Merge branch 'master' into ninja_always_execute

13 files changed, 209 insertions, 149 deletions

diff --git a/SCons/Action.py b/SCons/Action.py
index 0849178..6e67c7f 100644
--- a/SCons/Action.py
+++ b/SCons/Action.py
@@ -732,7 +732,7 @@ def _string_from_cmd_list(cmd_list):
 default_ENV = None
 
 
-def get_default_ENV(env, target=None, source=None):
+def get_default_ENV(env):
     """
     A fiddlin' little function that has an 'import SCons.Environment' which
     can't be moved to the top level without creating an import loop.  Since
@@ -755,6 +755,29 @@ def get_default_ENV(env, target=None, source=None):
         return default_ENV
 
 
+def _resolve_shell_env(env, target, source):
+    """
+    First get default environment.
+    Then if SHELL_ENV_GENERATORS is set and is iterable,
+    call each callable in that list to allow it to alter
+    the created execution environment.
+    """
+    ENV = get_default_ENV(env)
+    shell_gen = env.get('SHELL_ENV_GENERATORS')
+    if shell_gen:
+        try:
+            shell_gens = iter(shell_gen)
+        except TypeError:
+            raise SCons.Errors.UserError("SHELL_ENV_GENERATORS must be iteratable.")
+        else:
+            ENV = ENV.copy()
+            for generator in shell_gens:
+                ENV = generator(env, target, source, ENV)
+                if not isinstance(ENV, dict):
+                    raise SCons.Errors.UserError(f"SHELL_ENV_GENERATORS function: {generator} must return a dict.")
+    return ENV
+
+
 def _subproc(scons_env, cmd, error='ignore', **kw):
     """Wrapper for subprocess which pulls from construction env.
 
@@ -924,10 +947,9 @@ class CommandAction(_ActionAction):
 
         escape = env.get('ESCAPE', lambda x: x)
 
-        ENV = env.get('SHELL_ENV_GENERATOR', get_default_ENV)(env, target, source)
+        ENV = _resolve_shell_env(env, target, source)
 
         # Ensure that the ENV values are all strings:
-
         for key, value in ENV.items():
             if not is_String(value):
                 if is_List(value):
diff --git a/SCons/Action.xml b/SCons/Action.xml
index 2c18d55..1346db2 100644
--- a/SCons/Action.xml
+++ b/SCons/Action.xml
@@ -200,18 +200,32 @@ in which the command should be executed.
 </summary>
 </cvar>
 
-<cvar name="SHELL_ENV_GENERATOR">
+<cvar name="SHELL_ENV_GENERATORS">
   <summary>
     <para>
-A function to generate or alter the environment dictionary which will be used
-when executing the &cv-link-SPAWN; function. This primarily give the
-user a chance to customize the execution environment for particular Actions.
-It must return a dictionary containing the environment variables as
-keys and the values as values.
+Must be a list (or an iterable) containing functions where each function generates or
+alters the environment dictionary which will be used
+when executing the &cv-link-SPAWN; function. The functions will initially 
+be passed a reference of the current execution environment (e.g. env['ENV']), 
+and each called while iterating the list. Each function must return a dictionary
+which will then be passed to the next function iterated. The return dictionary 
+should contain keys which represent the environment variables and their respective
+values.
+
+This primary purpose of this construction variable is to give the user the ability
+to substitute execution environment variables based on env, targets, and sources. 
+If desired, the user can completely customize the execution environment for particular
+targets.
     </para>
 
     <example_commands>
-def custom_shell_env(env, target, source):
+def custom_shell_env(env, target, source, shell_env):
+    """customize shell_env if desired"""
+    if str(target[0]) == 'special_target':
+      shell_env['SPECIAL_VAR'] = env.subst('SOME_VAR', target=target, source=source)
+    return shell_env
+  
+env["SHELL_ENV_GENERATORS"] = [custom_shell_env]
     </example_commands>
 
     <para>
@@ -223,10 +237,15 @@ execution environment can be derived from.
     <varname>target</varname>
 The list of targets associated with this action.
     </para>
-        <para>
+    <para>
     <varname>source</varname>
 The list of sources associated with this action.
     </para>
+    <para>
+    <varname>shell_env</varname>
+The current shell_env after iterating other SHELL_ENV_GENERATORS functions. This can be compared
+to the passed env['ENV'] to detect any changes.
+    </para>
   </summary>
 </cvar>
 
diff --git a/SCons/Environment.xml b/SCons/Environment.xml
index 3a6df97..5c4326c 100644
--- a/SCons/Environment.xml
+++ b/SCons/Environment.xml
@@ -318,7 +318,7 @@ Added methods propagate through &f-env-Clone; calls.
 </para>
 
 <para>
-Examples:
+More examples:
 </para>
 
 <example_commands>
@@ -3416,42 +3416,41 @@ env.UpdateValue(target = Value(output), source = Value(input))
 </arguments>
 <summary>
 <para>
-Sets up an alternate build location.
-When building in the <parameter>variant_dir</parameter>,
-&SCons; backfills as needed with files from <parameter>src_dir</parameter>
-to create a complete build directory.
+Sets up a mapping to define a variant build directory in
+<parameter>variant_dir</parameter>.
+<parameter>src_dir</parameter> may not be underneath
+<parameter>variant_dir</parameter>.
+A &f-VariantDir; mapping is global, even if called using the
+&f-env-VariantDir; form.
 &f-VariantDir;
 can be called multiple times with the same
 <parameter>src_dir</parameter>
-to set up multiple builds with different options
-(<emphasis>variants</emphasis>).
+to set up multiple variant builds with different options.
 </para>
 
 <para>
-The
-<parameter>variant</parameter>
-location must be in or underneath the project top directory,
-and <parameter>src_dir</parameter>
-may not be underneath
-<parameter>variant_dir</parameter>.
+Note if <parameter>variant_dir</parameter>
+is not under the project top directory,
+target selection rules will not pick targets in the
+variant directory unless they are explicitly specified.
 </para>
 
 <para>
+When files in <parameter>variant_dir</parameter> are referenced,
+&SCons; backfills as needed with files from <parameter>src_dir</parameter>
+to create a complete build directory.
 By default, &SCons;
-physically duplicates the source files and SConscript files
-as needed into the variant tree.
-Thus, a build performed in the variant tree is guaranteed to be identical
-to a build performed in the source tree even if
+physically duplicates the source files, SConscript files,
+and directory structure as needed into the variant directory.
+Thus, a build performed in the variant directory is guaranteed to be identical
+to a build performed in the source directory even if
 intermediate source files are generated during the build,
 or if preprocessors or other scanners search for included files
-relative to the source file,
+using paths relative to the source file,
 or if individual compilers or other invoked tools are hard-coded
 to put derived files in the same directory as source files.
 Only the files &SCons; calculates are needed for the build are
 duplicated into <parameter>variant_dir</parameter>.
-</para>
-
-<para>
 If possible on the platform,
 the duplication is performed by linking rather than copying.
 This behavior is affected by the
@@ -3470,44 +3469,46 @@ to invoke Builders using the path names of source files in
 <parameter>src_dir</parameter>
 and the path names of derived files within
 <parameter>variant_dir</parameter>.
-This is more efficient than
-<literal>duplicate=True</literal>,
+This is more efficient than duplicating,
 and is safe for most builds;
-revert to <constant>True</constant>
+revert to <literal>duplicate=True</literal>
 if it causes problems.
 </para>
 
 <para>
 &f-VariantDir;
-works most naturally with used with a subsidiary SConscript file.
-The subsidiary SConscript file is called as if it
-were in
+works most naturally when used with a subsidiary SConscript file.
+The subsidiary SConscript file must be called as if it were in
 <parameter>variant_dir</parameter>,
 regardless of the value of
 <parameter>duplicate</parameter>.
-This is how you tell
-&scons;
-which variant of a source tree to build:
+When calling an SConscript file, you can use the 
+<parameter>exports</parameter> keyword argument
+to pass parameters (individually or as an appropriately set up environment)
+so the SConscript can pick up the right settings for that variant build.
+The SConscript must &f-link-Import; these to use them. Example:
 </para>
 
 <example_commands>
+env1 = Environment(...settings for variant1...)
+env2 = Environment(...settings for variant2...)
+
 # run src/SConscript in two variant directories
 VariantDir('build/variant1', 'src')
-SConscript('build/variant1/SConscript')
+SConscript('build/variant1/SConscript', exports={"env": env1})
 VariantDir('build/variant2', 'src')
-SConscript('build/variant2/SConscript')
+SConscript('build/variant2/SConscript', exports={"env": env2})
 </example_commands>
 
 <para>
 See also the
-&f-link-SConscript;
-function, described above,
+&f-link-SConscript; function
 for another way to specify a variant directory
 in conjunction with calling a subsidiary SConscript file.
 </para>
 
 <para>
-Examples:
+More examples:
 </para>
 
 <example_commands>
diff --git a/SCons/Scanner/ScannerTests.py b/SCons/Scanner/ScannerTests.py
index 68332a0..b9cb209 100644
--- a/SCons/Scanner/ScannerTests.py
+++ b/SCons/Scanner/ScannerTests.py
@@ -621,7 +621,9 @@ def suite():
                  ClassicCPPTestCase,
                ]
     for tclass in tclasses:
-        names = unittest.getTestCaseNames(tclass, 'test_')
+        loader = unittest.TestLoader()
+        loader.testMethodPrefix = 'test_'
+        names = loader.getTestCaseNames(tclass)
         suite.addTests(list(map(tclass, names)))
     return suite
 
diff --git a/SCons/Script/SConscript.xml b/SCons/Script/SConscript.xml
index 3c5b907..eb52acc 100644
--- a/SCons/Script/SConscript.xml
+++ b/SCons/Script/SConscript.xml
@@ -363,42 +363,38 @@ Return('val1 val2')
 <!-- (scripts, [exports, variant_dir, src_dir, duplicate, must_exist]) -->
 </arguments>
 <arguments>
-(dirs=subdirs, [name=script, exports, variant_dir, duplicate, must_exist])
-<!-- (dirs=subdirs, [name=script, exports, variant_dir, src_dir, duplicate, must_exist]) -->
+(dirs=subdirs, [name=scriptname, exports, variant_dir, duplicate, must_exist])
+<!-- (dirs=subdirs, [name=scriptname, exports, variant_dir, src_dir, duplicate, must_exist]) -->
 </arguments>
 <summary>
 <para>
-Execute one or more subsidiary SConscript (configuration) files.
+Executes one or more subsidiary SConscript (configuration) files.
 There are two ways to call the
 &f-SConscript; function.
 </para>
 
 <para>
-The first calling style
-is to explicitly specify one or more
-<varname>scripts</varname>
-as the first argument.
+The first calling style is to supply
+one or more SConscript file names
+as the first (positional) argument.
 A single script may be specified as a string;
-multiple scripts must be specified as a list
+multiple scripts must be specified as a list of strings
 (either explicitly or as created by
 a function like
 &f-link-Split;).
 Examples:
 </para>
 <example_commands>
-SConscript('SConscript')      # run SConscript in the current directory
+SConscript('SConscript')  # run SConscript in the current directory
 SConscript('src/SConscript')  # run SConscript in the src directory
 SConscript(['src/SConscript', 'doc/SConscript'])
 config = SConscript('MyConfig.py')
 </example_commands>
 
 <para>
-The second way to call
-&f-SConscript;
-is to specify a list of (sub)directory names
-as a
-<varname>dirs</varname>=<replaceable>subdirs</replaceable>
-keyword argument.
+The other calling style is to omit the positional argument naming
+scripts and instead specify a list of directory names using the
+<varname>dirs</varname> keyword argument.
 In this case,
 &scons;
 will
@@ -408,14 +404,14 @@ in each of the specified directories.
 You may specify a name other than
 &SConscript;
 by supplying an optional
-<varname>name</varname>=<replaceable>script</replaceable>
+<varname>name</varname>=<replaceable>scriptname</replaceable>
 keyword argument.
 The first three examples below have the same effect
 as the first three examples above:
 </para>
 <example_commands>
-SConscript(dirs='.')      # run SConscript in the current directory
-SConscript(dirs='src')    # run SConscript in the src directory
+SConscript(dirs='.')  # run SConscript in the current directory
+SConscript(dirs='src')  # run SConscript in the src directory
 SConscript(dirs=['src', 'doc'])
 SConscript(dirs=['sub1', 'sub2'], name='MySConscript')
 </example_commands>
@@ -423,8 +419,12 @@ SConscript(dirs=['sub1', 'sub2'], name='MySConscript')
 <para>
 The optional
 <varname>exports</varname>
-argument provides a string or list of strings representing
+keyword argument provides a string or list of strings representing
 variable names, or a dictionary of named values, to export.
+For the first calling style only, a second positional argument
+will be interpreted as <varname>exports</varname>; the
+second calling style must use the keyword argument form
+for <varname>exports</varname>.
 These variables are locally exported only to the called
 SConscript file(s)
 and do not affect the global pool of variables managed by the
@@ -448,38 +448,24 @@ SConscript(dirs=['one', 'two', 'three'], exports='shared_info')
 If the optional
 <varname>variant_dir</varname>
 argument is present, it causes an effect equivalent to the
-&f-link-VariantDir; function.
+&f-link-VariantDir; function,
+but in effect only within the scope of the &f-SConscript; call.
 The <varname>variant_dir</varname>
-argument is interpreted relative to the directory of the calling
-SConscript file.
-The optional
-<varname>duplicate</varname> argument is
-interpreted as for &f-link-VariantDir;.
-If <varname>variant_dir</varname>
-is omitted, the <varname>duplicate</varname> argument is ignored.
-See the description of
-&f-link-VariantDir;
-below for additional details and restrictions.
-</para>
-
-<para>
-If
-<varname>variant_dir</varname>
-is present,
-the source directory is the directory in which the
-SConscript
-file resides and the
-SConscript
+argument is interpreted relative to the directory of the
+<emphasis>calling</emphasis> SConscript file.
+The source directory is the directory in which the
+<emphasis>called</emphasis> SConscript
+file resides and the SConscript
 file is evaluated as if it were in the
 <varname>variant_dir</varname>
-directory:
+directory. Thus:
 </para>
 <example_commands>
 SConscript('src/SConscript', variant_dir='build')
 </example_commands>
 
 <para>
-is equivalent to
+is equivalent to:
 </para>
 
 <example_commands>
@@ -488,9 +474,8 @@ SConscript('build/SConscript')
 </example_commands>
 
 <para>
-This later paradigm is often used when the sources are
-in the same directory as the
-&SConstruct;:
+If the sources are in the same directory as the
+&SConstruct;,
 </para>
 
 <example_commands>
@@ -498,7 +483,7 @@ SConscript('SConscript', variant_dir='build')
 </example_commands>
 
 <para>
-is equivalent to
+is equivalent to:
 </para>
 
 <example_commands>
@@ -507,6 +492,17 @@ SConscript('build/SConscript')
 </example_commands>
 
 <para>
+The optional
+<varname>duplicate</varname> argument is
+interpreted as for &f-link-VariantDir;.
+If the <varname>variant_dir</varname> argument
+is omitted, the <varname>duplicate</varname> argument is ignored.
+See the description of
+&f-link-VariantDir;
+for additional details and restrictions.
+</para>
+
+<para>
 <!--
 If
 <varname>variant_dir</varname>
@@ -589,11 +585,11 @@ SConscript('src/SConscript', variant_dir='build/ppc', duplicate=0)
 
 <para>
 &f-SConscript; returns the values of any variables
-named by the executed SConscript(s) in arguments
-to the &f-link-Return; function (see above for details).
+named by the executed SConscript file(s) in arguments
+to the &f-link-Return; function.
 If a single &f-SConscript; call causes multiple scripts to
 be executed, the return value is a tuple containing
-the returns of all of the scripts. If an executed
+the returns of each of the scripts. If an executed
 script does not explicitly call &Return;, it returns
 <constant>None</constant>.
 </para>
diff --git a/SCons/Tool/MSCommon/common.py b/SCons/Tool/MSCommon/common.py
index f542e02..c9f07f5 100644
--- a/SCons/Tool/MSCommon/common.py
+++ b/SCons/Tool/MSCommon/common.py
@@ -35,6 +35,10 @@ from contextlib import suppress
 from pathlib import Path
 
 import SCons.Util
+import SCons.Warnings
+
+class MSVCCacheInvalidWarning(SCons.Warnings.WarningOnByDefault):
+    pass
 
 # SCONS_MSCOMMON_DEBUG is internal-use so undocumented:
 # set to '-' to print to console, else set to filename to log to
@@ -110,7 +114,15 @@ def read_script_env_cache():
                 # json to the cache dictionary. Reconstruct the cache key
                 # tuple from the key list written to json.
                 envcache_list = json.load(f)
-                envcache = {tuple(d['key']): d['data'] for d in envcache_list}
+                if isinstance(envcache_list, list):
+                    envcache = {tuple(d['key']): d['data'] for d in envcache_list}
+                else:
+                    # don't fail if incompatible format, just proceed without it
+                    warn_msg = "Incompatible format for msvc cache file {}: file may be overwritten.".format(
+                        repr(CONFIG_CACHE)
+                    )
+                    SCons.Warnings.warn(MSVCCacheInvalidWarning, warn_msg)
+                    debug(warn_msg)
         except FileNotFoundError:
             # don't fail if no cache file, just proceed without it
             pass
diff --git a/SCons/Tool/ToolTests.py b/SCons/Tool/ToolTests.py
index 7cff7c8..9338c2d 100644
--- a/SCons/Tool/ToolTests.py
+++ b/SCons/Tool/ToolTests.py
@@ -116,7 +116,9 @@ class ToolTestCase(unittest.TestCase):
 
 
 if __name__ == "__main__":
-    suite = unittest.makeSuite(ToolTestCase, 'test_')
+    loader = unittest.TestLoader()
+    loader.testMethodPrefix = 'test_'
+    suite = loader.loadTestsFromTestCase(ToolTestCase)
     TestUnit.run(suite)
 
 # Local Variables:
diff --git a/SCons/Tool/msvsTests.py b/SCons/Tool/msvsTests.py
index 4cbaf0e..c4d2e98 100644
--- a/SCons/Tool/msvsTests.py
+++ b/SCons/Tool/msvsTests.py
@@ -982,7 +982,9 @@ if __name__ == "__main__":
                 if k in os.environ:
                     del os.environ[k]
 
-            suite = unittest.makeSuite(test_class, 'test_')
+            loader = unittest.TestLoader()
+            loader.testMethodPrefix = 'test_'
+            suite = loader.loadTestsFromTestCase(test_class)
             if not TestUnit.cli.get_runner()().run(suite).wasSuccessful():
                 exit_val = 1
         finally:
diff --git a/SCons/Tool/ninja/Methods.py b/SCons/Tool/ninja/Methods.py
index 2be576f..c0afab8 100644
--- a/SCons/Tool/ninja/Methods.py
+++ b/SCons/Tool/ninja/Methods.py
@@ -81,7 +81,7 @@ def get_generic_shell_command(env, node, action, targets, sources, executor=None
         "GENERATED_CMD",
         {
             "cmd": generate_command(env, node, action, targets, sources, executor=executor),
-            "env": get_command_env(env),
+            "env": get_command_env(env, targets, sources),
         },
         # Since this function is a rule mapping provider, it must return a list of dependencies,
         # and usually this would be the path to a tool, such as a compiler, used for this rule.
@@ -266,7 +266,7 @@ def gen_get_response_file_command(env, rule, tool, tool_is_dynamic=False, custom
 
         variables = {"rspc": rsp_content, rule: cmd}
         if use_command_env:
-            variables["env"] = get_command_env(env)
+            variables["env"] = get_command_env(env, targets, sources)
 
             for key, value in custom_env.items():
                 variables["env"] += env.subst(
diff --git a/SCons/Tool/ninja/NinjaState.py b/SCons/Tool/ninja/NinjaState.py
index 770da07..70be248 100644
--- a/SCons/Tool/ninja/NinjaState.py
+++ b/SCons/Tool/ninja/NinjaState.py
@@ -821,6 +821,15 @@ class SConsToNinjaTranslator:
 
             # Remove all preceding and proceeding whitespace
             cmdline = cmdline.strip()
+            env = node.env if node.env else self.env
+            executor = node.get_executor()
+            if executor is not None:
+                targets = executor.get_all_targets()
+            else:
+                if hasattr(node, "target_peers"):
+                    targets = node.target_peers
+                else:
+                    targets = [node]
 
             # Make sure we didn't generate an empty cmdline
             if cmdline:
@@ -829,7 +838,7 @@ class SConsToNinjaTranslator:
                     "rule": get_rule(node, "GENERATED_CMD"),
                     "variables": {
                         "cmd": cmdline,
-                        "env": get_command_env(node.env if node.env else self.env),
+                        "env": get_command_env(env, targets, node.sources),
                     },
                     "implicit": dependencies,
                 }
diff --git a/SCons/Tool/ninja/Utils.py b/SCons/Tool/ninja/Utils.py
index c5f7ee4..b2c3cd3 100644
--- a/SCons/Tool/ninja/Utils.py
+++ b/SCons/Tool/ninja/Utils.py
@@ -262,7 +262,7 @@ def ninja_noop(*_args, **_kwargs):
     return None
 
 
-def get_command_env(env):
+def get_command_env(env, target, source):
     """
     Return a string that sets the environment for any environment variables that
     differ between the OS environment and the SCons command ENV.
@@ -278,7 +278,7 @@ def get_command_env(env):
     # os.environ or differ from it. We assume if it's a new or
     # differing key from the process environment then it's
     # important to pass down to commands in the Ninja file.
-    ENV = get_default_ENV(env)
+    ENV = SCons.Action._resolve_shell_env(env, target, source)
     scons_specified_env = {
         key: value
         for key, value in ENV.items()
diff --git a/SCons/Tool/swig.xml b/SCons/Tool/swig.xml
index 19ec21f..a6d85ce 100644
--- a/SCons/Tool/swig.xml
+++ b/SCons/Tool/swig.xml
@@ -26,7 +26,7 @@ See its __doc__ string for a discussion of the format.
 <tool name="swig">
 <summary>
 <para>
-Sets construction variables for the SWIG interface generator.
+Sets construction variables for the &swig; interface compiler.
 </para>
 </summary>
 <sets>
@@ -50,7 +50,7 @@ Sets construction variables for the SWIG interface generator.
 <cvar name="SWIG">
 <summary>
 <para>
-The scripting language wrapper and interface generator.
+The name of the &swig; compiler to use.
 </para>
 </summary>
 </cvar>
@@ -59,10 +59,11 @@ The scripting language wrapper and interface generator.
 <summary>
 <para>
 The suffix that will be used for intermediate C
-source files generated by
-the scripting language wrapper and interface generator.
-The default value is
-<filename>_wrap</filename>&cv-link-CFILESUFFIX;.
+source files generated by &swig;.
+The default value is <literal>'_wrap$CFILESUFFIX'</literal> -
+that is, the concatenation of the string
+<literal>_wrap</literal>
+and the current C suffix &cv-link-CFILESUFFIX;.
 By default, this value is used whenever the
 <option>-c++</option>
 option is
@@ -78,8 +79,8 @@ construction variable.
 <summary>
 <para>
 The suffix that will be used for intermediate C++ header
-files generated by the scripting language wrapper and interface generator.
-These are only generated for C++ code when the SWIG 'directors' feature is
+files generated by &swig;.
+These are only generated for C++ code when the &swig; 'directors' feature is
 turned on.
 The default value is
 <filename>_wrap.h</filename>.
@@ -90,8 +91,7 @@ The default value is
 <cvar name="SWIGCOM">
 <summary>
 <para>
-The command line used to call
-the scripting language wrapper and interface generator.
+The command line used to call &swig;.
 </para>
 </summary>
 </cvar>
@@ -99,8 +99,7 @@ the scripting language wrapper and interface generator.
 <cvar name="SWIGCOMSTR">
 <summary>
 <para>
-The string displayed when calling
-the scripting language wrapper and interface generator.
+The string displayed when calling &swig;.
 If this is not set, then &cv-link-SWIGCOM; (the command line) is displayed.
 </para>
 </summary>
@@ -110,12 +109,13 @@ If this is not set, then &cv-link-SWIGCOM; (the command line) is displayed.
 <summary>
 <para>
 The suffix that will be used for intermediate C++
-source files generated by
-the scripting language wrapper and interface generator.
-The default value is
-<filename>_wrap</filename>&cv-link-CFILESUFFIX;.
+source files generated by &swig;.
+The default value is <literal>'_wrap$CXXFILESUFFIX'</literal> -
+that is, the concatenation of the string
+<literal>_wrap</literal>
+and the current C++ suffix &cv-link-CXXFILESUFFIX;.
 By default, this value is used whenever the
-<filename>-c++</filename>
+<option>-c++</option>
 option is specified as part of the
 &cv-link-SWIGFLAGS;
 construction variable.
@@ -126,22 +126,14 @@ construction variable.
 <cvar name="SWIGFLAGS">
 <summary>
 <para>
-General options passed to
-the scripting language wrapper and interface generator.
-This is where you should set
-<option>-python</option>,
+General options passed to &swig;.
+This is where you should set the target language
+(<option>-python</option>,
 <option>-perl5</option>,
-<option>-tcl</option>,
-or whatever other options you want to specify to SWIG.
-If you set the
-<option>-c++</option>
-option in this variable,
-&scons;
-will, by default,
-generate a C++ intermediate source file
-with the extension that is specified as the
-&cv-link-CXXFILESUFFIX;
-variable.
+<option>-tcl</option>, etc.)
+and whatever other options you want to specify to &swig;,
+such as the <option>-c++</option> to generate C++ code
+instead of C Code.
 </para>
 </summary>
 </cvar>
@@ -150,7 +142,7 @@ variable.
 <summary>
 <para>
 An automatically-generated construction variable
-containing the SWIG command-line options
+containing the &swig; command-line options
 for specifying directories to be searched for included files.
 The value of &cv-_SWIGINCFLAGS; is created
 by respectively prepending and appending
@@ -164,7 +156,7 @@ of each directory in &cv-SWIGPATH;.
 <cvar name="SWIGINCPREFIX">
 <summary>
 <para>
-The prefix used to specify an include directory on the SWIG command line.
+The prefix used to specify an include directory on the &swig; command line.
 This will be prepended to the beginning of each directory
 in the &cv-SWIGPATH; construction variable
 when the &cv-_SWIGINCFLAGS; variable is automatically generated.
@@ -175,7 +167,7 @@ when the &cv-_SWIGINCFLAGS; variable is automatically generated.
 <cvar name="SWIGINCSUFFIX">
 <summary>
 <para>
-The suffix used to specify an include directory on the SWIG command line.
+The suffix used to specify an include directory on the &swig; command line.
 This will be appended to the end of each directory
 in the &cv-SWIGPATH; construction variable
 when the &cv-_SWIGINCFLAGS; variable is automatically generated.
@@ -186,8 +178,7 @@ when the &cv-_SWIGINCFLAGS; variable is automatically generated.
 <cvar name="SWIGOUTDIR">
 <summary>
 <para>
-Specifies the output directory in which
-the scripting language wrapper and interface generator
+Specifies the output directory in which &swig;
 should place generated language-specific files.
 This will be used by SCons to identify
 the files that will be generated by the &swig; call,
@@ -200,22 +191,24 @@ and translated into the
 <cvar name="SWIGPATH">
 <summary>
 <para>
-The list of directories that the scripting language wrapper
-and interface generate will search for included files.
-The SWIG implicit dependency scanner will search these
+The list of directories that &swig;
+will search for included files.
+&SCons;' SWIG implicit dependency scanner will search these
 directories for include files. The default value is an empty list.
 </para>
 
 <para>
 Don't explicitly put include directory
-arguments in SWIGFLAGS;
+arguments in &cv-link-SWIGFLAGS;
 the result will be non-portable
 and the directories will not be searched by the dependency scanner.
-Note: directory names in SWIGPATH will be looked-up relative to the SConscript
+Note: directory names in &cv-link-SWIGPATH;
+will be looked-up relative to the SConscript
 directory when they are used in a command.
 To force
 &scons;
-to look-up a directory relative to the root of the source tree use #:
+to look-up a directory relative to the root of the source tree use
+a top-relative path (<literal>#</literal>):
 </para>
 
 <example_commands>
@@ -258,7 +251,7 @@ env = Environment(SWIGCOM="my_swig -o $TARGET $_SWIGINCFLAGS $SOURCES")
 <cvar name="SWIGVERSION">
 <summary>
 <para>
-The version number of the SWIG tool.
+The detected version string of the &swig; tool.
 </para>
 </summary>
 </cvar>
diff --git a/SCons/cppTests.py b/SCons/cppTests.py
index a9aef9d..f20c302 100644
--- a/SCons/cppTests.py
+++ b/SCons/cppTests.py
@@ -876,7 +876,9 @@ if __name__ == '__main__':
                  fileTestCase,
                ]
     for tclass in tclasses:
-        names = unittest.getTestCaseNames(tclass, 'test_')
+        loader = unittest.TestLoader()
+        loader.testMethodPrefix = 'test_'
+        names = loader.getTestCaseNames(tclass)
         try:
             names = sorted(set(names))
         except NameError: