---

yaml
---
r: 340962
b: refs/heads/rxwei-patch-1
c: b39ea60
h: refs/heads/master

Author: dan-zheng

[refs]

@@ -1015,7 +1015,7 @@ refs/tags/swift-DEVELOPMENT-SNAPSHOT-2018-08-18-a: b10b1fce14385faa6d44f6b933e95
 refs/heads/rdar-43033749-fix-batch-mode-no-diags-swift-5.0-branch: a14e64eaad30de89f0f5f0b2a782eed7ecdcb255
 refs/heads/revert-19006-error-bridging-integer-type: 8a9065a3696535305ea53fe9b71f91cbe6702019
 refs/heads/revert-19050-revert-19006-error-bridging-integer-type: ecf752d54b05dd0a20f510f0bfa54a3fec3bcaca
-refs/heads/rxwei-patch-1: bd14b0511465aa769fb2a945cc2dc5660dd197f8
+refs/heads/rxwei-patch-1: b39ea603b896e33f585427a1135cd42535c83c80
 refs/heads/shahmishal-patch-1: e58ec0f7488258d42bef51bc3e6d7b3dc74d7b2a
 refs/heads/typelist-existential: 4046359efd541fb5c72d69a92eefc0a784df8f5e
 refs/tags/swift-4.2-DEVELOPMENT-SNAPSHOT-2018-08-20-a: 4319ba09e4fb8650ee86061075c74a016b6baab9

branches/rxwei-patch-1/lib/SILGen/SILGenPoly.cpp

@@ -3257,19 +3257,23 @@ static ManagedValue createAutoDiffThunk(SILGenFunction &SGF,
 
   auto withoutDifferentiablePattern = [](AbstractionPattern pattern)
       -> AbstractionPattern {
-    auto patternType = cast<AnyFunctionType>(pattern.getType());
+    auto patternType = pattern.getAs<AnyFunctionType>();
+    // If pattern does not store an `AnyFunctionType`, return original pattern.
+    // This logic handles opaque abstraction patterns.
+    if (!patternType)
+      return pattern;
     pattern.rewriteType(
         pattern.getGenericSignature(),
         patternType->getWithoutDifferentiability()->getCanonicalType());
     return pattern;
   };
 
+  auto inputOrigTypeNotDiff = withoutDifferentiablePattern(inputOrigType);
   CanAnyFunctionType inputSubstTypeNotDiff(
       inputSubstType->getWithoutDifferentiability());
-  auto inputOrigTypeNotDiff = withoutDifferentiablePattern(inputOrigType);
+  auto outputOrigTypeNotDiff = withoutDifferentiablePattern(outputOrigType);
   CanAnyFunctionType outputSubstTypeNotDiff(
       outputSubstType->getWithoutDifferentiability());
-  auto outputOrigTypeNotDiff = withoutDifferentiablePattern(outputOrigType);
   auto &expectedTLNotDiff = SGF.getTypeLowering(outputOrigTypeNotDiff,
                                                 outputSubstTypeNotDiff);
   // `autodiff_function_extract` is consuming; copy `fn` before passing as
@@ -3301,18 +3305,21 @@ static ManagedValue createAutoDiffThunk(SILGenFunction &SGF,
   auto getAssocFnPattern =
       [&](AbstractionPattern pattern, AutoDiffAssociatedFunctionKind kind)
           -> AbstractionPattern {
+        // If pattern does not store an `AnyFunctionType`, return original
+        // pattern. This logic handles opaque abstraction patterns.
+        auto patternType = pattern.getAs<AnyFunctionType>();
+        if (!patternType)
+          return pattern;
         return AbstractionPattern(
-            pattern.getGenericSignature(),
-            getAssocFnTy(cast<AnyFunctionType>(pattern.getType()), kind));
+            pattern.getGenericSignature(), getAssocFnTy(patternType, kind));
       };
   auto createAssocFnThunk = [&](AutoDiffAssociatedFunctionKind kind)
       -> ManagedValue {
+    auto assocFnInputOrigType = getAssocFnPattern(inputOrigTypeNotDiff, kind);
     auto assocFnInputSubstType = getAssocFnTy(inputSubstTypeNotDiff, kind);
-    auto assocFnInputOrigType = getAssocFnPattern(inputOrigTypeNotDiff,
-                                                  kind);
-    auto assocFnOutputSubstType = getAssocFnTy(outputSubstTypeNotDiff, kind);
     auto assocFnOutputOrigType = getAssocFnPattern(outputOrigTypeNotDiff,
                                                    kind);
+    auto assocFnOutputSubstType = getAssocFnTy(outputSubstTypeNotDiff, kind);
     auto &assocFnExpectedTL = SGF.getTypeLowering(assocFnOutputOrigType,
                                                   assocFnOutputSubstType);
     // `autodiff_function_extract` is consuming; copy `fn` before passing as

branches/rxwei-patch-1/test/AutoDiff/differentiable_func_sil.swift

@@ -0,0 +1,17 @@
+// RUN: not --crash %target-swift-frontend -emit-sil %s 2>&1
+// REQUIRES: asserts
+
+// NOTE: Remove `not --crash` from RUN line when TF-123 is fixed.
+
+// FIXME(TF-123): `@differentiable` function thunking with opaque
+// abstraction patterns.
+func blackHole(_ x: Any) {}
+let f: @differentiable (Float) -> Float = { $0 }
+blackHole(f)
+
+// FIXME(TF-123): `@differentiable` function thunking with opaque
+// abstraction patterns.
+struct TF_123 {
+  var f: @differentiable (Float) -> Float
+}
+_ = \TF_123.f