Author: Michael Klemm Date: 2023-11-28T14:20:30-06:00 New Revision: 17feb330aab39c6c0c21ee9b02efb484dfb2261e
URL: https://github.com/llvm/llvm-project/commit/17feb330aab39c6c0c21ee9b02efb484dfb2261e DIFF: https://github.com/llvm/llvm-project/commit/17feb330aab39c6c0c21ee9b02efb484dfb2261e.diff LOG: [flang][Driver] Let the linker fail on multiple definitions of main() (#73124) The flang driver was silently ignoring the `main()` function in `Fortran_main.a` for entry into the Fortran program unit if an external `main()` as supplied (e.g., via cross-language linkage with Fortran and C/C++). This PR fixes this by making sure that the linker always pulls in the `main()` definition from `Fortran_main.a` and consequently fails due to multiple definitions of the same symbol if another object file also has a definition of `main()`. Added: flang/test/Driver/Inputs/no_duplicate_main.ll flang/test/Driver/no_duplicate_main.f90 Modified: clang/lib/Driver/ToolChains/CommonArgs.cpp clang/lib/Driver/ToolChains/CommonArgs.h clang/lib/Driver/ToolChains/Darwin.cpp clang/lib/Driver/ToolChains/DragonFly.cpp clang/lib/Driver/ToolChains/FreeBSD.cpp clang/lib/Driver/ToolChains/Gnu.cpp clang/lib/Driver/ToolChains/Haiku.cpp clang/lib/Driver/ToolChains/MSVC.cpp clang/lib/Driver/ToolChains/MinGW.cpp clang/lib/Driver/ToolChains/NetBSD.cpp clang/lib/Driver/ToolChains/OpenBSD.cpp clang/lib/Driver/ToolChains/Solaris.cpp flang/test/Driver/linker-flags.f90 Removed: ################################################################################ diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp index 1f31c6395206ee8..efb8b71f24a932c 100644 --- a/clang/lib/Driver/ToolChains/CommonArgs.cpp +++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp @@ -977,14 +977,60 @@ bool tools::addOpenMPRuntime(ArgStringList &CmdArgs, const ToolChain &TC, return true; } -void tools::addFortranRuntimeLibs(const ToolChain &TC, +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 (!TC.getTriple().isKnownWindowsMSVCEnvironment()) { + // 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; + } + + if (!WholeArchiveActive) + CmdArgs.push_back("--whole-archive"); CmdArgs.push_back("-lFortran_main"); + if (!WholeArchiveActive) + CmdArgs.push_back("--no-whole-archive"); + + // Perform regular linkage of the remaining runtime libraries. CmdArgs.push_back("-lFortranRuntime"); CmdArgs.push_back("-lFortranDecimal"); + } else { + 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; + } } } diff --git a/clang/lib/Driver/ToolChains/CommonArgs.h b/clang/lib/Driver/ToolChains/CommonArgs.h index f364c9793c9be62..0a0951c5386e601 100644 --- a/clang/lib/Driver/ToolChains/CommonArgs.h +++ b/clang/lib/Driver/ToolChains/CommonArgs.h @@ -116,7 +116,7 @@ bool addOpenMPRuntime(llvm::opt::ArgStringList &CmdArgs, const ToolChain &TC, bool IsOffloadingHost = false, bool GompNeedsRT = false); /// Adds Fortran runtime libraries to \p CmdArgs. -void addFortranRuntimeLibs(const ToolChain &TC, +void addFortranRuntimeLibs(const ToolChain &TC, const llvm::opt::ArgList &Args, llvm::opt::ArgStringList &CmdArgs); /// Adds the path for the Fortran runtime libraries to \p CmdArgs. diff --git a/clang/lib/Driver/ToolChains/Darwin.cpp b/clang/lib/Driver/ToolChains/Darwin.cpp index 1f61bb02c6ae226..7c3d4982d8f6a8c 100644 --- a/clang/lib/Driver/ToolChains/Darwin.cpp +++ b/clang/lib/Driver/ToolChains/Darwin.cpp @@ -678,7 +678,7 @@ void darwin::Linker::ConstructJob(Compilation &C, const JobAction &JA, // to generate executables. if (getToolChain().getDriver().IsFlangMode()) { addFortranRuntimeLibraryPath(getToolChain(), Args, CmdArgs); - addFortranRuntimeLibs(getToolChain(), CmdArgs); + addFortranRuntimeLibs(getToolChain(), Args, CmdArgs); } if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) diff --git a/clang/lib/Driver/ToolChains/DragonFly.cpp b/clang/lib/Driver/ToolChains/DragonFly.cpp index 181d0ad0d834b2b..9942fc632e0a917 100644 --- a/clang/lib/Driver/ToolChains/DragonFly.cpp +++ b/clang/lib/Driver/ToolChains/DragonFly.cpp @@ -153,7 +153,7 @@ void dragonfly::Linker::ConstructJob(Compilation &C, const JobAction &JA, // AddRunTimeLibs). if (D.IsFlangMode()) { addFortranRuntimeLibraryPath(ToolChain, Args, CmdArgs); - addFortranRuntimeLibs(ToolChain, CmdArgs); + addFortranRuntimeLibs(ToolChain, Args, CmdArgs); CmdArgs.push_back("-lm"); } diff --git a/clang/lib/Driver/ToolChains/FreeBSD.cpp b/clang/lib/Driver/ToolChains/FreeBSD.cpp index d08764aeef77539..d46feb3459a6344 100644 --- a/clang/lib/Driver/ToolChains/FreeBSD.cpp +++ b/clang/lib/Driver/ToolChains/FreeBSD.cpp @@ -310,7 +310,7 @@ void freebsd::Linker::ConstructJob(Compilation &C, const JobAction &JA, // AddRunTimeLibs). if (D.IsFlangMode()) { addFortranRuntimeLibraryPath(ToolChain, Args, CmdArgs); - addFortranRuntimeLibs(ToolChain, CmdArgs); + addFortranRuntimeLibs(ToolChain, Args, CmdArgs); if (Profiling) CmdArgs.push_back("-lm_p"); else diff --git a/clang/lib/Driver/ToolChains/Gnu.cpp b/clang/lib/Driver/ToolChains/Gnu.cpp index 16cf5707227264d..b875991844ffff5 100644 --- a/clang/lib/Driver/ToolChains/Gnu.cpp +++ b/clang/lib/Driver/ToolChains/Gnu.cpp @@ -564,7 +564,7 @@ void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA, // AddRunTimeLibs). if (D.IsFlangMode()) { addFortranRuntimeLibraryPath(ToolChain, Args, CmdArgs); - addFortranRuntimeLibs(ToolChain, CmdArgs); + addFortranRuntimeLibs(ToolChain, Args, CmdArgs); CmdArgs.push_back("-lm"); } diff --git a/clang/lib/Driver/ToolChains/Haiku.cpp b/clang/lib/Driver/ToolChains/Haiku.cpp index 3fe92054ac53e15..e0d94035823fd37 100644 --- a/clang/lib/Driver/ToolChains/Haiku.cpp +++ b/clang/lib/Driver/ToolChains/Haiku.cpp @@ -118,7 +118,7 @@ void haiku::Linker::ConstructJob(Compilation &C, const JobAction &JA, // AddRunTimeLibs). if (D.IsFlangMode()) { addFortranRuntimeLibraryPath(ToolChain, Args, CmdArgs); - addFortranRuntimeLibs(ToolChain, CmdArgs); + addFortranRuntimeLibs(ToolChain, Args, CmdArgs); } CmdArgs.push_back("-lgcc"); diff --git a/clang/lib/Driver/ToolChains/MSVC.cpp b/clang/lib/Driver/ToolChains/MSVC.cpp index 4966d102c51f1ac..8a4a174c90ea855 100644 --- a/clang/lib/Driver/ToolChains/MSVC.cpp +++ b/clang/lib/Driver/ToolChains/MSVC.cpp @@ -131,7 +131,7 @@ void visualstudio::Linker::ConstructJob(Compilation &C, const JobAction &JA, if (C.getDriver().IsFlangMode()) { addFortranRuntimeLibraryPath(TC, Args, CmdArgs); - addFortranRuntimeLibs(TC, CmdArgs); + addFortranRuntimeLibs(TC, Args, CmdArgs); // Inform the MSVC linker that we're generating a console application, i.e. // one with `main` as the "user-defined" entry point. The `main` function is diff --git a/clang/lib/Driver/ToolChains/MinGW.cpp b/clang/lib/Driver/ToolChains/MinGW.cpp index 39d767795445dbe..5d7f8675daf8d28 100644 --- a/clang/lib/Driver/ToolChains/MinGW.cpp +++ b/clang/lib/Driver/ToolChains/MinGW.cpp @@ -249,7 +249,7 @@ void tools::MinGW::Linker::ConstructJob(Compilation &C, const JobAction &JA, if (C.getDriver().IsFlangMode()) { addFortranRuntimeLibraryPath(TC, Args, CmdArgs); - addFortranRuntimeLibs(TC, CmdArgs); + addFortranRuntimeLibs(TC, Args, CmdArgs); } // TODO: Add profile stuff here diff --git a/clang/lib/Driver/ToolChains/NetBSD.cpp b/clang/lib/Driver/ToolChains/NetBSD.cpp index 90b195a007caa78..240bf5764b9cce2 100644 --- a/clang/lib/Driver/ToolChains/NetBSD.cpp +++ b/clang/lib/Driver/ToolChains/NetBSD.cpp @@ -325,7 +325,7 @@ void netbsd::Linker::ConstructJob(Compilation &C, const JobAction &JA, // AddRunTimeLibs). if (D.IsFlangMode()) { addFortranRuntimeLibraryPath(ToolChain, Args, CmdArgs); - addFortranRuntimeLibs(ToolChain, CmdArgs); + addFortranRuntimeLibs(ToolChain, Args, CmdArgs); CmdArgs.push_back("-lm"); } diff --git a/clang/lib/Driver/ToolChains/OpenBSD.cpp b/clang/lib/Driver/ToolChains/OpenBSD.cpp index 133b5ff13a4c7e2..21b9004ef2d52d1 100644 --- a/clang/lib/Driver/ToolChains/OpenBSD.cpp +++ b/clang/lib/Driver/ToolChains/OpenBSD.cpp @@ -237,7 +237,7 @@ void openbsd::Linker::ConstructJob(Compilation &C, const JobAction &JA, // AddRunTimeLibs). if (D.IsFlangMode()) { addFortranRuntimeLibraryPath(ToolChain, Args, CmdArgs); - addFortranRuntimeLibs(ToolChain, CmdArgs); + addFortranRuntimeLibs(ToolChain, Args, CmdArgs); if (Profiling) CmdArgs.push_back("-lm_p"); else diff --git a/clang/lib/Driver/ToolChains/Solaris.cpp b/clang/lib/Driver/ToolChains/Solaris.cpp index 32b6cbe647da6ad..485730da7df1f8c 100644 --- a/clang/lib/Driver/ToolChains/Solaris.cpp +++ b/clang/lib/Driver/ToolChains/Solaris.cpp @@ -226,7 +226,7 @@ void solaris::Linker::ConstructJob(Compilation &C, const JobAction &JA, // these dependencies need to be listed before the C runtime below. if (D.IsFlangMode()) { addFortranRuntimeLibraryPath(getToolChain(), Args, CmdArgs); - addFortranRuntimeLibs(getToolChain(), CmdArgs); + addFortranRuntimeLibs(getToolChain(), Args, CmdArgs); CmdArgs.push_back("-lm"); } if (Args.hasArg(options::OPT_fstack_protector) || diff --git a/flang/test/Driver/Inputs/no_duplicate_main.ll b/flang/test/Driver/Inputs/no_duplicate_main.ll new file mode 100644 index 000000000000000..ff2b19dfe9e288b --- /dev/null +++ b/flang/test/Driver/Inputs/no_duplicate_main.ll @@ -0,0 +1,7 @@ +; Create the symbol 'main'; does not have to be the correct +; signature for 'main', we just need the symbol for the linker +; to fail during the test. + +define i32 @main() { + ret i32 0 +} diff --git a/flang/test/Driver/linker-flags.f90 b/flang/test/Driver/linker-flags.f90 index 85c4d60b3f09862..ea91946316cfaa6 100644 --- a/flang/test/Driver/linker-flags.f90 +++ b/flang/test/Driver/linker-flags.f90 @@ -28,7 +28,7 @@ ! executable and may find the GNU linker from MinGW or Cygwin. ! UNIX-LABEL: "{{.*}}ld{{(\.exe)?}}" ! UNIX-SAME: "[[object_file]]" -! UNIX-SAME: "-lFortran_main" "-lFortranRuntime" "-lFortranDecimal" "-lm" +! UNIX-SAME: "--whole-archive" "-lFortran_main" "--no-whole-archive" "-lFortranRuntime" "-lFortranDecimal" "-lm" ! DARWIN-LABEL: "{{.*}}ld{{(\.exe)?}}" ! DARWIN-SAME: "[[object_file]]" @@ -38,7 +38,7 @@ ! HAIKU-LABEL: "{{.*}}ld{{(\.exe)?}}" ! HAIKU-SAME: "[[object_file]]" -! HAIKU-SAME: "-lFortran_main" "-lFortranRuntime" "-lFortranDecimal" +! HAIKU-SAME: "--whole-archive" "-lFortran_main" "--no-whole-archive" "-lFortranRuntime" "-lFortranDecimal" ! MINGW-LABEL: "{{.*}}ld{{(\.exe)?}}" ! MINGW-SAME: "[[object_file]]" diff --git a/flang/test/Driver/no_duplicate_main.f90 b/flang/test/Driver/no_duplicate_main.f90 new file mode 100644 index 000000000000000..4e33f4f2aeba3f7 --- /dev/null +++ b/flang/test/Driver/no_duplicate_main.f90 @@ -0,0 +1,14 @@ +! UNSUPPORTED: system-windows + +! RUN: %flang -x ir -o %t.c-object -c %S/Inputs/no_duplicate_main.ll +! RUN: %flang -o %t -c %s +! RUN: not %flang -o %t.exe %t %t.c-object 2>&1 + +! TODO: potentially add further checks to ensure that proper +! linker error messages are detected and checked via +! FileCheck. + +program main_dupes + ! Irrelevant what to do in here. + ! Test is supposed to fail at link time. +end program main_dupes _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
