Frontend: Introduce -experimental-lazy-typecheck action

include/swift/Frontend/FrontendOptions.h

@@ -155,6 +155,7 @@ class FrontendOptions {
     NoneAction,        ///< No specific action
     Parse,             ///< Parse only
     ResolveImports,    ///< Parse and resolve imports only
+    LazyTypecheck,     ///< Parse and then do minimal type-checking for outputs
     Typecheck,         ///< Parse and type-check only
     DumpParse,         ///< Parse only and dump AST
     DumpInterfaceHash, ///< Parse and dump the interface token hash.

include/swift/Option/Options.td

@@ -1160,6 +1160,9 @@ def resolve_imports : Flag<["-"], "resolve-imports">,
 def typecheck : Flag<["-"], "typecheck">,
   HelpText<"Parse and type-check input file(s)">, ModeOpt,
   Flags<[FrontendOption, NoInteractiveOption, DoesNotAffectIncrementalBuild]>;
+def experimental_lazy_typecheck : Flag<["-"], "experimental-lazy-typecheck">,
+  HelpText<"Parse input file(s), then type-check lazily as needed to produce requested outputs">, ModeOpt,
+  Flags<[FrontendOption, NoInteractiveOption, HelpHidden, DoesNotAffectIncrementalBuild]>;
 def dump_parse : Flag<["-"], "dump-parse">,
   HelpText<"Parse input file(s) and dump AST(s)">, ModeOpt,
   Flags<[FrontendOption, NoInteractiveOption, DoesNotAffectIncrementalBuild]>;

lib/Driver/Driver.cpp

@@ -1607,6 +1607,7 @@ void Driver::buildOutputInfo(const ToolChain &TC, const DerivedArgList &Args,
 
     case options::OPT_parse:
     case options::OPT_resolve_imports:
+    case options::OPT_experimental_lazy_typecheck:
     case options::OPT_typecheck:
     case options::OPT_dump_parse:
     case options::OPT_print_ast:

lib/Frontend/ArgsToFrontendOptionsConverter.cpp

@@ -552,6 +552,8 @@ ArgsToFrontendOptionsConverter::determineRequestedAction(const ArgList &args) {
     return FrontendOptions::ActionType::Parse;
   if (Opt.matches(OPT_resolve_imports))
     return FrontendOptions::ActionType::ResolveImports;
+  if (Opt.matches(OPT_experimental_lazy_typecheck))
+    return FrontendOptions::ActionType::LazyTypecheck;
   if (Opt.matches(OPT_typecheck))
     return FrontendOptions::ActionType::Typecheck;
   if (Opt.matches(OPT_dump_parse))

lib/Frontend/FrontendOptions.cpp

@@ -33,6 +33,7 @@ bool FrontendOptions::needsProperModuleName(ActionType action) {
   case ActionType::NoneAction:
   case ActionType::Parse:
   case ActionType::ResolveImports:
+  case ActionType::LazyTypecheck:
   case ActionType::Typecheck:
   case ActionType::DumpParse:
   case ActionType::DumpAST:
@@ -104,6 +105,7 @@ bool FrontendOptions::doesActionRequireSwiftStandardLibrary(ActionType action) {
   case ActionType::PrintFeature:
     return false;
   case ActionType::ResolveImports:
+  case ActionType::LazyTypecheck:
   case ActionType::Typecheck:
   case ActionType::DumpAST:
   case ActionType::PrintAST:
@@ -149,6 +151,7 @@ bool FrontendOptions::doesActionRequireInputs(ActionType action) {
   case ActionType::CompileModuleFromInterface:
   case ActionType::TypecheckModuleFromInterface:
   case ActionType::ResolveImports:
+  case ActionType::LazyTypecheck:
   case ActionType::Typecheck:
   case ActionType::DumpAST:
   case ActionType::PrintAST:
@@ -191,6 +194,7 @@ bool FrontendOptions::doesActionPerformEndOfPipelineActions(ActionType action) {
   case ActionType::CompileModuleFromInterface:
   case ActionType::TypecheckModuleFromInterface:
   case ActionType::ResolveImports:
+  case ActionType::LazyTypecheck:
   case ActionType::Typecheck:
   case ActionType::DumpAST:
   case ActionType::PrintAST:
@@ -230,6 +234,7 @@ bool FrontendOptions::supportCompilationCaching(ActionType action) {
   case ActionType::EmitImportedModules:
   case ActionType::ScanDependencies:
   case ActionType::ResolveImports:
+  case ActionType::LazyTypecheck:
   case ActionType::Typecheck:
   case ActionType::DumpAST:
   case ActionType::PrintAST:
@@ -290,6 +295,7 @@ FrontendOptions::formatForPrincipalOutputFileForAction(ActionType action) {
 
   case ActionType::Parse:
   case ActionType::ResolveImports:
+  case ActionType::LazyTypecheck:
   case ActionType::Typecheck:
   case ActionType::TypecheckModuleFromInterface:
   case ActionType::DumpParse:
@@ -377,6 +383,7 @@ bool FrontendOptions::canActionEmitDependencies(ActionType action) {
   case ActionType::PrintFeature:
     return false;
   case ActionType::ResolveImports:
+  case ActionType::LazyTypecheck:
   case ActionType::Typecheck:
   case ActionType::MergeModules:
   case ActionType::EmitModuleOnly:
@@ -403,6 +410,7 @@ bool FrontendOptions::canActionEmitReferenceDependencies(ActionType action) {
   case ActionType::NoneAction:
   case ActionType::Parse:
   case ActionType::ResolveImports:
+  case ActionType::LazyTypecheck:
   case ActionType::DumpParse:
   case ActionType::DumpInterfaceHash:
   case ActionType::DumpAST:
@@ -445,6 +453,7 @@ bool FrontendOptions::canActionEmitModuleSummary(ActionType action) {
   case ActionType::NoneAction:
   case ActionType::Parse:
   case ActionType::ResolveImports:
+  case ActionType::LazyTypecheck:
   case ActionType::DumpParse:
   case ActionType::DumpInterfaceHash:
   case ActionType::DumpAST:
@@ -506,6 +515,7 @@ bool FrontendOptions::canActionEmitClangHeader(ActionType action) {
   case ActionType::PrintVersion:
   case ActionType::PrintFeature:
     return false;
+  case ActionType::LazyTypecheck:
   case ActionType::Typecheck:
   case ActionType::MergeModules:
   case ActionType::EmitModuleOnly:
@@ -547,6 +557,7 @@ bool FrontendOptions::canActionEmitLoadedModuleTrace(ActionType action) {
   case ActionType::PrintFeature:
     return false;
   case ActionType::ResolveImports:
+  case ActionType::LazyTypecheck:
   case ActionType::Typecheck:
   case ActionType::MergeModules:
   case ActionType::EmitModuleOnly:
@@ -576,6 +587,7 @@ bool FrontendOptions::canActionEmitModuleSemanticInfo(ActionType action) {
   case ActionType::NoneAction:
   case ActionType::Parse:
   case ActionType::ResolveImports:
+  case ActionType::LazyTypecheck:
   case ActionType::DumpParse:
   case ActionType::DumpInterfaceHash:
   case ActionType::DumpAST:
@@ -619,6 +631,7 @@ bool FrontendOptions::canActionEmitConstValues(ActionType action) {
   case ActionType::NoneAction:
   case ActionType::Parse:
   case ActionType::ResolveImports:
+  case ActionType::LazyTypecheck:
   case ActionType::DumpParse:
   case ActionType::DumpInterfaceHash:
   case ActionType::DumpAST:
@@ -660,6 +673,7 @@ bool FrontendOptions::canActionEmitModule(ActionType action) {
   case ActionType::NoneAction:
   case ActionType::Parse:
   case ActionType::ResolveImports:
+  case ActionType::LazyTypecheck:
   case ActionType::Typecheck:
   case ActionType::DumpParse:
   case ActionType::DumpInterfaceHash:
@@ -727,6 +741,7 @@ bool FrontendOptions::canActionEmitInterface(ActionType action) {
   case ActionType::PrintFeature:
     return false;
   case ActionType::ResolveImports:
+  case ActionType::LazyTypecheck:
   case ActionType::Typecheck:
   case ActionType::MergeModules:
   case ActionType::EmitModuleOnly:
@@ -747,6 +762,7 @@ bool FrontendOptions::doesActionProduceOutput(ActionType action) {
   switch (action) {
   case ActionType::Parse:
   case ActionType::ResolveImports:
+  case ActionType::LazyTypecheck:
   case ActionType::Typecheck:
   case ActionType::DumpParse:
   case ActionType::DumpAST:
@@ -805,6 +821,7 @@ bool FrontendOptions::doesActionProduceTextualOutput(ActionType action) {
 
   case ActionType::Parse:
   case ActionType::ResolveImports:
+  case ActionType::LazyTypecheck:
   case ActionType::Typecheck:
   case ActionType::DumpParse:
   case ActionType::DumpInterfaceHash:
@@ -834,6 +851,7 @@ bool FrontendOptions::doesActionGenerateSIL(ActionType action) {
   case ActionType::NoneAction:
   case ActionType::Parse:
   case ActionType::ResolveImports:
+  case ActionType::LazyTypecheck:
   case ActionType::Typecheck:
   case ActionType::DumpParse:
   case ActionType::DumpInterfaceHash:
@@ -885,6 +903,7 @@ bool FrontendOptions::doesActionGenerateIR(ActionType action) {
   case ActionType::DumpTypeInfo:
   case ActionType::CompileModuleFromInterface:
   case ActionType::TypecheckModuleFromInterface:
+  case ActionType::LazyTypecheck:
   case ActionType::Typecheck:
   case ActionType::ResolveImports:
   case ActionType::MergeModules:

lib/FrontendTool/FrontendTool.cpp

@@ -1359,6 +1359,9 @@ static bool performAction(CompilerInstance &Instance,
     return performParseOnly(*Instance.getMainModule());
   case FrontendOptions::ActionType::ResolveImports:
     return Instance.performParseAndResolveImportsOnly();
+  case FrontendOptions::ActionType::LazyTypecheck:
+    // For now, this action is just an alias of ResolveImports.
+    return Instance.performParseAndResolveImportsOnly();
   case FrontendOptions::ActionType::Typecheck:
     return withSemanticAnalysis(Instance, observer,
                                 [](CompilerInstance &Instance) {

test/Driver/emit-interface.swift

@@ -26,3 +26,9 @@
 // CHECK-FILELIST: swift{{(-frontend|c)?(\.exe)?"?}} -frontend
 // CHECK-FILELIST-SAME: -supplementary-output-file-map
 // CHECK-FILELIST-NOT: emit-interface.swift{{ }}
+
+// RUN: %swiftc_driver -driver-print-jobs -target x86_64-apple-macosx10.9 -experimental-lazy-typecheck %s -emit-module-interface -o %t/foo 2>&1 | %FileCheck -check-prefix=CHECK-LAZY-TYPECHECK %s
+
+// CHECK-LAZY-TYPECHECK: swift{{(-frontend|c)?(\.exe)?"?}} -frontend
+// CHECK-LAZY-TYPECHECK-SAME: -experimental-lazy-typecheck
+// CHECK-LAZY-TYPECHECK-SAME: emit-interface.swift

test/ModuleInterface/resolve-imports.swift → test/ModuleInterface/lazy-typecheck.swift

@@ -1,6 +1,7 @@
 // RUN: %empty-directory(%t)
 
 // RUN: %target-swift-frontend -resolve-imports %s -emit-module-interface-path %t/main.swiftinterface -enable-library-evolution
+// RUN: %target-swift-frontend -experimental-lazy-typecheck %s -emit-module-interface-path %t/main.swiftinterface -enable-library-evolution
 // RUN: %FileCheck %s < %t/main.swiftinterface
 
 // CHECK: import Swift
@@ -22,4 +23,4 @@ public class C {}
 // CHECK: }
 
 // Globals
-public var year = 2023
+public var year = 2023

test/TBD/resolve_imports.swift → test/TBD/lazy_typecheck.swift

@@ -1,6 +1,8 @@
 // RUN: %empty-directory(%t)
 // RUN: %target-swift-frontend -resolve-imports -emit-tbd -emit-tbd-path %t/resolve_imports.tbd %s -disable-availability-checking
+// RUN: %target-swift-frontend -experimental-lazy-typecheck -emit-tbd -emit-tbd-path %t/lazy_typecheck.tbd %s -disable-availability-checking
 // RUN: %FileCheck %s < %t/resolve_imports.tbd
+// RUN: %FileCheck %s < %t/lazy_typecheck.tbd
 
 // REQUIRES: OS=macosx 
 
@@ -27,8 +29,17 @@ extension PrivateProto {
 
 public struct S: PrivateProto {}
 
-// CHECK: symbols: [ '_$s15resolve_imports1CCMa', '_$s15resolve_imports1CCMm', 
-// CHECK-NEXT:       '_$s15resolve_imports1CCMn', '_$s15resolve_imports1CCN', '_$s15resolve_imports1CCfD', 
-// CHECK-NEXT:       '_$s15resolve_imports1CCfd', '_$s15resolve_imports1SVMa', 
-// CHECK-NEXT:       '_$s15resolve_imports1SVMn', '_$s15resolve_imports1SVN', '_$s15resolve_imports1SVSQAAMc', 
-// CHECK-NEXT:       '_$s15resolve_imports1SVSQAASQ2eeoiySbx_xtFZTW', _main ]
+// CHECK: symbols: [
+// CHECK: '_$s14lazy_typecheck1CCMa',
+// CHECK: '_$s14lazy_typecheck1CCMm',
+// CHECK: '_$s14lazy_typecheck1CCMn',
+// CHECK: '_$s14lazy_typecheck1CCN',
+// CHECK: '_$s14lazy_typecheck1CCfD',
+// CHECK: '_$s14lazy_typecheck1CCfd',
+// CHECK: '_$s14lazy_typecheck1SVMa',
+// CHECK: '_$s14lazy_typecheck1SVMn',
+// CHECK: '_$s14lazy_typecheck1SVN',
+// CHECK: '_$s14lazy_typecheck1SVSQAAMc',
+// CHECK: '_$s14lazy_typecheck1SVSQAASQ2eeoiySbx_xtFZTW',
+// CHECK: _main
+// CHECK: ]