[clang] [clang][modules] Invalidate module cache when SDKSettings.json changes (PR #139751)

[Ben Langmuir via cfe-commits]

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@@ -0,0 +1,49 @@
+// This test checks that the module cache gets invalidated when the SDKSettings.json file changes.
+
+// RUN: rm -rf %t
+// RUN: split-file %s %t
+
+//--- AppleTVOS15.0.sdk/SDKSettings-old.json
+{
+  "DisplayName": "tvOS 15.0",
+  "Version": "15.0",
+  "CanonicalName": "appletvos15.0",
+  "MaximumDeploymentTarget": "15.0.99",
+  "PropertyConditionFallbackNames": []
+}
+//--- AppleTVOS15.0.sdk/SDKSettings-new.json
+{
+  "DisplayName": "tvOS 15.0",
+  "Version": "15.0",
+  "CanonicalName": "appletvos15.0",
+  "MaximumDeploymentTarget": "15.0.99",
+  "PropertyConditionFallbackNames": [],
+  "VersionMap": {
+    "iOS_tvOS": {
+      "13.2": "13.1"
+    },
+    "tvOS_iOS": {
+      "13.1": "13.2"
+    }
+  }
+}
+//--- module.modulemap
+module M { header "M.h" }
+//--- M.h
+void foo(void) __attribute__((availability(iOS, obsoleted = 13.2)));
+void test() { foo(); }
+
+//--- tu.m
+#include "M.h"
+
+// Compiling for tvOS 13.1 without "VersionMap" should succeed, since by default iOS 13.2 gets mapped to tvOS 13.2,
+// and \c foo is therefore **not** deprecated.
+// RUN: cp %t/AppleTVOS15.0.sdk/SDKSettings-old.json %t/AppleTVOS15.0.sdk/SDKSettings.json
+// RUN: %clang -target x86_64-apple-tvos13.1 -isysroot %t/AppleTVOS15.0.sdk \
+// RUN:   -fsyntax-only %t/tu.m -o %t/tu.o -fmodules -Xclang -fdisable-module-hash -fmodules-cache-path=%t/cache
+
+// Compiling for tvOS 13.1 with "VersionMap" saying it maps to iOS 13.2 should fail, since \c foo is now deprecated.
+// RUN: sleep 1
+// RUN: cp %t/AppleTVOS15.0.sdk/SDKSettings-new.json %t/AppleTVOS15.0.sdk/SDKSettings.json
+// RUN: not %clang -target x86_64-apple-tvos13.1 -isysroot %t/AppleTVOS15.0.sdk \
----------------
benlangmuir wrote:

Could this test use `-verify` to validate it's the availability error causing the failure? Not a blocker.

https://github.com/llvm/llvm-project/pull/139751