Implement reading of float64 value

_fixtures/testvariables.go

@@ -9,12 +9,14 @@ type FooBar struct {
 
 func main() {
 	var (
-		bar = "foo"
-		foo = 6
-		sl  = []int{1, 2, 3, 4, 5}
-		arr = [1]int{1}
-		baz = &FooBar{Baz: 5, Bur: "strum"}
+		a1 = "foo"
+		a2 = 6
+		a3 = 7.23
+		a4 = []int{1, 2, 3, 4, 5}
+		a5 = [1]int{1}
+		a6 = FooBar{Baz: 8, Bur: "word"}
+		a7 = &FooBar{Baz: 5, Bur: "strum"}
 	)
 
-	fmt.Println(bar, foo, arr, sl, baz)
+	fmt.Println(a1, a2, a3, a4, a5, a6, a7)
 }

proctl/proctl_linux_amd64.go

@@ -384,6 +384,17 @@ func (dbp *DebuggedProcess) extractValue(instructions []byte, typ interface{}) (
 		n := binary.LittleEndian.Uint64(val)
 
 		return strconv.Itoa(int(n)), nil
+	case *dwarf.FloatType:
+		var n float64
+		addr := uintptr(int64(regs.Rsp) + off)
+		val, err := dbp.readMemory(addr, 8)
+		if err != nil {
+			return "", err
+		}
+		buf := bytes.NewBuffer(val)
+		binary.Read(buf, binary.LittleEndian, &n)
+
+		return strconv.FormatFloat(n, 'f', -1, 64), nil
 	}
 
 	return "", fmt.Errorf("could not find value for type %s", typ)

proctl/proctl_test.go

@@ -231,17 +231,18 @@ func TestVariableEvaluation(t *testing.T) {
 		value   string
 		varType string
 	}{
-		{"foo", "6", "int"},
+		{"a2", "6", "int"},
+		{"a3", "7.23", "float64"},
 	}
 
 	helper.WithTestProcess(executablePath, t, func(p *proctl.DebuggedProcess) {
-		pc, _, _ := p.GoSymTable.LineToPC(fp, 19)
+		pc, _, _ := p.GoSymTable.LineToPC(fp, 21)
 
 		_, err := p.Break(uintptr(pc))
 		assertNoError(err, t, "Break() returned an error")
 
 		err = p.Continue()
-		assertNoError(err, t, "Break() returned an error")
+		assertNoError(err, t, "Continue() returned an error")
 
 		for _, tc := range testcases {
 			variable, err := p.EvalSymbol(tc.name)