[flang-commits] [flang] [clang] [flang][nfc] Refactor linker invocation logic (PR #75534)

via flang-commits flang-commits at lists.llvm.org
Thu Dec 14 13:43:32 PST 2023


llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Andrzej WarzyƄski (banach-space)

<details>
<summary>Changes</summary>

Refactor how the Fortran runtime libs are added to the linker
invocation. This is a non-functional change.


---
Full diff: https://github.com/llvm/llvm-project/pull/75534.diff


2 Files Affected:

- (modified) clang/lib/Driver/ToolChains/CommonArgs.cpp (+75-61) 
- (modified) flang/test/Driver/linker-flags.f90 (+4-4) 


``````````diff
diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index 3d1df58190ce05..35f3db31db9b8f 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -1116,73 +1116,87 @@ bool tools::addOpenMPRuntime(ArgStringList &CmdArgs, const ToolChain &TC,
   return true;
 }
 
+/// Determines if --whole-archive is active in the list of arguments.
+static bool isWholeArchivePresent(const ArgList &Args) {
+  bool WholeArchiveActive = false;
+  for (auto *Arg : Args.filtered(options::OPT_Wl_COMMA)) {
+    if (Arg) {
+      for (StringRef ArgValue : Arg->getValues()) {
+        if (ArgValue == "--whole-archive")
+          WholeArchiveActive = true;
+        if (ArgValue == "--no-whole-archive")
+          WholeArchiveActive = false;
+      }
+    }
+  }
+
+  return WholeArchiveActive;
+}
+
+/// Add Fortran runtime libs for MSVC
+static void addFortranRuntimeLibsMSVC(const ArgList &Args,
+                                      llvm::opt::ArgStringList &CmdArgs) {
+  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("/WHOLEARCHIVE:Fortran_main.static.lib");
+    break;
+  case options::OPT__SLASH_MTd:
+    CmdArgs.push_back("/WHOLEARCHIVE:Fortran_main.static_dbg.lib");
+    break;
+  case options::OPT__SLASH_MD:
+    CmdArgs.push_back("/WHOLEARCHIVE:Fortran_main.dynamic.lib");
+    break;
+  case options::OPT__SLASH_MDd:
+    CmdArgs.push_back("/WHOLEARCHIVE:Fortran_main.dynamic_dbg.lib");
+    break;
+  }
+}
+
+/// Add Fortran runtime libs
 void tools::addFortranRuntimeLibs(const ToolChain &TC, const ArgList &Args,
                                   llvm::opt::ArgStringList &CmdArgs) {
-  // These are handled earlier on Windows by telling the frontend driver to add
-  // the correct libraries to link against as dependents in the object file.
-
-  // if -fno-fortran-main has been passed, skip linking Fortran_main.a
-  bool LinkFortranMain = !Args.hasArg(options::OPT_no_fortran_main);
+  // 1. Link FortranRuntime and FortranDecimal
+  // These are handled earlier on Windows by telling the frontend driver to
+  // add the correct libraries to link against as dependents in the object
+  // file.
   if (!TC.getTriple().isKnownWindowsMSVCEnvironment()) {
-    if (LinkFortranMain) {
-      // The --whole-archive option needs to be part of the link line to
-      // make sure that the main() function from Fortran_main.a is pulled
-      // in by the linker.  Determine if --whole-archive is active when
-      // flang will try to link Fortran_main.a.  If it is, don't add the
-      // --whole-archive flag to the link line.  If it's not, add a proper
-      // --whole-archive/--no-whole-archive bracket to the link line.
-      bool WholeArchiveActive = false;
-      for (auto *Arg : Args.filtered(options::OPT_Wl_COMMA)) {
-        if (Arg) {
-          for (StringRef ArgValue : Arg->getValues()) {
-            if (ArgValue == "--whole-archive")
-              WholeArchiveActive = true;
-            if (ArgValue == "--no-whole-archive")
-              WholeArchiveActive = false;
-          }
-        }
-      }
+    CmdArgs.push_back("-lFortranRuntime");
+    CmdArgs.push_back("-lFortranDecimal");
+  }
 
-      // TODO: Find an equivalent of `--whole-archive` for Darwin.
-      if (!WholeArchiveActive && !TC.getTriple().isMacOSX()) {
-        CmdArgs.push_back("--whole-archive");
-        CmdArgs.push_back("-lFortran_main");
-        CmdArgs.push_back("--no-whole-archive");
-      } else {
-        CmdArgs.push_back("-lFortran_main");
-      }
+  // 2. Link FortranMain
+  // If -fno-fortran-main has been passed, skip linking Fortran_main.a
+  if (Args.hasArg(options::OPT_no_fortran_main))
+    return;
 
-      // Perform regular linkage of the remaining runtime libraries.
-      CmdArgs.push_back("-lFortranRuntime");
-      CmdArgs.push_back("-lFortranDecimal");
-    }
-  } else {
-    if (LinkFortranMain) {
-      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("/WHOLEARCHIVE:Fortran_main.static.lib");
-        break;
-      case options::OPT__SLASH_MTd:
-        CmdArgs.push_back("/WHOLEARCHIVE:Fortran_main.static_dbg.lib");
-        break;
-      case options::OPT__SLASH_MD:
-        CmdArgs.push_back("/WHOLEARCHIVE:Fortran_main.dynamic.lib");
-        break;
-      case options::OPT__SLASH_MDd:
-        CmdArgs.push_back("/WHOLEARCHIVE:Fortran_main.dynamic_dbg.lib");
-        break;
-      }
-    }
+  // 2.1. MSVC
+  if (TC.getTriple().isKnownWindowsMSVCEnvironment()) {
+    addFortranRuntimeLibsMSVC(Args, CmdArgs);
+    return;
   }
+
+  // 2.2. GNU and similar
+  // The --whole-archive option needs to be part of the link line to make
+  // sure that the main() function from Fortran_main.a is pulled in by the
+  // linker. However, it shouldn't be used if it's already active.
+  // TODO: Find an equivalent of `--whole-archive` for Darwin.
+  if (!isWholeArchivePresent(Args) && !TC.getTriple().isMacOSX()) {
+    CmdArgs.push_back("--whole-archive");
+    CmdArgs.push_back("-lFortran_main");
+    CmdArgs.push_back("--no-whole-archive");
+    return;
+  } 
+
+  CmdArgs.push_back("-lFortran_main");
 }
 
 void tools::addFortranRuntimeLibraryPath(const ToolChain &TC,
diff --git a/flang/test/Driver/linker-flags.f90 b/flang/test/Driver/linker-flags.f90
index ea91946316cfaa..31e7ab71aacdb1 100644
--- a/flang/test/Driver/linker-flags.f90
+++ b/flang/test/Driver/linker-flags.f90
@@ -28,23 +28,23 @@
 !       executable and may find the GNU linker from MinGW or Cygwin.
 ! UNIX-LABEL:  "{{.*}}ld{{(\.exe)?}}"
 ! UNIX-SAME: "[[object_file]]"
-! UNIX-SAME: "--whole-archive" "-lFortran_main" "--no-whole-archive" "-lFortranRuntime" "-lFortranDecimal" "-lm"
+! UNIX-SAME: "-lFortranRuntime" "-lFortranDecimal" "--whole-archive" "-lFortran_main" "--no-whole-archive" "-lm"
 
 ! DARWIN-LABEL:  "{{.*}}ld{{(\.exe)?}}"
 ! DARWIN-SAME: "[[object_file]]"
-! DARWIN-SAME: -lFortran_main
 ! DARWIN-SAME: -lFortranRuntime
 ! DARWIN-SAME: -lFortranDecimal
+! DARWIN-SAME: -lFortran_main
 
 ! HAIKU-LABEL:  "{{.*}}ld{{(\.exe)?}}"
 ! HAIKU-SAME: "[[object_file]]"
-! HAIKU-SAME: "--whole-archive" "-lFortran_main" "--no-whole-archive" "-lFortranRuntime" "-lFortranDecimal"
+! HAIKU-SAME: "-lFortranRuntime" "-lFortranDecimal" "--whole-archive" "-lFortran_main" "--no-whole-archive"
 
 ! MINGW-LABEL:  "{{.*}}ld{{(\.exe)?}}"
 ! MINGW-SAME: "[[object_file]]"
-! MINGW-SAME: -lFortran_main
 ! MINGW-SAME: -lFortranRuntime
 ! MINGW-SAME: -lFortranDecimal
+! MINGW-SAME: -lFortran_main
 
 ! NOTE: This also matches lld-link (when CLANG_DEFAULT_LINKER=lld) and
 !       any .exe suffix that is added when resolving to the full path of

``````````

</details>


https://github.com/llvm/llvm-project/pull/75534


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