[Driver] Add toolchain for X86_64 UEFI target (#76838)

Introduce changes necessary for UEFI X86_64 target Clang driver.
Addressed the review comments originally suggested in Phabricator.

Differential Revision: https://reviews.llvm.org/D159541

1 files changed, 21 insertions, 0 deletions

diff --git a/clang/unittests/Driver/ToolChainTest.cpp b/clang/unittests/Driver/ToolChainTest.cpp
index 6c8b32d..672742c 100644
--- a/clang/unittests/Driver/ToolChainTest.cpp
+++ b/clang/unittests/Driver/ToolChainTest.cpp
@@ -14,6 +14,7 @@
 #include "clang/Basic/DiagnosticIDs.h"
 #include "clang/Basic/DiagnosticOptions.h"
 #include "clang/Basic/LLVM.h"
+#include "clang/Basic/TargetInfo.h"
 #include "clang/Basic/TargetOptions.h"
 #include "clang/Driver/Compilation.h"
 #include "clang/Driver/Driver.h"
@@ -574,6 +575,26 @@ TEST(CompilerInvocation, SplitSwarfSingleCrash) {
   EXPECT_TRUE(CI); // no-crash
 }
 
+TEST(ToolChainTest, UEFICallingConventionTest) {
+  clang::CompilerInstance compiler;
+  compiler.createDiagnostics();
+
+  std::string TrStr = "x86_64-unknown-uefi";
+  llvm::Triple Tr(TrStr);
+  Tr.setOS(llvm::Triple::OSType::UEFI);
+  Tr.setVendor(llvm::Triple::VendorType::UnknownVendor);
+  Tr.setEnvironment(llvm::Triple::EnvironmentType::UnknownEnvironment);
+  Tr.setArch(llvm::Triple::ArchType::x86_64);
+
+  compiler.getTargetOpts().Triple = Tr.getTriple();
+  compiler.setTarget(clang::TargetInfo::CreateTargetInfo(
+      compiler.getDiagnostics(),
+      std::make_shared<clang::TargetOptions>(compiler.getTargetOpts())));
+
+  EXPECT_EQ(compiler.getTarget().getCallingConvKind(true),
+            TargetInfo::CallingConvKind::CCK_MicrosoftWin64);
+}
+
 TEST(GetDriverMode, PrefersLastDriverMode) {
   static constexpr const char *Args[] = {"clang-cl", "--driver-mode=foo",
                                          "--driver-mode=bar", "foo.cpp"};