Index: flang/tools/f18/f18.cpp
===================================================================
--- flang/tools/f18/f18.cpp
+++ flang/tools/f18/f18.cpp
@@ -368,20 +368,24 @@
   return {};
 }
 
-void Link(std::vector<std::string> &relocatables, DriverOptions &driver) {
+void Link(std::vector<std::string> &liblist, std::vector<std::string> &objects,
+    DriverOptions &driver) {
   if (!ParentProcess()) {
     std::vector<char *> argv;
     for (size_t j{0}; j < driver.F18_FCArgs.size(); ++j) {
       argv.push_back(driver.F18_FCArgs[j].data());
     }
-    for (auto &relo : relocatables) {
-      argv.push_back(relo.data());
+    for (auto &obj : objects) {
+      argv.push_back(obj.data());
     }
     if (!driver.outputPath.empty()) {
       char dashO[3] = "-o";
       argv.push_back(dashO);
       argv.push_back(driver.outputPath.data());
     }
+    for (auto &lib : liblist) {
+      argv.push_back(lib.data());
+    }
     Exec(argv, driver.verbose);
   }
 }
@@ -396,6 +400,7 @@
   bool isPGF90{driver.F18_FCArgs.back().rfind("pgf90") != std::string::npos};
 
   std::list<std::string> args{argList(argc, argv)};
+  std::vector<std::string> objlist, liblist;
   std::string prefix{args.front()};
   args.pop_front();
   prefix += ": ";
@@ -412,32 +417,37 @@
 
   Fortran::common::IntrinsicTypeDefaultKinds defaultKinds;
 
-  std::vector<std::string> fortranSources, otherSources, relocatables;
+  std::vector<std::string> fortranSources, otherSources;
   bool anyFiles{false};
 
   while (!args.empty()) {
     std::string arg{std::move(args.front())};
+    auto dot{arg.rfind(".")};
+    std::string suffix{arg.substr(dot + 1)};
+    std::string prefix{arg.substr(0, 2)};
     args.pop_front();
     if (arg.empty()) {
     } else if (arg.at(0) != '-') {
       anyFiles = true;
-      auto dot{arg.rfind(".")};
       if (dot == std::string::npos) {
         driver.F18_FCArgs.push_back(arg);
       } else {
-        std::string suffix{arg.substr(dot + 1)};
         if (suffix == "f" || suffix == "F" || suffix == "ff" ||
             suffix == "f90" || suffix == "F90" || suffix == "ff90" ||
             suffix == "f95" || suffix == "F95" || suffix == "ff95" ||
             suffix == "cuf" || suffix == "CUF" || suffix == "f18" ||
             suffix == "F18" || suffix == "ff18") {
           fortranSources.push_back(arg);
-        } else if (suffix == "o" || suffix == "a") {
-          relocatables.push_back(arg);
+        } else if (suffix == "o" || suffix == "so") {
+          objlist.push_back(arg);
+        } else if (suffix == "a") {
+          liblist.push_back(arg);
         } else {
           otherSources.push_back(arg);
         }
       }
+    } else if (prefix == "-l" || suffix == "a") {
+      liblist.push_back(arg);
     } else if (arg == "-") {
       fortranSources.push_back("-");
     } else if (arg == "--") {
@@ -674,17 +684,17 @@
   for (const auto &path : fortranSources) {
     std::string relo{CompileFortran(path, options, driver, defaultKinds)};
     if (!driver.compileOnly && !relo.empty()) {
-      relocatables.push_back(relo);
+      objlist.push_back(relo);
     }
   }
   for (const auto &path : otherSources) {
     std::string relo{CompileOtherLanguage(path, driver)};
     if (!driver.compileOnly && !relo.empty()) {
-      relocatables.push_back(relo);
+      objlist.push_back(relo);
     }
   }
-  if (!relocatables.empty()) {
-    Link(relocatables, driver);
+  if (!objlist.empty()) {
+    Link(liblist, objlist, driver);
   }
   return exitStatus;
 }