[Version] Don't allow effective sub-versions, only major versions

include/swift/AST/DiagnosticsFrontend.def

@@ -97,6 +97,11 @@ ERROR(error_no_source_location_scope_map,none,
   "-dump-scope-maps argument must be 'expanded' or a list of source locations",
   ())
 
+NOTE(note_swift_version_major, none,
+     "use major version, as in '-swift-version %0'", (unsigned))
+NOTE(note_valid_swift_versions, none,
+     "valid arguments to '-swift-version' are %0", (StringRef))
+
 ERROR(error_mode_cannot_emit_dependencies,none,
   "this mode does not support emitting dependency files", ())
 ERROR(error_mode_cannot_emit_header,none,

include/swift/Basic/Version.h

@@ -103,6 +103,9 @@ class Version {
   /// Whether this version is in the Swift 3 family
   bool isVersion3() const { return !empty() && Components[0] == 3; }
 
+  /// Return this Version struct with minor and sub-minor components stripped
+  Version asMajorVersion() const;
+
   /// Parse a version in the form used by the _compiler_version \#if condition.
   static Version parseCompilerVersionString(StringRef VersionString,
                                             SourceLoc Loc,
@@ -124,6 +127,12 @@ class Version {
   /// Returns a version from the currently defined SWIFT_VERSION_MAJOR and
   /// SWIFT_VERSION_MINOR.
   static Version getCurrentLanguageVersion();
+
+  // Whitelist of backward-compatibility versions that we permit passing as
+  // -swift-version <vers>
+  static std::array<StringRef, 2> getValidEffectiveVersions() {
+    return {{"3", "4"}};
+  };
 };
 
 bool operator>=(const Version &lhs, const Version &rhs);

lib/Basic/Version.cpp

@@ -310,29 +310,24 @@ Version::operator clang::VersionTuple() const
   }
 }
 
-bool
-Version::isValidEffectiveLanguageVersion() const
-{
-  // Whitelist of backward-compatibility versions that we permit passing as
-  // -swift-version <vers>
-  char const *whitelist[] = {
-    // Swift 3 family
-    "3",
-    "3.0",
-
-    // Swift 4 family
-    "4",
-    "4.0",
-  };
-  for (auto const i : whitelist) {
-    auto v = parseVersionString(i, SourceLoc(), nullptr);
+bool Version::isValidEffectiveLanguageVersion() const {
+  for (auto verStr : getValidEffectiveVersions()) {
+    auto v = parseVersionString(verStr, SourceLoc(), nullptr);
     assert(v.hasValue());
     if (v == *this)
       return true;
   }
   return false;
 }
 
+Version Version::asMajorVersion() const {
+  if (empty())
+    return {};
+  Version res;
+  res.Components.push_back(Components[0]);
+  return res;
+}
+
 bool operator>=(const class Version &lhs,
                 const class Version &rhs) {
 

lib/Frontend/CompilerInvocation.cpp

@@ -761,6 +761,26 @@ static bool ParseFrontendArgs(FrontendOptions &Opts, ArgList &Args,
   return false;
 }
 
+static void diagnoseSwiftVersion(Optional<version::Version> &vers, Arg *verArg,
+                                 ArgList &Args, DiagnosticEngine &diags) {
+  // General invalid version error
+  diags.diagnose(SourceLoc(), diag::error_invalid_arg_value,
+                 verArg->getAsString(Args), verArg->getValue());
+
+  // Check for an unneeded minor version, otherwise just list valid verions
+  if (vers.hasValue() && !vers.getValue().empty() &&
+      vers.getValue().asMajorVersion().isValidEffectiveLanguageVersion()) {
+    diags.diagnose(SourceLoc(), diag::note_swift_version_major,
+                   vers.getValue()[0]);
+  } else {
+    // Note valid versions instead
+    auto validVers = version::Version::getValidEffectiveVersions();
+    auto versStr =
+        "'" + llvm::join(validVers.begin(), validVers.end(), "', '") + "'";
+    diags.diagnose(SourceLoc(), diag::note_valid_swift_versions, versStr);
+  }
+}
+
 static bool ParseLangArgs(LangOptions &Opts, ArgList &Args,
                           DiagnosticEngine &Diags,
                           const FrontendOptions &FrontendOpts) {
@@ -773,8 +793,7 @@ static bool ParseLangArgs(LangOptions &Opts, ArgList &Args,
         vers.getValue().isValidEffectiveLanguageVersion()) {
       Opts.EffectiveLanguageVersion = vers.getValue();
     } else {
-      Diags.diagnose(SourceLoc(), diag::error_invalid_arg_value,
-                     A->getAsString(Args), A->getValue());
+      diagnoseSwiftVersion(vers, A, Args, Diags);
     }
   }
 

test/APINotes/versioned.swift

@@ -1,8 +1,8 @@
 // RUN: rm -rf %t && mkdir -p %t
 
-// RUN: %target-swift-ide-test  -F %S/Inputs/custom-frameworks -print-module -source-filename %s -module-to-print=APINotesFrameworkTest -function-definitions=false -print-regular-comments -swift-version 4.0 | %FileCheck -check-prefix=CHECK-SWIFT-4 %s 
+// RUN: %target-swift-ide-test  -F %S/Inputs/custom-frameworks -print-module -source-filename %s -module-to-print=APINotesFrameworkTest -function-definitions=false -print-regular-comments -swift-version 4 | %FileCheck -check-prefix=CHECK-SWIFT-4 %s
 
-// RUN: %target-swift-ide-test  -F %S/Inputs/custom-frameworks -print-module -source-filename %s -module-to-print=APINotesFrameworkTest -function-definitions=false -print-regular-comments -swift-version 3.0 | %FileCheck -check-prefix=CHECK-SWIFT-3 %s 
+// RUN: %target-swift-ide-test  -F %S/Inputs/custom-frameworks -print-module -source-filename %s -module-to-print=APINotesFrameworkTest -function-definitions=false -print-regular-comments -swift-version 3 | %FileCheck -check-prefix=CHECK-SWIFT-3 %s
 
 // CHECK-SWIFT-4: func jumpTo(x: Double, y: Double, z: Double)
 // CHECK-SWIFT-3: func jumpTo(x: Double, y: Double, z: Double)

test/Driver/swift-version.swift

@@ -1,11 +1,18 @@
 // RUN: %target-swiftc_driver -swift-version 3 %s
-// RUN: %target-swiftc_driver -swift-version 3.0 %s
+// RUN: not %target-swiftc_driver -swift-version foo %s 2>&1 | %FileCheck --check-prefix BAD %s
 // RUN: not %target-swiftc_driver -swift-version 1 %s 2>&1 | %FileCheck --check-prefix BAD %s
 // RUN: not %target-swiftc_driver -swift-version 2 %s 2>&1 | %FileCheck --check-prefix BAD %s
 // RUN: not %target-swiftc_driver -swift-version 2.3 %s 2>&1 | %FileCheck --check-prefix BAD %s
 // RUN: not %target-swiftc_driver -swift-version 7 %s 2>&1 | %FileCheck --check-prefix BAD %s
 // RUN: not %target-swiftc_driver -swift-version 7.2 %s 2>&1 | %FileCheck --check-prefix BAD %s
+// RUN: not %target-swiftc_driver -swift-version 3.0 %s 2>&1 | %FileCheck --check-prefix FIXIT_3 %s
+// RUN: not %target-swiftc_driver -swift-version 3.3 %s 2>&1 | %FileCheck --check-prefix FIXIT_3 %s
+// RUN: not %target-swiftc_driver -swift-version 4.3 %s 2>&1 | %FileCheck --check-prefix FIXIT_4 %s
 
 // BAD: invalid value
+// BAD: note: valid arguments to '-swift-version' are '3', '4'
+
+// FIXIT_3: use major version, as in '-swift-version 3'
+// FIXIT_4: use major version, as in '-swift-version 4'
 
 let x = 1

test/api-digester/compare-dump.swift

@@ -3,7 +3,7 @@
 // RUN: rm -rf %t.module-cache && mkdir -p %t.module-cache
 // RUN: %swift -emit-module -o %t.mod/cake1.swiftmodule %S/Inputs/cake1.swift -parse-as-library
 // RUN: %swift -emit-module -o %t.mod/cake2.swiftmodule %S/Inputs/cake2.swift -parse-as-library
-// RUN: %api-digester -dump-sdk -module cake1 -o %t.dump1.json -module-cache-path %t.module-cache -sdk %t.sdk -swift-version 3.0 -I %t.mod
-// RUN: %api-digester -dump-sdk -module cake2 -o %t.dump2.json -module-cache-path %t.module-cache -sdk %t.sdk -swift-version 3.0 -I %t.mod
+// RUN: %api-digester -dump-sdk -module cake1 -o %t.dump1.json -module-cache-path %t.module-cache -sdk %t.sdk -swift-version 3 -I %t.mod
+// RUN: %api-digester -dump-sdk -module cake2 -o %t.dump2.json -module-cache-path %t.module-cache -sdk %t.sdk -swift-version 3 -I %t.mod
 // RUN: %api-digester -diagnose-sdk --input-paths %t.dump1.json -input-paths %t.dump2.json > %t.result
 // RUN: diff -u %S/Outputs/Cake.txt %t.result

test/api-digester/dump-module.swift

@@ -2,6 +2,6 @@
 // RUN: rm -rf %t.sdk && mkdir -p %t.sdk
 // RUN: rm -rf %t.module-cache && mkdir -p %t.module-cache
 // RUN: %swift -emit-module -o %t.mod/cake.swiftmodule %S/Inputs/cake.swift -parse-as-library
-// RUN: %api-digester -dump-sdk -module cake -o %t.dump.json -module-cache-path %t.module-cache -sdk %t.sdk -swift-version 3.0 -I %t.mod
+// RUN: %api-digester -dump-sdk -module cake -o %t.dump.json -module-cache-path %t.module-cache -sdk %t.sdk -swift-version 3 -I %t.mod
 // RUN: diff -u %t.dump.json %S/Outputs/cake.json
 // RUN: %api-digester -diagnose-sdk --input-paths %t.dump.json -input-paths %S/Outputs/cake.json

test/api-digester/source-stability.swift

@@ -1,6 +1,6 @@
 // REQUIRES: OS=macosx
 // RUN: rm -rf %S/tmp && mkdir %S/tmp && mkdir %S/tmp/module-cache && mkdir %S/tmp/dummy.sdk
-// RUN: %api-digester -dump-sdk -module Swift -o %S/tmp/current-stdlib.json -module-cache-path %S/tmp/module-cache -sdk %S/tmp/dummy.sdk -swift-version 3.0
+// RUN: %api-digester -dump-sdk -module Swift -o %S/tmp/current-stdlib.json -module-cache-path %S/tmp/module-cache -sdk %S/tmp/dummy.sdk -swift-version 3
 // RUN: %api-digester -diagnose-sdk -input-paths %S/stdlib-stable.json -input-paths %S/tmp/current-stdlib.json >> %S/tmp/changes.txt
 // RUN: %clang -E -P -x c %S/source-stability.swift.expected -o - | sed '/^\s*$/d' > %S/tmp/source-stability.swift.expected
 // RUN: %clang -E -P -x c %S/tmp/changes.txt -o - | sed '/^\s*$/d' > %S/tmp/changes.txt.tmp

test/attr/attr_availability_swift_deserialize.swift

@@ -1,7 +1,7 @@
 // RUN: rm -rf %t && mkdir -p %t
 // RUN: %target-swift-frontend -emit-module -emit-module-path %t/OldAndNew.swiftmodule -module-name OldAndNew %S/Inputs/OldAndNew.swift 
-// RUN: not %target-swift-frontend -parse -I %t -swift-version 3.0 %s 2>&1 | %FileCheck -check-prefix THREE %s
-// RUN: not %target-swift-frontend -parse -I %t -swift-version 4.0 %s 2>&1 | %FileCheck -check-prefix FOUR %s
+// RUN: not %target-swift-frontend -parse -I %t -swift-version 3 %s 2>&1 | %FileCheck -check-prefix THREE %s
+// RUN: not %target-swift-frontend -parse -I %t -swift-version 4 %s 2>&1 | %FileCheck -check-prefix FOUR %s
 
 import OldAndNew