[clang] UEFI handle unsupported triples. (#124824)

The only architecture currently being supported (still a WIP) is
x86_64. Other UEFI triples targeting other architectures will now
report an `unknown target triple` error.

Author: Prabhuk

clang/lib/Driver/Driver.cpp

@@ -637,6 +637,10 @@ static llvm::Triple computeTargetTriple(const Driver &D,
     }
   }
 
+  // Currently the only architecture supported by *-uefi triples are x86_64.
+  if (Target.isUEFI() && Target.getArch() != llvm::Triple::x86_64)
+    D.Diag(diag::err_target_unknown_triple) << Target.str();
+
   // The `-maix[32|64]` flags are only valid for AIX targets.
   if (Arg *A = Args.getLastArgNoClaim(options::OPT_maix32, options::OPT_maix64);
       A && !Target.isOSAIX())

clang/test/Driver/uefi-constructed-args.c

@@ -1,3 +1,5 @@
+// RUN: %clang -### --target=x86_64-unknown-uefi -g -- %s 2>&1 \
+// RUN:     | FileCheck -check-prefixes=CHECK %s
 // RUN: %clang_cl -### --target=x86_64-unknown-uefi -g -- %s 2>&1 \
 // RUN:     | FileCheck -check-prefixes=CHECK %s
 // CHECK: "-cc1"

clang/test/Driver/unsupported-target-arch.c

@@ -63,3 +63,21 @@
 // RUN: not %clang --target=powerpc-apple-darwin -o /dev/null %s 2> %t.err
 // RUN: FileCheck --input-file=%t.err --check-prefix=CHECK-PPCMAC %s
 // CHECK-PPCMAC: error: unknown target triple 'unknown-apple-macosx{{.*}}'
+
+// RUN: not %clang --target=aarch64-unknown-uefi -o %t.o %s 2> %t.err
+// RUN: FileCheck --input-file=%t.err --check-prefix=CHECK-AARCH64 %s
+// RUN: not %clang_cl --target=aarch64-unknown-uefi -o %t.o %s 2> %t.err
+// RUN: FileCheck --input-file=%t.err --check-prefix=CHECK-AARCH64 %s
+// CHECK-AARCH64: error: unknown target triple 'aarch64-unknown-uefi'{{$}}
+
+// RUN: not %clang --target=arm-unknown-uefi -o %t.o %s 2> %t.err
+// RUN: FileCheck --input-file=%t.err -check-prefixes=CHECK-ARM %s
+// RUN: not %clang_cl --target=arm-unknown-uefi -o %t.o %s 2> %t.err
+// RUN: FileCheck --input-file=%t.err -check-prefixes=CHECK-ARM %s
+// CHECK-ARM: error: unknown target triple 'arm-unknown-uefi'{{$}}
+
+// RUN: not %clang --target=x86-unknown-uefi -o %t.o %s 2> %t.err
+// RUN: FileCheck --input-file=%t.err -check-prefixes=CHECK-x86 %s
+// RUN: not %clang_cl --target=x86-unknown-uefi -o %t.o %s 2> %t.err
+// RUN: FileCheck --input-file=%t.err -check-prefixes=CHECK-x86 %s
+// CHECK-x86: error: unknown target triple 'x86-unknown-uefi'{{$}}