[clang] 565603c - [clang][driver] set macOS as the target OS for -arch arm64 when clang

[Alex Lorenz via cfe-commits]

Author: Alex Lorenz
Date: 2020-06-23T21:08:11-07:00
New Revision: 565603cc94d79a8d0de6df840fd53714899fb890

URL: https://github.com/llvm/llvm-project/commit/565603cc94d79a8d0de6df840fd53714899fb890
DIFF: https://github.com/llvm/llvm-project/commit/565603cc94d79a8d0de6df840fd53714899fb890.diff

LOG: [clang][driver] set macOS as the target OS for -arch arm64 when clang
is running on an Apple Silicon mac

This change allows users to use `-arch arm64` to build for mac when
running it on Apple Silicon mac without explicit `-target` option.

Differential Revision: https://reviews.llvm.org/D82428

Added: 
    clang/test/Driver/apple-arm64-arch.c
    clang/test/Driver/apple-silicon-arch.c

Modified: 
    clang/lib/Driver/ToolChains/Darwin.cpp
    clang/test/lit.cfg.py

Removed: 
    


################################################################################
diff  --git a/clang/lib/Driver/ToolChains/Darwin.cpp b/clang/lib/Driver/ToolChains/Darwin.cpp
index bb7c7f768b35..1b3a3e934995 100644
--- a/clang/lib/Driver/ToolChains/Darwin.cpp
+++ b/clang/lib/Driver/ToolChains/Darwin.cpp
@@ -1672,8 +1672,16 @@ inferDeploymentTargetFromArch(DerivedArgList &Args, const Darwin &Toolchain,
   llvm::Triple::OSType OSTy = llvm::Triple::UnknownOS;
 
   StringRef MachOArchName = Toolchain.getMachOArchName(Args);
-  if (MachOArchName == "armv7" || MachOArchName == "armv7s" ||
-      MachOArchName == "arm64")
+  if (MachOArchName == "arm64") {
+#if __arm64__
+    // A clang running on an Apple Silicon mac defaults
+    // to building for mac when building for arm64 rather than
+    // defaulting to iOS.
+    OSTy = llvm::Triple::MacOSX;
+#else
+    OSTy = llvm::Triple::IOS;
+#endif
+  } else if (MachOArchName == "armv7" || MachOArchName == "armv7s")
     OSTy = llvm::Triple::IOS;
   else if (MachOArchName == "armv7k" || MachOArchName == "arm64_32")
     OSTy = llvm::Triple::WatchOS;

diff  --git a/clang/test/Driver/apple-arm64-arch.c b/clang/test/Driver/apple-arm64-arch.c
new file mode 100644
index 000000000000..fd9f9a2ccedb
--- /dev/null
+++ b/clang/test/Driver/apple-arm64-arch.c
@@ -0,0 +1,6 @@
+// RUN: env SDKROOT="/" %clang -arch arm64 -c -### %s 2>&1 | \
+// RUN:   FileCheck %s
+//
+// XFAIL: apple-silicon-mac
+//
+// CHECK: "-triple" "arm64-apple-ios{{[0-9.]+}}"

diff  --git a/clang/test/Driver/apple-silicon-arch.c b/clang/test/Driver/apple-silicon-arch.c
new file mode 100644
index 000000000000..b1201fa2d7dd
--- /dev/null
+++ b/clang/test/Driver/apple-silicon-arch.c
@@ -0,0 +1,6 @@
+// RUN: env SDKROOT="/" %clang -arch arm64 -c -### %s 2>&1 | \
+// RUN:   FileCheck %s
+//
+// REQUIRES: apple-silicon-mac
+//
+// CHECK: "-triple" "arm64-apple-macosx{{[0-9.]+}}"

diff  --git a/clang/test/lit.cfg.py b/clang/test/lit.cfg.py
index 413f81175420..ade32988b9a8 100644
--- a/clang/test/lit.cfg.py
+++ b/clang/test/lit.cfg.py
@@ -155,6 +155,10 @@ def is_filesystem_case_insensitive():
 if not re.match(r'.*-(cygwin)$', config.target_triple):
     config.available_features.add('clang-driver')
 
+# Tests that are specific to the Apple Silicon macOS.
+if re.match(r'^arm64(e)?-apple-(macos|darwin)', config.target_triple):
+    config.available_features.add('apple-silicon-mac')
+
 # [PR18856] Depends to remove opened file. On win32, a file could be removed
 # only if all handles were closed.
 if platform.system() not in ['Windows']: