Refactor Skylark Environment-s
Make Environment-s freezable: Introduce a class Mutability
as a revokable capability to mutate objects in an Environment.
For now, only Environment-s carry this capability.
Make sure that every Mutability is revoked in the same function that create...
This reinstates a change that previously rolled-back because it broke the
serializability of SkylarkLookupValue. Bad news: serializing it succeeds for the
wrong reason, because a SkylarkEnvironment was stored as a result (now an
Environment.Extension) that was Serializable but inherited its bindings from an Environment (now an Environment.BaseExtension) which wasn't Serializable.
Apparently, Java doesn't try to serialize the bindings then (or at least doesn't
error out when it fails), because these bindings map variable names to pretty
arbitrary objects, and a lot of those we find in practice aren't Serializable.
Thus the current code passes the same tests as the previous code, but obviously
the serialization is just as ineffective as it used to be.
--
MOS_MIGRATED_REVID=102776694
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 2ef5d83..1e4497b 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
@@ -36,6 +36,8 @@
import java.util.Map;
import java.util.concurrent.ExecutionException;
+import javax.annotation.Nullable;
+
/**
* Syntax node for a function call expression.
*/
@@ -125,6 +127,7 @@
return methodMap.build();
}
+ @Nullable
private static SkylarkCallable getAnnotationFromParentClass(Class<?> classObj, Method method) {
boolean keepLooking = false;
try {
@@ -167,7 +170,7 @@
}
}
- private final Expression obj;
+ @Nullable private final Expression obj;
private final Identifier func;
@@ -182,7 +185,7 @@
* arbitrary expressions. In any case, the "func" expression is always
* evaluated, so functions and variables share a common namespace.
*/
- public FuncallExpression(Expression obj, Identifier func,
+ public FuncallExpression(@Nullable Expression obj, Identifier func,
List<Argument.Passed> args) {
this.obj = obj;
this.func = func;
@@ -353,21 +356,11 @@
// TODO(bazel-team): If there's exactly one usable method, this works. If there are multiple
// matching methods, it still can be a problem. Figure out how the Java compiler does it
// exactly and copy that behaviour.
- // TODO(bazel-team): check if this and SkylarkBuiltInFunctions.createObject can be merged.
- private Object invokeJavaMethod(
- Object obj, Class<?> objClass, String methodName, List<Object> args, boolean hasKwArgs)
- throws EvalException {
+ private MethodDescriptor findJavaMethod(
+ Class<?> objClass, String methodName, List<Object> args) throws EvalException {
MethodDescriptor matchingMethod = null;
List<MethodDescriptor> methods = getMethods(objClass, methodName, args.size(), getLocation());
if (methods != null) {
- if (hasKwArgs) {
- throw new EvalException(
- func.getLocation(),
- String.format(
- "Keyword arguments are not allowed when calling a java method"
- + "\nwhile calling method '%s' on object of type %s",
- func.getName(), EvalUtils.getDataTypeNameFromClass(objClass)));
- }
for (MethodDescriptor method : methods) {
Class<?>[] params = method.getMethod().getParameterTypes();
int i = 0;
@@ -384,7 +377,7 @@
matchingMethod = method;
} else {
throw new EvalException(
- func.getLocation(),
+ getLocation(),
String.format(
"Type %s has multiple matches for %s",
EvalUtils.getDataTypeNameFromClass(objClass),
@@ -394,15 +387,14 @@
}
}
if (matchingMethod != null && !matchingMethod.getAnnotation().structField()) {
- return callMethod(matchingMethod, methodName, obj, args.toArray(), getLocation());
- } else {
- throw new EvalException(
- getLocation(),
- String.format(
- "Type %s has no %s",
- EvalUtils.getDataTypeNameFromClass(objClass),
- formatMethod(args)));
+ return matchingMethod;
}
+ throw new EvalException(
+ getLocation(),
+ String.format(
+ "Type %s has no %s",
+ EvalUtils.getDataTypeNameFromClass(objClass),
+ formatMethod(args)));
}
private String formatMethod(List<Object> args) {
@@ -496,20 +488,7 @@
@Override
Object eval(Environment env) throws EvalException, InterruptedException {
- // Adds the calling rule to the stack trace of the Environment if it is a BUILD environment.
- // There are two reasons for this:
- // a) When using aliases in load(), the rule class name in the BUILD file will differ from
- // the implementation name in the bzl file. Consequently, we need to store the calling name.
- // b) We need the location of the calling rule inside the BUILD file.
- boolean hasAddedElement =
- env.isSkylark() ? false : env.tryAddingStackTraceRoot(new StackTraceElement(func, args));
- try {
- return (obj != null) ? invokeObjectMethod(env) : invokeGlobalFunction(env);
- } finally {
- if (hasAddedElement) {
- env.removeStackTraceRoot();
- }
- }
+ return (obj != null) ? invokeObjectMethod(env) : invokeGlobalFunction(env);
}
/**
@@ -556,15 +535,28 @@
// When calling a Java method, the name is not in the Environment,
// so evaluating 'func' would fail.
evalArguments(posargs, kwargs, env, null);
+ Class<?> objClass;
+ Object obj;
if (objValue instanceof Class<?>) {
- // Static Java method call. We can return the value from here directly because
- // invokeJavaMethod() has special checks.
- return invokeJavaMethod(
- null, (Class<?>) objValue, func.getName(), posargs.build(), !kwargs.isEmpty());
+ // Static call
+ obj = null;
+ objClass = (Class<?>) objValue;
} else {
- return invokeJavaMethod(
- objValue, objValue.getClass(), func.getName(), posargs.build(), !kwargs.isEmpty());
+ obj = objValue;
+ objClass = objValue.getClass();
}
+ String name = func.getName();
+ ImmutableList<Object> args = posargs.build();
+ MethodDescriptor method = findJavaMethod(objClass, name, args);
+ if (!kwargs.isEmpty()) {
+ throw new EvalException(
+ func.getLocation(),
+ String.format(
+ "Keyword arguments are not allowed when calling a java method"
+ + "\nwhile calling method '%s' for type %s",
+ name, EvalUtils.getDataTypeNameFromClass(objClass)));
+ }
+ return callMethod(method, name, obj, args.toArray(), getLocation());
} else {
throw new EvalException(
getLocation(),
@@ -616,6 +608,25 @@
? ArgConversion.TO_SKYLARK : ArgConversion.NO_CONVERSION;
}
+ /**
+ * Returns the value of the argument 'name' (or null if there is none).
+ * This function is used to associate debugging information to rules created by skylark "macros".
+ */
+ @Nullable
+ public String getNameArg() {
+ for (Argument.Passed arg : args) {
+ if (arg != null) {
+ String name = arg.getName();
+ if (name != null && name.equals("name")) {
+ Expression expr = arg.getValue();
+ return (expr != null && expr instanceof StringLiteral)
+ ? ((StringLiteral) expr).getValue() : null;
+ }
+ }
+ }
+ return null;
+ }
+
@Override
public void accept(SyntaxTreeVisitor visitor) {
visitor.visit(this);
