From fef6cae00ce2138d3714fce5d4dfbde4f3c68922 Mon Sep 17 00:00:00 2001
From: Guillaume Giudicelli <guillaume.giudicelli@inl.gov>
Date: Mon, 13 Jan 2025 15:54:30 -0700
Subject: [PATCH 1/3] Use DWARF unwinding with Clang to avoid overproduction of
 linking warnings with clang + gfortran refs idaholab/moose#29009

---
 acsm_compiler_flags.m4 | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/acsm_compiler_flags.m4 b/acsm_compiler_flags.m4
index dc075fb..e35a37d 100644
--- a/acsm_compiler_flags.m4
+++ b/acsm_compiler_flags.m4
@@ -585,6 +585,10 @@ AC_DEFUN([ACSM_SET_CXX_FLAGS],
                        ],
 
             [clang], [
+                       dnl On Darwin with clang + gfortran, we get very many warnings for compact unwinding issues
+                       dnl We deliberately keep relying on the less performant dwarf unwinding until the over-production of warnings is solved.
+                       ACSM_LDFLAGS="-Wl,-keep_dwarf_unwind -Wl,-no_compact_unwind"
+
                        ACSM_CXXFLAGS_OPT="$ACSM_CXXFLAGS_OPT -O2 -felide-constructors -Qunused-arguments -Wunused-parameter -Wunused"
                        dnl devel flags are added on two lines since there are so many
                        ACSM_CXXFLAGS_DEVEL="$ACSM_CXXFLAGS_DEVEL -O2 -felide-constructors -g -pedantic -W -Wall -Wextra -Wno-long-long"

From ac331541486f35c6a54d47abd2d996e897270a85 Mon Sep 17 00:00:00 2001
From: Guillaume Giudicelli <guillaume.giudicelli@inl.gov>
Date: Thu, 30 Jan 2025 08:17:16 -0700
Subject: [PATCH 2/3] Add a linking test before adding linking flags to disable
 compact unwinding

---
 acsm_compiler_flags.m4 | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/acsm_compiler_flags.m4 b/acsm_compiler_flags.m4
index e35a37d..2def975 100644
--- a/acsm_compiler_flags.m4
+++ b/acsm_compiler_flags.m4
@@ -587,7 +587,21 @@ AC_DEFUN([ACSM_SET_CXX_FLAGS],
             [clang], [
                        dnl On Darwin with clang + gfortran, we get very many warnings for compact unwinding issues
                        dnl We deliberately keep relying on the less performant dwarf unwinding until the over-production of warnings is solved.
-                       ACSM_LDFLAGS="-Wl,-keep_dwarf_unwind -Wl,-no_compact_unwind"
+                       OLD_ACSM_LDFLAGS="$ACSM_LDFLAGS"
+                       ACSM_LDFLAGS+=" -Wl,-femit-dwarf-unwind=no_compact_unwind"
+                       AC_LINK_IFELSE([AC_LANG_SOURCE([[
+                           void main(int argc, char **argv)
+                           {
+                             std::cout << "Hello World!" << std::endl;
+                           }
+                       ]])],
+                        [
+                          AC_MSG_RESULT(<<<Disabling compact unwinding, retaining dwarf unwinding for gfortran compatibility>>>)
+                        ],[
+                          dnl Failed to link with new flags, remove them
+                          ACSM_LDFLAGS="$OLD_ACSM_LDFLAGS"
+                       ])
+
 
                        ACSM_CXXFLAGS_OPT="$ACSM_CXXFLAGS_OPT -O2 -felide-constructors -Qunused-arguments -Wunused-parameter -Wunused"
                        dnl devel flags are added on two lines since there are so many

From 20bfad5b31b55f9bbb0d7234eac5f53b236431e8 Mon Sep 17 00:00:00 2001
From: Guillaume Giudicelli <guillaume.giudicelli@inl.gov>
Date: Thu, 30 Jan 2025 17:07:44 -0700
Subject: [PATCH 3/3] Fix linking test

---
 acsm_compiler_flags.m4 | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/acsm_compiler_flags.m4 b/acsm_compiler_flags.m4
index 2def975..b6b5202 100644
--- a/acsm_compiler_flags.m4
+++ b/acsm_compiler_flags.m4
@@ -587,9 +587,10 @@ AC_DEFUN([ACSM_SET_CXX_FLAGS],
             [clang], [
                        dnl On Darwin with clang + gfortran, we get very many warnings for compact unwinding issues
                        dnl We deliberately keep relying on the less performant dwarf unwinding until the over-production of warnings is solved.
-                       OLD_ACSM_LDFLAGS="$ACSM_LDFLAGS"
-                       ACSM_LDFLAGS+=" -Wl,-femit-dwarf-unwind=no_compact_unwind"
+                       old_LDFLAGS="$LDFLAGS"
+                       LDFLAGS+=" -Wl,-femit-dwarf-unwind=no_compact_unwind"
                        AC_LINK_IFELSE([AC_LANG_SOURCE([[
+                           #include <iostream>
                            void main(int argc, char **argv)
                            {
                              std::cout << "Hello World!" << std::endl;
@@ -597,10 +598,12 @@ AC_DEFUN([ACSM_SET_CXX_FLAGS],
                        ]])],
                         [
                           AC_MSG_RESULT(<<<Disabling compact unwinding, retaining dwarf unwinding for gfortran compatibility>>>)
+                          ACSM_LDFLAGS+=" -Wl,-femit-dwarf-unwind=no_compact_unwind"
                         ],[
-                          dnl Failed to link with new flags, remove them
-                          ACSM_LDFLAGS="$OLD_ACSM_LDFLAGS"
+                          dnl Failed to link with new flags, do not add them
                        ])
+                       dnl Reset to old flags in case for any potential other test
+                       LDFLAGS="$old_LDFLAGS"
 
 
                        ACSM_CXXFLAGS_OPT="$ACSM_CXXFLAGS_OPT -O2 -felide-constructors -Qunused-arguments -Wunused-parameter -Wunused"