Swift: aggregate default output directories

In case the extractor is run in isolation for debugging/testing, this
will avoid littering the current working directory with artifacts, and
instead having a single `extractor-out` directory to inspect or clean
up.

Also extractor logs have been nested into a `swift` directory, as the
log directory provided by the `codeql` cli is actually shared between
languages.

Author: redsun82

swift/extractor/infra/log/SwiftLogging.cpp

@@ -94,7 +94,8 @@ void Log::configure() {
   // as we are configuring logging right now, we collect problems and log them at the end
   auto problems = collectSeverityRulesAndReturnProblems("CODEQL_EXTRACTOR_SWIFT_LOG_LEVELS");
   if (text || binary) {
-    std::filesystem::path logFile = getEnvOr("CODEQL_EXTRACTOR_SWIFT_LOG_DIR", ".");
+    std::filesystem::path logFile = getEnvOr("CODEQL_EXTRACTOR_SWIFT_LOG_DIR", "extractor-out/log");
+    logFile /= "swift";
     logFile /= logRootName;
     logFile /= std::to_string(std::chrono::system_clock::now().time_since_epoch().count());
     std::error_code ec;

swift/extractor/main.cpp

@@ -177,9 +177,11 @@ codeql::TrapDomain invocationTrapDomain(codeql::SwiftExtractorState& state) {
 
 codeql::SwiftExtractorConfiguration configure(int argc, char** argv) {
   codeql::SwiftExtractorConfiguration configuration{};
-  configuration.trapDir = getenv_or("CODEQL_EXTRACTOR_SWIFT_TRAP_DIR", ".");
-  configuration.sourceArchiveDir = getenv_or("CODEQL_EXTRACTOR_SWIFT_SOURCE_ARCHIVE_DIR", ".");
-  configuration.scratchDir = getenv_or("CODEQL_EXTRACTOR_SWIFT_SCRATCH_DIR", ".");
+  configuration.trapDir = getenv_or("CODEQL_EXTRACTOR_SWIFT_TRAP_DIR", "extractor-out/trap/swift");
+  configuration.sourceArchiveDir =
+      getenv_or("CODEQL_EXTRACTOR_SWIFT_SOURCE_ARCHIVE_DIR", "extractor-out/src");
+  configuration.scratchDir =
+      getenv_or("CODEQL_EXTRACTOR_SWIFT_SCRATCH_DIR", "extractor-out/working");
   configuration.frontendOptions.assign(argv + 1, argv + argc);
   return configuration;
 }