private boolean maybeAddReferenceUsingMode(
NodeTraversal t, FunctionState fs, Node callNode, JSModule module, InliningMode mode) {
// If many functions are inlined into the same function F in the same
// inlining round, then the size of F may exceed the max size.
// This could be avoided if we bail later, during the inlining phase, eg,
// in Inline#visitCallSite. However, that is not safe, because at that
// point expression decomposition has already run, and we want to
// decompose expressions only for the calls that are actually inlined.
if (enforceMaxSizeAfterInlining && targetSizeAfterInlineExceedsLimit(t, fs)) {
return false;
}
Reference candidate = new Reference(callNode, t.getScope(), module, mode);
CanInlineResult result =
injector.canInlineReferenceToFunction(
candidate,
fs.getFn().getFunctionNode(),
fs.getNamesToAlias(),
fs.getReferencesThis(),
fs.hasInnerFunctions());
if (result != CanInlineResult.NO) {
// Yeah!
candidate.setRequiresDecomposition(result == CanInlineResult.AFTER_PREPARATION);
fs.addReference(candidate);
return true;
}
return false;
}
@Override
public void visitCallSite(NodeTraversal t, Node callNode, FunctionState fs) {
Preconditions.checkState(fs.hasExistingFunctionDefinition());
if (fs.canInline()) {
Reference ref = fs.getReference(callNode);
// There are two cases ref can be null: if the call site was introduced
// because it was part of a function that was inlined during this pass
// or if the call site was trimmed from the list of references because
// the function couldn't be inlined at this location.
if (ref != null) {
if (specializationState != null) {
Node containingFunction = getContainingFunction(t);
if (containingFunction != null) {
// Report that the function was specialized so that
// {@link SpecializeModule} can fix it up.
specializationState.reportSpecializedFunction(containingFunction);
}
}
inlineFunction(t, ref, fs);
// Keep track of references that have been inlined so that
// we can verify that none have been missed.
ref.inlined = true;
}
}
}
private boolean maybeAddReferenceUsingMode(
NodeTraversal t, FunctionState fs, Node callNode, JSModule module, InliningMode mode) {
if (specializationState != null) {
// If we're specializing, make sure we can fixup
// the containing function before inlining
Node containingFunction = getContainingFunction(t);
if (containingFunction != null
&& !specializationState.canFixupFunction(containingFunction)) {
return false;
}
}
CanInlineResult result =
injector.canInlineReferenceToFunction(
t,
callNode,
fs.getFn().getFunctionNode(),
fs.getNamesToAlias(),
mode,
fs.getReferencesThis(),
fs.hasInnerFunctions());
if (result != CanInlineResult.NO) {
// Yeah!
boolean decompose = (result == CanInlineResult.AFTER_PREPARATION);
fs.addReference(new Reference(callNode, module, mode, decompose));
return true;
}
return false;
}
/** Remove entries that aren't a valid inline candidates, from the list of encountered names. */
private void trimCandidatesNotMeetingMinimumRequirements() {
Iterator<Entry<String, FunctionState>> i;
for (i = fns.entrySet().iterator(); i.hasNext(); ) {
FunctionState fs = i.next().getValue();
if (!fs.hasExistingFunctionDefinition() || !fs.canInline()) {
i.remove();
}
}
}
/** @see #resolveInlineConflicts */
private void resolveInlineConflictsForFunction(FunctionState fs) {
// Functions that aren't referenced don't cause conflicts.
if (!fs.hasReferences() || !fs.canInline()) {
return;
}
Node fnNode = fs.getFn().getFunctionNode();
Set<String> names = findCalledFunctions(fnNode);
if (!names.isEmpty()) {
// Prevent the removal of the referenced functions.
for (String name : names) {
FunctionState fsCalled = fns.get(name);
if (fsCalled != null && fsCalled.canRemove()) {
fsCalled.setRemove(false);
// For functions that can no longer be removed, check if they should
// still be inlined.
if (!mimimizeCost(fsCalled)) {
// It can't be inlined remove it from the list.
fsCalled.setInline(false);
}
}
}
// Make a copy of the Node, so it isn't changed by other inlines.
fs.setSafeFnNode(fs.getFn().getFunctionNode().cloneTree());
}
}
/** Removed inlined functions that no longer have any references. */
void removeInlinedFunctions() {
for (FunctionState fs : fns.values()) {
if (fs.canRemove()) {
Function fn = fs.getFn();
Preconditions.checkState(fs.canInline());
Preconditions.checkState(fn != null);
verifyAllReferencesInlined(fs);
fn.remove();
}
}
}
/** Inline a function into the call site. */
private void inlineFunction(NodeTraversal t, Reference ref, FunctionState fs) {
Function fn = fs.getFn();
String fnName = fn.getName();
Node fnNode = fs.getSafeFnNode();
Node newExpr = injector.inline(ref, fnName, fnNode);
if (!newExpr.isEquivalentTo(ref.callNode)) {
t.getCompiler().reportChangeToEnclosingScope(newExpr);
}
t.getCompiler().addToDebugLog("Inlined function: " + fn.getName());
}
/**
* For any call-site that needs it, prepare the call-site for inlining by rewriting the containing
* expression.
*/
private void decomposeExpressions() {
for (FunctionState fs : fns.values()) {
if (fs.canInline()) {
for (Reference ref : fs.getReferences()) {
if (ref.requiresDecomposition) {
injector.maybePrepareCall(ref);
}
}
}
}
}
/**
* Determines if the function is worth inlining and potentially trims references that increase the
* cost.
*
* @return Whether inlining the references lowers the overall cost.
*/
private boolean mimimizeCost(FunctionState fs) {
if (!inliningLowersCost(fs)) {
// Try again without Block inlining references
if (fs.hasBlockInliningReferences()) {
fs.setRemove(false);
fs.removeBlockInliningReferences();
if (!fs.hasReferences() || !inliningLowersCost(fs)) {
return false;
}
} else {
return false;
}
}
return true;
}
/** Removed inlined functions that no longer have any references. */
void removeInlinedFunctions() {
for (FunctionState fs : fns.values()) {
if (fs.canRemove()) {
Function fn = fs.getFn();
Preconditions.checkState(fs.canInline());
Preconditions.checkState(fn != null);
verifyAllReferencesInlined(fs);
if (specializationState != null) {
specializationState.reportRemovedFunction(fn.getFunctionNode(), fn.getDeclaringBlock());
}
fn.remove();
}
}
}
/** Remove entries from the list of candidates that can't be inlined. */
private void trimCandidatesUsingOnCost() {
Iterator<Entry<String, FunctionState>> i;
for (i = fns.entrySet().iterator(); i.hasNext(); ) {
FunctionState fs = i.next().getValue();
if (fs.hasReferences()) {
// Only inline function if it decreases the code size.
boolean lowersCost = mimimizeCost(fs);
if (!lowersCost) {
// It shouldn't be inlined; remove it from the list.
i.remove();
}
} else if (!fs.canRemove()) {
// Don't bother tracking functions without references that can't be
// removed.
i.remove();
}
}
}
/** Find functions that can be inlined. */
private void checkNameUsage(Node n, Node parent) {
Preconditions.checkState(n.isName());
if (isCandidateUsage(n)) {
return;
}
// Other refs to a function name remove its candidacy for inlining
String name = n.getString();
FunctionState fs = fns.get(name);
if (fs == null) {
return;
}
// Unlike normal call/new parameters, references passed to
// JSCompiler_ObjectPropertyString are not aliases of a value, but
// a reference to the name itself, as such the value of the name is
// unknown and can not be inlined.
if (parent.isNew()) {
Node target = parent.getFirstChild();
if (target.isName()
&& target
.getString()
.equals(ObjectPropertyStringPreprocess.EXTERN_OBJECT_PROPERTY_STRING)) {
// This method is going to be replaced so don't inline it anywhere.
fs.setInline(false);
}
}
// If the name is being assigned to it can not be inlined.
if (parent.isAssign() && parent.getFirstChild() == n) {
// e.g. bar = something; <== we can't inline "bar"
// so mark the function as uninlinable.
// TODO(johnlenz): Should we just remove it from fns here?
fs.setInline(false);
} else {
// e.g. var fn = bar; <== we can't inline "bar"
// As this reference can't be inlined mark the function as
// unremovable.
fs.setRemove(false);
}
}
/** Sanity check to verify, that expression rewriting didn't make a call inaccessible. */
void verifyAllReferencesInlined(FunctionState fs) {
for (Reference ref : fs.getReferences()) {
if (!ref.inlined) {
throw new IllegalStateException(
"Call site missed.\n call: "
+ ref.callNode.toStringTree()
+ "\n parent: "
+ ref.callNode.getParent().toStringTree());
}
}
}
void maybeAddReference(NodeTraversal t, FunctionState fs, Node callNode, JSModule module) {
if (!fs.canInline()) {
return;
}
InliningMode mode = fs.canInlineDirectly() ? InliningMode.DIRECT : InliningMode.BLOCK;
boolean referenceAdded = maybeAddReferenceUsingMode(t, fs, callNode, module, mode);
if (!referenceAdded && mode == InliningMode.DIRECT && blockFunctionInliningEnabled) {
// This reference can not be directly inlined, see if
// block replacement inlining is possible.
mode = InliningMode.BLOCK;
referenceAdded = maybeAddReferenceUsingMode(t, fs, callNode, module, mode);
}
if (!referenceAdded) {
// Don't try to remove a function if we can't inline all
// the references.
fs.setRemove(false);
}
}
/** @return Whether inlining the function reduces code size. */
private boolean inliningLowersCost(FunctionState fs) {
return injector.inliningLowersCost(
fs.getModule(),
fs.getFn().getFunctionNode(),
fs.getReferences(),
fs.getNamesToAlias(),
fs.canRemove(),
fs.getReferencesThis());
}
private boolean targetSizeAfterInlineExceedsLimit(NodeTraversal t, FunctionState fs) {
Node containingFunction = getContainingFunction(t);
// Always inline at the top level,
// unless maybeAddFunction has marked fs as not inlinable.
if (containingFunction == null) {
return false;
}
Node inlinedFun = fs.getFn().getFunctionNode();
if (isAlwaysInlinable(inlinedFun)) {
return false;
}
int inlinedFunSize =
NodeUtil.countAstSizeUpToLimit(NodeUtil.getFunctionBody(inlinedFun), maxSizeAfterInlining);
int targetFunSize = NodeUtil.countAstSizeUpToLimit(containingFunction, maxSizeAfterInlining);
return inlinedFunSize + targetFunSize > maxSizeAfterInlining;
}
/**
* 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);
}
}
}
}
