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::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;
}
}