/**
* Inline a function that fulfills the requirements of canInlineReferenceDirectly into the call
* site, replacing only the CALL node.
*/
private Node inlineReturnValue(Node callNode, Node fnNode) {
Node block = fnNode.getLastChild();
Node callParentNode = callNode.getParent();
// NOTE: As the normalize pass guarantees globals aren't being
// shadowed and an expression can't introduce new names, there is
// no need to check for conflicts.
// Create an argName -> expression map, checking for side effects.
Map<String, Node> argMap =
FunctionArgumentInjector.getFunctionCallParameterMap(
fnNode, callNode, this.safeNameIdSupplier);
Node newExpression;
if (!block.hasChildren()) {
Node srcLocation = block;
newExpression = NodeUtil.newUndefinedNode(srcLocation);
} else {
Node returnNode = block.getFirstChild();
Preconditions.checkArgument(returnNode.getType() == Token.RETURN);
// Clone the return node first.
Node safeReturnNode = returnNode.cloneTree();
Node inlineResult = FunctionArgumentInjector.inject(safeReturnNode, null, argMap);
Preconditions.checkArgument(safeReturnNode == inlineResult);
newExpression = safeReturnNode.removeFirstChild();
}
callParentNode.replaceChild(callNode, newExpression);
return newExpression;
}
/**
* Determines whether a function can be inlined at a particular call site. - Don't inline if the
* calling function contains an inner function and inlining would introduce new globals.
*/
private boolean callMeetsBlockInliningRequirements(
NodeTraversal t, Node callNode, Node fnNode, Set<String> namesToAlias) {
// Note: functions that contain function definitions are filtered out
// in isCanidateFunction.
// TODO(johnlenz): Determining if the called function contains VARs
// or if the caller contains inner functions accounts for 20% of the
// runtime cost of this pass.
// Don't inline functions with var declarations into a scope with inner
// functions as the new vars would leak into the inner function and
// cause memory leaks.
boolean fnContainsVars =
NodeUtil.has(
NodeUtil.getFunctionBody(fnNode),
new NodeUtil.MatchDeclaration(),
new NodeUtil.MatchShallowStatement());
boolean callerContainsFunction = false;
if (!t.inGlobalScope()) {
Node fnCaller = t.getScopeRoot();
Node fnCallerBody = fnCaller.getLastChild();
callerContainsFunction = NodeUtil.containsFunction(fnCallerBody);
}
if (fnContainsVars && callerContainsFunction) {
return false;
}
// If the caller contains functions, verify we aren't adding any
// additional VAR declarations because aliasing is needed.
if (callerContainsFunction) {
Map<String, Node> args =
FunctionArgumentInjector.getFunctionCallParameterMap(
fnNode, callNode, this.safeNameIdSupplier);
boolean hasArgs = !args.isEmpty();
if (hasArgs) {
// Limit the inlining
Set<String> allNamesToAlias = Sets.newHashSet(namesToAlias);
FunctionArgumentInjector.maybeAddTempsForCallArguments(
fnNode, args, allNamesToAlias, compiler.getCodingConvention());
if (!allNamesToAlias.isEmpty()) {
return false;
}
}
}
return true;
}
/**
* Updates the FunctionState object for the given function. Checks if the given function matches
* the criteria for an inlinable function.
*/
private void maybeAddFunction(Function fn, JSModule module) {
String name = fn.getName();
FunctionState fs = getOrCreateFunctionState(name);
// TODO(johnlenz): Maybe "smarten" FunctionState by adding this logic
// to it?
// If the function has multiple definitions, don't inline it.
if (fs.hasExistingFunctionDefinition()) {
fs.setInline(false);
return;
}
Node fnNode = fn.getFunctionNode();
if (enforceMaxSizeAfterInlining
&& !isAlwaysInlinable(fnNode)
&& maxSizeAfterInlining <= NodeUtil.countAstSizeUpToLimit(fnNode, maxSizeAfterInlining)) {
fs.setInline(false);
return;
}
// verify the function hasn't already been marked as "don't inline"
if (fs.canInline()) {
// store it for use when inlining.
fs.setFn(fn);
if (FunctionInjector.isDirectCallNodeReplacementPossible(fn.getFunctionNode())) {
fs.inlineDirectly(true);
}
// verify the function meets all the requirements.
// TODO(johnlenz): Minimum requirement checks are about 5% of the
// run-time cost of this pass.
if (!isCandidateFunction(fn)) {
// It doesn't meet the requirements.
fs.setInline(false);
}
// Set the module and gather names that need temporaries.
if (fs.canInline()) {
fs.setModule(module);
Set<String> namesToAlias = FunctionArgumentInjector.findModifiedParameters(fnNode);
if (!namesToAlias.isEmpty()) {
fs.inlineDirectly(false);
fs.setNamesToAlias(namesToAlias);
}
Node block = NodeUtil.getFunctionBody(fnNode);
if (NodeUtil.referencesThis(block)) {
fs.setReferencesThis(true);
}
if (NodeUtil.containsFunction(block)) {
fs.setHasInnerFunctions(true);
// If there are inner functions, we can inline into global scope
// if there are no local vars or named functions.
// TODO(johnlenz): this can be improved by looking at the possible
// values for locals. If there are simple values, or constants
// we could still inline.
if (!assumeMinimumCapture && hasLocalNames(fnNode)) {
fs.setInline(false);
}
}
}
// Check if block inlining is allowed.
if (fs.canInline() && !fs.canInlineDirectly()) {
if (!blockFunctionInliningEnabled) {
fs.setInline(false);
}
}
}
}