bool migrator::updateCodeAndEmitRemap(CompilerInstance *Instance,
const CompilerInvocation &Invocation) {
// Delete the remap file, in case someone is re-running the Migrator. If the
// file fails to compile and we don't get a chance to overwrite it, the old
// changes may get picked up.
llvm::sys::fs::remove(Invocation.getMigratorOptions().EmitRemapFilePath);
Migrator M { Instance, Invocation }; // Provide inputs and configuration
// Phase 1: Pre Fix-it passes
// These uses the initial frontend invocation to apply any obvious fix-its
// to see if we can get an error-free AST to get to Phase 2.
std::unique_ptr<swift::CompilerInstance> PreFixItInstance;
if (Instance->getASTContext().hadError()) {
PreFixItInstance = M.repeatFixitMigrations(2,
Invocation.getLangOptions().EffectiveLanguageVersion);
// If we still couldn't fix all of the errors, give up.
if (PreFixItInstance == nullptr ||
!PreFixItInstance->hasASTContext() ||
PreFixItInstance->getASTContext().hadError()) {
return true;
}
M.StartInstance = PreFixItInstance.get();
}
// Phase 2: Syntactic Transformations
auto FailedSyntacticPasses = M.performSyntacticPasses();
if (FailedSyntacticPasses) {
return true;
}
// Phase 3: Post Fix-it Passes
// Perform fix-it based migrations on the compiler, some number of times in
// order to give the compiler an opportunity to
// take its time reaching a fixed point.
// This is the end of the pipeline, so we throw away the compiler instance(s)
// we used in these fix-it runs.
if (M.getMigratorOptions().EnableMigratorFixits) {
M.repeatFixitMigrations(Migrator::MaxCompilerFixitPassIterations,
{4, 0, 0});
}
// OK, we have a final resulting text. Now we compare against the input
// to calculate a replacement map describing the changes to the input
// necessary to get the output.
// TODO: Document replacement map format.
auto EmitRemapFailed = M.emitRemap();
auto EmitMigratedFailed = M.emitMigratedFile();
auto DumpMigrationStatesFailed = M.dumpStates();
return EmitRemapFailed || EmitMigratedFailed || DumpMigrationStatesFailed;
}
