api-digester: Don’t compare invalid attributes

The API digester represents unknown attributes as DAK_Count, but passing this value to the `is{Adding,Removing}Breaking{API,ABI}()` functions is not permitted. On some platforms this would cause a crash; on others it hit unreachable code which happened to end up working.

Skip these unknown attributes during comparisons to avoid this problem.

Author: beccadax

lib/APIDigester/ModuleAnalyzerNodes.cpp

@@ -2897,6 +2897,10 @@ void swift::ide::api::SDKNodeDecl::diagnose(SDKNode *Right) {
 
   // Diagnose removing attributes.
   for (auto Kind: getDeclAttributes()) {
+    if (Kind == swift::DAK_Count)
+      // Unknown attribute, diagnosed elsewhere.
+      continue;
+
     if (!RD->hasDeclAttribute(Kind)) {
       if ((Ctx.checkingABI() ? DeclAttribute::isRemovingBreakingABI(Kind) :
                                DeclAttribute::isRemovingBreakingAPI(Kind)) &&
@@ -2909,6 +2913,10 @@ void swift::ide::api::SDKNodeDecl::diagnose(SDKNode *Right) {
 
   // Diagnose adding attributes.
   for (auto Kind: RD->getDeclAttributes()) {
+    if (Kind == swift::DAK_Count)
+      // Unknown attribute, diagnosed elsewhere.
+      continue;
+
     if (!hasDeclAttribute(Kind)) {
       if ((Ctx.checkingABI() ? DeclAttribute::isAddingBreakingABI(Kind) :
                                DeclAttribute::isAddingBreakingAPI(Kind)) &&

test/api-digester/Inputs/diagnostics-compare.json

@@ -0,0 +1,15 @@
+{
+  "kind": "Root",
+  "name": "TopLevel",
+  "printedName": "TopLevel",
+  "children": [
+    {
+      "kind": "Function",
+      "declAttributes": ["Available", "ObjC"],
+      "declKind": "Func",
+      "name": "foo",
+      "children": [],
+      "usr": "s:11diagnostics3fooP"
+    }
+  ]
+}

test/api-digester/diagnostics.json renamed to test/api-digester/Inputs/diagnostics.json

@@ -9,6 +9,14 @@
       "typeAttributes": ["autoclosure", "fnord", "inout", "Available"],
       "declAttributes": ["Available", "Fnord", "ObjC", "inout"],
       "declKind": "Subroutine"
+    },
+    {
+      "kind": "Function",
+      "declAttributes": ["Available", "Fnord", "ObjC", "inout"],
+      "declKind": "Func",
+      "name": "foo",
+      "children": [],
+      "usr": "s:11diagnostics3fooP"
     }
   ]
 }

test/api-digester/diagnostics.swift

@@ -1,6 +1,13 @@
 // REQUIRES: OS=macosx
-// RUN: not %api-digester -deserialize-sdk -input-paths %S/diagnostics.json -o - 2>&1 | %FileCheck %s
-// RUN: not %api-digester -diagnose-sdk -input-paths %S/diagnostics.json -input-paths %S/diagnostics.json -compiler-style-diags -o - 2>&1 | %FileCheck %s
+// RUN: %empty-directory(%t)
+
+// RUN: not %api-digester -deserialize-sdk -input-paths %S/Inputs/diagnostics.json -o - >%t/deserialize.txt 2>&1
+// RUN: %FileCheck --input-file %t/deserialize.txt %s
+// RUN-X: %FileCheck --input-file %t/deserialize.txt --check-prefix NEGATIVE %s
+
+// RUN: not %api-digester -diagnose-sdk -input-paths %S/Inputs/diagnostics.json -input-paths %S/Inputs/diagnostics-compare.json -compiler-style-diags -o - >%t/diagnose.txt 2>&1
+// RUN: %FileCheck --input-file %t/diagnose.txt %s
+// RUN: %FileCheck --input-file %t/diagnose.txt --check-prefix NEGATIVE %s
 
 // CHECK: diagnostics.json:5:3: error: unrecognized key 'badKey' in SDK node
 // CHECK: diagnostics.json:8:15: error: unrecognized SDK node kind 'Zyzyx'
@@ -11,4 +18,7 @@
 // CHECK: diagnostics.json:11:19: error: unrecognized declaration kind 'Subroutine' in SDK node
 
 // Make sure we don't try to output a result:
-// CHECK-NOT: "kind": "Root",
+// NEGATIVE-NOT: "kind": "Root",
+
+// Should not have any errors in the diagnostics-compare file.
+// NEGATIVE-NOT: diagnostics-compare.json:{{.*}}: error: