[clang] [clang][driver][darwin] DarwinSDKInfo doesn't match sufficiently modified triples, doesn't warn for unsupported architectures (PR #204061)

[Steven Wu via cfe-commits]

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@@ -107,10 +107,9 @@ TEST(DarwinSDKInfo, PlatformPrefix) {
   ASSERT_TRUE(SDKInfo);
   EXPECT_EQ(SDKInfo->getPlatformPrefix(Triple("arm64-apple-macos26.0")),
             "/System/macOSSupport");
-  // The triple's architecture doesn't matter.
-  EXPECT_EQ(SDKInfo->getPlatformPrefix(Triple("ppc-apple-macos26.0")),
-            "/System/macOSSupport");
-  // OSes that aren't specified in the SDK never get a system prefix.
+  // When there are multiple system prefixes, non-matching triples don't get a
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cachemeifyoucan wrote:

`...  which has undergone modifications from the original -target value, which can sometimes even include changes to the triple's environment...` Does any test cover this case? I wonder what is the case that trigger this?

https://github.com/llvm/llvm-project/pull/204061