[flang] Add dependent-lib option to flang -fc1 on Windows (#72121)

This patch adds a --dependent-lib option to flang -fc1 on Windows to
embed library link options into the object file. This is needed to
properly select the Windows CRT to link against.

clang/include/clang/Driver/Options.td

@@ -6796,9 +6796,6 @@ def vectorize_loops : Flag<["-"], "vectorize-loops">,
 def vectorize_slp : Flag<["-"], "vectorize-slp">,
   HelpText<"Run the SLP vectorization passes">,
   MarshallingInfoFlag<CodeGenOpts<"VectorizeSLP">>;
-def dependent_lib : Joined<["--"], "dependent-lib=">,
-  HelpText<"Add dependent library">,
-  MarshallingInfoStringVector<CodeGenOpts<"DependentLibraries">>;
 def linker_option : Joined<["--"], "linker-option=">,
   HelpText<"Add linker option">,
   MarshallingInfoStringVector<CodeGenOpts<"LinkerOptions">>;
@@ -7369,6 +7366,11 @@ def pic_is_pie : Flag<["-"], "pic-is-pie">,
   HelpText<"File is for a position independent executable">,
   MarshallingInfoFlag<LangOpts<"PIE">>;
 
+
+def dependent_lib : Joined<["--"], "dependent-lib=">,
+  HelpText<"Add dependent library">,
+  MarshallingInfoStringVector<CodeGenOpts<"DependentLibraries">>;
+
 } // let Visibility = [CC1Option, FC1Option]
 
 let Visibility = [CC1Option] in {

flang/include/flang/Frontend/CodeGenOptions.h

@@ -70,6 +70,9 @@ public:
   /// The format used for serializing remarks (default: YAML)
   std::string OptRecordFormat;
 
+  /// Options to add to the linker for the object file
+  std::vector<std::string> DependentLibs;
+
   // The RemarkKind enum class and OptRemark struct are identical to what Clang
   // has
   // TODO: Share with clang instead of re-implementing here

flang/lib/Frontend/CompilerInvocation.cpp

@@ -1054,6 +1054,27 @@ static bool parseVScaleArgs(CompilerInvocation &invoc, llvm::opt::ArgList &args,
   return true;
 }
 
+static bool parseLinkerOptionsArgs(CompilerInvocation &invoc,
+                                   llvm::opt::ArgList &args,
+                                   clang::DiagnosticsEngine &diags) {
+  llvm::Triple triple = llvm::Triple(invoc.getTargetOpts().triple);
+
+  // TODO: support --dependent-lib on other platforms when MLIR supports
+  //       !llvm.dependent.lib
+  if (args.hasArg(clang::driver::options::OPT_dependent_lib) &&
+      !triple.isOSWindows()) {
+    const unsigned diagID =
+        diags.getCustomDiagID(clang::DiagnosticsEngine::Error,
+                              "--dependent-lib is only supported on Windows");
+    diags.Report(diagID);
+    return false;
+  }
+
+  invoc.getCodeGenOpts().DependentLibs =
+      args.getAllArgValues(clang::driver::options::OPT_dependent_lib);
+  return true;
+}
+
 bool CompilerInvocation::createFromArgs(
     CompilerInvocation &res, llvm::ArrayRef<const char *> commandLineArgs,
     clang::DiagnosticsEngine &diags, const char *argv0) {
@@ -1163,6 +1184,8 @@ bool CompilerInvocation::createFromArgs(
 
   success &= parseVScaleArgs(res, args, diags);
 
+  success &= parseLinkerOptionsArgs(res, args, diags);
+
   // Set the string to be used as the return value of the COMPILER_OPTIONS
   // intrinsic of iso_fortran_env. This is either passed in from the parent
   // compiler driver invocation with an environment variable, or failing that

flang/lib/Frontend/FrontendActions.cpp

@@ -203,6 +203,26 @@ static void setMLIRDataLayout(mlir::ModuleOp &mlirModule,
   mlirModule->setAttr(mlir::DLTIDialect::kDataLayoutAttrName, dlSpec);
 }
 
+static void addDepdendentLibs(mlir::ModuleOp &mlirModule,
+                              CompilerInstance &ci) {
+  const std::vector<std::string> &libs =
+      ci.getInvocation().getCodeGenOpts().DependentLibs;
+  if (libs.empty()) {
+    return;
+  }
+  // dependent-lib is currently only supported on Windows, so the list should be
+  // empty on non-Windows platforms
+  assert(
+      llvm::Triple(ci.getInvocation().getTargetOpts().triple).isOSWindows() &&
+      "--dependent-lib is only supported on Windows");
+  // Add linker options specified by --dependent-lib
+  auto builder = mlir::OpBuilder(mlirModule.getRegion());
+  for (const std::string &lib : libs) {
+    builder.create<mlir::LLVM::LinkerOptionsOp>(
+        mlirModule.getLoc(), builder.getStrArrayAttr({"/DEFAULTLIB:", lib}));
+  }
+}
+
 bool CodeGenAction::beginSourceFileAction() {
   llvmCtx = std::make_unique<llvm::LLVMContext>();
   CompilerInstance &ci = this->getInstance();
@@ -304,6 +324,9 @@ bool CodeGenAction::beginSourceFileAction() {
   Fortran::parser::Program &parseTree{*ci.getParsing().parseTree()};
   lb.lower(parseTree, ci.getInvocation().getSemanticsContext());
 
+  // Add dependent libraries
+  addDepdendentLibs(*mlirModule, ci);
+
   // run the default passes.
   mlir::PassManager pm((*mlirModule)->getName(),
                        mlir::OpPassManager::Nesting::Implicit);

flang/test/Driver/dependent-lib.f90

@@ -0,0 +1,16 @@
+! REQUIRES aarch64-registered-target && x86-registered-target
+! DEFINE: %{triple} =
+! DEFINE: %{compile} = %flang_fc1 -emit-mlir -triple %{triple} --dependent-lib=libtest %s -o - 2>&1
+! REDEFINE: %{triple} = aarch64-pc-windows-msvc
+! RUN: %{compile} | FileCheck %s
+! REDEFINE: %{triple} = x86_64-pc-windows-msvc
+! RUN: %{compile} | FileCheck %s
+! REDEFINE: %{triple} = x86_64-linux-unknown-gnu
+! RUN: not %{compile} | FileCheck %s --check-prefixes=CHECK-NOWIN
+! REDEFINE: %{triple} = aarch64-apple-darwin
+! RUN: not %{compile} | FileCheck %s --check-prefixes=CHECK-NOWIN
+
+! CHECK: llvm.linker_options ["/DEFAULTLIB:", "libtest"]
+program test
+end program test
+! CHECK-NOWIN: --dependent-lib is only supported on Windows

flang/test/Driver/driver-help.f90

@@ -141,6 +141,7 @@
 ! HELP-FC1-EMPTY:
 ! HELP-FC1-NEXT:OPTIONS:
 ! HELP-FC1-NEXT: -cpp                    Enable predefined and command line preprocessor macros
+! HELP-FC1-NEXT: --dependent-lib=<value> Add dependent library
 ! HELP-FC1-NEXT: -D <macro>=<value>      Define <macro> to <value> (or 1 if <value> omitted)
 ! HELP-FC1-NEXT: -emit-fir               Build the parse tree, then lower it to FIR
 ! HELP-FC1-NEXT: -emit-hlfir             Build the parse tree, then lower it to HLFIR