[clang] [flang] [flang][driver] Add -fno-fortran-main (link time) option to remove Fortran_main from link line (PR #74139)

2023-12-11 Thread Michael Klemm via cfe-commits 

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 
Date: Fri, 1 Dec 2023 21:41:44 +0100
Subject: [PATCH 1/9] 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 19d04e82aed4d6..aa26344f67b313 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -6345,6 +6345,10 @@ def J : JoinedOrSeparate<["-"], "J">,
   Group,
   Alias;
 
+def no_fortran_main : Flag<["-"], "fno-fortran-main">,
+  Visibility<[FlangOption]>, Group,
+  HelpText<"Don't link in Fortran main">;
+
 
//===--===//
 // FC1 Options
 
//===--===//

>From 44b684ae43a6da37bb56c5b699628c6807257ad9 Mon Sep 17 00:00:00 2001
From: Michael Klemm 
Date: Fri, 1 Dec 2023 21:42:09 +0100
Subject: [PATCH 2/9] 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 0ae8e2dce32e94..2899f07cb7490c 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -1116,33 +1116,37 @@ bool tools::addOpenMPRuntime(ArgStringList , 
const ToolChain ,
   return true;
 }
 
+// TODO: add -fno-fortran-main option and check it in this function.
 void tools::addFortranRuntimeLibs(const ToolChain , const ArgList ,
   llvm::opt::ArgStringList ) {
   // 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 
Date: Fri, 1 Dec 2023 15:10:29 -0600
Subject: [PATCH 3/9] 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 2899f07cb7490c..f0e3df2a63ae98 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++

[clang] [flang] [flang][driver] Add -fno-fortran-main (link time) option to remove Fortran_main from link line (PR #74139)

2023-12-08 Thread Andrzej Warzyński via cfe-commits 


@@ -6345,6 +6345,10 @@ def J : JoinedOrSeparate<["-"], "J">,
   Group,
   Alias;
 
+def no_fortran_main : Flag<["-"], "fno-fortran-main">,
+  Visibility<[FlangOption]>, Group,
+  HelpText<"Don't link in Fortran main">;

banach-space wrote:

[nit] For folks less familiar with the compiler internals, it would be a good 
to be a bit more specific, e.g:

```bash
Skip Fortran_main.a (provided by Flang) when linking
```

WDYT? This is also something worth documenting ;-)

https://github.com/llvm/llvm-project/pull/74139
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[clang] [flang] [flang][driver] Add -fno-fortran-main (link time) option to remove Fortran_main from link line (PR #74139)

2023-12-07 Thread Michael Klemm via cfe-commits 

mjklemm wrote:

> I know that it's extra work, but it's also super useful bit of documentation. 
> And I would only rarely try to track the history beyond commit messages 
> (there's just too much otherwise).

I can absolutely do that.  I'll craft some wording for the rationale behind 
that change and add it to the PR.

https://github.com/llvm/llvm-project/pull/74139
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[clang] [flang] [flang][driver] Add -fno-fortran-main (link time) option to remove Fortran_main from link line (PR #74139)

2023-12-07 Thread Michael Klemm via cfe-commits 


@@ -6345,6 +6345,10 @@ def J : JoinedOrSeparate<["-"], "J">,
   Group,
   Alias;
 
+def no_fortran_main : Flag<["-"], "fno-fortran-main">,
+  Visibility<[FlangOption]>, Group,
+  HelpText<"Don't link in Fortran main">;
+

mjklemm wrote:

@banach-space 

```
let Visibility = [FlangOption] in {
def no_fortran_main : Flag<["-"], "fno-fortran-main">,
  Visibility<[FlangOption]>, Group,
  HelpText<"Don't link in Fortran main">;
} // let Visibility = [ FlangOption ]
```

Was that the suggested edit?  I guess  `-J` should not be be modified as part 
of the edit, right?

https://github.com/llvm/llvm-project/pull/74139
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[clang] [flang] [flang][driver] Add -fno-fortran-main (link time) option to remove Fortran_main from link line (PR #74139)

2023-12-07 Thread Michael Klemm via cfe-commits 

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 
Date: Fri, 1 Dec 2023 21:41:44 +0100
Subject: [PATCH 1/8] 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,
   Alias;
 
+def no_fortran_main : Flag<["-"], "fno-fortran-main">,
+  Visibility<[FlangOption]>, Group,
+  HelpText<"Don't link in Fortran main">;
+
 
//===--===//
 // FC1 Options
 
//===--===//

>From 44b684ae43a6da37bb56c5b699628c6807257ad9 Mon Sep 17 00:00:00 2001
From: Michael Klemm 
Date: Fri, 1 Dec 2023 21:42:09 +0100
Subject: [PATCH 2/8] 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 , 
const ToolChain ,
   return true;
 }
 
+// TODO: add -fno-fortran-main option and check it in this function.
 void tools::addFortranRuntimeLibs(const ToolChain , const ArgList ,
   llvm::opt::ArgStringList ) {
   // 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 
Date: Fri, 1 Dec 2023 15:10:29 -0600
Subject: [PATCH 3/8] 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
+++

[clang] [flang] [flang][driver] Add -fno-fortran-main (link time) option to remove Fortran_main from link line (PR #74139)

2023-12-07 Thread Michael Klemm via cfe-commits 

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 
Date: Fri, 1 Dec 2023 21:41:44 +0100
Subject: [PATCH 1/7] 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,
   Alias;
 
+def no_fortran_main : Flag<["-"], "fno-fortran-main">,
+  Visibility<[FlangOption]>, Group,
+  HelpText<"Don't link in Fortran main">;
+
 
//===--===//
 // FC1 Options
 
//===--===//

>From 44b684ae43a6da37bb56c5b699628c6807257ad9 Mon Sep 17 00:00:00 2001
From: Michael Klemm 
Date: Fri, 1 Dec 2023 21:42:09 +0100
Subject: [PATCH 2/7] 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 , 
const ToolChain ,
   return true;
 }
 
+// TODO: add -fno-fortran-main option and check it in this function.
 void tools::addFortranRuntimeLibs(const ToolChain , const ArgList ,
   llvm::opt::ArgStringList ) {
   // 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 
Date: Fri, 1 Dec 2023 15:10:29 -0600
Subject: [PATCH 3/7] 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
+++

[clang] [flang] [flang][driver] Add -fno-fortran-main (link time) option to remove Fortran_main from link line (PR #74139)

2023-12-07 Thread Andrzej Warzyński via cfe-commits 

https://github.com/banach-space commented:

Thanks for pushing on!

I've made one small suggestion and I also have one more request for the 
summary. I know that you added links to relevant PRs, but I would still 
appreciate if the summary (and the commit msg) where self-contained and 
included the justification for this new flag. You could use the example by 
@tblah to show where the flag might be needed. Please do keep the links :) 

I think that it would also be helpful to include what could be an alternative 
to this and that wouldn't require a flag - I think that the only option would 
be to mimic what Classic Flang does?

I know that it's extra work, but it's also super useful bit of documentation. 
And I would only rarely try to track the history beyond commit messages 
(there's just too much otherwise). 

https://github.com/llvm/llvm-project/pull/74139
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[clang] [flang] [flang][driver] Add -fno-fortran-main (link time) option to remove Fortran_main from link line (PR #74139)

2023-12-04 Thread Michael Klemm via cfe-commits 

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 
Date: Fri, 1 Dec 2023 21:41:44 +0100
Subject: [PATCH 1/6] 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,
   Alias;
 
+def no_fortran_main : Flag<["-"], "fno-fortran-main">,
+  Visibility<[FlangOption]>, Group,
+  HelpText<"Don't link in Fortran main">;
+
 
//===--===//
 // FC1 Options
 
//===--===//

>From 44b684ae43a6da37bb56c5b699628c6807257ad9 Mon Sep 17 00:00:00 2001
From: Michael Klemm 
Date: Fri, 1 Dec 2023 21:42:09 +0100
Subject: [PATCH 2/6] 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 , 
const ToolChain ,
   return true;
 }
 
+// TODO: add -fno-fortran-main option and check it in this function.
 void tools::addFortranRuntimeLibs(const ToolChain , const ArgList ,
   llvm::opt::ArgStringList ) {
   // 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 
Date: Fri, 1 Dec 2023 15:10:29 -0600
Subject: [PATCH 3/6] 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
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[clang] [flang] [flang][driver] Add -fno-fortran-main (link time) option to remove Fortran_main from link line (PR #74139)

2023-12-04 Thread David Truby via cfe-commits 

DavidTruby wrote:

I think this solution is fine, at least in the short term. 

I had a think after reviewing the initial patch and looking at the failure that 
@tblah showed in #73124; my thoughts are that the “correct” way of doing this 
would be instead of linking Fortran_main all the time, we could insert a linker 
directive in the object file containing the program statement. That way we 
would only link Fortran_main when there is actually a program statement in the 
Fortran. However that’s more work and would need a bit more thought anyway so 
we at least need something like this or the revert in the interim.

https://github.com/llvm/llvm-project/pull/74139
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