go/types: better error for assignment count mismatches

This matches the error message of cmd/compile (for assignments).

Change-Id: I42a428f5d72f034e7b7e97b090a929e317e812af
Reviewed-on: https://go-review.googlesource.com/38315
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>

diff --git a/src/go/types/assignments.go b/src/go/types/assignments.go
index 18f893d478126478022767522d07c044b5ae7d35..e5ea071e864dd8112fd52484f8682e67becf27dc 100644 (file)
--- a/src/go/types/assignments.go
+++ b/src/go/types/assignments.go
@@ -219,7 +219,7 @@ func (check *Checker) initVars(lhs []*Var, rhs []ast.Expr, returnPos token.Pos)
                        check.errorf(returnPos, "wrong number of return values (want %d, got %d)", l, r)
                        return
                }
-               check.errorf(rhs[0].Pos(), "assignment count mismatch (%d vs %d)", l, r)
+               check.errorf(rhs[0].Pos(), "cannot initialize %d variables with %d values", l, r)
                return
        }
 
@@ -253,7 +253,7 @@ func (check *Checker) assignVars(lhs, rhs []ast.Expr) {
        }
        if l != r {
                check.useGetter(get, r)
-               check.errorf(rhs[0].Pos(), "assignment count mismatch (%d vs %d)", l, r)
+               check.errorf(rhs[0].Pos(), "cannot assign %d values to %d variables", r, l)
                return
        }
 

diff --git a/src/go/types/testdata/decls1.src b/src/go/types/testdata/decls1.src
index cb162f7aa7bb7c824dfc2c0342168041b7902216..1ef2806764588db3454df4bcd3d4c9d4ff8691ee 100644 (file)
--- a/src/go/types/testdata/decls1.src
+++ b/src/go/types/testdata/decls1.src
@@ -78,7 +78,7 @@ var (
        u2 = iface.([]int)
        u3 = iface.(a /* ERROR "not a type" */ )
        u4, ok = iface.(int)
-       u5, ok2, ok3 = iface /* ERROR "assignment count mismatch" */ .(int)
+       u5, ok2, ok3 = iface /* ERROR "cannot initialize" */ .(int)
 )
 
 // Constant expression initializations

diff --git a/src/go/types/testdata/issues.src b/src/go/types/testdata/issues.src
index 6579aa3b117b65450f4cb4ef9b2cdf6acaed5738..e44c1c2521aaef6cad4319867e1f6e008c1667f1 100644 (file)
--- a/src/go/types/testdata/issues.src
+++ b/src/go/types/testdata/issues.src
@@ -98,8 +98,8 @@ func issue10979() {
 // issue11347
 // These should not crash.
 var a1, b1 /* ERROR cycle */ , c1 /* ERROR cycle */ b1 = 0 > 0<<""[""[c1]]>c1
-var a2, b2 /* ERROR cycle */ = 0 /* ERROR mismatch */ /* ERROR mismatch */ > 0<<""[b2]
-var a3, b3 /* ERROR cycle */ = int /* ERROR mismatch */ /* ERROR mismatch */ (1<<""[b3])
+var a2, b2 /* ERROR cycle */ = 0 /* ERROR cannot initialize */ /* ERROR cannot initialize */ > 0<<""[b2]
+var a3, b3 /* ERROR cycle */ = int /* ERROR cannot initialize */ /* ERROR cannot initialize */ (1<<""[b3])
 
 // issue10260
 // Check that error messages explain reason for interface assignment failures.

diff --git a/src/go/types/testdata/stmt0.src b/src/go/types/testdata/stmt0.src
index 87f08e4314f0a32db3bb39bb408f554768d1d897..446997ac098d917701c120bf324ce8a5006eea56 100644 (file)
--- a/src/go/types/testdata/stmt0.src
+++ b/src/go/types/testdata/stmt0.src
@@ -15,19 +15,19 @@ func assignments0() (int, int) {
        f3 := func() (int, int, int) { return 1, 2, 3 }
 
        a, b, c = 1, 2, 3
-       a, b, c = 1 /* ERROR "assignment count mismatch" */ , 2
-       a, b, c = 1 /* ERROR "assignment count mismatch" */ , 2, 3, 4
+       a, b, c = 1 /* ERROR "cannot assign [1-9]+ values to [1-9]+ variables" */ , 2
+       a, b, c = 1 /* ERROR "cannot assign [1-9]+ values to [1-9]+ variables" */ , 2, 3, 4
        _, _, _ = a, b, c
 
        a = f0 /* ERROR "used as value" */ ()
        a = f1()
-       a = f2 /* ERROR "assignment count mismatch" */ ()
+       a = f2 /* ERROR "cannot assign [1-9]+ values to [1-9]+ variables" */ ()
        a, b = f2()
-       a, b, c = f2 /* ERROR "assignment count mismatch" */ ()
+       a, b, c = f2 /* ERROR "cannot assign [1-9]+ values to [1-9]+ variables" */ ()
        a, b, c = f3()
-       a, b = f3 /* ERROR "assignment count mismatch" */ ()
+       a, b = f3 /* ERROR "cannot assign [1-9]+ values to [1-9]+ variables" */ ()
 
-       a, b, c = <- /* ERROR "assignment count mismatch" */ ch
+       a, b, c = <- /* ERROR "cannot assign [1-9]+ values to [1-9]+ variables" */ ch
 
        return /* ERROR "wrong number of return values" */
        return /* ERROR "wrong number of return values" */ 1
@@ -43,7 +43,7 @@ func assignments1() {
        c = s /* ERROR "cannot use .* in assignment" */
        s = b /* ERROR "cannot use .* in assignment" */
 
-       v0, v1, v2 := 1 /* ERROR "mismatch" */ , 2, 3, 4
+       v0, v1, v2 := 1 /* ERROR "cannot initialize" */ , 2, 3, 4
        _, _, _ = v0, v1, v2
 
        b = true
@@ -108,7 +108,7 @@ func assignments2() {
        s, b = m["foo"]
        _, d = m["bar"]
        m["foo"] = nil
-       m["foo"] = nil /* ERROR assignment count mismatch */ , false
+       m["foo"] = nil /* ERROR cannot assign [1-9]+ values to [1-9]+ variables */ , false
        _ = append(m["foo"])
        _ = append(m["foo"], true)
 
@@ -116,12 +116,12 @@ func assignments2() {
        _, b = <-c
        _, d = <-c
        <- /* ERROR cannot assign */ c = 0
-       <-c = 0 /* ERROR assignment count mismatch */ , false
+       <-c = 0 /* ERROR cannot assign [1-9]+ values to [1-9]+ variables */ , false
 
        var x interface{}
        _, b = x.(int)
        x /* ERROR cannot assign */ .(int) = 0
-       x.(int) = 0 /* ERROR assignment count mismatch */ , false
+       x.(int) = 0 /* ERROR cannot assign [1-9]+ values to [1-9]+ variables */ , false
 
        assignments2 /* ERROR used as value */ () = nil
        int /* ERROR not an expression */ = 0

diff --git a/src/go/types/testdata/vardecl.src b/src/go/types/testdata/vardecl.src
index 00825371f2c7569d6959983921b6daabb0666011..35f44e6c48b3aff4cda1e0dc32ac5f10d3fee939 100644 (file)
--- a/src/go/types/testdata/vardecl.src
+++ b/src/go/types/testdata/vardecl.src
@@ -28,39 +28,39 @@ var _ = f /* ERROR "used as value" */ ()
 // Identifier and expression arity must match.
 var _, _ = 1, 2
 var _ = 1, 2 /* ERROR "extra init expr 2" */
-var _, _ = 1 /* ERROR "assignment count mismatch" */
+var _, _ = 1 /* ERROR "cannot initialize [0-9]+ variables with [0-9]+ values" */
 var _, _, _ /* ERROR "missing init expr for _" */ = 1, 2
 
 var _ = g /* ERROR "2-valued g" */ ()
 var _, _ = g()
-var _, _, _ = g /* ERROR "assignment count mismatch" */ ()
+var _, _, _ = g /* ERROR "cannot initialize [0-9]+ variables with [0-9]+ values" */ ()
 
 var _ = m["foo"]
 var _, _ = m["foo"]
-var _, _, _ = m  /* ERROR "assignment count mismatch" */ ["foo"]
+var _, _, _ = m  /* ERROR "cannot initialize [0-9]+ variables with [0-9]+ values" */ ["foo"]
 
 var _, _ int = 1, 2
 var _ int = 1, 2 /* ERROR "extra init expr 2" */
-var _, _ int = 1 /* ERROR "assignment count mismatch" */
+var _, _ int = 1 /* ERROR "cannot initialize [0-9]+ variables with [0-9]+ values" */
 var _, _, _ /* ERROR "missing init expr for _" */ int = 1, 2
 
 var (
        _, _ = 1, 2
        _ = 1, 2 /* ERROR "extra init expr 2" */
-       _, _ = 1 /* ERROR "assignment count mismatch" */
+       _, _ = 1 /* ERROR "cannot initialize [0-9]+ variables with [0-9]+ values" */
        _, _, _ /* ERROR "missing init expr for _" */ = 1, 2
 
        _ = g /* ERROR "2-valued g" */ ()
        _, _ = g()
-       _, _, _ = g /* ERROR "assignment count mismatch" */ ()
+       _, _, _ = g /* ERROR "cannot initialize [0-9]+ variables with [0-9]+ values" */ ()
 
        _ = m["foo"]
        _, _ = m["foo"]
-       _, _, _ = m /* ERROR "assignment count mismatch" */ ["foo"]
+       _, _, _ = m /* ERROR "cannot initialize [0-9]+ variables with [0-9]+ values" */ ["foo"]
 
        _, _ int = 1, 2
        _ int = 1, 2 /* ERROR "extra init expr 2" */
-       _, _ int = 1 /* ERROR "assignment count mismatch" */
+       _, _ int = 1 /* ERROR "cannot initialize [0-9]+ variables with [0-9]+ values" */
        _, _, _ /* ERROR "missing init expr for _" */ int = 1, 2
 )
 
@@ -155,7 +155,7 @@ func (r T) _(a, b, c int) (u, v, w int) {
 func _() {
        var a, b, c int
        var x, y int
-       x, y = a /* ERROR assignment count mismatch */ , b, c
+       x, y = a /* ERROR cannot assign [0-9]+ values to [0-9]+ variables */ , b, c
        _ = x
        _ = y
 }