cmd/gc: fix call order in array literal of slice literal of make chan

Fixes issue 8761.

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews, r
https://codereview.appspot.com/144530045

4 files changed, 150 insertions, 16 deletions

diff --git a/test/fixedbugs/bug491.go b/test/fixedbugs/bug491.go
new file mode 100644
index 000000000..f4b58af1e
--- /dev/null
+++ b/test/fixedbugs/bug491.go
@@ -0,0 +1,110 @@
+// run
+
+// Copyright 2014 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test order of calls to builtin functions.
+// Discovered during CL 144530045 review.
+
+package main
+
+func main() {
+	// append
+	{
+		x := make([]int, 0)
+		f := func() int { x = make([]int, 2); return 2 }
+		a, b, c := append(x, 1), f(), append(x, 1)
+		if len(a) != 1 || len(c) != 3 {
+			bug()
+			println("append call not ordered:", len(a), b, len(c))
+		}
+	}
+
+	// cap
+	{
+		x := make([]int, 1)
+		f := func() int { x = make([]int, 3); return 2 }
+		a, b, c := cap(x), f(), cap(x)
+		if a != 1 || c != 3 {
+			bug()
+			println("cap call not ordered:", a, b, c)
+		}
+	}
+
+	// complex
+	{
+		x := 1.0
+		f := func() int { x = 3; return 2 }
+		a, b, c := complex(x, 0), f(), complex(x, 0)
+		if real(a) != 1 || real(c) != 3 {
+			bug()
+			println("complex call not ordered:", a, b, c)
+		}
+	}
+
+	// copy
+	{
+		tmp := make([]int, 100)
+		x := make([]int, 1)
+		f := func() int { x = make([]int, 3); return 2 }
+		a, b, c := copy(tmp, x), f(), copy(tmp, x)
+		if a != 1 || c != 3 {
+			bug()
+			println("copy call not ordered:", a, b, c)
+		}
+	}
+
+	// imag
+	{
+		x := 1i
+		f := func() int { x = 3i; return 2 }
+		a, b, c := imag(x), f(), imag(x)
+		if a != 1 || c != 3 {
+			bug()
+			println("imag call not ordered:", a, b, c)
+		}
+	}
+
+	// len
+	{
+		x := make([]int, 1)
+		f := func() int { x = make([]int, 3); return 2 }
+		a, b, c := len(x), f(), len(x)
+		if a != 1 || c != 3 {
+			bug()
+			println("len call not ordered:", a, b, c)
+		}
+	}
+
+	// make
+	{
+		x := 1
+		f := func() int { x = 3; return 2 }
+		a, b, c := make([]int, x), f(), make([]int, x)
+		if len(a) != 1 || len(c) != 3 {
+			bug()
+			println("make call not ordered:", len(a), b, len(c))
+		}
+	}
+
+	// real
+	{
+		x := 1 + 0i
+		f := func() int { x = 3; return 2 }
+		a, b, c := real(x), f(), real(x)
+		if a != 1 || c != 3 {
+			bug()
+			println("real call not ordered:", a, b, c)
+		}
+	}
+}
+
+var bugged = false
+
+func bug() {
+	if !bugged {
+		println("BUG")
+		bugged = true
+	}
+}
\ No newline at end of file
diff --git a/test/fixedbugs/issue8761.go b/test/fixedbugs/issue8761.go
new file mode 100644
index 000000000..badf639fc
--- /dev/null
+++ b/test/fixedbugs/issue8761.go
@@ -0,0 +1,26 @@
+// compile
+
+// Copyright 2014 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// issue 8761
+// used to confuse code generator into using temporary before initialization.
+// caused 'variable live at entry' error in liveness analysis.
+
+package p
+
+func _() {
+	type C chan int
+	_ = [1][]C{[]C{make(chan int)}}
+}
+
+func _() {
+	type C interface{}
+	_ = [1][]C{[]C{recover()}}
+}
+
+func _() {
+	type C *int
+	_ = [1][]C{[]C{new(int)}}
+}
diff --git a/test/live.go b/test/live.go
index ad2db27fa..f15bb74ba 100644
--- a/test/live.go
+++ b/test/live.go
@@ -586,14 +586,16 @@ func f39a() (x []int) {
 }
 
 func f39b() (x [10]*int) {
-	x = [10]*int{new(int)} // ERROR "live at call to newobject: x"
-	println()              // ERROR "live at call to printnl: x"
+	x = [10]*int{}
+	x[0] = new(int) // ERROR "live at call to newobject: x"
+	println()       // ERROR "live at call to printnl: x"
 	return x
 }
 
 func f39c() (x [10]*int) {
-	x = [10]*int{new(int)} // ERROR "live at call to newobject: x"
-	println()              // ERROR "live at call to printnl: x"
+	x = [10]*int{}
+	x[0] = new(int) // ERROR "live at call to newobject: x"
+	println()       // ERROR "live at call to printnl: x"
 	return
 }
 
@@ -605,9 +607,8 @@ type T40 struct {
 }
 
 func newT40() *T40 {
-	ret := T40{ // ERROR "live at call to makemap: &ret"
-		make(map[int]int),
-	}
+	ret := T40{}
+	ret.m = make(map[int]int) // ERROR "live at call to makemap: &ret"
 	return &ret
 }
 
@@ -618,9 +619,8 @@ func bad40() {
 }
 
 func good40() {
-	ret := T40{ // ERROR "live at call to makemap: ret"
-		make(map[int]int),
-	}
+	ret := T40{}
+	ret.m = make(map[int]int) // ERROR "live at call to makemap: ret"
 	t := &ret
 	println() // ERROR "live at call to printnl: ret"
 	_ = t
diff --git a/test/live2.go b/test/live2.go
index 5762b2e28..ef6ad994c 100644
--- a/test/live2.go
+++ b/test/live2.go
@@ -17,9 +17,8 @@ type T40 struct {
 }
 
 func newT40() *T40 {
-	ret := T40{ // ERROR "live at call to makemap: &ret"
-		make(map[int]int),
-	}
+	ret := T40{}
+	ret.m = make(map[int]int) // ERROR "live at call to makemap: &ret"
 	return &ret
 }
 
@@ -30,9 +29,8 @@ func bad40() {
 }
 
 func good40() {
-	ret := T40{ // ERROR "live at call to makemap: ret"
-		make(map[int]int),
-	}
+	ret := T40{}
+	ret.m = make(map[int]int) // ERROR "live at call to makemap: ret"
 	t := &ret
 	println() // ERROR "live at call to printnl: ret"
 	_ = t