Merge pull request #39493 from allevato/fix-new-driver-response-file

Propagate response files correctly to the new driver.

Author: allevato

lib/DriverTool/driver.cpp

@@ -184,7 +184,8 @@ static bool appendSwiftDriverName(SmallString<256> &buffer) {
 }
 
 static int run_driver(StringRef ExecName,
-                       const ArrayRef<const char *> argv) {
+                       const ArrayRef<const char *> argv,
+                       const ArrayRef<const char *> originalArgv) {
   // This is done here and not done in FrontendTool.cpp, because
   // FrontendTool.cpp is linked to tools, which don't use swift modules.
   initializeSwiftModules();
@@ -244,7 +245,8 @@ static int run_driver(StringRef ExecName,
       subCommandArgs.push_back(NewDriverPath.c_str());
 
       // Push on the source program arguments
-      subCommandArgs.insert(subCommandArgs.end(), argv.begin() + 1, argv.end());
+      subCommandArgs.insert(subCommandArgs.end(),
+                            originalArgv.begin() + 1, originalArgv.end());
 
       // Execute the subcommand.
       subCommandArgs.push_back(nullptr);
@@ -393,12 +395,13 @@ int swift::mainEntry(int argc_, const char **argv_) {
     return 2;
   }
 
+  ArrayRef<const char *> originalArgv(argv_, &argv_[argc_]);
   if (isRepl) {
     // Preserve argv for the stack trace.
     SmallVector<const char *, 256> replArgs(argv.begin(), argv.end());
     replArgs.erase(&replArgs[1]);
-    return run_driver(ExecName, replArgs);
+    return run_driver(ExecName, replArgs, originalArgv);
   } else {
-    return run_driver(ExecName, argv);
+    return run_driver(ExecName, argv, originalArgv);
   }
 }

test/Driver/LegacyDriver/Inputs/print-args.sh

@@ -0,0 +1,5 @@
+#!/usr/bin/env sh
+
+for arg in "$@" ; do
+  echo "$arg"
+done

test/Driver/LegacyDriver/legacy-driver-propagates-response-file-to-new-driver.swift

@@ -0,0 +1,17 @@
+// Verify that when the legacy driver (swift-frontend executable invoked as
+// swiftc) spawns the new driver, it passes the original arguments (i.e.,
+// preserving response files) instead of trying to spawn the process with the
+// expansion, which may exceed `ARG_MAX`.
+
+// REQUIRES: shell
+// RUN: %{python} -c 'for i in range(500001): print("-DTEST5_" + str(i))' > %t.resp
+// RUN: cp %S/Inputs/print-args.sh %swift_obj_root/bin/legacy-driver-propagates-response-file.sh
+// RUN: env SWIFT_USE_NEW_DRIVER=legacy-driver-propagates-response-file.sh %swiftc_driver_plain %s @%t.resp | %FileCheck %s
+// RUN: rm %swift_obj_root/bin/legacy-driver-propagates-response-file.sh
+
+// CHECK:      -Xfrontend
+// CHECK-NEXT: -new-driver-path
+// CHECK-NEXT: -Xfrontend
+// CHECK-NEXT: legacy-driver-propagates-response-file.sh
+// CHECK:      @{{.*}}.resp
+// CHECK-NOT:  -DTEST5_{{.*}}

test/Driver/LegacyDriver/lit.local.cfg

@@ -0,0 +1,7 @@
+# Make a local copy of the environment.
+config.environment = dict(config.environment)
+
+# Remove the settings that force tests to use the old driver so that tests
+# in this directory can set `SWIFT_USE_NEW_DRIVER` to test those code paths.
+del config.environment['SWIFT_USE_OLD_DRIVER']
+del config.environment['SWIFT_AVOID_WARNING_USING_OLD_DRIVER']