Java Environment.lookup方法代碼示例

import com.google.devtools.build.lib.syntax.Environment; //導入方法依賴的package包/類
/**
 * Get the PackageContext by looking up in the environment.
 */
public static PackageContext getContext(Environment env, FuncallExpression ast)
    throws EvalException {
  PackageContext value = (PackageContext) env.lookup(PKG_CONTEXT);
  if (value == null) {
    // if PKG_CONTEXT is missing, we're not called from a BUILD file. This happens if someone
    // uses native.some_func() in the wrong place.
    throw new EvalException(ast.getLocation(),
        "The native module cannot be accessed from here. "
        + "Wrap the function in a macro and call it from a BUILD file");
  }
  return value;
}
 

import com.google.devtools.build.lib.syntax.Environment; //導入方法依賴的package包/類
/** Get the {@link PackageContext} by looking up in the environment. */
public static PackageContext getPackageContext(Environment env, FuncallExpression ast)
    throws EvalException {
  @Nullable PackageContext value = (PackageContext) env.lookup(PACKAGE_CONTEXT);
  if (value == null) {
    // if package context is missing, we're not called from a build file. This happens if someone
    // uses native.some_func() in the wrong place.
    throw new EvalException(
        ast.getLocation(),
        "The native module cannot be accessed from here. "
            + "Wrap the function in a macro and call it from a BUCK file");
  }
  return value;
}
 

import com.google.devtools.build.lib.syntax.Environment; //導入方法依賴的package包/類
/** Get the {@link ParseContext} by looking up in the environment. */
private static ParseContext getParseContext(Environment env, FuncallExpression ast)
    throws EvalException {
  @Nullable ParseContext value = (ParseContext) env.lookup(PARSE_CONTEXT);
  if (value == null) {
    // if PARSE_CONTEXT is missing, we're not called from a build file. This happens if someone
    // uses native.some_func() in the wrong place.
    throw new EvalException(
        ast.getLocation(),
        "The native module cannot be accessed from here. "
            + "Wrap the function in a macro and call it from a BUCK file");
  }
  return value;
}
 

import com.google.devtools.build.lib.syntax.Environment; //導入方法依賴的package包/類
public String invoke(FuncallExpression ast, Environment env)
    throws EvalException, ConversionException {
  env.checkLoadingPhase("native.package_name", ast.getLocation());
  return (String) env.lookup("PACKAGE_NAME");
}
 

import com.google.devtools.build.lib.syntax.Environment; //導入方法依賴的package包/類
@Override
@SuppressWarnings("unchecked") // the magic hidden $pkg_context variable is guaranteed
// to be a PackageContext
public Object call(Object[] args, FuncallExpression ast, Environment env)
    throws EvalException, InterruptedException, ConversionException {
  env.checkLoadingPhase(getName(), ast.getLocation());
  if (ruleClass == null) {
    throw new EvalException(ast.getLocation(),
        "Invalid rule class hasn't been exported by a Skylark file");
  }

  for (Attribute attribute : ruleClass.getAttributes()) {
    // TODO(dslomov): If a Skylark parameter extractor is specified for this aspect, its
    // attributes may not be required.
    for (Map.Entry<String, ImmutableSet<String>> attrRequirements :
        attribute.getRequiredAspectParameters().entrySet()) {
      for (String required : attrRequirements.getValue()) {
        if (!ruleClass.hasAttr(required, Type.STRING)) {
          throw new EvalException(definitionLocation, String.format(
              "Aspect %s requires rule %s to specify attribute '%s' with type string.",
              attrRequirements.getKey(),
              ruleClass.getName(),
              required));
        }
      }
    }
  }

  BuildLangTypedAttributeValuesMap attributeValues =
      new BuildLangTypedAttributeValuesMap((Map<String, Object>) args[0]);
  try {
    PackageContext pkgContext = (PackageContext) env.lookup(PackageFactory.PKG_CONTEXT);
    if (pkgContext == null) {
      throw new EvalException(ast.getLocation(),
          "Cannot instantiate a rule when loading a .bzl file. Rules can only be called from "
              + "a BUILD file (possibly via a macro).");
    }
    RuleFactory.createAndAddRule(
        pkgContext,
        ruleClass,
        attributeValues,
        ast,
        env,
        pkgContext.getAttributeContainerFactory().apply(ruleClass));
    return Runtime.NONE;
  } catch (InvalidRuleException | NameConflictException e) {
    throw new EvalException(ast.getLocation(), e.getMessage());
  }
}
 

import com.google.devtools.build.lib.syntax.Environment; //導入方法依賴的package包/類
@SuppressWarnings("unused")
public String invoke(FuncallExpression ast, Environment env) throws EvalException {
  env.checkLoadingPhase("native.package_name", ast.getLocation());
  return (String) env.lookup("PACKAGE_NAME");
}