IRGen: Put type descriptors in their own section to collocated them

include/swift/AST/IRGenOptions.h

@@ -428,6 +428,9 @@ class IRGenOptions {
   /// Collocate metadata functions in their own section.
   unsigned CollocatedMetadataFunctions : 1;
 
+  /// Colocate type descriptors in their own section.
+  unsigned ColocateTypeDescriptors : 1;
+
   /// Use relative (and constant) protocol witness tables.
   unsigned UseRelativeProtocolWitnessTables : 1;
 
@@ -503,6 +506,7 @@ class IRGenOptions {
         EmitGenericRODatas(false), NoPreallocatedInstantiationCaches(false),
         DisableReadonlyStaticObjects(false),
         CollocatedMetadataFunctions(false),
+        ColocateTypeDescriptors(true),
         UseRelativeProtocolWitnessTables(false), CmdArgs(),
         SanitizeCoverage(llvm::SanitizerCoverageOptions()),
         TypeInfoFilter(TypeInfoDumpFilter::All) {

include/swift/Option/FrontendOptions.td

@@ -1132,6 +1132,13 @@ def disable_collocate_metadata_functions :
   Flag<["-"], "disable-collocate-metadata-functions">,
   HelpText<"Disable collocate metadata functions">;
 
+def enable_colocate_type_descriptors :
+  Flag<["-"], "enable-colocate-type-descriptors">,
+  HelpText<"Enable colocate type descriptors">;
+def disable_colocate_type_descriptors :
+  Flag<["-"], "disable-colocate-type-descriptors">,
+  HelpText<"Disable colocate type descriptors">;
+
 def enable_relative_protocol_witness_tables :
   Flag<["-"], "enable-relative-protocol-witness-tables">,
   HelpText<"Enable relative protocol witness tables">;

lib/Frontend/CompilerInvocation.cpp

@@ -2534,6 +2534,9 @@ static bool ParseIRGenArgs(IRGenOptions &Opts, ArgList &Args,
       Args.hasFlag(OPT_disable_new_llvm_pass_manager,
                    OPT_enable_new_llvm_pass_manager,
                    Opts.LegacyPassManager);
+  Opts.ColocateTypeDescriptors = Args.hasFlag(OPT_enable_colocate_type_descriptors,
+                                              OPT_disable_colocate_type_descriptors,
+                                              Opts.ColocateTypeDescriptors);
   Opts.CollocatedMetadataFunctions =
       Args.hasFlag(OPT_enable_collocate_metadata_functions,
                    OPT_disable_collocate_metadata_functions,

lib/IRGen/GenDecl.cpp

@@ -5980,6 +5980,27 @@ IRGenModule::getOrCreateHelperFunction(StringRef fnName, llvm::Type *resultTy,
   return fn;
 }
 
+void IRGenModule::setColocateTypeDescriptorSection(llvm::GlobalVariable *v) {
+  switch (TargetInfo.OutputObjectFormat) {
+  case llvm::Triple::MachO:
+    if (IRGen.Opts.ColocateTypeDescriptors)
+      v->setSection("__TEXT,__textg_swiftt,regular");
+    else
+      setTrueConstGlobal(v);
+    break;
+  case llvm::Triple::DXContainer:
+  case llvm::Triple::GOFF:
+  case llvm::Triple::SPIRV:
+  case llvm::Triple::UnknownObjectFormat:
+  case llvm::Triple::Wasm:
+  case llvm::Triple::ELF:
+  case llvm::Triple::XCOFF:
+  case llvm::Triple::COFF:
+    setTrueConstGlobal(v);
+    break;
+  }
+
+}
 void IRGenModule::setColocateMetadataSection(llvm::Function *f) {
   if (!IRGen.Opts.CollocatedMetadataFunctions)
     return;

lib/IRGen/GenMeta.cpp

@@ -627,7 +627,7 @@ namespace {
       auto var = cast<llvm::GlobalVariable>(addr);
 
       var->setConstant(true);
-      IGM.setTrueConstGlobal(var);
+      IGM.setColocateTypeDescriptorSection(var);
     }
   };
 
@@ -685,7 +685,7 @@ namespace {
       auto var = cast<llvm::GlobalVariable>(addr);
 
       var->setConstant(true);
-      IGM.setTrueConstGlobal(var);
+      IGM.setColocateTypeDescriptorSection(var);
     }
   };
 
@@ -763,7 +763,7 @@ namespace {
       auto var = cast<llvm::GlobalVariable>(addr);
 
       var->setConstant(true);
-      IGM.setTrueConstGlobal(var);
+      IGM.setColocateTypeDescriptorSection(var);
     }
   };
 
@@ -831,7 +831,7 @@ namespace {
       auto var = cast<llvm::GlobalVariable>(addr);
 
       var->setConstant(true);
-      IGM.setTrueConstGlobal(var);
+      IGM.setColocateTypeDescriptorSection(var);
     }
 
     void addName() {
@@ -1361,7 +1361,7 @@ namespace {
       }
 
       var->setConstant(true);
-      IGM.setTrueConstGlobal(var);
+      IGM.setColocateTypeDescriptorSection(var);
       return var;
     }
 
@@ -2172,7 +2172,7 @@ namespace {
       auto var = cast<llvm::GlobalVariable>(addr);
 
       var->setConstant(true);
-      IGM.setTrueConstGlobal(var);
+      IGM.setColocateTypeDescriptorSection(var);
       IGM.emitOpaqueTypeDescriptorAccessor(O);
     }
 

lib/IRGen/IRGenModule.h

@@ -1588,6 +1588,7 @@ private:                                                                       \
                                       const ProtocolConformance *conformance);
 
   void setColocateMetadataSection(llvm::Function *f);
+  void setColocateTypeDescriptorSection(llvm::GlobalVariable *v);
 
   llvm::Constant *
   getAddrOfTypeMetadata(CanType concreteType,

test/IRGen/class_update_callback_with_stub.swift

@@ -54,7 +54,7 @@ import resilient_objc_class
 // CHECK-SAME: @"$s31class_update_callback_with_stub17ResilientSubclassCACycfC"
 // -- class stub
 // CHECK-SAME: @"$s31class_update_callback_with_stub17ResilientSubclassCMt"
-// CHECK-SAME: }>, section "__TEXT,__const", align 4
+// CHECK-SAME: }>, section "__TEXT,__textg_swiftt,regular", align 4
 
 
 // -- Symbols for full stubs; the address point is one word in, and defined below

test/IRGen/foreign_type_metadata.swift

@@ -8,7 +8,7 @@ import Foundation
 // metadata is not required by this TU. Another TU could require it and the
 // linker could choose the less defined one of the two.
 
-// CHECK: @"$sSo8_NSRangeVMn" = linkonce_odr hidden constant <{ {{.*}}sSo8_NSRangeVMa{{.*}} }>, section "__TEXT,__const"
+// CHECK: @"$sSo8_NSRangeVMn" = linkonce_odr hidden constant <{ {{.*}}sSo8_NSRangeVMa{{.*}} }>, section "__TEXT,__textg_swiftt,regular"
 
 func use(_ closure: @escaping (Int) -> ()) {}
 

test/IRGen/nominal-type-section.swift

@@ -2,7 +2,7 @@
 // RUN: %swift -target x86_64-unknown-linux-gnu -emit-ir -disable-legacy-type-info -parse-stdlib -primary-file %s -module-name main -o - | %FileCheck %s -check-prefix CHECK-ELF
 // RUN: %swift -target x86_64-unknown-windows-itanium -emit-ir -disable-legacy-type-info -parse-stdlib -primary-file %s -module-name main -o - | %FileCheck %s -check-prefix CHECK-COFF
 
-// CHECK-MACHO: @"$s4main1sVMn" = constant {{.*}}, section "__TEXT,__const"
+// CHECK-MACHO: @"$s4main1sVMn" = constant {{.*}}, section "__TEXT,__textg_swiftt,regular"
 // CHECK-ELF: @"$s4main1sVMn" = {{.*}}constant {{.*}}, section ".rodata"
 // CHECK-COFF: @"$s4main1sVMn" = {{.*}}constant {{.*}}, section ".rdata"
 

test/IRGen/objc_implementation.swift

@@ -97,9 +97,9 @@
 // CHECK: [[_DATA_SwiftSubclass:@[^, ]+]] = internal constant { i32, i32, i32, i32, i8*, i8*, { i32, i32, [2 x { i8*, i8*, i8* }] }*, i8*, i8*, i8*, i8* } { i32 128, i32 24, i32 24, i32 0, i8* null, i8* getelementptr inbounds ([41 x i8], [41 x i8]* @.str.40._TtC19objc_implementation13SwiftSubclass, i64 0, i64 0), { i32, i32, [2 x { i8*, i8*, i8* }] }* [[_INSTANCE_METHODS_SwiftSubclass]], i8* null, i8* null, i8* null, i8* null }, section "__DATA, __objc_data", align 8
 
 // Swift metadata
-// CHECK: @"$s19objc_implementationMXM" = linkonce_odr hidden constant <{ i32, i32, i32 }> <{ i32 0, i32 0, i32 trunc (i64 sub (i64 ptrtoint ([20 x i8]* @.str.19.objc_implementation to i64), i64 ptrtoint (i32* getelementptr inbounds (<{ i32, i32, i32 }>, <{ i32, i32, i32 }>* @"$s19objc_implementationMXM", i32 0, i32 2) to i64)) to i32) }>, section "__TEXT,__const", align 4
+// CHECK: @"$s19objc_implementationMXM" = linkonce_odr hidden constant <{ i32, i32, i32 }> <{ i32 0, i32 0, i32 trunc (i64 sub (i64 ptrtoint ([20 x i8]* @.str.19.objc_implementation to i64), i64 ptrtoint (i32* getelementptr inbounds (<{ i32, i32, i32 }>, <{ i32, i32, i32 }>* @"$s19objc_implementationMXM", i32 0, i32 2) to i64)) to i32) }>, section "__TEXT,__textg_swiftt,regular", align 4
 // CHECK: @"symbolic So9ImplClassC" = linkonce_odr hidden constant <{ [13 x i8], i8 }> <{ [13 x i8] c"So9ImplClassC", i8 0 }>, section "__TEXT,__swift5_typeref, regular", align 2
-// CHECK: @"$s19objc_implementation13SwiftSubclassCMn" = constant <{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }> <{ i32 80, i32 trunc (i64 sub (i64 ptrtoint (<{ i32, i32, i32 }>* @"$s19objc_implementationMXM" to i64), i64 ptrtoint (i32* getelementptr inbounds (<{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>, <{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>* @"$s19objc_implementation13SwiftSubclassCMn", i32 0, i32 1) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([14 x i8]* @.str.13.SwiftSubclass to i64), i64 ptrtoint (i32* getelementptr inbounds (<{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>, <{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>* @"$s19objc_implementation13SwiftSubclassCMn", i32 0, i32 2) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (%swift.metadata_response (i64)* @"$s19objc_implementation13SwiftSubclassCMa" to i64), i64 ptrtoint (i32* getelementptr inbounds (<{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>, <{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>* @"$s19objc_implementation13SwiftSubclassCMn", i32 0, i32 3) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ({ i32, i32, i16, i16, i32 }* @"$s19objc_implementation13SwiftSubclassCMF" to i64), i64 ptrtoint (i32* getelementptr inbounds (<{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>, <{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>* @"$s19objc_implementation13SwiftSubclassCMn", i32 0, i32 4) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (<{ [13 x i8], i8 }>* @"symbolic So9ImplClassC" to i64), i64 ptrtoint (i32* getelementptr inbounds (<{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>, <{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>* @"$s19objc_implementation13SwiftSubclassCMn", i32 0, i32 5) to i64)) to i32), i32 3, i32 10, i32 0, i32 0, i32 10 }>, section "__TEXT,__const", align 4
+// CHECK: @"$s19objc_implementation13SwiftSubclassCMn" = constant <{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }> <{ i32 80, i32 trunc (i64 sub (i64 ptrtoint (<{ i32, i32, i32 }>* @"$s19objc_implementationMXM" to i64), i64 ptrtoint (i32* getelementptr inbounds (<{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>, <{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>* @"$s19objc_implementation13SwiftSubclassCMn", i32 0, i32 1) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([14 x i8]* @.str.13.SwiftSubclass to i64), i64 ptrtoint (i32* getelementptr inbounds (<{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>, <{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>* @"$s19objc_implementation13SwiftSubclassCMn", i32 0, i32 2) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (%swift.metadata_response (i64)* @"$s19objc_implementation13SwiftSubclassCMa" to i64), i64 ptrtoint (i32* getelementptr inbounds (<{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>, <{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>* @"$s19objc_implementation13SwiftSubclassCMn", i32 0, i32 3) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ({ i32, i32, i16, i16, i32 }* @"$s19objc_implementation13SwiftSubclassCMF" to i64), i64 ptrtoint (i32* getelementptr inbounds (<{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>, <{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>* @"$s19objc_implementation13SwiftSubclassCMn", i32 0, i32 4) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (<{ [13 x i8], i8 }>* @"symbolic So9ImplClassC" to i64), i64 ptrtoint (i32* getelementptr inbounds (<{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>, <{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>* @"$s19objc_implementation13SwiftSubclassCMn", i32 0, i32 5) to i64)) to i32), i32 3, i32 10, i32 0, i32 0, i32 10 }>, section "__TEXT,__textg_swiftt,regular", align 4
 // CHECK: @"$s19objc_implementation13SwiftSubclassCMf" = internal global <{ i8*, void (%T19objc_implementation13SwiftSubclassC*)*, i8**, i64, %objc_class*, %swift.opaque*, %swift.opaque*, {{i64|%swift.opaque\*}}, i32, i32, i32, i16, i16, i32, i32, <{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>*, i8* }> <{ i8* null, {{.*}}* @"$s19objc_implementation13SwiftSubclassCfD{{(\.ptrauth)?}}"{{( to void \(.*\)\*\))?}}, i8** @"$sBOWV", i64 ptrtoint (%objc_class* @"OBJC_METACLASS_$__TtC19objc_implementation13SwiftSubclass" to i64), %objc_class* bitcast (<{ i64, %objc_class*, %swift.opaque*, %swift.opaque*, { i32, i32, i32, i32, i8*, i8*, { i32, i32, [5 x { i8*, i8*, i8* }] }*, i8*, { i32, i32, [2 x { i64*, i8*, i8*, i32, i32 }] }*, i8*, { i32, i32, [1 x { i8*, i8* }] }* }* }>* @"OBJC_CLASS_$_ImplClass" to %objc_class*), %swift.opaque* @_objc_empty_cache, %swift.opaque* null, {{i64 add \(i64 ptrtoint|%swift.opaque\* bitcast \(i8\* getelementptr \(i8, i8\* bitcast}} ({ i32, i32, i32, i32, i8*, i8*, { i32, i32, [2 x { i8*, i8*, i8* }] }*, i8*, i8*, i8*, i8* }* @_DATA__TtC19objc_implementation13SwiftSubclass to {{i64\), i64 1|i8\*\), i64 1\) to %swift.opaque\*}}), i32 0, i32 0, i32 24, i16 7, i16 0, i32 104, i32 24, <{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>* {{(bitcast \(\{ i8\*, i32, i64, i64 \}\* )?}}@"$s19objc_implementation13SwiftSubclassCMn{{(\.ptrauth)?}}"{{( to <\{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 \}>\*\))?}}, i8* null }>, section "__DATA,__objc_data, regular", align 8
 // CHECK: @"symbolic _____ 19objc_implementation13SwiftSubclassC" = linkonce_odr hidden constant <{ i8, i32, i8 }> <{ i8 1, i32 trunc (i64 sub (i64 ptrtoint (<{ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }>* @"$s19objc_implementation13SwiftSubclassCMn" to i64), i64 ptrtoint (i32* getelementptr inbounds (<{ i8, i32, i8 }>, <{ i8, i32, i8 }>* @"symbolic _____ 19objc_implementation13SwiftSubclassC", i32 0, i32 1) to i64)) to i32), i8 0 }>, section "__TEXT,__swift5_typeref, regular", align 2
 // CHECK: @"$s19objc_implementation13SwiftSubclassCMF" = internal constant { i32, i32, i16, i16, i32 } { i32 trunc (i64 sub (i64 ptrtoint (<{ i8, i32, i8 }>* @"symbolic _____ 19objc_implementation13SwiftSubclassC" to i64), i64 ptrtoint ({ i32, i32, i16, i16, i32 }* @"$s19objc_implementation13SwiftSubclassCMF" to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (<{ [13 x i8], i8 }>* @"symbolic So9ImplClassC" to i64), i64 ptrtoint (i32* getelementptr inbounds ({ i32, i32, i16, i16, i32 }, { i32, i32, i16, i16, i32 }* @"$s19objc_implementation13SwiftSubclassCMF", i32 0, i32 1) to i64)) to i32), i16 7, i16 12, i32 0 }, section "__TEXT,__swift5_fieldmd, regular", align 4