SILGen: Remove usages of SubstitutionMap::combineSubstitutionMaps()

Author: slavapestov

lib/SILGen/SILGenConvert.cpp

@@ -531,17 +531,14 @@ SILGenFunction::emitPointerToPointer(SILLocation loc,
     origValue = emitManagedBufferWithCleanup(origBuf);
   }
   // Invoke the conversion intrinsic to convert to the destination type.
-  auto *proto = getPointerProtocol();
-  auto firstSubMap = inputType->getContextSubstitutionMap(proto);
-  auto secondSubMap = outputType->getContextSubstitutionMap(proto);
+  SmallVector<Type, 2> replacementTypes;
+  replacementTypes.push_back(inputType);
+  replacementTypes.push_back(outputType);
 
   auto genericSig = converter->getGenericSignature();
   auto subMap =
-    SubstitutionMap::combineSubstitutionMaps(firstSubMap,
-                                             secondSubMap,
-                                             CombineSubstitutionMaps::AtIndex,
-                                             1, 0,
-                                             genericSig);
+    SubstitutionMap::get(genericSig, replacementTypes,
+                         LookUpConformanceInModule());
 
   return emitApplyOfLibraryIntrinsic(loc, converter, subMap, origValue, C);
 }

lib/SILGen/SILGenExpr.cpp

@@ -1507,24 +1507,20 @@ RValue SILGenFunction::emitCollectionConversion(SILLocation loc,
                                                 CanType toCollection,
                                                 ManagedValue mv,
                                                 SGFContext C) {
-  auto *fromDecl = fromCollection->getAnyNominal();
-  auto *toDecl = toCollection->getAnyNominal();
+  SmallVector<Type, 4> replacementTypes;
 
-  auto fromSubMap = fromCollection->getContextSubstitutionMap(fromDecl);
-  auto toSubMap = toCollection->getContextSubstitutionMap(toDecl);
+  auto fromArgs = cast<BoundGenericType>(fromCollection)->getGenericArgs();
+  auto toArgs = cast<BoundGenericType>(toCollection)->getGenericArgs();
+  replacementTypes.insert(replacementTypes.end(),
+                          fromArgs.begin(), fromArgs.end());
+  replacementTypes.insert(replacementTypes.end(),
+                          toArgs.begin(), toArgs.end());
 
   // Form type parameter substitutions.
   auto genericSig = fn->getGenericSignature();
-  unsigned fromParamCount = fromDecl->getGenericSignature()
-    .getGenericParams().size();
-
   auto subMap =
-    SubstitutionMap::combineSubstitutionMaps(fromSubMap,
-                                             toSubMap,
-                                             CombineSubstitutionMaps::AtIndex,
-                                             fromParamCount,
-                                             0,
-                                             genericSig);
+    SubstitutionMap::get(genericSig, replacementTypes,
+                         LookUpConformanceInModule());
   return emitApplyOfLibraryIntrinsic(loc, fn, subMap, {mv}, C);
 }
 
@@ -6353,19 +6349,18 @@ SILGenFunction::emitArrayToPointer(SILLocation loc, ManagedValue array,
     assert(array.isLValue());
   }
 
+  diagnoseImplicitRawConversion(accessInfo.ArrayType, accessInfo.PointerType,
+                                loc, *this);
+
   // Invoke the conversion intrinsic, which will produce an owner-pointer pair.
-  auto firstSubMap =
-      accessInfo.ArrayType->getContextSubstitutionMap();
-  auto secondSubMap = accessInfo.PointerType->getContextSubstitutionMap(
-      getPointerProtocol());
+  SmallVector<Type, 2> replacementTypes;
+  replacementTypes.push_back(
+      accessInfo.ArrayType->castTo<BoundGenericStructType>()->getGenericArgs()[0]);
+  replacementTypes.push_back(accessInfo.PointerType);
 
   auto genericSig = converter->getGenericSignature();
-  auto subMap = SubstitutionMap::combineSubstitutionMaps(
-      firstSubMap, secondSubMap, CombineSubstitutionMaps::AtIndex, 1, 0,
-      genericSig);
-
-  diagnoseImplicitRawConversion(accessInfo.ArrayType, accessInfo.PointerType,
-                                loc, *this);
+  auto subMap = SubstitutionMap::get(genericSig, replacementTypes,
+                                     LookUpConformanceInModule());
 
   SmallVector<ManagedValue, 2> resultScalars;
   emitApplyOfLibraryIntrinsic(loc, converter, subMap, array, SGFContext())