Driver: add an option to avoid emitting .swiftsourceinfo files

Author: nkcsgexi

include/swift/Option/Options.td

@@ -419,6 +419,11 @@ def emit_module_interface_path :
          ArgumentIsPath]>,
   MetaVarName<"<path>">, HelpText<"Output module interface file to <path>">;
 
+def avoid_emit_module_source_info :
+  Flag<["-"], "avoid-emit-module-source-info">,
+  Flags<[NoInteractiveOption, DoesNotAffectIncrementalBuild]>,
+  HelpText<"don't emit Swift source info file">;
+
 def emit_module_source_info_path :
   Separate<["-"], "emit-module-source-info-path">,
   Flags<[FrontendOption, NoInteractiveOption, DoesNotAffectIncrementalBuild,

lib/Driver/Driver.cpp

@@ -2718,7 +2718,10 @@ Job *Driver::buildJobsForAction(Compilation &C, const JobAction *JA,
   if (OI.ShouldGenerateModule &&
       (isa<CompileJobAction>(JA) || isa<MergeModuleJobAction>(JA))) {
     chooseSwiftModuleDocOutputPath(C, OutputMap, workingDirectory, Output.get());
-    chooseSwiftSourceInfoOutputPath(C, OutputMap, workingDirectory, Output.get());
+    if (!C.getArgs().hasArg(options::OPT_avoid_emit_module_source_info)) {
+      chooseSwiftSourceInfoOutputPath(C, OutputMap, workingDirectory,
+                                      Output.get());
+    }
   }
 
   if (C.getArgs().hasArg(options::OPT_emit_module_interface,

test/Driver/sourceinfo_file.swift

@@ -14,3 +14,8 @@
 // RUN: %swiftc_driver -driver-print-jobs -emit-module %s -emit-module-path %t/build/sourceinfo_file.swiftmodule -module-name sourceinfo_file -emit-module-source-info-path %t/build/DriverPath.swiftsourceinfo | %FileCheck %s -check-prefix CHECK-DRIVER-OPT
 
 // CHECK-DRIVER-OPT: build{{[/\\]}}DriverPath.swiftsourceinfo
+
+// RUN: %empty-directory(%t/build)
+// RUN: %swiftc_driver -driver-print-jobs -emit-module %s -emit-module-path %t/build/sourceinfo_file.swiftmodule -module-name sourceinfo_file -avoid-emit-module-source-info | %FileCheck %s -check-prefix CHECK-DRIVER-AVOID
+
+// CHECK-DRIVER-AVOID-NOT: swiftsourceinfo