--- scons-3.1.2.orig/engine/SCons/Platform/__init__.py	2019-12-17 03:07:12.000000000 +0100
+++ scons-3.1.2/engine/SCons/Platform/__init__.py	2021-05-13 11:44:15.899865900 +0200
@@ -69,7 +69,7 @@
         osname = os._osType
     if osname == 'posix':
         if sys.platform == 'cygwin':
-            return 'cygwin'
+            return 'msys'
         elif sys.platform.find('irix') != -1:
             return 'irix'
         elif sys.platform.find('sunos') != -1:
diff -Naur scons-2.3.4-orig/engine/SCons/Platform/msys.py scons-2.3.4/engine/SCons/Platform/msys.py
--- /dev/null	2020-02-13 15:28:59.000000000 +0100
+++ scons-3.1.2/engine/SCons/Platform/msys.py	2020-02-13 15:28:52.358387400 +0100
@@ -0,0 +1,60 @@
+"""SCons.Platform.msys
+
+Platform-specific initialization for MSYS systems.
+
+There normally shouldn't be any need to import this module directly.  It
+will usually be imported through the generic SCons.Platform.Platform()
+selection method.
+"""
+
+#
+# Copyright (c) 2001 - 2019 The SCons Foundation
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+#
+
+__revision__ = "src/engine/SCons/Platform/cygwin.py bee7caf9defd6e108fc2998a2520ddb36a967691 2019-12-17 02:07:09 bdeegan"
+
+import os, subprocess
+from . import posix
+from SCons.Platform import TempFileMunge
+
+def generate(env):
+    posix.generate(env)
+
+    env['ENV']['PATH'] = os.getenv('PATH')
+    env['SPAWN']       = (lambda sh, esc, cmd, args, env_param:
+                          subprocess.call(['sh', '-c', ' '.join(args)]))
+    env['PROGPREFIX']  = ''
+    env['PROGSUFFIX']  = '.exe'
+    env['SHLIBPREFIX'] = ''
+    env['SHLIBSUFFIX'] = '.dll'
+    env['LIBPREFIXES'] = [ '$LIBPREFIX', '$SHLIBPREFIX', '$IMPLIBPREFIX' ]
+    env['LIBSUFFIXES'] = [ '$LIBSUFFIX', '$SHLIBSUFFIX', '$IMPLIBSUFFIX' ]
+    env['TEMPFILE']    = TempFileMunge
+    env['TEMPFILEPREFIX'] = '@'
+    env['MAXLINELENGTH']  = 2048
+
+# Local Variables:
+# tab-width:4
+# indent-tabs-mode:nil
+# End:
+# vim: set expandtab tabstop=4 shiftwidth=4:
+
diff -Naur scons-2.3.4-orig/engine/SCons/Script/Main.py scons-2.3.4/engine/SCons/Script/Main.py
--- scons-2.3.4-orig/engine/SCons/Script/Main.py	2014-09-27 19:51:48.000000000 +0300
+++ scons-2.3.4/engine/SCons/Script/Main.py	2014-11-05 01:00:42.034000000 +0300
@@ -770,7 +770,7 @@
     def homedir(d):
         return os.path.expanduser('~/'+d)
 
-    if platform == 'win32' or platform == 'cygwin':
+    if platform == 'win32' or platform == 'cygwin' or platform == 'msys':
         # Note we use $ here instead of %...% because older
         # pythons (prior to 2.6?) didn't expand %...% on Windows.
         # This set of dirs should work on XP, Vista, 7 and later.
diff -Naur scons-2.3.4-orig/engine/SCons/Tool/__init__.py scons-2.3.4/engine/SCons/Tool/__init__.py
--- scons-2.3.4-orig/engine/SCons/Tool/__init__.py	2014-09-27 19:51:48.000000000 +0300
+++ scons-2.3.4/engine/SCons/Tool/__init__.py	2014-11-05 01:00:42.034000000 +0300
@@ -1249,6 +1249,14 @@
         c_compilers = ['gcc', 'msvc', 'intelc', 'icc', 'cc']
         cxx_compilers = ['g++', 'msvc', 'intelc', 'icc', 'c++']
         assemblers = ['gas', 'nasm', 'masm']
+        fortran_compilers = ['gfortran', 'g77', 'ifort', 'ifl', 'f95', 'f90', 'f77']
+        ars = ['ar', 'mslib']
+    elif str(platform) == 'msys':
+        "prefer GNU tools on MSYS, except for a platform-specific linker"
+        linkers = ['msyslink', 'mslink', 'ilink']
+        c_compilers = ['gcc', 'msvc', 'intelc', 'icc', 'cc']
+        cxx_compilers = ['g++', 'msvc', 'intelc', 'icc', 'cxx']
+        assemblers = ['gas', 'nasm', 'masm']
         fortran_compilers = ['gfortran', 'g77', 'ifort', 'ifl', 'f95', 'f90', 'f77']
         ars = ['ar', 'mslib']
     else:
diff -Naur scons-2.3.4-orig/engine/SCons/Tool/g77.py scons-2.3.4/engine/SCons/Tool/g77.py
--- scons-2.3.4-orig/engine/SCons/Tool/g77.py	2014-09-27 19:51:48.000000000 +0300
+++ scons-2.3.4/engine/SCons/Tool/g77.py	2014-11-05 01:00:42.049600000 +0300
@@ -44,7 +44,7 @@
     add_f77_to_env(env)
 
     fcomp = env.Detect(compilers) or 'g77'
-    if env['PLATFORM'] in ['cygwin', 'win32']:
+    if env['PLATFORM'] in ['cygwin', 'msys', 'win32']:
         env['SHFORTRANFLAGS'] = SCons.Util.CLVar('$FORTRANFLAGS')
         env['SHF77FLAGS'] = SCons.Util.CLVar('$F77FLAGS')
     else:
diff -Naur scons-2.3.4-orig/engine/SCons/Tool/gcc.py scons-2.3.4/engine/SCons/Tool/gcc.py
--- scons-2.3.4-orig/engine/SCons/Tool/gcc.py	2014-09-27 19:51:48.000000000 +0300
+++ scons-2.3.4/engine/SCons/Tool/gcc.py	2014-11-05 01:00:42.049600000 +0300
@@ -51,7 +51,7 @@
 
     cc.generate(env)
 
-    if env['PLATFORM'] in ['cygwin', 'win32']:
+    if env['PLATFORM'] in ['cygwin', 'msys', 'win32']:
         env['SHCCFLAGS'] = SCons.Util.CLVar('$CCFLAGS')
     else:
         env['SHCCFLAGS'] = SCons.Util.CLVar('$CCFLAGS -fPIC')
diff -Naur scons-2.3.4-orig/engine/SCons/Tool/gfortran.py scons-2.3.4/engine/SCons/Tool/gfortran.py
--- scons-2.3.4-orig/engine/SCons/Tool/gfortran.py	2014-09-27 19:51:48.000000000 +0300
+++ scons-2.3.4/engine/SCons/Tool/gfortran.py	2014-11-05 01:00:42.049600000 +0300
@@ -46,7 +46,7 @@
     for dialect in ['F77', 'F90', 'FORTRAN', 'F95', 'F03', 'F08']:
         env['%s' % dialect] = 'gfortran'
         env['SH%s' % dialect] = '$%s' % dialect
-        if env['PLATFORM'] in ['cygwin', 'win32']:
+        if env['PLATFORM'] in ['cygwin', 'msys', 'win32']:
             env['SH%sFLAGS' % dialect] = SCons.Util.CLVar('$%sFLAGS' % dialect)
         else:
             env['SH%sFLAGS' % dialect] = SCons.Util.CLVar('$%sFLAGS -fPIC' % dialect)
--- a/engine/SCons/Tool/hpcxx.py.orig	2017-11-14 22:16:57.000000000 +0100
+++ b/engine/SCons/Tool/hpcxx.py	2018-06-17 18:57:36.738460100 +0200
@@ -72,7 +72,7 @@
         if line.find('aCC: HP ANSI C++') == 0:
             env['CXXVERSION'] = line.split()[-1]
 
-        if env['PLATFORM'] == 'cygwin':
+        if env['PLATFORM'] == 'cygwin' or env['PLATFORM'] == 'msys':
             env['SHCXXFLAGS'] = SCons.Util.CLVar('$CXXFLAGS')
         else:
             env['SHCXXFLAGS'] = SCons.Util.CLVar('$CXXFLAGS +Z')
diff -Naur /dev/null scons-3.0.4/engine/SCons/Tool/msyslink.py
--- /dev/null	2020-02-13 15:20:14.000000000 +0100
+++ scons-3.1.2/engine/SCons/Tool/msyslink.py	2020-02-13 14:13:48.506525300 +0100
@@ -0,0 +1,236 @@
+"""SCons.Tool.msyslink
+
+Customization of gnulink for MSYS
+
+There normally shouldn't be any need to import this module directly.
+It will usually be imported through the generic SCons.Tool.Tool()
+selection method.
+
+"""
+
+from __future__ import absolute_import, print_function
+
+import re
+import os
+
+import SCons.Action
+import SCons.Util
+import SCons.Tool
+
+#MAYBE:  from . import gnulink
+from . import gnulink
+from . import link
+
+def _lib_generator(target, source, env, for_signature, **kw):
+    try: cmd = kw['cmd']
+    except KeyError: cmd = SCons.Util.CLVar(['$SHLINK'])
+
+    try: vp = kw['varprefix']
+    except KeyError: vp = 'SHLIB'
+
+    dll = env.FindIxes(target, '%sPREFIX' % vp, '%sSUFFIX' % vp)
+    if dll: cmd.extend(['-o', dll])
+
+    cmd.extend(['$SHLINKFLAGS', '$__%sVERSIONFLAGS' % vp, '$__RPATH'])
+
+    implib = env.FindIxes(target, 'IMPLIBPREFIX', 'IMPLIBSUFFIX')
+    if implib:
+        cmd.extend([
+            '-Wl,--out-implib='+implib.get_string(for_signature),
+            '-Wl,--export-all-symbols',
+            '-Wl,--enable-auto-import',
+            '-Wl,--whole-archive', '$SOURCES',
+            '-Wl,--no-whole-archive', '$_LIBDIRFLAGS', '$_LIBFLAGS'
+            ])
+    else:
+        cmd.extend(['$SOURCES', '$_LIBDIRFLAGS', '$_LIBFLAGS'])
+
+    return [cmd]
+
+
+def shlib_generator(target, source, env, for_signature):
+    return _lib_generator(target, source, env, for_signature,
+                          varprefix='SHLIB',
+                          cmd = SCons.Util.CLVar(['$SHLINK']))
+
+def ldmod_generator(target, source, env, for_signature):
+    return _lib_generator(target, source, env, for_signature,
+                          varprefix='LDMODULE',
+                          cmd = SCons.Util.CLVar(['$LDMODULE']))
+
+def _lib_emitter(target, source, env, **kw):
+    Verbose = False
+
+    if Verbose:
+        print("_lib_emitter: target[0]=%r" % target[0].get_path())
+
+    try: vp = kw['varprefix']
+    except KeyError: vp = 'SHLIB'
+
+    try: libtype = kw['libtype']
+    except KeyError: libtype = 'ShLib'
+
+    dll = env.FindIxes(target, '%sPREFIX' % vp, '%sSUFFIX' % vp)
+    no_import_lib = env.get('no_import_lib', 0)
+
+    if Verbose:
+        print("_lib_emitter: dll=%r" % dll.get_path())
+
+    if not dll or len(target) > 1:
+        raise SCons.Errors.UserError("A shared library should have exactly one target with the suffix: %s" % env.subst("$%sSUFFIX" % vp))
+
+    # Remove any "lib" after the prefix
+    pre = env.subst('$%sPREFIX' % vp)
+    if dll.name[len(pre):len(pre)+3] == 'lib':
+        dll.name = pre + dll.name[len(pre)+3:]
+
+    if Verbose:
+        print("_lib_emitter: dll.name=%r" % dll.name)
+
+    orig_target = target
+    target = [env.fs.File(dll)]
+    target[0].attributes.shared = 1
+
+    if Verbose:
+        print("_lib_emitter: after target=[env.fs.File(dll)]: target[0]=%r" % target[0].get_path())
+
+    # Append an import lib target
+    if not no_import_lib:
+        # Create list of target libraries as strings
+        target_strings = env.ReplaceIxes(orig_target[0],
+                                         '%sPREFIX' % vp, '%sSUFFIX' % vp,
+                                         'IMPLIBPREFIX', 'IMPLIBSUFFIX')
+        if Verbose:
+            print("_lib_emitter: target_strings=%r" % target_strings)
+
+        implib_target = env.fs.File(target_strings)
+        if Verbose:
+            print("_lib_emitter: implib_target=%r" % implib_target.get_path())
+        implib_target.attributes.shared = 1
+        target.append(implib_target)
+
+    symlinks = SCons.Tool.ImpLibSymlinkGenerator(env, implib_target,
+                                                 implib_libtype=libtype,
+                                                 generator_libtype=libtype+'ImpLib')
+    if Verbose:
+        print("_lib_emitter: implib symlinks=%r" % SCons.Tool.StringizeLibSymlinks(symlinks))
+    if symlinks:
+        SCons.Tool.EmitLibSymlinks(env, symlinks, implib_target, clean_targets = target[0])
+        implib_target.attributes.shliblinks = symlinks
+
+    return (target, source)
+
+def shlib_emitter(target, source, env):
+    return _lib_emitter(target, source, env, varprefix='SHLIB', libtype='ShLib')
+
+def ldmod_emitter(target, source, env):
+    return _lib_emitter(target, source, env, varprefix='LDMODULE', libtype='LdMod')
+
+def _versioned_lib_suffix(env, suffix, version):
+    """Generate versioned shared library suffix from a unversioned one.
+       If suffix='.dll', and version='0.1.2', then it returns '-0-1-2.dll'"""
+    Verbose = False
+    if Verbose:
+        print("_versioned_lib_suffix: suffix= ", suffix)
+        print("_versioned_lib_suffix: version= ", version)
+    msysversion = re.sub('\.', '-', version)
+    if not suffix.startswith('-' + msysversion):
+        suffix = '-' + msysversion + suffix
+    if Verbose:
+        print("_versioned_lib_suffix: return suffix= ", suffix)
+    return suffix
+
+def _versioned_implib_name(env, libnode, version, prefix, suffix, **kw):
+    return link._versioned_lib_name(env, libnode, version, prefix, suffix,
+                                    SCons.Tool.ImpLibPrefixGenerator,
+                                    SCons.Tool.ImpLibSuffixGenerator,
+                                    implib_libtype=kw['libtype'])
+
+def _versioned_implib_symlinks(env, libnode, version, prefix, suffix, **kw):
+    """Generate link names that should be created for a versioned shared library.
+       Returns a list in the form [ (link, linktarget), ... ]
+    """
+    Verbose = False
+
+    if Verbose:
+        print("_versioned_implib_symlinks: libnode=%r" % libnode.get_path())
+        print("_versioned_implib_symlinks: version=%r" % version)
+
+    try: libtype = kw['libtype']
+    except KeyError: libtype = 'ShLib'
+
+
+    linkdir = os.path.dirname(libnode.get_path())
+    if Verbose:
+        print("_versioned_implib_symlinks: linkdir=%r" % linkdir)
+
+    name = SCons.Tool.ImpLibNameGenerator(env, libnode,
+                                          implib_libtype=libtype,
+                                          generator_libtype=libtype+'ImpLib')
+    if Verbose:
+        print("_versioned_implib_symlinks: name=%r" % name)
+
+    major = version.split('.')[0]
+
+    link0 = env.fs.File(os.path.join(linkdir, name))
+    symlinks = [(link0, libnode)]
+
+    if Verbose:
+        print("_versioned_implib_symlinks: return symlinks=%r" % SCons.Tool.StringizeLibSymlinks(symlinks))
+
+    return symlinks
+
+shlib_action = SCons.Action.Action(shlib_generator, generator=1)
+ldmod_action = SCons.Action.Action(ldmod_generator, generator=1)
+
+def generate(env):
+    """Add Builders and construction variables for msyslink to an Environment."""
+    gnulink.generate(env)
+
+    env['LINKFLAGS']   = SCons.Util.CLVar('-Wl,-no-undefined')
+
+    env['SHLINKCOM'] = shlib_action
+    env['LDMODULECOM'] = ldmod_action
+    env.Append(SHLIBEMITTER = [shlib_emitter])
+    env.Append(LDMODULEEMITTER = [ldmod_emitter])
+
+    env['SHLIBPREFIX']         = 'msys-'
+    env['SHLIBSUFFIX']         = '.dll'
+
+    env['IMPLIBPREFIX']        = 'lib'
+    env['IMPLIBSUFFIX']        = '.dll.a'
+
+    # Variables used by versioned shared libraries
+    env['_SHLIBVERSIONFLAGS']      = '$SHLIBVERSIONFLAGS'
+    env['_LDMODULEVERSIONFLAGS']   = '$LDMODULEVERSIONFLAGS'
+
+    # SHLIBVERSIONFLAGS and LDMODULEVERSIONFLAGS are same as in gnulink...
+
+    # LINKCALLBACKS are NOT inherited from gnulink
+    env['LINKCALLBACKS'] = {
+        'VersionedShLibSuffix'          : _versioned_lib_suffix,
+        'VersionedLdModSuffix'          : _versioned_lib_suffix,
+        'VersionedImpLibSuffix'         : _versioned_lib_suffix,
+        'VersionedShLibName'            : link._versioned_shlib_name,
+        'VersionedLdModName'            : link._versioned_ldmod_name,
+        'VersionedShLibImpLibName'      : lambda *args: _versioned_implib_name(*args, libtype='ShLib'),
+        'VersionedLdModImpLibName'      : lambda *args: _versioned_implib_name(*args, libtype='LdMod'),
+        'VersionedShLibImpLibSymlinks'  : lambda *args: _versioned_implib_symlinks(*args, libtype='ShLib'),
+        'VersionedLdModImpLibSymlinks'  : lambda *args: _versioned_implib_symlinks(*args, libtype='LdMod'),
+    }
+
+    # these variables were set by gnulink but are not used in msyslink
+    try: del env['_SHLIBSONAME']
+    except KeyError: pass
+    try: del env['_LDMODULESONAME']
+    except KeyError: pass
+
+def exists(env):
+    return gnulink.exists(env)
+
+
+# Local Variables:
+# tab-width:4
+# indent-tabs-mode:nil
+# End:
+# vim: set expandtab tabstop=4 shiftwidth=4:
diff -Naur scons-2.3.4-orig/MANIFEST scons-2.3.4/MANIFEST
--- scons-2.3.4-orig/MANIFEST	2014-09-27 19:52:20.000000000 +0300
+++ scons-2.3.4/MANIFEST	2014-11-05 01:00:42.065200000 +0300
@@ -31,6 +31,7 @@
 engine/SCons/Platform/hpux.py
 engine/SCons/Platform/irix.py
 engine/SCons/Platform/mingw.py
+engine/SCons/Platform/msys.py
 engine/SCons/Platform/os2.py
 engine/SCons/Platform/posix.py
 engine/SCons/Platform/sunos.py
@@ -139,6 +141,7 @@
 engine/SCons/Tool/mssdk.py
 engine/SCons/Tool/msvc.py
 engine/SCons/Tool/msvs.py
+engine/SCons/Tool/msyslink.py
 engine/SCons/Tool/mwcc.py
 engine/SCons/Tool/mwld.py
 engine/SCons/Tool/nasm.py
