Skylark: Remove static type checking of variables/functions.

There are still some static checks (check existence of variable/function,
readonly variables, etc.). More cleanup will come later.

--
MOS_MIGRATED_REVID=90979748

10 files changed, 24 insertions, 85 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/syntax/AssignmentStatement.java b/src/main/java/com/google/devtools/build/lib/syntax/AssignmentStatement.java
index 601f128aa3..6994231ea1 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/AssignmentStatement.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/AssignmentStatement.java
@@ -63,6 +63,7 @@ public final class AssignmentStatement extends Statement {
 
   @Override
   void validate(ValidationEnvironment env) throws EvalException {
-    lvalue.validate(env, getLocation(), expression.validate(env));
+    expression.validate(env);
+    lvalue.validate(env, getLocation());
   }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/DictComprehension.java b/src/main/java/com/google/devtools/build/lib/syntax/DictComprehension.java
index 4c7278be94..a2d05eaba2 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/DictComprehension.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/DictComprehension.java
@@ -67,8 +67,7 @@ public class DictComprehension extends Expression {
   @Override
   SkylarkType validate(ValidationEnvironment env) throws EvalException {
     SkylarkType elementsType = listExpression.validate(env);
-    SkylarkType listElementType = SkylarkType.getGenericArgType(elementsType);
-    loopVar.validate(env, getLocation(), listElementType);
+    loopVar.validate(env, getLocation());
     SkylarkType keyType = keyExpression.validate(env);
     if (!keyType.isSimple()) {
       // TODO(bazel-team): this is most probably dead code but it's better to have it here
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/EvaluationContext.java b/src/main/java/com/google/devtools/build/lib/syntax/EvaluationContext.java
index c361bb3fca..8ccca055d5 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/EvaluationContext.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/EvaluationContext.java
@@ -191,8 +191,7 @@ public final class EvaluationContext {
   public EvaluationContext update(String varname, Object value) throws EvalException {
     env.update(varname, value);
     if (validationEnv != null) {
-      validationEnv.update(
-          varname, SkylarkType.typeForInference(SkylarkType.of(value.getClass())), null);
+      validationEnv.declare(varname, null);
     }
     return this;
   }
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/ForStatement.java b/src/main/java/com/google/devtools/build/lib/syntax/ForStatement.java
index 2faf06c857..054b21f1e6 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/ForStatement.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/ForStatement.java
@@ -87,9 +87,8 @@ public final class ForStatement extends Statement {
           "'For' is not allowed as a top level statement");
     }
     // TODO(bazel-team): validate variable. Maybe make it temporarily readonly.
-    SkylarkType type = collection.validate(env);
-    env.checkIterable(type, getLocation());
-    variable.validate(env, getLocation(), SkylarkType.UNKNOWN);
+    collection.validate(env);
+    variable.validate(env, getLocation());
     for (Statement stmt : block) {
       stmt.validate(env);
     }
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/FuncallExpression.java b/src/main/java/com/google/devtools/build/lib/syntax/FuncallExpression.java
index 41fe33238f..0f6cf14af1 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/FuncallExpression.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/FuncallExpression.java
@@ -556,15 +556,11 @@ public final class FuncallExpression extends Expression {
     }
 
     if (obj != null) {
-      // TODO(bazel-team): validate function calls on objects too.
-      return env.getReturnType(obj.validate(env), func.getName(), getLocation());
-    } else {
-      // TODO(bazel-team): Imported functions are not validated properly.
-      if (!env.hasSymbolInEnvironment(func.getName())) {
-        throw new EvalException(getLocation(),
-            String.format("function '%s' does not exist", func.getName()));
-      }
-      return env.getReturnType(func.getName(), getLocation());
+      obj.validate(env);
+    } else if (!env.hasSymbolInEnvironment(func.getName())) {
+      throw new EvalException(getLocation(),
+          String.format("function '%s' does not exist", func.getName()));
     }
+    return SkylarkType.UNKNOWN;
   }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/FunctionDefStatement.java b/src/main/java/com/google/devtools/build/lib/syntax/FunctionDefStatement.java
index 5b0119ee88..56ad4b60cf 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/FunctionDefStatement.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/FunctionDefStatement.java
@@ -117,7 +117,7 @@ public class FunctionDefStatement extends Statement {
           }
         }
       }
-      localEnv.update(name, argType, getLocation());
+      localEnv.declare(name, getLocation());
     }
     for (Statement stmts : statements) {
       stmts.validate(localEnv);
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/LValue.java b/src/main/java/com/google/devtools/build/lib/syntax/LValue.java
index e7f15d7d5b..846c5b58fc 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/LValue.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/LValue.java
@@ -107,21 +107,20 @@ public class LValue implements Serializable {
     env.update(ident.getName(), result);
   }
 
-  void validate(ValidationEnvironment env, Location loc, SkylarkType rvalueType)
-      throws EvalException {
-    validate(env, loc, expr, rvalueType);
+  void validate(ValidationEnvironment env, Location loc) throws EvalException {
+    validate(env, loc, expr);
   }
 
-  private static void validate(ValidationEnvironment env, Location loc, Expression expr,
-      SkylarkType rvalueType) throws EvalException {
+  private static void validate(ValidationEnvironment env, Location loc, Expression expr)
+      throws EvalException {
     if (expr instanceof Ident) {
       Ident ident = (Ident) expr;
-      env.update(ident.getName(), rvalueType, loc);
+      env.declare(ident.getName(), loc);
       return;
     }
     if (expr instanceof ListLiteral) {
       for (Expression e : ((ListLiteral) expr).getElements()) {
-        validate(env, loc, e, SkylarkType.UNKNOWN);
+        validate(env, loc, e);
       }
       return;
     }
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/ListComprehension.java b/src/main/java/com/google/devtools/build/lib/syntax/ListComprehension.java
index 26cbfc0e0b..90cbddd41a 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/ListComprehension.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/ListComprehension.java
@@ -122,10 +122,8 @@ public final class ListComprehension extends Expression {
   @Override
   SkylarkType validate(ValidationEnvironment env) throws EvalException {
     for (Map.Entry<LValue, Expression> list : lists) {
-      // TODO(bazel-team): Get the type of elements
-      SkylarkType type = list.getValue().validate(env);
-      env.checkIterable(type, getLocation());
-      list.getKey().validate(env, getLocation(), SkylarkType.UNKNOWN);
+      list.getValue().validate(env);
+      list.getKey().validate(env, getLocation());
     }
     elementExpression.validate(env);
     return SkylarkType.LIST;
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/LoadStatement.java b/src/main/java/com/google/devtools/build/lib/syntax/LoadStatement.java
index 9c59989415..414429ebd2 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/LoadStatement.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/LoadStatement.java
@@ -75,9 +75,8 @@ public final class LoadStatement extends Statement {
     if (!importPath.isAbsolute() && importPath.segmentCount() > 1) {
       throw new EvalException(getLocation(), String.format(PATH_ERROR_MSG, importPath));
     }
-    // TODO(bazel-team): implement semantical check.
     for (Ident symbol : symbols) {
-      env.update(symbol.getName(), SkylarkType.UNKNOWN, getLocation());
+      env.declare(symbol.getName(), getLocation());
     }
   }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/ValidationEnvironment.java b/src/main/java/com/google/devtools/build/lib/syntax/ValidationEnvironment.java
index 95d7f30847..668688e264 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/ValidationEnvironment.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/ValidationEnvironment.java
@@ -104,11 +104,9 @@ public class ValidationEnvironment {
   }
 
   /**
-   * Updates the variable type if the new type is "stronger" then the old one.
-   * The old and the new vartype has to be compatible, otherwise an EvalException is thrown.
-   * The new type is stronger if the old one doesn't exist or is unknown.
+   * Declare a variable and add it to the environment.
    */
-  public void update(String varname, SkylarkType newVartype, Location location)
+  public void declare(String varname, Location location)
       throws EvalException {
     checkReadonly(varname, location);
     if (parent == null) {  // top-level values are immutable
@@ -118,12 +116,7 @@ public class ValidationEnvironment {
         futureReadOnlyVariables.peek().add(varname);
       }
     }
-    SkylarkType oldVartype = variableTypes.get(SkylarkType.GLOBAL).get(varname);
-    if (oldVartype != null) {
-      newVartype = oldVartype.infer(newVartype, "variable '" + varname + "'",
-          location, variableLocations.get(varname));
-    }
-    variableTypes.get(SkylarkType.GLOBAL).put(varname, newVartype);
+    variableTypes.get(SkylarkType.GLOBAL).put(varname, SkylarkType.UNKNOWN);
     variableLocations.put(varname, location);
     clonable = false;
   }
@@ -134,19 +127,6 @@ public class ValidationEnvironment {
     }
   }
 
-  public void checkIterable(SkylarkType type, Location loc) throws EvalException {
-    if (type == SkylarkType.UNKNOWN) {
-      // Until all the language is properly typed, we ignore Object types.
-      return;
-    }
-    if (!Iterable.class.isAssignableFrom(type.getType())
-        && !Map.class.isAssignableFrom(type.getType())
-        && !String.class.equals(type.getType())) {
-      throw new EvalException(loc,
-          "type '" + EvalUtils.getDataTypeNameFromClass(type.getType()) + "' is not iterable");
-    }
-  }
-
   /**
    * Returns true if the symbol exists in the validation environment.
    */
@@ -171,37 +151,6 @@ public class ValidationEnvironment {
     return currentFunction;
   }
 
-  /**
-   * Returns the return type of the function.
-   */
-  public SkylarkType getReturnType(String funcName, Location loc) throws EvalException {
-    return getReturnType(SkylarkType.GLOBAL, funcName, loc);
-  }
-
-  /**
-   * Returns the return type of the object function.
-   */
-  public SkylarkType getReturnType(SkylarkType objectType, String funcName, Location loc)
-      throws EvalException {
-    // All functions are registered in the top level ValidationEnvironment.
-    Map<String, SkylarkType> functions = topLevel().variableTypes.get(objectType);
-    // TODO(bazel-team): eventually not finding the return type should be a validation error,
-    // because it means the function doesn't exist. First we have to make sure that we register
-    // every possible function before.
-    if (functions != null) {
-      SkylarkType functionType = functions.get(funcName);
-      if (functionType != null && functionType != SkylarkType.UNKNOWN) {
-        if (!(functionType instanceof SkylarkFunctionType)) {
-          throw new EvalException(loc, String.format("%s%s is not a function but a(n) %s",
-                  (objectType == SkylarkType.GLOBAL ? "" : objectType + "."),
-                  funcName, functionType));
-        }
-        return ((SkylarkFunctionType) functionType).getReturnType();
-      }
-    }
-    return SkylarkType.UNKNOWN;
-  }
-
   private ValidationEnvironment topLevel() {
     return Preconditions.checkNotNull(parent == null ? this : parent);
   }