Merge remote-tracking branch 'origin/master' into master-rebranch

include/swift/Frontend/FrontendOptions.h

@@ -250,6 +250,9 @@ public:
   /// Should we enable the dependency verifier for all primary files known to this frontend?
   bool EnableIncrementalDependencyVerifier = false;
 
+  /// The path of the swift-frontend executable.
+  std::string MainExecutablePath;
+
   /// The directory path we should use when print #include for the bridging header.
   /// By default, we include ImplicitObjCHeaderPath directly.
   llvm::Optional<std::string> BridgingHeaderDirForPrint;

include/swift/Frontend/ModuleInterfaceLoader.h

@@ -266,10 +266,12 @@ struct ModuleInterfaceLoaderOptions {
   bool remarkOnRebuildFromInterface = false;
   bool disableInterfaceLock = false;
   bool disableImplicitSwiftModule = false;
+  std::string mainExecutablePath;
   ModuleInterfaceLoaderOptions(const FrontendOptions &Opts):
     remarkOnRebuildFromInterface(Opts.RemarkOnRebuildFromModuleInterface),
     disableInterfaceLock(Opts.DisableInterfaceFileLock),
-    disableImplicitSwiftModule(Opts.DisableImplicitModules) {}
+    disableImplicitSwiftModule(Opts.DisableImplicitModules),
+    mainExecutablePath(Opts.MainExecutablePath) {}
   ModuleInterfaceLoaderOptions() = default;
 };
 

lib/Frontend/CompilerInvocation.cpp

@@ -52,6 +52,7 @@ void CompilerInvocation::computeRuntimeResourcePathFromExecutablePath(
 }
 
 void CompilerInvocation::setMainExecutablePath(StringRef Path) {
+  FrontendOpts.MainExecutablePath = Path.str();
   llvm::SmallString<128> LibPath;
   computeRuntimeResourcePathFromExecutablePath(Path, LibPath);
   setRuntimeResourcePath(LibPath.str());

lib/Frontend/ModuleInterfaceLoader.cpp

@@ -1268,6 +1268,7 @@ InterfaceSubContextDelegateImpl::InterfaceSubContextDelegateImpl(
     StringRef prebuiltCachePath,
     bool serializeDependencyHashes,
     bool trackSystemDependencies): SM(SM), Diags(Diags), ArgSaver(Allocator) {
+  subInvocation.setMainExecutablePath(LoaderOpts.mainExecutablePath);
   inheritOptionsForBuildingInterface(searchPathOpts, langOpts);
   // Configure front-end input.
   auto &SubFEOpts = subInvocation.getFrontendOptions();

lib/IRGen/GenDecl.cpp

@@ -1908,11 +1908,7 @@ void irgen::updateLinkageForDefinition(IRGenModule &IGM,
 
   // Everything externally visible is considered used in Swift.
   // That mostly means we need to be good at not marking things external.
-  //
-  // Exclude "main", because it should naturally be used, and because adding it
-  // to llvm.used leaves a dangling use when the REPL attempts to discard
-  // intermediate mains.
-  if (LinkInfo::isUsed(IRL) && global->getName() != SWIFT_ENTRY_POINT_FUNCTION)
+  if (LinkInfo::isUsed(IRL))
     IGM.addUsedGlobal(global);
 }
 
@@ -2003,11 +1999,7 @@ llvm::Function *irgen::createFunction(IRGenModule &IGM,
 
   // Everything externally visible is considered used in Swift.
   // That mostly means we need to be good at not marking things external.
-  //
-  // Exclude "main", because it should naturally be used, and because adding it
-  // to llvm.used leaves a dangling use when the REPL attempts to discard
-  // intermediate mains.
-  if (linkInfo.isUsed() && name != SWIFT_ENTRY_POINT_FUNCTION) {
+  if (linkInfo.isUsed()) {
     IGM.addUsedGlobal(fn);
   }
 

test/IRGen/unused.sil

@@ -3,6 +3,8 @@
 // REQUIRES: CPU=x86_64
 
 sil_stage canonical
+import Builtin
+import Swift
 
 sil private @foo : $@convention(thin) () -> () {
 bb0:
@@ -43,12 +45,20 @@ bb0:
   return %1 : $()
 }
 
-// CHECK-macho: @llvm.used = appending global [2 x i8*] [i8* bitcast (void ()* @frieda to i8*), i8* bitcast (i16* @__swift_reflection_version to i8*)], section "llvm.metadata"
-// CHECK-elf: @llvm.used = appending global [3 x i8*] [i8* bitcast (void ()* @frieda to i8*), i8* bitcast (i16* @__swift_reflection_version to i8*), i8* getelementptr inbounds ([0 x i8], [0 x i8]* @_swift1_autolink_entries, i32 0, i32 0)], section "llvm.metadata"
+sil @main : $@convention(c) (Int32, UnsafeMutablePointer<Optional<UnsafeMutablePointer<Int8>>>) -> Int32 {
+bb0(%0 : $Int32, %1 : $UnsafeMutablePointer<Optional<UnsafeMutablePointer<Int8>>>):
+  %2 = integer_literal $Builtin.Int32, 0          // user: %3
+  %3 = struct $Int32 (%2 : $Builtin.Int32)        // user: %4
+  return %3 : $Int32                              // id: %4
+}
+
+// CHECK-macho: @llvm.used = appending global [3 x i8*] [i8* bitcast (void ()* @frieda to i8*), i8* bitcast (i32 (i32, i8**)* @main to i8*), i8* bitcast (i16* @__swift_reflection_version to i8*)], section "llvm.metadata"
+// CHECK-elf: @llvm.used = appending global [4 x i8*] [i8* bitcast (void ()* @frieda to i8*), i8* bitcast (i32 (i32, i8**)* @main to i8*), i8* bitcast (i16* @__swift_reflection_version to i8*), i8* getelementptr inbounds ([{{[0-9]+}} x i8], [{{[0-9]+}} x i8]* @_swift1_autolink_entries, i32 0, i32 0)], section "llvm.metadata"
 
 // CHECK: define linkonce_odr hidden swiftcc void @qux()
 // CHECK: define hidden swiftcc void @fred()
 // CHECK: define{{( dllexport)?}}{{( protected)?}} swiftcc void @frieda()
+// CHECK: define{{( dllexport)?}}{{( protected)?}} i32 @main
 
 // NEGATIVE-NOT: @foo
 // NEGATIVE-NOT: @bar

test/Runtime/linux-fatal-backtrace.swift

@@ -1,3 +1,4 @@
+// REQUIRES: rdar66283479
 // RUN: %empty-directory(%t)
 // RUN: %target-build-swift %s -o %t/a.out
 // RUN: %{python} %S/../Inputs/not.py "%target-run %t/a.out" 2>&1 | %{lldb-python} %utils/symbolicate-linux-fatal %t/a.out - | %{python} %utils/backtrace-check -u