refactor cleanup. circular import issues resolved by moving isolated imports into the few functions they are used in rather than globally in the module

14 files changed, 76 insertions, 57 deletions

diff --git a/SCons/Defaults.py b/SCons/Defaults.py
index b3f6d1d..c23d564 100644
--- a/SCons/Defaults.py
+++ b/SCons/Defaults.py
@@ -10,8 +10,6 @@ from distutils.msvccompiler.
 """
 
 #
-# __COPYRIGHT__
-#
 # 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
@@ -31,7 +29,6 @@ from distutils.msvccompiler.
 # 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__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 
 import os
diff --git a/SCons/Tool/FortranCommon.py b/SCons/Tool/FortranCommon.py
index bfa1c1c..f8d9fdc 100644
--- a/SCons/Tool/FortranCommon.py
+++ b/SCons/Tool/FortranCommon.py
@@ -5,8 +5,6 @@ Stuff for processing Fortran, common to all fortran dialects.
 """
 
 #
-# __COPYRIGHT__
-#
 # 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
@@ -26,13 +24,11 @@ Stuff for processing Fortran, common to all fortran dialects.
 # 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__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import re
 import os.path
 
 import SCons.Action
-import SCons.Defaults
 import SCons.Scanner.Fortran
 import SCons.Tool
 import SCons.Util
@@ -78,10 +74,12 @@ def _fortranEmitter(target, source, env):
     return (target, source)
 
 def FortranEmitter(target, source, env):
+    import SCons.Defaults
     target, source = _fortranEmitter(target, source, env)
     return SCons.Defaults.StaticObjectEmitter(target, source, env)
 
 def ShFortranEmitter(target, source, env):
+    import SCons.Defaults
     target, source = _fortranEmitter(target, source, env)
     return SCons.Defaults.SharedObjectEmitter(target, source, env)
 
diff --git a/SCons/Tool/aixlink.py b/SCons/Tool/aixlink.py
index fed4342..dc0de2a 100644
--- a/SCons/Tool/aixlink.py
+++ b/SCons/Tool/aixlink.py
@@ -8,8 +8,6 @@ selection method.
 """
 
 #
-# __COPYRIGHT__
-#
 # 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
@@ -30,8 +28,6 @@ selection method.
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
 
-__revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
-
 import os
 import os.path
 
@@ -42,7 +38,6 @@ from . import link
 
 import SCons.Tool.cxx
 cplusplus = SCons.Tool.cxx
-#cplusplus = __import__('cxx', globals(), locals(), [])
 
 
 def smart_linkflags(source, target, env, for_signature):
@@ -52,6 +47,7 @@ def smart_linkflags(source, target, env, for_signature):
             return '-qtempinc=' + os.path.join(build_dir, 'tempinc')
     return ''
 
+
 def generate(env):
     """
     Add Builders and construction variables for Visual Age linker to
@@ -64,12 +60,13 @@ def generate(env):
     env['SHLINKFLAGS']    = SCons.Util.CLVar('$LINKFLAGS -qmkshrobj -qsuppress=1501-218')
     env['SHLIBSUFFIX']    = '.a'
 
+
 def exists(env):
     # TODO: sync with link.smart_link() to choose a linker
     linkers = { 'CXX': ['aixc++'], 'CC': ['aixcc'] }
     alltools = []
     for langvar, linktools in linkers.items():
-        if langvar in env: # use CC over CXX when user specified CC but not CXX
+        if langvar in env:  # use CC over CXX when user specified CC but not CXX
             return SCons.Tool.FindTool(linktools, env)
         alltools.extend(linktools)
     return SCons.Tool.FindTool(alltools, env)
diff --git a/SCons/Tool/applelink.py b/SCons/Tool/applelink.py
index 9463308..f51a6af 100644
--- a/SCons/Tool/applelink.py
+++ b/SCons/Tool/applelink.py
@@ -9,8 +9,6 @@ selection method.
 """
 
 #
-# __COPYRIGHT__
-#
 # 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
@@ -31,8 +29,6 @@ selection method.
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
 
-__revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
-
 import SCons.Tool.linkCommon
 import SCons.Util
 
diff --git a/SCons/Tool/cxx.py b/SCons/Tool/cxx.py
index 430851c..128cdc4 100644
--- a/SCons/Tool/cxx.py
+++ b/SCons/Tool/cxx.py
@@ -8,8 +8,6 @@ selection method.
 """
 
 #
-# __COPYRIGHT__
-#
 # 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
@@ -30,11 +28,8 @@ selection method.
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
 
-__revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
-
 import os.path
 
-import SCons.Tool
 import SCons.Defaults
 import SCons.Util
 
diff --git a/SCons/Tool/cyglink.py b/SCons/Tool/cyglink.py
index fd8c1fd..e85797b 100644
--- a/SCons/Tool/cyglink.py
+++ b/SCons/Tool/cyglink.py
@@ -12,14 +12,13 @@ import re
 import os
 
 import SCons.Action
-import SCons.Tool.linkCommon
+import SCons.Tool.linkCommon as linkCommon
 from SCons.Tool.linkCommon import ImpLibSymlinkGenerator, StringizeLibSymlinks, EmitLibSymlinks, ImpLibPrefixGenerator, \
     ImpLibSuffixGenerator, ImpLibNameGenerator
 import SCons.Util
 import SCons.Tool
 
 from . import gnulink
-from . import link
 
 
 def _lib_generator(target, source, env, for_signature, **kw):
@@ -157,7 +156,7 @@ def _versioned_lib_suffix(env, suffix, version):
 
 
 def _versioned_implib_name(env, libnode, version, prefix, suffix, **kw):
-    return SCons.Tool.linkCommon._versioned_lib_name(env, libnode, version, prefix, suffix,
+    return linkCommon._versioned_lib_name(env, libnode, version, prefix, suffix,
                                                      ImpLibPrefixGenerator,
                                                      ImpLibSuffixGenerator,
                                                      implib_libtype=kw['libtype'])
@@ -231,8 +230,8 @@ def generate(env):
         'VersionedShLibSuffix': _versioned_lib_suffix,
         'VersionedLdModSuffix': _versioned_lib_suffix,
         'VersionedImpLibSuffix': _versioned_lib_suffix,
-        'VersionedShLibName': SCons.Tool.linkCommon._versioned_shlib_name,
-        'VersionedLdModName': SCons.Tool.linkCommon._versioned_ldmod_name,
+        'VersionedShLibName': linkCommon._versioned_shlib_name,
+        'VersionedLdModName': linkCommon._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'),
diff --git a/SCons/Tool/gnulink.py b/SCons/Tool/gnulink.py
index 51932da..2b09549 100644
--- a/SCons/Tool/gnulink.py
+++ b/SCons/Tool/gnulink.py
@@ -9,8 +9,6 @@ selection method.
 """
 
 #
-# __COPYRIGHT__
-#
 # 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
@@ -31,7 +29,6 @@ selection method.
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
 
-__revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import SCons.Tool.linkCommon
 import SCons.Util
@@ -39,6 +36,7 @@ import SCons.Tool
 import sys
 
 from . import link
+import SCons.Tool.linkCommon as linkCommon
 
 
 def generate(env):
@@ -56,11 +54,8 @@ def generate(env):
 
     # OpenBSD doesn't usually use SONAME for libraries
     use_soname = not sys.platform.startswith('openbsd')
-    SCons.Tool.linkCommon._setup_versioned_lib_variables(env, tool='gnulink', use_soname=use_soname)
-    env['LINKCALLBACKS'] = SCons.Tool.linkCommon._versioned_lib_callbacks()
-
-    # # For backward-compatibility with older SCons versions
-    # env['SHLIBVERSIONFLAGS'] = SCons.Util.CLVar('')
+    linkCommon._setup_versioned_lib_variables(env, tool='gnulink', use_soname=use_soname)
+    env['LINKCALLBACKS'] = linkCommon._versioned_lib_callbacks()
 
 
 def exists(env):
diff --git a/SCons/Tool/hplink.py b/SCons/Tool/hplink.py
index 10ef30b..ba182f1 100644
--- a/SCons/Tool/hplink.py
+++ b/SCons/Tool/hplink.py
@@ -8,8 +8,6 @@ selection method.
 """
 
 #
-# __COPYRIGHT__
-#
 # 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
@@ -30,9 +28,6 @@ selection method.
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
 
-__revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
-
-import os
 import os.path
 
 import SCons.Util
diff --git a/SCons/Tool/ilink.py b/SCons/Tool/ilink.py
index aa6bcaa..4112825 100644
--- a/SCons/Tool/ilink.py
+++ b/SCons/Tool/ilink.py
@@ -9,8 +9,6 @@ selection method.
 """
 
 #
-# __COPYRIGHT__
-#
 # 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
@@ -31,8 +29,6 @@ selection method.
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
 
-__revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
-
 import SCons.Defaults
 import SCons.Tool
 import SCons.Util
diff --git a/SCons/Tool/linkCommon/README.md b/SCons/Tool/linkCommon/README.md
new file mode 100644
index 0000000..26bc9a5
--- /dev/null
+++ b/SCons/Tool/linkCommon/README.md
@@ -0,0 +1,56 @@
+
+
+# Versioned Shared Library and Loadable modules requirements
+
+The following env variables can affect the command line and created files for these
+
+* `SHLIBVERSION`
+* `SONAME`
+* `SOVERSION`
+* `APPLELINK_NO_CURRENT_VERSION`    (applelink only)
+* `APPLELINK_CURRENT_VERSION`       (applelink only)
+* `APPLELINK_COMPATIBILITY_VERSION` (applelink only)
+
+In most cases the linker will create a file named as
+
+`${SHLIBPREFIX}lib_name${SHLIBVERSION}${SHLIBSUFFIX}`
+
+Which will have a soname baked into it as one of the
+
+* `${SONAME}`
+* `${SHLIBPREFIX}lib_name${SOVERSION}${SHLIBSUFFIX}`
+* (for applelink only)
+   * `${SHLIBPREFIX}lib_name${major version only from SHLIBVERSION}${SHLIBSUFFIX}`
+   * `-Wl,-compatibility_version,%s`
+   * `-Wl,-current_version,%s`
+   
+For **applelink** the version has to follow these rules to verify that the version # is valid.
+
+* For version # = X[.Y[.Z]]
+* where X 0-65535
+* where Y either not specified or 0-255
+* where Z either not specified or 0-255
+
+
+   
+For most platforms this will lead to a series of symlinks eventually pointing to the actual shared library (or loadable module file).
+1. `${SHLIBPREFIX}lib_name${SHLIBSUFFIX} -> ${SHLIBPREFIX}lib_name${SHLIBVERSION}${SHLIBSUFFIX}`
+1. `${SHLIBPREFIX}lib_name${SOVERSION}${SHLIBSUFFIX} -> ${SHLIBPREFIX}lib_name${SHLIBVERSION}${SHLIBSUFFIX}`
+
+For **openbsd** the following rules for symlinks apply
+
+   * OpenBSD uses x.y shared library versioning numbering convention and doesn't use symlinks to backwards-compatible libraries
+
+
+The current code provides the following hooks a compiler can use to customize:
+
+```        
+        'VersionedShLibSuffix': _versioned_lib_suffix,
+        'VersionedLdModSuffix': _versioned_lib_suffix,
+        'VersionedShLibSymlinks': _versioned_shlib_symlinks,
+        'VersionedLdModSymlinks': _versioned_ldmod_symlinks,
+        'VersionedShLibName': _versioned_shlib_name,
+        'VersionedLdModName': _versioned_ldmod_name,
+        'VersionedShLibSoname': _versioned_shlib_soname,
+        'VersionedLdModSoname': _versioned_ldmod_soname,
+```
\ No newline at end of file
diff --git a/SCons/Tool/linkCommon/__init__.py b/SCons/Tool/linkCommon/__init__.py
index c3ccd7a..c787e0c 100644
--- a/SCons/Tool/linkCommon/__init__.py
+++ b/SCons/Tool/linkCommon/__init__.py
@@ -30,8 +30,6 @@ from typing import Callable
 import SCons.Util
 import SCons.Warnings
 from SCons.Tool.DCommon import isD
-from SCons.Tool.FortranCommon import isfortran
-from SCons.Tool.cxx import iscplusplus
 from SCons.Util import is_List
 
 
@@ -512,8 +510,11 @@ def _call_env_subst(env, string, *args, **kw):
 
 
 def smart_link(source, target, env, for_signature):
-    has_cplusplus = iscplusplus(source)
-    has_fortran = isfortran(env, source)
+    import SCons.Tool.cxx
+    import SCons.Tool.fortran
+
+    has_cplusplus = SCons.Tool.cxx.iscplusplus(source)
+    has_fortran = SCons.Tool.fortran.isfortran(env, source)
     has_d = isD(env, source)
     if has_cplusplus and has_fortran and not has_d:
         global issued_mixed_link_warning
diff --git a/SCons/Tool/mslink.py b/SCons/Tool/mslink.py
index bab78d8..8fd7922 100644
--- a/SCons/Tool/mslink.py
+++ b/SCons/Tool/mslink.py
@@ -9,8 +9,6 @@ selection method.
 """
 
 #
-# __COPYRIGHT__
-#
 # 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
@@ -30,7 +28,6 @@ selection method.
 # 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__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import os
 import os.path
diff --git a/SCons/Tool/sgilink.py b/SCons/Tool/sgilink.py
index b1e7921..e92c7b9 100644
--- a/SCons/Tool/sgilink.py
+++ b/SCons/Tool/sgilink.py
@@ -9,8 +9,6 @@ selection method.
 """
 
 #
-# __COPYRIGHT__
-#
 # 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
@@ -31,7 +29,6 @@ selection method.
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
 
-__revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import SCons.Util
 
diff --git a/SCons/Tool/sunlink.py b/SCons/Tool/sunlink.py
index c33ba5a..f668903 100644
--- a/SCons/Tool/sunlink.py
+++ b/SCons/Tool/sunlink.py
@@ -30,7 +30,7 @@ selection method.
 
 import os.path
 
-import SCons.Tool.linkCommon
+import SCons.Tool.linkCommon as linkCommon
 import SCons.Util
 
 from . import link
@@ -63,12 +63,12 @@ def generate(env):
     env['_RPATH'] = '${_concat(RPATHPREFIX, RPATH, RPATHSUFFIX, __env__)}'
 
     # Support for versioned libraries
-    SCons.Tool.linkCommon._setup_versioned_lib_variables(env, tool ='sunlink', use_soname=True)
+    linkCommon._setup_versioned_lib_variables(env, tool='sunlink', use_soname=True)
 
     env['_SHLIBVERSIONFLAGS'] = '$SHLIBVERSIONFLAGS -h $_SHLIBSONAME'
     env['_LDMODULEVERSIONFLAGS'] = '$LDMODULEVERSIONFLAGS -h $_LDMODULESONAME'
 
-    env['LINKCALLBACKS'] = SCons.Tool.linkCommon._versioned_lib_callbacks()
+    env['LINKCALLBACKS'] = linkCommon._versioned_lib_callbacks()
 
 def exists(env):
     return ccLinker