[flang][driver] Add support for `-J/-module-dir`

Add support for option -J/-module-dir in the new Flang driver.  This
will allow for including module files in other directories, as the
default search path is currently the working folder. This also provides
an option of storing the output module in the specified folder.

Differential Revision: https://reviews.llvm.org/D95448

1 files changed, 36 insertions, 0 deletions

diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
index 563953f7..445feaa 100644
--- a/flang/lib/Frontend/CompilerInvocation.cpp
+++ b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -221,6 +221,25 @@ static void parsePreprocessorArgs(
     opts.searchDirectoriesFromDashI.emplace_back(currentArg->getValue());
 }
 
+/// Parses all semantic related arguments and populates the variables
+/// options accordingly.
+static void parseSemaArgs(std::string &moduleDir, llvm::opt::ArgList &args,
+    clang::DiagnosticsEngine &diags) {
+
+  auto moduleDirList =
+      args.getAllArgValues(clang::driver::options::OPT_module_dir);
+  // User can only specify -J/-module-dir once
+  // https://gcc.gnu.org/onlinedocs/gfortran/Directory-Options.html
+  if (moduleDirList.size() > 1) {
+    const unsigned diagID =
+        diags.getCustomDiagID(clang::DiagnosticsEngine::Error,
+            "Only one '-module-dir/-J' option allowed");
+    diags.Report(diagID);
+  }
+  if (moduleDirList.size() == 1)
+    moduleDir = moduleDirList[0];
+}
+
 bool CompilerInvocation::CreateFromArgs(CompilerInvocation &res,
     llvm::ArrayRef<const char *> commandLineArgs,
     clang::DiagnosticsEngine &diags) {
@@ -250,6 +269,8 @@ bool CompilerInvocation::CreateFromArgs(CompilerInvocation &res,
   ParseFrontendArgs(res.frontendOpts(), args, diags);
   // Parse the preprocessor args
   parsePreprocessorArgs(res.preprocessorOpts(), args);
+  // Parse semantic args
+  parseSemaArgs(res.moduleDir(), args, diags);
 
   return success;
 }
@@ -314,6 +335,7 @@ void CompilerInvocation::setFortranOpts() {
   auto &fortranOptions = fortranOpts();
   const auto &frontendOptions = frontendOpts();
   const auto &preprocessorOptions = preprocessorOpts();
+  auto &moduleDirJ = moduleDir();
 
   if (frontendOptions.fortranForm_ != FortranForm::Unknown) {
     fortranOptions.isFixedForm =
@@ -327,4 +349,18 @@ void CompilerInvocation::setFortranOpts() {
       fortranOptions.searchDirectories.end(),
       preprocessorOptions.searchDirectoriesFromDashI.begin(),
       preprocessorOptions.searchDirectoriesFromDashI.end());
+
+  // Add the directory supplied through -J/-module-dir to the list of search
+  // directories
+  if (moduleDirJ.compare(".") != 0)
+    fortranOptions.searchDirectories.emplace_back(moduleDirJ);
+}
+
+void CompilerInvocation::setSemanticsOpts(
+    Fortran::semantics::SemanticsContext &semaCtxt) {
+  auto &fortranOptions = fortranOpts();
+  auto &moduleDirJ = moduleDir();
+  semaCtxt.set_moduleDirectory(moduleDirJ)
+      .set_searchDirectories(fortranOptions.searchDirectories);
+  return;
 }