Move Statement.exec methods to a separate class.
RELNOTES: None.
PiperOrigin-RevId: 166689144
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 facf5dd..b21ea17 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
@@ -57,12 +57,6 @@
}
@Override
- void doExec(Environment env) throws EvalException, InterruptedException {
- Object rvalue = expression.eval(env);
- lvalue.assign(rvalue, env, getLocation());
- }
-
- @Override
public void accept(SyntaxTreeVisitor visitor) {
visitor.visit(this);
}
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/AugmentedAssignmentStatement.java b/src/main/java/com/google/devtools/build/lib/syntax/AugmentedAssignmentStatement.java
index 2520348..ec23b20 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/AugmentedAssignmentStatement.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/AugmentedAssignmentStatement.java
@@ -59,11 +59,6 @@
}
@Override
- void doExec(Environment env) throws EvalException, InterruptedException {
- lvalue.assignAugmented(operator, expression, env, getLocation());
- }
-
- @Override
public void accept(SyntaxTreeVisitor visitor) {
visitor.visit(this);
}
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/Eval.java b/src/main/java/com/google/devtools/build/lib/syntax/Eval.java
new file mode 100644
index 0000000..d4c6edb
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/syntax/Eval.java
@@ -0,0 +1,211 @@
+// Copyright 2017 The Bazel Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.devtools.build.lib.syntax;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Evaluation code for the Skylark AST. At the moment, it can execute only statements (and defers to
+ * Expression.eval for evaluating expressions).
+ */
+public class Eval {
+ private final Environment env;
+
+ /** An exception that signals changes in the control flow (e.g. break or continue) */
+ private static class FlowException extends EvalException {
+ FlowException(String message) {
+ super(null, message);
+ }
+
+ @Override
+ public boolean canBeAddedToStackTrace() {
+ return false;
+ }
+ }
+
+ private static final FlowException breakException = new FlowException("FlowException - break");
+ private static final FlowException continueException =
+ new FlowException("FlowException - continue");
+
+ public Eval(Environment env) {
+ this.env = env;
+ }
+
+ void execAssignment(AssignmentStatement node) throws EvalException, InterruptedException {
+ Object rvalue = node.getExpression().eval(env);
+ node.getLValue().assign(rvalue, env, node.getLocation());
+ }
+
+ void execAugmentedAssignment(AugmentedAssignmentStatement node)
+ throws EvalException, InterruptedException {
+ node.getLValue()
+ .assignAugmented(node.getOperator(), node.getExpression(), env, node.getLocation());
+ }
+
+ void execIfBranch(IfStatement.ConditionalStatements node)
+ throws EvalException, InterruptedException {
+ for (Statement stmt : node.getStatements()) {
+ exec(stmt);
+ }
+ }
+
+ void execFor(ForStatement node) throws EvalException, InterruptedException {
+ Object o = node.getCollection().eval(env);
+ Iterable<?> col = EvalUtils.toIterable(o, node.getLocation(), env);
+ EvalUtils.lock(o, node.getLocation());
+ try {
+ for (Object it : col) {
+ node.getVariable().assign(it, env, node.getLocation());
+
+ try {
+ for (Statement stmt : node.getBlock()) {
+ stmt.exec(env);
+ }
+ } catch (FlowException ex) {
+ if (ex == breakException) {
+ return;
+ }
+ }
+ }
+ } finally {
+ EvalUtils.unlock(o, node.getLocation());
+ }
+ }
+
+ void execDef(FunctionDefStatement node) throws EvalException, InterruptedException {
+ List<Expression> defaultExpressions = node.getSignature().getDefaultValues();
+ ArrayList<Object> defaultValues = null;
+
+ if (defaultExpressions != null) {
+ defaultValues = new ArrayList<>(defaultExpressions.size());
+ for (Expression expr : defaultExpressions) {
+ defaultValues.add(expr.eval(env));
+ }
+ }
+
+ FunctionSignature sig = node.getSignature().getSignature();
+ if (env.getSemantics().incompatibleDisallowKeywordOnlyArgs
+ && sig.getShape().getMandatoryNamedOnly() > 0) {
+ throw new EvalException(
+ node.getLocation(),
+ "Keyword-only argument is forbidden. You can temporarily disable this "
+ + "error using the flag --incompatible_disallow_keyword_only_args=false");
+ }
+
+ env.update(
+ node.getIdentifier().getName(),
+ new UserDefinedFunction(
+ node.getIdentifier().getName(),
+ node.getIdentifier().getLocation(),
+ FunctionSignature.WithValues.create(sig, defaultValues, /*types=*/ null),
+ node.getStatements(),
+ env.getGlobals()));
+ }
+
+ void execIf(IfStatement node) throws EvalException, InterruptedException {
+ for (IfStatement.ConditionalStatements stmt : node.getThenBlocks()) {
+ if (EvalUtils.toBoolean(stmt.getCondition().eval(env))) {
+ exec(stmt);
+ return;
+ }
+ }
+ for (Statement stmt : node.getElseBlock()) {
+ exec(stmt);
+ }
+ }
+
+ void execLoad(LoadStatement node) throws EvalException, InterruptedException {
+ if (env.getSemantics().incompatibleLoadArgumentIsLabel) {
+ String s = node.getImport().getValue();
+ if (!s.startsWith("//") && !s.startsWith(":")) {
+ throw new EvalException(
+ node.getLocation(),
+ "First argument of 'load' must be a label and start with either '//' or ':'. "
+ + "Use --incompatible_load_argument_is_label=false to temporarily disable this "
+ + "check.");
+ }
+ }
+
+ for (Map.Entry<Identifier, String> entry : node.getSymbolMap().entrySet()) {
+ try {
+ Identifier name = entry.getKey();
+ Identifier declared = new Identifier(entry.getValue());
+
+ if (declared.isPrivate()) {
+ throw new EvalException(
+ node.getLocation(),
+ "symbol '" + declared.getName() + "' is private and cannot be imported.");
+ }
+ // The key is the original name that was used to define the symbol
+ // in the loaded bzl file.
+ env.importSymbol(node.getImport().getValue(), name, declared.getName());
+ } catch (Environment.LoadFailedException e) {
+ throw new EvalException(node.getLocation(), e.getMessage());
+ }
+ }
+ }
+
+ void execReturn(ReturnStatement node) throws EvalException, InterruptedException {
+ Expression ret = node.getReturnExpression();
+ if (ret == null) {
+ throw new ReturnStatement.ReturnException(node.getLocation(), Runtime.NONE);
+ }
+ throw new ReturnStatement.ReturnException(ret.getLocation(), ret.eval(env));
+ }
+
+ /**
+ * Execute the statement.
+ *
+ * @throws EvalException if execution of the statement could not be completed.
+ * @throws InterruptedException may be thrown in a sub class.
+ */
+ public void exec(Statement st) throws EvalException, InterruptedException {
+ switch (st.kind()) {
+ case ASSIGNMENT:
+ execAssignment((AssignmentStatement) st);
+ break;
+ case AUGMENTED_ASSIGNMENT:
+ execAugmentedAssignment((AugmentedAssignmentStatement) st);
+ break;
+ case CONDITIONAL:
+ execIfBranch((IfStatement.ConditionalStatements) st);
+ break;
+ case EXPRESSION:
+ ((ExpressionStatement) st).getExpression().eval(env);
+ break;
+ case FLOW:
+ throw ((FlowStatement) st).getKind() == FlowStatement.Kind.BREAK
+ ? breakException
+ : continueException;
+ case FOR:
+ execFor((ForStatement) st);
+ break;
+ case FUNCTION_DEF:
+ execDef((FunctionDefStatement) st);
+ break;
+ case IF:
+ execIf((IfStatement) st);
+ break;
+ case LOAD:
+ execLoad((LoadStatement) st);
+ break;
+ case RETURN:
+ execReturn((ReturnStatement) st);
+ break;
+ }
+ }
+}
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/ExpressionStatement.java b/src/main/java/com/google/devtools/build/lib/syntax/ExpressionStatement.java
index 7367fdc..54f4fb7 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/ExpressionStatement.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/ExpressionStatement.java
@@ -39,11 +39,6 @@
}
@Override
- void doExec(Environment env) throws EvalException, InterruptedException {
- expression.eval(env);
- }
-
- @Override
public void accept(SyntaxTreeVisitor visitor) {
visitor.visit(this);
}
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/FlowStatement.java b/src/main/java/com/google/devtools/build/lib/syntax/FlowStatement.java
index e2d5344..1022caf 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/FlowStatement.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/FlowStatement.java
@@ -29,10 +29,13 @@
private Kind(String name) {
this.name = name;
}
+
+ public String getName() {
+ return name;
+ }
}
private final Kind kind;
- private final FlowException ex;
/**
*
@@ -40,7 +43,6 @@
*/
public FlowStatement(Kind kind) {
this.kind = kind;
- this.ex = new FlowException(kind);
}
public Kind getKind() {
@@ -48,11 +50,6 @@
}
@Override
- void doExec(Environment env) throws EvalException {
- throw ex;
- }
-
- @Override
public void prettyPrint(Appendable buffer, int indentLevel) throws IOException {
printIndent(buffer, indentLevel);
buffer.append(kind.name);
@@ -73,30 +70,4 @@
public Statement.Kind kind() {
return Statement.Kind.FLOW;
}
-
- /**
- * An exception that signals changes in the control flow (e.g. break or continue)
- */
- class FlowException extends EvalException {
- private final Kind kind;
-
- public FlowException(Kind kind) {
- super(FlowStatement.this.getLocation(), "FlowException with kind = " + kind.name);
- this.kind = kind;
- }
-
- /**
- * Returns whether the enclosing loop should be terminated completely (break)
- *
- * @return {@code True} for 'break', {@code false} for 'continue'
- */
- public boolean mustTerminateLoop() {
- return kind == Kind.BREAK;
- }
-
- @Override
- public boolean canBeAddedToStackTrace() {
- return false;
- }
- }
}
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 32a1d26..f285935 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
@@ -14,7 +14,6 @@
package com.google.devtools.build.lib.syntax;
import com.google.common.collect.ImmutableList;
-import com.google.devtools.build.lib.syntax.FlowStatement.FlowException;
import com.google.devtools.build.lib.util.Preconditions;
import java.io.IOException;
import java.util.List;
@@ -69,30 +68,6 @@
}
@Override
- void doExec(Environment env) throws EvalException, InterruptedException {
- Object o = collection.eval(env);
- Iterable<?> col = EvalUtils.toIterable(o, getLocation(), env);
- EvalUtils.lock(o, getLocation());
- try {
- for (Object it : col) {
- variable.assign(it, env, getLocation());
-
- try {
- for (Statement stmt : block) {
- stmt.exec(env);
- }
- } catch (FlowException ex) {
- if (ex.mustTerminateLoop()) {
- return;
- }
- }
- }
- } finally {
- EvalUtils.unlock(o, getLocation());
- }
- }
-
- @Override
public void accept(SyntaxTreeVisitor visitor) {
visitor.visit(this);
}
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 544870e..0f27ada 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
@@ -15,8 +15,6 @@
import com.google.common.collect.ImmutableList;
import java.io.IOException;
-import java.util.ArrayList;
-import java.util.List;
/**
* Syntax node for a function definition.
@@ -39,37 +37,6 @@
}
@Override
- void doExec(Environment env) throws EvalException, InterruptedException {
- List<Expression> defaultExpressions = signature.getDefaultValues();
- ArrayList<Object> defaultValues = null;
-
- if (defaultExpressions != null) {
- defaultValues = new ArrayList<>(defaultExpressions.size());
- for (Expression expr : defaultExpressions) {
- defaultValues.add(expr.eval(env));
- }
- }
-
- FunctionSignature sig = signature.getSignature();
- if (env.getSemantics().incompatibleDisallowKeywordOnlyArgs
- && sig.getShape().getMandatoryNamedOnly() > 0) {
- throw new EvalException(
- getLocation(),
- "Keyword-only argument is forbidden. You can temporarily disable this "
- + "error using the flag --incompatible_disallow_keyword_only_args=false");
- }
-
- env.update(
- identifier.getName(),
- new UserDefinedFunction(
- identifier.getName(),
- identifier.getLocation(),
- FunctionSignature.WithValues.create(sig, defaultValues, /*types=*/null),
- statements,
- env.getGlobals()));
- }
-
- @Override
public void prettyPrint(Appendable buffer, int indentLevel) throws IOException {
printIndent(buffer, indentLevel);
buffer.append("def ");
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/IfStatement.java b/src/main/java/com/google/devtools/build/lib/syntax/IfStatement.java
index c49613d..f2f5c4b 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/IfStatement.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/IfStatement.java
@@ -26,8 +26,8 @@
/**
* Syntax node for an [el]if statement.
*
- * <p>This extends Statement because it implements {@code doExec}, but it is not actually an
- * independent statement in the grammar.
+ * <p>This extends Statement, but it is not actually an independent statement in the grammar. We
+ * should probably eliminate it in favor of a recursive representation of if/else chains.
*/
public static final class ConditionalStatements extends Statement {
@@ -39,13 +39,6 @@
this.statements = ImmutableList.copyOf(statements);
}
- @Override
- void doExec(Environment env) throws EvalException, InterruptedException {
- for (Statement stmt : statements) {
- stmt.exec(env);
- }
- }
-
// No prettyPrint function; handled directly by IfStatement#prettyPrint.
@Override
public void prettyPrint(Appendable buffer, int indentLevel) throws IOException {
@@ -122,19 +115,6 @@
}
@Override
- void doExec(Environment env) throws EvalException, InterruptedException {
- for (ConditionalStatements stmt : thenBlocks) {
- if (EvalUtils.toBoolean(stmt.getCondition().eval(env))) {
- stmt.exec(env);
- return;
- }
- }
- for (Statement stmt : elseBlock) {
- stmt.exec(env);
- }
- }
-
- @Override
public void accept(SyntaxTreeVisitor visitor) {
visitor.visit(this);
}
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 084ffa8..1808021 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
@@ -73,37 +73,6 @@
}
@Override
- void doExec(Environment env) throws EvalException, InterruptedException {
- if (env.getSemantics().incompatibleLoadArgumentIsLabel) {
- String s = imp.getValue();
- if (!s.startsWith("//") && !s.startsWith(":")) {
- throw new EvalException(
- getLocation(),
- "First argument of 'load' must be a label and start with either '//' or ':'. "
- + "Use --incompatible_load_argument_is_label=false to temporarily disable this "
- + "check.");
- }
- }
-
- for (Map.Entry<Identifier, String> entry : symbolMap.entrySet()) {
- try {
- Identifier name = entry.getKey();
- Identifier declared = new Identifier(entry.getValue());
-
- if (declared.isPrivate()) {
- throw new EvalException(getLocation(),
- "symbol '" + declared.getName() + "' is private and cannot be imported.");
- }
- // The key is the original name that was used to define the symbol
- // in the loaded bzl file.
- env.importSymbol(imp.getValue(), name, declared.getName());
- } catch (Environment.LoadFailedException e) {
- throw new EvalException(getLocation(), e.getMessage());
- }
- }
- }
-
- @Override
public void accept(SyntaxTreeVisitor visitor) {
visitor.visit(this);
}
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/ReturnStatement.java b/src/main/java/com/google/devtools/build/lib/syntax/ReturnStatement.java
index 8366119..10b1fd2 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/ReturnStatement.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/ReturnStatement.java
@@ -53,14 +53,6 @@
this.returnExpression = returnExpression;
}
- @Override
- void doExec(Environment env) throws EvalException, InterruptedException {
- if (returnExpression == null) {
- throw new ReturnException(getLocation(), Runtime.NONE);
- }
- throw new ReturnException(returnExpression.getLocation(), returnExpression.eval(env));
- }
-
@Nullable
public Expression getReturnExpression() {
return returnExpression;
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/Statement.java b/src/main/java/com/google/devtools/build/lib/syntax/Statement.java
index 1795af1..b8505c3 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/Statement.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/Statement.java
@@ -37,13 +37,13 @@
}
/**
- * Executes the statement in the specified build environment, which may be
- * modified.
+ * Executes the statement in the specified build environment, which may be modified.
*
* @throws EvalException if execution of the statement could not be completed.
* @throws InterruptedException may be thrown in a sub class.
*/
- final void exec(Environment env) throws EvalException, InterruptedException {
+ @Deprecated // use Eval class instead
+ final void exec(Environment env) throws EvalException, InterruptedException {
try {
doExec(env);
} catch (EvalException ex) {
@@ -60,7 +60,10 @@
* @throws EvalException if execution of the statement could not be completed.
* @throws InterruptedException may be thrown in a sub class.
*/
- abstract void doExec(Environment env) throws EvalException, InterruptedException;
+ @Deprecated
+ final void doExec(Environment env) throws EvalException, InterruptedException {
+ new Eval(env).exec(this);
+ }
/**
* Kind of the statement. This is similar to using instanceof, except that it's more efficient and
