diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td index b959fd20fe413..cf969cb0b318a 100644 --- a/clang/include/clang/Driver/Options.td +++ b/clang/include/clang/Driver/Options.td @@ -6354,6 +6354,12 @@ def J : JoinedOrSeparate<["-"], "J">, Group, Alias; +let Visibility = [FlangOption] in { +def no_fortran_main : Flag<["-"], "fno-fortran-main">, + Visibility<[FlangOption]>, Group, + HelpText<"Do not include Fortran_main.a (provided by Flang) when linking">; +} // let Visibility = [ FlangOption ] + //===----------------------------------------------------------------------===// // FC1 Options //===----------------------------------------------------------------------===// diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp index 51b336216c565..31e7d68161ff1 100644 --- a/clang/lib/Driver/ToolChains/CommonArgs.cpp +++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp @@ -1120,55 +1120,61 @@ 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"); + // if -fno-fortran-main has been passed, skip linking Fortran_main.a + bool LinkFortranMain = !Args.hasArg(options::OPT_no_fortran_main); + 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; + } + 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(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; + if (LinkFortranMain) { + unsigned RTOptionID = options::OPT__SLASH_MT; + if (auto *rtl = Args.getLastArg(options::OPT_fms_runtime_lib_EQ)) { + RTOptionID = llvm::StringSwitch(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/Flang.cpp b/clang/lib/Driver/ToolChains/Flang.cpp index 9b21fe952af7a..502b9f17a06c5 100644 --- a/clang/lib/Driver/ToolChains/Flang.cpp +++ b/clang/lib/Driver/ToolChains/Flang.cpp @@ -231,6 +231,8 @@ static void processVSRuntimeLibrary(const ToolChain &TC, const ArgList &Args, ArgStringList &CmdArgs) { assert(TC.getTriple().isKnownWindowsMSVCEnvironment() && "can only add VS runtime library on Windows!"); + // if -fno-fortran-main has been passed, skip linking Fortran_main.a + bool LinkFortranMain = !Args.hasArg(options::OPT_no_fortran_main); if (TC.getTriple().isKnownWindowsMSVCEnvironment()) { CmdArgs.push_back(Args.MakeArgString( "--dependent-lib=" + TC.getCompilerRTBasename(Args, "builtins"))); @@ -248,7 +250,8 @@ static void processVSRuntimeLibrary(const ToolChain &TC, const ArgList &Args, case options::OPT__SLASH_MT: CmdArgs.push_back("-D_MT"); CmdArgs.push_back("--dependent-lib=libcmt"); - CmdArgs.push_back("--dependent-lib=Fortran_main.static.lib"); + if (LinkFortranMain) + CmdArgs.push_back("--dependent-lib=Fortran_main.static.lib"); CmdArgs.push_back("--dependent-lib=FortranRuntime.static.lib"); CmdArgs.push_back("--dependent-lib=FortranDecimal.static.lib"); break; @@ -256,7 +259,8 @@ static void processVSRuntimeLibrary(const ToolChain &TC, const ArgList &Args, CmdArgs.push_back("-D_MT"); CmdArgs.push_back("-D_DEBUG"); CmdArgs.push_back("--dependent-lib=libcmtd"); - CmdArgs.push_back("--dependent-lib=Fortran_main.static_dbg.lib"); + if (LinkFortranMain) + CmdArgs.push_back("--dependent-lib=Fortran_main.static_dbg.lib"); CmdArgs.push_back("--dependent-lib=FortranRuntime.static_dbg.lib"); CmdArgs.push_back("--dependent-lib=FortranDecimal.static_dbg.lib"); break; @@ -264,7 +268,8 @@ static void processVSRuntimeLibrary(const ToolChain &TC, const ArgList &Args, CmdArgs.push_back("-D_MT"); CmdArgs.push_back("-D_DLL"); CmdArgs.push_back("--dependent-lib=msvcrt"); - CmdArgs.push_back("--dependent-lib=Fortran_main.dynamic.lib"); + if (LinkFortranMain) + CmdArgs.push_back("--dependent-lib=Fortran_main.dynamic.lib"); CmdArgs.push_back("--dependent-lib=FortranRuntime.dynamic.lib"); CmdArgs.push_back("--dependent-lib=FortranDecimal.dynamic.lib"); break; @@ -273,7 +278,8 @@ static void processVSRuntimeLibrary(const ToolChain &TC, const ArgList &Args, CmdArgs.push_back("-D_DEBUG"); CmdArgs.push_back("-D_DLL"); CmdArgs.push_back("--dependent-lib=msvcrtd"); - CmdArgs.push_back("--dependent-lib=Fortran_main.dynamic_dbg.lib"); + if (LinkFortranMain) + CmdArgs.push_back("--dependent-lib=Fortran_main.dynamic_dbg.lib"); CmdArgs.push_back("--dependent-lib=FortranRuntime.dynamic_dbg.lib"); CmdArgs.push_back("--dependent-lib=FortranDecimal.dynamic_dbg.lib"); break; diff --git a/flang/test/Driver/driver-help-hidden.f90 b/flang/test/Driver/driver-help-hidden.f90 index 8cb8b54d59412..9a11a7a571ffc 100644 --- a/flang/test/Driver/driver-help-hidden.f90 +++ b/flang/test/Driver/driver-help-hidden.f90 @@ -64,6 +64,7 @@ ! CHECK-NEXT: Select Windows run-time library ! CHECK-NEXT: -fno-automatic Implies the SAVE attribute for non-automatic local objects in subprograms unless RECURSIVE ! CHECK-NEXT: -fno-color-diagnostics Disable colors in diagnostics +! CHECK-NEXT: -fno-fortran-main Do not include Fortran_main.a (provided by Flang) when linking ! CHECK-NEXT: -fno-integrated-as Disable the integrated assembler ! CHECK-NEXT: -fno-lto Disable LTO mode (default) ! CHECK-NEXT: -fno-ppc-native-vector-element-order diff --git a/flang/test/Driver/driver-help.f90 b/flang/test/Driver/driver-help.f90 index 0607ffde23789..e0e74dc56f331 100644 --- a/flang/test/Driver/driver-help.f90 +++ b/flang/test/Driver/driver-help.f90 @@ -54,6 +54,7 @@ ! HELP-NEXT: Select Windows run-time library ! HELP-NEXT: -fno-automatic Implies the SAVE attribute for non-automatic local objects in subprograms unless RECURSIVE ! HELP-NEXT: -fno-color-diagnostics Disable colors in diagnostics +! HELP-NEXT: -fno-fortran-main Do not include Fortran_main.a (provided by Flang) when linking ! HELP-NEXT: -fno-integrated-as Disable the integrated assembler ! HELP-NEXT: -fno-lto Disable LTO mode (default) ! HELP-NEXT: -fno-ppc-native-vector-element-order diff --git a/flang/test/Driver/no-duplicate-main.f90 b/flang/test/Driver/no-duplicate-main.f90 index 4e33f4f2aeba3..12d5e46247bad 100644 --- a/flang/test/Driver/no-duplicate-main.f90 +++ b/flang/test/Driver/no-duplicate-main.f90 @@ -4,6 +4,8 @@ ! RUN: %flang -o %t -c %s ! RUN: not %flang -o %t.exe %t %t.c-object 2>&1 +! RUN: %flang -fno-fortran-main -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.