internal/core/adt: fix error gobbling of internal nodes

In some cases, errors in erroneous nodes
would not be carried over. This is because CUE
assumes that if a reference requires a scalar,
it is okay to proceed when a scalar is found as
the value can only be changed to an error,
which is then assumed to be reported at the
site where the error occurred.

This is not the case for "non-addressable" nodes,
though, as they will not be output. In such cases,
the error is lost.

We now detect such cases during evaluation and
require all task nodes to be completed, thereby
forcing the error if there is any.

This can only be done for non-addressable nodes
to avoid getting into spurious cycles.

Fixes #3977

Signed-off-by: Marcel van Lohuizen <[email protected]>
Change-Id: Ia51f4586ce9b0b142ab11d73c67a480039b276fb
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1217228
TryBot-Result: CUEcueckoo <[email protected]>
Reviewed-by: Daniel Martí <[email protected]>
Unity-Result: CUE porcuepine <[email protected]>

Author: mpvl

cue/testdata/eval/nonrooted.txtar

@@ -58,12 +58,21 @@ Conjuncts:    87
 Disjuncts:    68
 -- out/evalalpha --
 Errors:
+issue3977.inlineLet.p.x: conflicting values 1 and 2:
+    ./in.cue:38:14
+    ./in.cue:43:6
+x: conflicting values 1 and 2:
+    ./in.cue:2:14
+    ./in.cue:8:18
 x: conflicting values 2 and 1:
     ./in.cue:20:14
     ./in.cue:26:19
 x: conflicting values 4 and 1:
     ./in.cue:20:14
     ./in.cue:26:23
+x: invalid interpolation: 3 errors in empty disjunction::
+    ./in.cue:14:8
+    ./in.cue:14:17
 x: 2 errors in empty disjunction::
     ./in.cue:23:8
 
@@ -72,15 +81,21 @@ Result:
   // [eval]
   issue3977: (_|_){
     // [eval]
-    inlineExpr: (struct){
+    inlineExpr: (_|_){
+      // [eval]
       #NetworkID: (int){ 1 }
       #fn: (#struct){
         x: (int){ 1 }
         out: (int){ 2 }
       }
-      err: (int){ 3 }
+      err: (_|_){
+        // [eval] x: conflicting values 1 and 2:
+        //     ./in.cue:2:14
+        //     ./in.cue:8:18
+      }
     }
-    inlineDisj1: (struct){
+    inlineDisj1: (_|_){
+      // [eval]
       #NetworkID: (string){ |((string){ "2" }, (string){ "3" }, (string){ "4" }) }
       #fn: (#struct){
         x: (string){ |((string){ "2" }, (string){ "3" }, (string){ "4" }) }
@@ -89,7 +104,11 @@ Result:
           //     ./in.cue:14:8
         }
       }
-      err: (string){ "value=invalid" }
+      err: (_|_){
+        // [eval] x: invalid interpolation: 3 errors in empty disjunction::
+        //     ./in.cue:14:8
+        //     ./in.cue:14:17
+      }
     }
     inlineDisj2: (_|_){
       // [eval]
@@ -117,7 +136,8 @@ Result:
       }
       err: (int){ 11 }
     }
-    inlineLet: (struct){
+    inlineLet: (_|_){
+      // [eval]
       #NetworkID: (int){ 1 }
       let p#1 = (_|_){
         // [eval]
@@ -132,16 +152,26 @@ Result:
           //     ./in.cue:43:6
         }
       }
-      err: (int){ 12 }
+      err: (_|_){
+        // [eval] issue3977.inlineLet.p.x: conflicting values 1 and 2:
+        //     ./in.cue:38:14
+        //     ./in.cue:43:6
+      }
     }
   }
 }
 -- diff/-out/evalalpha<==>+out/eval --
 diff old new
 --- old
 +++ new
-@@ -1,13 +1,9 @@
+@@ -1,14 +1,19 @@
  Errors:
++issue3977.inlineLet.p.x: conflicting values 1 and 2:
++    ./in.cue:38:14
++    ./in.cue:43:6
++x: conflicting values 1 and 2:
++    ./in.cue:2:14
++    ./in.cue:8:18
  x: conflicting values 2 and 1:
      ./in.cue:20:14
 -    ./in.cue:22:8
@@ -152,9 +182,52 @@ diff old new
 -    ./in.cue:22:8
 -    ./in.cue:26:8
      ./in.cue:26:23
++x: invalid interpolation: 3 errors in empty disjunction::
++    ./in.cue:14:8
++    ./in.cue:14:17
  x: 2 errors in empty disjunction::
      ./in.cue:23:8
-@@ -46,13 +42,9 @@
+ 
+@@ -17,15 +22,21 @@
+   // [eval]
+   issue3977: (_|_){
+     // [eval]
+-    inlineExpr: (struct){
++    inlineExpr: (_|_){
++      // [eval]
+       #NetworkID: (int){ 1 }
+       #fn: (#struct){
+         x: (int){ 1 }
+         out: (int){ 2 }
+       }
+-      err: (int){ 3 }
+-    }
+-    inlineDisj1: (struct){
++      err: (_|_){
++        // [eval] x: conflicting values 1 and 2:
++        //     ./in.cue:2:14
++        //     ./in.cue:8:18
++      }
++    }
++    inlineDisj1: (_|_){
++      // [eval]
+       #NetworkID: (string){ |((string){ "2" }, (string){ "3" }, (string){ "4" }) }
+       #fn: (#struct){
+         x: (string){ |((string){ "2" }, (string){ "3" }, (string){ "4" }) }
+@@ -34,7 +45,11 @@
+           //     ./in.cue:14:8
+         }
+       }
+-      err: (string){ "value=invalid" }
++      err: (_|_){
++        // [eval] x: invalid interpolation: 3 errors in empty disjunction::
++        //     ./in.cue:14:8
++        //     ./in.cue:14:17
++      }
+     }
+     inlineDisj2: (_|_){
+       // [eval]
+@@ -46,13 +61,9 @@
        err: (_|_){
          // [eval] x: conflicting values 2 and 1:
          //     ./in.cue:20:14
@@ -168,7 +241,14 @@ diff old new
          //     ./in.cue:26:23
          // x: 2 errors in empty disjunction::
          //     ./in.cue:23:8
-@@ -71,15 +63,13 @@
+@@ -66,24 +77,27 @@
+       }
+       err: (int){ 11 }
+     }
+-    inlineLet: (struct){
++    inlineLet: (_|_){
++      // [eval]
+       #NetworkID: (int){ 1 }
        let p#1 = (_|_){
          // [eval]
          x: (_|_){
@@ -181,16 +261,30 @@ diff old new
 -          // [eval] issue3977.inlineLet.p.x: conflicting values 2 and 1:
 -          //     ./in.cue:38:14
 -          //     ./in.cue:40:8
+-          //     ./in.cue:43:6
+-        }
+-      }
+-      err: (int){ 12 }
 +          // [eval] issue3977.inlineLet.p.x: conflicting values 1 and 2:
 +          //     ./in.cue:38:14
 +          //     ./in.cue:43:6
 +        }
 +        out: (_|_){
 +          // [eval] issue3977.inlineLet.p.x: conflicting values 1 and 2:
 +          //     ./in.cue:38:14
-           //     ./in.cue:43:6
-         }
-       }
++          //     ./in.cue:43:6
++        }
++      }
++      err: (_|_){
++        // [eval] issue3977.inlineLet.p.x: conflicting values 1 and 2:
++        //     ./in.cue:38:14
++        //     ./in.cue:43:6
++      }
+     }
+   }
+ }
+-- diff/explanation --
+evalv3 correctly fails on all places marked with "err"
 -- out/eval --
 Errors:
 x: conflicting values 2 and 1:

internal/core/adt/context.go

@@ -706,6 +706,10 @@ func (c *OpContext) evalStateCI(v Expr, state combinedFlags) (result Value, ci C
 		if arc == nil {
 			return nil, c.ci
 		}
+		if arc.Internal() && c.isDevVersion() {
+			mode := state.conditions()
+			state = final(partial, mode|allTasksCompleted)
+		}
 		orig := arc
 		// TODO(deref): what is the right level of dereferencing here?
 		// DerefValue seems to work too.