SIL: Consistently drop substitution map when forming apply instructions

Fixes rdar://129298104.

Author: slavapestov

include/swift/SIL/SILInstruction.h

@@ -2678,6 +2678,8 @@ class ApplyInstBase<Impl, Base, false> : public Base {
         SpecializationInfo(specializationInfo), NumCallArguments(args.size()),
         NumTypeDependentOperands(typeDependentOperands.size()),
         Substitutions(subs) {
+    assert(!!subs == !!callee->getType().castTo<SILFunctionType>()
+        ->getInvocationGenericSignature());
 
     // Initialize the operands.
     auto allOperands = getAllOperands();

lib/SILGen/SILGenApply.cpp

@@ -1886,6 +1886,11 @@ static void emitRawApply(SILGenFunction &SGF,
                          SILValue indirectErrorAddr,
                          SmallVectorImpl<SILValue> &rawResults,
                          ExecutorBreadcrumb prevExecutor) {
+  // We completely drop the generic signature if all generic parameters were
+  // concrete.
+  if (subs && subs.getGenericSignature()->areAllParamsConcrete())
+    subs = SubstitutionMap();
+
   SILFunctionConventions substFnConv(substFnType, SGF.SGM.M);
   // Get the callee value.
   bool isConsumed = substFnType->isCalleeConsumed();
@@ -5857,6 +5862,11 @@ SILValue SILGenFunction::emitApplyWithRethrow(SILLocation loc, SILValue fn,
                                               SILType substFnType,
                                               SubstitutionMap subs,
                                               ArrayRef<SILValue> args) {
+  // We completely drop the generic signature if all generic parameters were
+  // concrete.
+  if (subs && subs.getGenericSignature()->areAllParamsConcrete())
+    subs = SubstitutionMap();
+
   CanSILFunctionType silFnType = substFnType.castTo<SILFunctionType>();
   SILFunctionConventions fnConv(silFnType, SGM.M);
   SILType resultType = fnConv.getSILResultType(getTypeExpansionContext());

lib/SILGen/SILGenDestructor.cpp

@@ -118,9 +118,16 @@ void SILGenFunction::emitDestroyingDestructor(DestructorDecl *dd) {
     SILValue baseSelf = B.createUpcast(cleanupLoc, selfValue, baseSILTy);
     ManagedValue dtorValue;
     SILType dtorTy;
+
     auto subMap
       = superclassTy->getContextSubstitutionMap(SGM.M.getSwiftModule(),
                                                 superclass);
+
+    // We completely drop the generic signature if all generic parameters were
+    // concrete.
+    if (subMap && subMap.getGenericSignature()->areAllParamsConcrete())
+      subMap = SubstitutionMap();
+
     std::tie(dtorValue, dtorTy)
       = emitSiblingMethodRef(cleanupLoc, baseSelf, dtorConstant, subMap);
 
@@ -191,12 +198,11 @@ void SILGenFunction::emitDeallocatingClassDestructor(DestructorDecl *dd) {
   // Form a reference to the destroying destructor.
   SILDeclRef dtorConstant(dd, SILDeclRef::Kind::Destroyer);
   auto classTy = initialSelfValue->getType();
-  auto classDecl = classTy.getASTType()->getAnyNominal();
+
+  auto subMap = F.getForwardingSubstitutionMap();
+
   ManagedValue dtorValue;
   SILType dtorTy;
-  auto subMap = classTy.getASTType()
-    ->getContextSubstitutionMap(SGM.M.getSwiftModule(),
-                                classDecl);
   std::tie(dtorValue, dtorTy)
     = emitSiblingMethodRef(loc, initialSelfValue, dtorConstant, subMap);
 

lib/SILGen/SILGenFunction.cpp

@@ -987,7 +987,13 @@ SILGenFunction::emitClosureValue(SILLocation loc, SILDeclRef constant,
         constant, loweredCaptureInfo, subs);
   }
 
-  if (subs) {
+  // We completely drop the generic signature if all generic parameters were
+  // concrete.
+  if (!pft->isPolymorphic()) {
+    subs = SubstitutionMap();
+  } else {
+    assert(!subs.getGenericSignature()->areAllParamsConcrete());
+
     auto specialized =
         pft->substGenericArgs(F.getModule(), subs, getTypeExpansionContext());
     functionTy = SILType::getPrimitiveObjectType(specialized);

test/SILOptimizer/performance-annotations-noassert-stdlib.swift

@@ -0,0 +1,9 @@
+// RUN: %target-swift-frontend -parse-as-library -disable-availability-checking -import-objc-header %S/Inputs/perf-annotations.h -emit-sil %s -o /dev/null -verify
+
+// REQUIRES: swift_in_compiler
+// REQUIRES: swift_stdlib_no_asserts,optimized_stdlib
+
+@_noAllocation
+func createEmptyArray() {
+  _ = [Int]() // expected-error {{ending the lifetime of a value of type}}
+}

test/SILOptimizer/performance-annotations.swift

@@ -1,6 +1,7 @@
 // RUN: %target-swift-frontend -parse-as-library -disable-availability-checking -enable-experimental-feature RawLayout -import-objc-header %S/Inputs/perf-annotations.h -emit-sil %s -o /dev/null -verify
-// REQUIRES: swift_stdlib_no_asserts,optimized_stdlib
+
 // REQUIRES: swift_in_compiler
+// REQUIRES: optimized_stdlib
 
 protocol P {
   func protoMethod(_ a: Int) -> Int
@@ -233,11 +234,6 @@ func closueWhichModifiesLocalVar() -> Int {
   return x
 }
 
-@_noAllocation
-func createEmptyArray() {
-  _ = [Int]() // expected-error {{ending the lifetime of a value of type}}
-}
-
 struct Buffer {
   var p: UnsafeMutableRawBufferPointer
 
@@ -527,3 +523,35 @@ public struct RawLayoutWrapper: ~Copyable {
 public struct RawLayout<T>: ~Copyable {
   public func test() {}
 }
+
+func takesClosure(_: () -> ()) {}
+
+@_noLocks
+func testClosureExpression<T>(_ t: T) {
+  takesClosure {
+  // expected-error@-1 {{generic closures or local functions can cause metadata allocation or locks}}
+    _ = T.self
+  }
+}
+
+@_noLocks
+func testLocalFunction<T>(_ t: T) {
+  func localFunc() {
+    _ = T.self
+  }
+
+  takesClosure(localFunc)
+  // expected-error@-1 {{generic closures or local functions can cause metadata allocation or locks}}
+}
+
+func takesGInt(_ x: G<Int>) {}
+
+struct G<T> {}
+
+extension G where T == Int {
+  @_noAllocation func method() {
+    takesClosure {
+      takesGInt(self) // OK
+    }
+  }
+}