEffectResult{severity: sideEffectNone}, nil
-	case "runtime._panic":
+	case name == "runtime._panic":
 		return &sideEffectResult{severity: sideEffectLimited}, nil
-	case "runtime.interfaceImplements":
+	case name == "runtime.interfaceImplements":
 		return &sideEffectResult{severity: sideEffectNone}, nil
-	case "runtime.sliceCopy":
+	case name == "runtime.sliceCopy":
 		return &sideEffectResult{severity: sideEffectNone}, nil
-	case "runtime.trackPointer":
+	case name == "runtime.trackPointer":
 		return &sideEffectResult{severity: sideEffectNone}, nil
-	case "llvm.dbg.value":
+	case name == "llvm.dbg.value":
+		return &sideEffectResult{severity: sideEffectNone}, nil
+	case strings.HasPrefix(name, "llvm.lifetime."):
 		return &sideEffectResult{severity: sideEffectNone}, nil
 	}
 	if fn.IsDeclaration() {

interp/testdata/map.ll

@@ -0,0 +1,36 @@
+target datalayout = "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64"
+target triple = "armv6m-none-eabi"
+
+%runtime._string = type { i8*, i32 }
+%runtime.hashmap = type { %runtime.hashmap*, i8*, i32, i8, i8, i8 }
+
+@main.m = global %runtime.hashmap* null
+@main.init.string = internal unnamed_addr constant [7 x i8] c"CONNECT"
+
+declare %runtime.hashmap* @runtime.hashmapMake(i8, i8, i32, i8* %context, i8* %parentHandle)
+declare void @runtime.hashmapBinarySet(%runtime.hashmap*, i8*, i8*, i8* %context, i8* %parentHandle)
+declare void @llvm.lifetime.end.p0i8(i64, i8*)
+declare void @llvm.lifetime.start.p0i8(i64, i8*)
+
+define void @runtime.initAll() unnamed_addr {
+entry:
+  call void @main.init(i8* undef, i8* null)
+  ret void
+}
+
+define internal void @main.init(i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+  %hashmap.key = alloca i8
+  %hashmap.value = alloca %runtime._string
+  %0 = call %runtime.hashmap* @runtime.hashmapMake(i8 1, i8 8, i32 1, i8* undef, i8* null)
+  %hashmap.value.bitcast = bitcast %runtime._string* %hashmap.value to i8*
+  call void @llvm.lifetime.start.p0i8(i64 8, i8* %hashmap.value.bitcast)
+  store %runtime._string { i8* getelementptr inbounds ([7 x i8], [7 x i8]* @main.init.string, i32 0, i32 0), i32 7 }, %runtime._string* %hashmap.value
+  call void @llvm.lifetime.start.p0i8(i64 1, i8* %hashmap.key)
+  store i8 1, i8* %hashmap.key
+  call void @runtime.hashmapBinarySet(%runtime.hashmap* %0, i8* %hashmap.key, i8* %hashmap.value.bitcast, i8* undef, i8* null)
+  call void @llvm.lifetime.end.p0i8(i64 1, i8* %hashmap.key)
+  call void @llvm.lifetime.end.p0i8(i64 8, i8* %hashmap.value.bitcast)
+  store %runtime.hashmap* %0, %runtime.hashmap** @main.m
+  ret void
+}

interp/testdata/map.out.ll

@@ -0,0 +1,15 @@
+target datalayout = "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64"
+target triple = "armv6m-none-eabi"
+
+%runtime.hashmap = type { %runtime.hashmap*, i8*, i32, i8, i8, i8 }
+%runtime._string = type { i8*, i32 }
+
+@main.m = local_unnamed_addr global %runtime.hashmap* @"main$map"
+@main.init.string = internal unnamed_addr constant [7 x i8] c"CONNECT"
+@"main$mapbucket" = internal unnamed_addr global { [8 x i8], i8*, [8 x i8], [8 x %runtime._string] } { [8 x i8] c"\04\00\00\00\00\00\00\00", i8* null, [8 x i8] c"\01\00\00\00\00\00\00\00", [8 x %runtime._string] [%runtime._string { i8* getelementptr inbounds ([7 x i8], [7 x i8]* @main.init.string, i32 0, i32 0), i32 7 }, %runtime._string zeroinitializer, %runtime._string zeroinitializer, %runtime._string zeroinitializer, %runtime._string zeroinitializer, %runtime._string zeroinitializer, %runtime._string zeroinitializer, %runtime._string zeroinitializer] }
+@"main$map" = internal unnamed_addr global %runtime.hashmap { %runtime.hashmap* null, i8* getelementptr inbounds ({ [8 x i8], i8*, [8 x i8], [8 x %runtime._string] }, { [8 x i8], i8*, [8 x i8], [8 x %runtime._string] }* @"main$mapbucket", i32 0, i32 0, i32 0), i32 1, i8 1, i8 8, i8 0 }
+
+define void @runtime.initAll() unnamed_addr {
+entry:
+  ret void
+}

interp/values.go

@@ -367,10 +367,14 @@ func (v *MapValue) PutBinary(keyPtr, valPtr *LocalValue) {
 		}
 	}
 
-	if keyPtr.Underlying.Opcode() == llvm.BitCast {
-		keyPtr = &LocalValue{v.Eval, keyPtr.Underlying.Operand(0)}
-	} else if keyPtr.Underlying.Opcode() == llvm.GetElementPtr {
-		keyPtr = &LocalValue{v.Eval, keyPtr.Underlying.Operand(0)}
+	keyPtr.Underlying.Dump()
+	println()
+	if !keyPtr.Underlying.IsAConstantExpr().IsNil() {
+		if keyPtr.Underlying.Opcode() == llvm.BitCast {
+			keyPtr = &LocalValue{v.Eval, keyPtr.Underlying.Operand(0)}
+		} else if keyPtr.Underlying.Opcode() == llvm.GetElementPtr {
+			keyPtr = &LocalValue{v.Eval, keyPtr.Underlying.Operand(0)}
+		}
 	}
 	key := keyPtr.Load()
 	if v.KeyType.IsNil() {