Merge pull request #59623 from rxwei/cherry-42611 (#61793)

* Merge pull request #59623 from rxwei/cherry-42611

* Fixup switch.swift test from bad merge.

Co-authored-by: Richard Wei <[email protected]>

Author: stephentyrone

lib/Frontend/CompilerInvocation.cpp

@@ -496,6 +496,27 @@ static bool ParseLangArgs(LangOptions &Opts, ArgList &Args,
       = A->getOption().matches(OPT_enable_deserialization_recovery);
   }
 
+  // Whether '/.../' regex literals are enabled. This implies experimental
+  // string processing.
+  if (Args.hasArg(OPT_enable_bare_slash_regex)) {
+    Opts.EnableBareSlashRegexLiterals = true;
+    Opts.EnableExperimentalStringProcessing = true;
+  }
+
+  // Experimental string processing.
+  if (auto A = Args.getLastArg(OPT_enable_experimental_string_processing,
+                               OPT_disable_experimental_string_processing)) {
+    Opts.EnableExperimentalStringProcessing =
+        A->getOption().matches(OPT_enable_experimental_string_processing);
+
+    // When experimental string processing is explicitly disabled, also disable
+    // forward slash regex `/.../`.
+    if (!Opts.EnableExperimentalStringProcessing)
+      Opts.EnableBareSlashRegexLiterals = false;
+  } else {
+    Opts.EnableExperimentalStringProcessing = true;
+  }
+
   Opts.DisableAvailabilityChecking |=
       Args.hasArg(OPT_disable_availability_checking);
   Opts.CheckAPIAvailabilityOnly |=

stdlib/cmake/modules/AddSwiftStdlib.cmake

@@ -1787,6 +1787,12 @@ function(add_swift_target_library name)
                       "-Xfrontend;-disable-implicit-string-processing-module-import")
   endif()
 
+  # Turn off implicit import of _StringProcessing when building libraries
+  if(SWIFT_ENABLE_EXPERIMENTAL_STRING_PROCESSING)
+    list(APPEND SWIFTLIB_SWIFT_COMPILE_FLAGS
+                      "-Xfrontend;-disable-implicit-string-processing-module-import")
+  endif()
+
   if(SWIFTLIB_IS_STDLIB AND SWIFT_STDLIB_ENABLE_PRESPECIALIZATION)
     list(APPEND SWIFTLIB_SWIFT_COMPILE_FLAGS "-Xfrontend;-prespecialize-generic-metadata")
   endif()

test/Parse/switch.swift

@@ -336,9 +336,9 @@ func f1(x: String, y: Whichever) {
         break
     case Whichever.buzz: // expected-error {{type 'Whichever' has no member 'buzz'}}
         break
+    // expected-note @+1 {{overloads for '~=' exist with these partially matching parameter lists: (Substring, String)}}
     case Whichever.alias: // expected-error {{expression pattern of type 'Whichever' cannot match values of type 'String'}}
-    // expected-note@-1 {{overloads for '~=' exist}}
-    // expected-error@-2 {{'case' label in a 'switch' must have at least one executable statement}}
+    // expected-error@-1 {{'case' label in a 'switch' must have at least one executable statement}}
     default:
       break
   }

test/SourceKit/InterfaceGen/gen_swift_module.swift

@@ -14,7 +14,7 @@ func f(s : inout [Int]) {
 // GROUP-EMPTY: <GROUPS>
 // GROUP-EMPTY-NEXT: <\GROUPS>
 
-// RUN: %swift -emit-module -o %t.mod/swift_mod_syn.swiftmodule %S/Inputs/swift_mod_syn.swift -parse-as-library -disable-implicit-concurrency-module-import
+// RUN: %swift -emit-module -o %t.mod/swift_mod_syn.swiftmodule %S/Inputs/swift_mod_syn.swift -parse-as-library -disable-implicit-concurrency-module-import -disable-implicit-string-processing-module-import
 // RUN: %sourcekitd-test -req=interface-gen-open -module swift_mod_syn -- -Xfrontend -disable-implicit-concurrency-module-import -Xfrontend -disable-implicit-string-processing-module-import  -I %t.mod == -req=cursor -pos=4:7 %s -- -Xfrontend -disable-implicit-concurrency-module-import -Xfrontend -disable-implicit-string-processing-module-import  %s -I %t.mod | %FileCheck -check-prefix=SYNTHESIZED-USR1 %s
 // SYNTHESIZED-USR1: s:SMsSkRzSL7ElementSTRpzrlE4sortyyF::SYNTHESIZED::s:Sa