[flang] [clang] [flang] Add runtimes using --dependent-lib on MSVC targets (PR #72519)

[David Truby via cfe-commits]

================
@@ -977,47 +977,10 @@ bool tools::addOpenMPRuntime(ArgStringList &CmdArgs, const ToolChain &TC,
   return true;
 }
 
-void tools::addFortranRuntimeLibs(const ToolChain &TC, const ArgList &Args,
+void tools::addFortranRuntimeLibs(const ToolChain &TC,
                                   llvm::opt::ArgStringList &CmdArgs) {
-  if (TC.getTriple().isKnownWindowsMSVCEnvironment()) {
-    CmdArgs.push_back(Args.MakeArgString(
-        "/DEFAULTLIB:" + TC.getCompilerRTBasename(Args, "builtins")));
-    unsigned RTOptionID = options::OPT__SLASH_MT;
-    if (auto *rtl = Args.getLastArg(options::OPT_fms_runtime_lib_EQ)) {
-      RTOptionID = llvm::StringSwitch<unsigned>(rtl->getValue())
-                       .Case("static", options::OPT__SLASH_MT)
-                       .Case("static_dbg", options::OPT__SLASH_MTd)
-                       .Case("dll", options::OPT__SLASH_MD)
-                       .Case("dll_dbg", options::OPT__SLASH_MDd)
-                       .Default(options::OPT__SLASH_MT);
-    }
-    switch (RTOptionID) {
-    case options::OPT__SLASH_MT:
-      CmdArgs.push_back("/DEFAULTLIB:libcmt");
-      CmdArgs.push_back("Fortran_main.static.lib");
-      CmdArgs.push_back("FortranRuntime.static.lib");
-      CmdArgs.push_back("FortranDecimal.static.lib");
-      break;
-    case options::OPT__SLASH_MTd:
-      CmdArgs.push_back("/DEFAULTLIB:libcmtd");
-      CmdArgs.push_back("Fortran_main.static_dbg.lib");
-      CmdArgs.push_back("FortranRuntime.static_dbg.lib");
-      CmdArgs.push_back("FortranDecimal.static_dbg.lib");
-      break;
-    case options::OPT__SLASH_MD:
-      CmdArgs.push_back("/DEFAULTLIB:msvcrt");
-      CmdArgs.push_back("Fortran_main.dynamic.lib");
-      CmdArgs.push_back("FortranRuntime.dynamic.lib");
-      CmdArgs.push_back("FortranDecimal.dynamic.lib");
-      break;
-    case options::OPT__SLASH_MDd:
-      CmdArgs.push_back("/DEFAULTLIB:msvcrtd");
-      CmdArgs.push_back("Fortran_main.dynamic_dbg.lib");
-      CmdArgs.push_back("FortranRuntime.dynamic_dbg.lib");
-      CmdArgs.push_back("FortranDecimal.dynamic_dbg.lib");
-      break;
-    }
-  } else {
+  // These are handled by adding link options to the object file on Windows
+  if (!TC.getTriple().isKnownWindowsMSVCEnvironment()) {
----------------
DavidTruby wrote:

No, these are added automatically. They're just added at a different place, because they aren't added to the link line but rather added as link directives in the object file, matching what cl.exe and clang do and therefore what link.exe expects.

https://github.com/llvm/llvm-project/pull/72519