[clang] [clang][driver] Don't emit an error on an unrecognized SDK name (PR #181897)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-driver

Author: Ian Anderson (ian-twilightcoder)

<details>
<summary>Changes</summary>

-isysroot can be an unrecognized value in unusual circumstances. Don't emit an error when checking the triple against such an isysroot, let the user try to do what they're trying to do.

---
Full diff: https://github.com/llvm/llvm-project/pull/181897.diff


3 Files Affected:

- (modified) clang/lib/Driver/ToolChains/Darwin.cpp (+6-7) 
- (added) clang/test/Driver/Inputs/XRSimulator1.0.sdk/usr/include/libxml/.keep () 
- (modified) clang/test/Driver/incompatible_sysroot.c (+1) 


``````````diff
diff --git a/clang/lib/Driver/ToolChains/Darwin.cpp b/clang/lib/Driver/ToolChains/Darwin.cpp
index 1c95a79a52a9c..0650b49017290 100644
--- a/clang/lib/Driver/ToolChains/Darwin.cpp
+++ b/clang/lib/Driver/ToolChains/Darwin.cpp
@@ -1145,11 +1145,11 @@ void Darwin::VerifyTripleForSDK(const llvm::opt::ArgList &Args,
       getDriver().Diag(diag::warn_incompatible_sysroot)
           << SDKInfo->getDisplayName() << Triple.getTriple();
   } else if (const Arg *A = Args.getLastArg(options::OPT_isysroot)) {
+    // If there is no SDK info, assume this is building against an SDK that
+    // predates SDKSettings.json. Try to match the triple to the SDK path.
     const char *isysroot = A->getValue();
-    StringRef SDK = getSDKName(isysroot);
-    if (!SDK.empty()) {
-      size_t StartVer = SDK.find_first_of("0123456789");
-      StringRef SDKName = SDK.slice(0, StartVer);
+    StringRef SDKName = getSDKName(isysroot);
+    if (!SDKName.empty()) {
       bool supported = true;
       if (Triple.isWatchOS())
         supported = SDKName.starts_with("Watch");
@@ -1161,9 +1161,8 @@ void Darwin::VerifyTripleForSDK(const llvm::opt::ArgList &Args,
         supported = SDKName.starts_with("iPhone");
       else if (Triple.isMacOSX())
         supported = SDKName.starts_with("MacOSX");
-      else
-        llvm::reportFatalUsageError(Twine("SDK at '") + isysroot +
-                                    "' missing SDKSettings.json.");
+      // If it's not an older SDK, then it might be a damaged SDK or a
+      // non-standard -isysroot path. Don't try to diagnose that here.
 
       if (!supported)
         getDriver().Diag(diag::warn_incompatible_sysroot)
diff --git a/clang/test/Driver/Inputs/XRSimulator1.0.sdk/usr/include/libxml/.keep b/clang/test/Driver/Inputs/XRSimulator1.0.sdk/usr/include/libxml/.keep
new file mode 100644
index 0000000000000..e69de29bb2d1d
diff --git a/clang/test/Driver/incompatible_sysroot.c b/clang/test/Driver/incompatible_sysroot.c
index a5f7d03da7254..ee88d241a3496 100644
--- a/clang/test/Driver/incompatible_sysroot.c
+++ b/clang/test/Driver/incompatible_sysroot.c
@@ -12,6 +12,7 @@
 // RUN: %clang -target arm64-apple-visionos1.0-simulator -Wincompatible-sysroot -isysroot %S/Inputs/XRSimulator1.0.sdk -S -o - %s 2>&1 | FileCheck -check-prefix CHECK-VISIONOSSIM %s
 // RUN: %clang -target arm64-apple-xros1.0 -Wincompatible-sysroot -isysroot %S/Inputs/XRSimulator1.0.sdk -S -o - %s 2>&1 | FileCheck -check-prefix CHECK-VISIONOSSIM-VISIONOS %s
 // RUN: %clang -target arm64-apple-ios17.1 -Wincompatible-sysroot -isysroot %S/Inputs/XRSimulator1.0.sdk -S -o - %s 2>&1 | FileCheck -check-prefix CHECK-VISIONOSSIM-IOS %s
+// RUN: %clang -target arm64-apple-visionos1.0-simulator -Wincompatible-sysroot -isysroot %S/Inputs/XRSimulator1.0.sdk/usr/include/libxml -S -o - %s 2>&1 | FileCheck -check-prefix CHECK-VISIONOSSIM %s
 
 int main() { return 0; }
 // CHECK-OSX-IOS: warning: using sysroot for 'MacOSX' but targeting 'x86_64-apple-ios9.0.0-simulator'

``````````

</details>


https://github.com/llvm/llvm-project/pull/181897