llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang-driver @llvm/pr-subscribers-clang Author: Michael Klemm (mjklemm) <details> <summary>Changes</summary> At present, when building static or shared libraries, Flang adds `-lFortran_main.a` (or `/WHOLEARCHIVE:Fortran.*.lib` pon Windows) to the link line. This leads to the problem that `_QQmain` and `_QQEnvironmentDefaults` (as of the time of this PR) are symbols marked as used, while `main` is being defined. This should not happen and this PR fixes this by detecting if `-shared` or `-static` is used on the Flang command line and removing the static `Fortran_main` library. --- Full diff: https://github.com/llvm/llvm-project/pull/75816.diff 2 Files Affected: - (modified) clang/lib/Driver/ToolChains/CommonArgs.cpp (+20) - (modified) flang/test/Driver/dynamic-linker.f90 (+6-2) ``````````diff diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp index 45901ee7157f77..05ebd42829c95d 100644 --- a/clang/lib/Driver/ToolChains/CommonArgs.cpp +++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp @@ -1133,6 +1133,16 @@ static bool isWholeArchivePresent(const ArgList &Args) { return WholeArchiveActive; } +/// Determine if driver is invoked to create a shared object library (-static) +static bool isSharedLinkage(const ArgList &Args) { + return Args.hasArg(options::OPT_shared); +} + +/// Determine if driver is invoked to create a static object library (-shared) +static bool isStaticLinkage(const ArgList &Args) { + return Args.hasArg(options::OPT_static); +} + /// Add Fortran runtime libs for MSVC static void addFortranRuntimeLibsMSVC(const ArgList &Args, llvm::opt::ArgStringList &CmdArgs) { @@ -1164,6 +1174,16 @@ static void addFortranRuntimeLibsMSVC(const ArgList &Args, // Add FortranMain runtime lib static void addFortranMain(const ToolChain &TC, const ArgList &Args, llvm::opt::ArgStringList &CmdArgs) { + // 0. Shared-library linkage + // If we are attempting to link a library, we should not add + // -lFortran_main.a to the link line, as the `main` symbol is not + // required for a library and should also be provided by one of + // the translation units of the code that this shared library + // will be linked against eventually. + if (isSharedLinkage(Args) || isStaticLinkage(Args)) { + return; + } + // 1. MSVC if (TC.getTriple().isKnownWindowsMSVCEnvironment()) { addFortranRuntimeLibsMSVC(Args, CmdArgs); diff --git a/flang/test/Driver/dynamic-linker.f90 b/flang/test/Driver/dynamic-linker.f90 index df119c22a2ea51..af07e2483f93fa 100644 --- a/flang/test/Driver/dynamic-linker.f90 +++ b/flang/test/Driver/dynamic-linker.f90 @@ -3,18 +3,22 @@ ! RUN: %flang -### --target=x86_64-linux-gnu -rpath /path/to/dir -shared \ ! RUN: -static %s 2>&1 | FileCheck \ -! RUN: --check-prefixes=GNU-LINKER-OPTIONS %s +! RUN: --check-prefixes=GNU-LINKER-OPTIONS \ +! RUN: --implicit-check-not=GNU-LINKER-OPTIONS-NOT %s ! RUN: %flang -### --target=x86_64-windows-msvc -rpath /path/to/dir -shared \ ! RUN: -static %s 2>&1 | FileCheck \ -! RUN: --check-prefixes=MSVC-LINKER-OPTIONS %s +! RUN: --check-prefixes=MSVC-LINKER-OPTIONS \ +! RUN: --implicit-check-not=MSVC-LINKER-OPTIONS-NOT %s ! TODO: Could the linker have an extension or a suffix? ! GNU-LINKER-OPTIONS: "{{.*}}ld{{(.exe)?}}" ! GNU-LINKER-OPTIONS-SAME: "-shared" ! GNU-LINKER-OPTIONS-SAME: "-static" ! GNU-LINKER-OPTIONS-SAME: "-rpath" "/path/to/dir" +! GNU-LINKER-OPTIONS-NOT: "-lFortran_main.a" ! For MSVC, adding -static does not add any additional linker options. ! MSVC-LINKER-OPTIONS: "{{.*}}link{{(.exe)?}}" ! MSVC-LINKER-OPTIONS-SAME: "-dll" ! MSVC-LINKER-OPTIONS-SAME: "-rpath" "/path/to/dir" +! MSVC-LINKER-OPTIONS-NOT: "/WHOLEARCHIVE:Fortran_main" `````````` </details> https://github.com/llvm/llvm-project/pull/75816 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
