[flang-commits] [flang] [clang] [flang][driver] Add -fno-fortran-main (link time) option to remove Fortran_main from link line (PR #74139)
Michael Klemm via flang-commits
flang-commits at lists.llvm.org
Mon Dec 4 04:49:22 PST 2023
https://github.com/mjklemm updated https://github.com/llvm/llvm-project/pull/74139
>From 2e41335a7de3d2efa88eacee659172a3b9525e45 Mon Sep 17 00:00:00 2001
From: Michael Klemm <michael.klemm at amd.com>
Date: Fri, 1 Dec 2023 21:41:44 +0100
Subject: [PATCH 1/5] Add -fno-fortran-main driver option
---
clang/include/clang/Driver/Options.td | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 19d04e82aed4d..aa26344f67b31 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -6345,6 +6345,10 @@ def J : JoinedOrSeparate<["-"], "J">,
Group<gfortran_Group>,
Alias<module_dir>;
+def no_fortran_main : Flag<["-"], "fno-fortran-main">,
+ Visibility<[FlangOption]>, Group<f_Group>,
+ HelpText<"Don't link in Fortran main">;
+
//===----------------------------------------------------------------------===//
// FC1 Options
//===----------------------------------------------------------------------===//
>From 44b684ae43a6da37bb56c5b699628c6807257ad9 Mon Sep 17 00:00:00 2001
From: Michael Klemm <michael.klemm at amd.com>
Date: Fri, 1 Dec 2023 21:42:09 +0100
Subject: [PATCH 2/5] Skip linking Fortran_main.a if -fno-fortran-main is
present
---
clang/lib/Driver/ToolChains/CommonArgs.cpp | 46 ++++++++++++----------
1 file changed, 25 insertions(+), 21 deletions(-)
diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index 0ae8e2dce32e9..2899f07cb7490 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -1116,33 +1116,37 @@ bool tools::addOpenMPRuntime(ArgStringList &CmdArgs, const ToolChain &TC,
return true;
}
+// TODO: add -fno-fortran-main option and check it in this function.
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 DontLinkFortranMain = Args.getLastArg(options::OPT_no_fortran_main) != nullptr;
+ if (!DontLinkFortranMain) {
+ // 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");
>From e1a472fa914ea9405be6589e89fbe8201448600f Mon Sep 17 00:00:00 2001
From: Michael Klemm <michael.klemm at amd.com>
Date: Fri, 1 Dec 2023 15:10:29 -0600
Subject: [PATCH 3/5] Cleanup and simplify the code a bit
---
clang/lib/Driver/ToolChains/CommonArgs.cpp | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index 2899f07cb7490..f0e3df2a63ae9 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -1116,14 +1116,13 @@ bool tools::addOpenMPRuntime(ArgStringList &CmdArgs, const ToolChain &TC,
return true;
}
-// TODO: add -fno-fortran-main option and check it in this function.
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()) {
// if -fno-fortran-main has been passed, skip linking Fortran_main.a
- bool DontLinkFortranMain = Args.getLastArg(options::OPT_no_fortran_main) != nullptr;
+ bool DontLinkFortranMain = Args.hasArg(options::OPT_no_fortran_main);
if (!DontLinkFortranMain) {
// 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
>From fd6cc81bd2ac594b23c6e8f96ad81e18fb1213d2 Mon Sep 17 00:00:00 2001
From: Michael Klemm <michael.klemm at amd.com>
Date: Fri, 1 Dec 2023 22:13:25 +0100
Subject: [PATCH 4/5] Update test to reflect positive outcome for
-fno-fortran-main
---
flang/test/Driver/no_duplicate_main.f90 | 2 ++
1 file changed, 2 insertions(+)
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.
>From ea737ae2f50938e5e20b300ac6fe7351413a3b07 Mon Sep 17 00:00:00 2001
From: Michael Klemm <michael at dontknow.de>
Date: Mon, 4 Dec 2023 13:48:27 +0100
Subject: [PATCH 5/5] Respect -fno-fortran-main also for MSVC
---
clang/lib/Driver/ToolChains/CommonArgs.cpp | 53 ++++++++++++----------
clang/lib/Driver/ToolChains/Flang.cpp | 14 ++++--
2 files changed, 38 insertions(+), 29 deletions(-)
diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index f0e3df2a63ae9..dd75314e989f9 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -1120,10 +1120,11 @@ 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);
if (!TC.getTriple().isKnownWindowsMSVCEnvironment()) {
- // if -fno-fortran-main has been passed, skip linking Fortran_main.a
- bool DontLinkFortranMain = Args.hasArg(options::OPT_no_fortran_main);
- if (!DontLinkFortranMain) {
+ 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
@@ -1150,28 +1151,30 @@ void tools::addFortranRuntimeLibs(const ToolChain &TC, const ArgList &Args,
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;
+ 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;
+ }
}
}
}
diff --git a/clang/lib/Driver/ToolChains/Flang.cpp b/clang/lib/Driver/ToolChains/Flang.cpp
index 98b337e60e4ff..0c6d097c54e21 100644
--- a/clang/lib/Driver/ToolChains/Flang.cpp
+++ b/clang/lib/Driver/ToolChains/Flang.cpp
@@ -209,6 +209,8 @@ 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")));
@@ -226,7 +228,8 @@ 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)
+ :wCmdArgs.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;
@@ -234,7 +237,8 @@ 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;
@@ -242,7 +246,8 @@ 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;
@@ -251,7 +256,8 @@ 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;
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