From 5b3a7e563e8b3b8da4c8e6f359fcd45dce873d70 Mon Sep 17 00:00:00 2001
From: Anthony Latsis <alatsis@apple.com>
Date: Wed, 10 Sep 2025 04:06:20 +0100
Subject: [PATCH] [test] Adjust `api-digester/dump-module.swift` for rebranch

The API digester queries the top-level declarations for the Swift module
`cake`. The first file in that module is a `ClangModuleUnit`, so we
proceed to import that file into Swift. The clang importer fetches the
lookup table, then looks up and imports everything in it.

rebranch:
1. The lookup table ends up containing `__Int64x2_t`, a new "neon vector
   type". These are not built-in types, but neither are they declared
   anywhere. You express them using an attribute combined with an
   integral type, e.g. `__attribute__((neon_vector_type(8))) int8_t`.
   For whatever reason, these types are for AArch64 only, which explains
   why we don't see the test failure on x86 runners.
2. The neon vector type is imported via
   `SwiftTypeConverter::VisitVectorType`, where we use
   `NominalTypeDecl::lookupConformance` to verify that the vector type's
   element type (imported as `Int` in this case) conforms to
   `SIMDScalar`.
3. Conformance lookup triggers extension loading. Because we haven't
   added any extensions to `Int` yet, and the standard library happens
   to come before `cake` in the list of module loaders, extensions from
   `cake` are added last.

main:
1. No neon vector types, so we happen not to look up `Int`'s
   conformances during importation of `cake.h`.
2. The next file is `cake.swift`. In the process of deserializing the
   AST for that file, we encounter `Int` extensions and add them to the
   nominal.

Eventually, while processing the collected top-level declarations, the
API digester calls `getAllConformances` on `Int`, and we see a
difference in the index of `P1` between main and rebranch because
conformances from extensions are added to the table in the order those
extensions were added to the nominal.
---
 test/api-digester/Outputs/cake-abi.json | 14 +++++++-------
 test/api-digester/Outputs/cake.json     | 14 +++++++-------
 2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/test/api-digester/Outputs/cake-abi.json b/test/api-digester/Outputs/cake-abi.json
index a1697144c7a31..58ca05d93ccc1 100644
--- a/test/api-digester/Outputs/cake-abi.json
+++ b/test/api-digester/Outputs/cake-abi.json
@@ -2154,13 +2154,6 @@
             "usr": "s:s9EscapableP",
             "mangledName": "$ss9EscapableP"
           },
-          {
-            "kind": "Conformance",
-            "name": "P1",
-            "printedName": "P1",
-            "usr": "s:4cake2P1P",
-            "mangledName": "$s4cake2P1P"
-          },
           {
             "kind": "Conformance",
             "name": "Encodable",
@@ -2351,6 +2344,13 @@
             "printedName": "BitwiseCopyable",
             "usr": "s:s15BitwiseCopyableP",
             "mangledName": "$ss15BitwiseCopyableP"
+          },
+          {
+            "kind": "Conformance",
+            "name": "P1",
+            "printedName": "P1",
+            "usr": "s:4cake2P1P",
+            "mangledName": "$s4cake2P1P"
           }
         ]
       }
diff --git a/test/api-digester/Outputs/cake.json b/test/api-digester/Outputs/cake.json
index 5f1d958671cea..f35d60de53c4b 100644
--- a/test/api-digester/Outputs/cake.json
+++ b/test/api-digester/Outputs/cake.json
@@ -2048,13 +2048,6 @@
             "usr": "s:s9EscapableP",
             "mangledName": "$ss9EscapableP"
           },
-          {
-            "kind": "Conformance",
-            "name": "P1",
-            "printedName": "P1",
-            "usr": "s:4cake2P1P",
-            "mangledName": "$s4cake2P1P"
-          },
           {
             "kind": "Conformance",
             "name": "Encodable",
@@ -2238,6 +2231,13 @@
             "printedName": "BitwiseCopyable",
             "usr": "s:s15BitwiseCopyableP",
             "mangledName": "$ss15BitwiseCopyableP"
+          },
+          {
+            "kind": "Conformance",
+            "name": "P1",
+            "printedName": "P1",
+            "usr": "s:4cake2P1P",
+            "mangledName": "$s4cake2P1P"
           }
         ]
       }