/**
* Saves byte code to a temporary directory prefixed with "skylarkbytecode" in the system default
* temporary directory.
*/
private void saveByteCode(Unloaded<CompiledFunction> unloadedImplementation) {
if (debugCompiler) {
try {
if (debugFolder == null) {
debugFolder = Files.createTempDirectory("skylarkbytecode").toFile();
}
unloadedImplementation.saveIn(debugFolder);
} catch (IOException e) {
throw new RuntimeException(e);
}
}
}
/**
* Generates a subclass of {@link CompiledFunction} with a static method "call" and static methods
* for getting information from a {@link DebugInfo} instance.
*
* <p>The "call" method contains the compiled version of this function's AST.
*/
private Optional<Method> buildCompiledFunction() throws EvalException {
// replace the / character in the path so we have file system compatible class names
// the java specification mentions that $ should be used in generated code
// see http://docs.oracle.com/javase/specs/jls/se7/html/jls-3.html#jls-3.8
String path =
location.getPath() != null ? location.getPath().getPathString().replace('/', '$') : "";
String compiledFunctionClassName =
CompiledFunction.class.getCanonicalName() + path + "$" + getName();
compilerDebug("Compiling " + getLocationPathAndLine() + " " + getName());
try {
int publicStatic = Visibility.PUBLIC.getMask() | Ownership.STATIC.getMask();
TypeDescription.Latent latentCompiledFunctionClass =
new TypeDescription.Latent(
compiledFunctionClassName,
publicStatic | TypeManifestation.FINAL.getMask(),
new TypeDescription.ForLoadedType(CompiledFunction.class),
Collections.<TypeDescription>emptyList());
MethodDescription getAstNode =
new MethodDescription.Latent(
latentCompiledFunctionClass,
new MethodDescription.Token(
"getAstNode",
publicStatic | MethodManifestation.FINAL.getMask(),
new TypeDescription.ForLoadedType(ASTNode.class),
Arrays.asList(new TypeDescription.ForLoadedType(int.class))));
MethodDescription getLocation =
new MethodDescription.Latent(
latentCompiledFunctionClass,
new MethodDescription.Token(
"getLocation",
publicStatic | MethodManifestation.FINAL.getMask(),
new TypeDescription.ForLoadedType(Location.class),
Arrays.asList(new TypeDescription.ForLoadedType(int.class))));
DebugInfo debugInfo = new DebugInfo(getAstNode, getLocation);
FunctionSignature sig = signature.getSignature();
VariableScope scope = VariableScope.function(sig.getNames());
Implementation compiledImplementation = compileBody(scope, debugInfo);
List<Class<?>> parameterTypes = sig.getShape().toClasses();
parameterTypes.add(Environment.class);
Unloaded<CompiledFunction> unloadedImplementation =
new ByteBuddy()
.withClassVisitor(new StackMapFrameClassVisitor(debugCompilerPrintByteCode))
.subclass(CompiledFunction.class)
.name(compiledFunctionClassName)
.defineMethod(
"call",
Object.class,
parameterTypes,
Visibility.PUBLIC,
Ownership.STATIC,
MethodManifestation.FINAL)
.intercept(compiledImplementation)
.defineMethod(getAstNode)
// TODO(bazel-team) unify the two delegate fields into one, probably needs a custom
// ImplementationDelegate that adds it only once? or just create the static field
// itself with the correct value and create getAstNode & getLocation with a custom
// implementation using it
.intercept(
MethodDelegation.to(debugInfo, DebugInfo.class, "getAstNodeDelegate")
.filter(ElementMatchers.named("getAstNode")))
.defineMethod(getLocation)
.intercept(
MethodDelegation.to(debugInfo, DebugInfo.class, "getLocationDelegate")
.filter(ElementMatchers.named("getLocation")))
.make();
saveByteCode(unloadedImplementation);
Class<? extends CompiledFunction> functionClass =
unloadedImplementation
.load(getClass().getClassLoader(), ClassLoadingStrategy.Default.WRAPPER)
.getLoaded();
return Optional.of(
ReflectionUtils.getMethod(
functionClass,
"call",
parameterTypes.toArray(new Class<?>[parameterTypes.size()]))
.getLoadedMethod());
} catch (EvalException e) {
// don't capture EvalExceptions
throw e;
} catch (Throwable e) {
compilerDebug("Error while compiling", e);
// TODO(bazel-team) don't capture all throwables? couldn't compile this, log somewhere?
}
return Optional.absent();
}
