SIL: Introduce SameShape requirements in SubstFunctionTypePatternVisitor

Author: slavapestov

lib/SIL/IR/AbstractionPattern.cpp

@@ -1993,9 +1993,21 @@ class SubstFunctionTypePatternVisitor
       return CanType(pack);
     }
 
+    auto substPatternType = visit(pack->getPatternType(),
+                                  pattern.getPackExpansionPatternType());
+    auto substCountType = visit(pack->getCountType(),
+                                pattern.getPackExpansionCountType());
+
+    SmallVector<Type> rootParameterPacks;
+    substPatternType->getTypeParameterPacks(rootParameterPacks);
+
+    for (auto parameterPack : rootParameterPacks) {
+      substRequirements.emplace_back(RequirementKind::SameShape,
+                                     parameterPack, substCountType);
+    }
+
     return CanType(PackExpansionType::get(
-        visit(pack->getPatternType(), pattern.getPackExpansionPatternType()),
-        visit(pack->getCountType(), pattern.getPackExpansionCountType())));
+        substPatternType, substCountType));
   }
 
   CanType visitExistentialType(ExistentialType *exist,

test/SILGen/pack_expansion_type.swift

@@ -14,8 +14,8 @@ public struct VariadicType<each T> {
   // CHECK: bb0(%0 : $*Pack{repeat (each T, each U)}, %1 : $*Pack{repeat each T}, %2 : $*Pack{repeat each U}, %3 : $VariadicType<repeat each T>):
   public func variadicMethod<each U>(t: repeat each T, u: repeat each U) -> (repeat (each T, each U)) {}
 
-  // CHECK-LABEL: sil [ossa] @$s19pack_expansion_type12VariadicTypeV13takesFunction1tyqd__qd__Qp_txxQpXE_tRvd__lF : $@convention(method) <each T><each U> (@guaranteed @noescape @callee_guaranteed @substituted <each τ_0_0, each τ_0_1, each τ_0_2, each τ_0_3> (@pack_guaranteed Pack{repeat each τ_0_0}) -> @pack_out Pack{repeat each τ_0_2} for <Pack{repeat each T}, Pack{repeat each T}, Pack{repeat each U}, Pack{repeat each U}>, VariadicType<repeat each T>) -> () {
-  // CHECK: bb0(%0 : @guaranteed $@noescape @callee_guaranteed @substituted <each τ_0_0, each τ_0_1, each τ_0_2, each τ_0_3> (@pack_guaranteed Pack{repeat each τ_0_0}) -> @pack_out Pack{repeat each τ_0_2} for <Pack{repeat each T}, Pack{repeat each T}, Pack{repeat each U}, Pack{repeat each U}>, %1 : $VariadicType<repeat each T>):
+  // CHECK-LABEL: sil [ossa] @$s19pack_expansion_type12VariadicTypeV13takesFunction1tyqd__qd__Qp_txxQpXE_tRvd__lF : $@convention(method) <each T><each U> (@guaranteed @noescape @callee_guaranteed @substituted <each τ_0_0, each τ_0_1, each τ_0_2, each τ_0_3 where (repeat (each τ_0_0, each τ_0_1)) : Any, (repeat (each τ_0_2, each τ_0_3)) : Any> (@pack_guaranteed Pack{repeat each τ_0_0}) -> @pack_out Pack{repeat each τ_0_2} for <Pack{repeat each T}, Pack{repeat each T}, Pack{repeat each U}, Pack{repeat each U}>, VariadicType<repeat each T>) -> () {
+  // CHECK: bb0(%0 : @guaranteed $@noescape @callee_guaranteed @substituted <each τ_0_0, each τ_0_1, each τ_0_2, each τ_0_3 where (repeat (each τ_0_0, each τ_0_1)) : Any, (repeat (each τ_0_2, each τ_0_3)) : Any> (@pack_guaranteed Pack{repeat each τ_0_0}) -> @pack_out Pack{repeat each τ_0_2} for <Pack{repeat each T}, Pack{repeat each T}, Pack{repeat each U}, Pack{repeat each U}>, %1 : $VariadicType<repeat each T>):
   public func takesFunction<each U>(t: (repeat each T) -> (repeat each U)) {}
 }