BuildValue ExternalCommand::
getResultForOutput(Node* node, const BuildValue& value) {
// If the value was a failed or skipped command, propagate the failure.
if (value.isFailedCommand() || value.isSkippedCommand())
return BuildValue::makeFailedInput();
// Otherwise, we should have a successful command -- return the actual
// result for the output.
assert(value.isSuccessfulCommand());
// If the node is virtual, the output is always a virtual input value.
if (static_cast<BuildNode*>(node)->isVirtual()) {
return BuildValue::makeVirtualInput();
}
// Find the index of the output node.
//
// FIXME: This is O(N). We don't expect N to be large in practice, but it
// could be.
auto it = std::find(outputs.begin(), outputs.end(), node);
assert(it != outputs.end());
auto idx = it - outputs.begin();
assert(idx < value.getNumOutputs());
auto& info = value.getNthOutputInfo(idx);
if (info.isMissing())
return BuildValue::makeMissingOutput();
return BuildValue::makeExistingInput(info);
}
void ExternalCommand::providePriorValue(BuildSystemCommandInterface&,
core::Task*,
const BuildValue& value) {
if (value.isSuccessfulCommand()) {
hasPriorResult = true;
priorResultCommandSignature = value.getCommandSignature();
}
}
bool ExternalCommand::isResultValid(BuildSystem& system,
const BuildValue& value) {
// Treat the command as always out-of-date, if requested.
if (alwaysOutOfDate)
return false;
// If the prior value wasn't for a successful command, recompute.
if (!value.isSuccessfulCommand())
return false;
// If the command's signature has changed since it was built, rebuild.
if (value.getCommandSignature() != getSignature())
return false;
// Check the timestamps on each of the outputs.
for (unsigned i = 0, e = outputs.size(); i != e; ++i) {
auto* node = outputs[i];
// Ignore virtual outputs.
if (node->isVirtual())
continue;
// Rebuild if the output information has changed.
//
// We intentionally allow missing outputs here, as long as they haven't
// changed. This is under the assumption that the commands themselves are
// behaving correctly when they exit successfully, and that downstream
// commands would diagnose required missing inputs.
//
// FIXME: CONSISTENCY: One consistency issue in this model currently is that
// if the output was missing, then appears, nothing will remove it; that
// results in an inconsistent build. What would be nice if we supported
// per-edge annotations on whether an output was optional -- in that case we
// could enforce and error on the missing output if not annotated, and we
// could enable behavior to remove such output files if annotated prior to
// running the command.
auto info = node->getFileInfo(system.getDelegate().getFileSystem());
// If this output is mutated by the build, we can't rely on equivalence,
// only existence.
if (node->isMutated()) {
if (value.getNthOutputInfo(i).isMissing() != info.isMissing())
return false;
continue;
}
if (value.getNthOutputInfo(i) != info)
return false;
}
// Otherwise, the result is ok.
return true;
}
bool ExternalCommand::canUpdateIfNewerWithResult(const BuildValue& result) {
// Unless `allowModifiedOutputs` is specified, we always need to update if
// ran.
if (!allowModifiedOutputs)
return false;
// If it was specified, then we can update if all of our outputs simply exist.
for (unsigned i = 0, e = result.getNumOutputs(); i != e; ++i) {
const FileInfo& outputInfo = result.getNthOutputInfo(i);
// If the output is missing, we need to rebuild.
if (outputInfo.isMissing())
return false;
}
return true;
}
void ExternalCommand::provideValue(BuildSystemCommandInterface& bsci,
core::Task*,
uintptr_t inputID,
const BuildValue& value) {
// Process the input value to see if we should skip this command.
// All direct inputs should be individual node values.
assert(!value.hasMultipleOutputs());
assert(value.isExistingInput() || value.isMissingInput() ||
value.isMissingOutput() || value.isFailedInput() ||
value.isVirtualInput());
// Predicate for whether the input should cause the command to skip.
auto shouldSkipForInput = [&] {
// If the value is an existing or virtual input, we are always good.
if (value.isExistingInput() || value.isVirtualInput())
return false;
// We explicitly allow running the command against a missing output, under
// the expectation that responsibility for reporting this situation falls to
// the command.
//
// FIXME: Eventually, it might be nice to harden the format so that we know
// when an output was actually required versus optional.
if (value.isMissingOutput())
return false;
// If the value is a missing input, but those are allowed, it is ok.
if (allowMissingInputs && value.isMissingInput())
return false;
// For anything else, this is an error and the command should be skipped.
return true;
};
// Check if we need to skip the command because of this input.
if (shouldSkipForInput()) {
shouldSkip = true;
if (value.isMissingInput()) {
hasMissingInput = true;
// FIXME: Design the logging and status output APIs.
bsci.getDelegate().error(
"", {}, (Twine("missing input '") + inputs[inputID]->getName() +
"' and no rule to build it"));
}
} else {
// If there is a missing input file (from a successful command), we always
// need to run the command.
if (value.isMissingOutput())
canUpdateIfNewer = false;
}
}
void ExternalCommand::provideValue(BuildSystemCommandInterface& bsci,
core::Task*,
uintptr_t inputID,
const BuildValue& value) {
// Process the input value to see if we should skip this command.
// All direct inputs should be individual node values.
assert(!value.hasMultipleOutputs());
assert(value.isExistingInput() || value.isMissingInput() ||
value.isMissingOutput() || value.isFailedInput() ||
value.isVirtualInput() || value.isSkippedCommand() ||
value.isDirectoryTreeSignature() || value.isStaleFileRemoval());
// If the input should cause this command to skip, how should it skip?
auto getSkipValueForInput = [&]() -> llvm::Optional<BuildValue> {
// If the value is an signature, existing, or virtual input, we are always
// good.
if (value.isDirectoryTreeSignature() | value.isExistingInput() ||
value.isVirtualInput() || value.isStaleFileRemoval())
return llvm::None;
// We explicitly allow running the command against a missing output, under
// the expectation that responsibility for reporting this situation falls to
// the command.
//
// FIXME: Eventually, it might be nice to harden the format so that we know
// when an output was actually required versus optional.
if (value.isMissingOutput())
return llvm::None;
// If the value is a missing input, but those are allowed, it is ok.
if (value.isMissingInput()) {
if (allowMissingInputs)
return llvm::None;
else
return BuildValue::makePropagatedFailureCommand();
}
// Propagate failure.
if (value.isFailedInput())
return BuildValue::makePropagatedFailureCommand();
// A skipped dependency doesn't cause this command to skip.
if (value.isSkippedCommand())
return llvm::None;
llvm_unreachable("unexpected input");
};
// Check if we need to skip the command because of this input.
auto skipValueForInput = getSkipValueForInput();
if (skipValueForInput.hasValue()) {
skipValue = std::move(skipValueForInput);
if (value.isMissingInput()) {
hasMissingInput = true;
// FIXME: Design the logging and status output APIs.
bsci.getDelegate().error(
"", {}, (Twine("missing input '") + inputs[inputID]->getName() +
"' and no rule to build it"));
}
} else {
// If there is a missing input file (from a successful command), we always
// need to run the command.
if (value.isMissingOutput())
canUpdateIfNewer = false;
}
}