Update Tool/msvs.py, update MSVS tests; and add additional tests for MSVS multi-project and solution builds.

Tool/msvs.py:
* Add "projectguid" argument to MSVSProject to enable user-defined GUID assignment per-project for multiple project solutions.
* Project GUID priority: (1) MSVSProject "projectguid" argument, (2) SCons env MSVS_PROJECT_GUID value, (3) internally generated GUID.  SCons env MSVS_PROJECT_GUID value should not be used for multiple project solutions without using projectguid arguments (otherwise, multiple projects will use the same GUID).
* Store the project GUID as a node Tag when generating the MSVSProject and retrieve the project GUIDs using GetTag when generating the solution.
* Move project node processing to a function so it can be called from multiple code locations.
* Filter out solution nodes from project list (bugfix: auto_build_solution enabled and returned value used as project list includes auto-generated solution as a Project in the solution file).
* Check for variant directory build of MSVSSolution and adjust src node accordingly similar to MSVSProject code. Bug fix: the solution file is generated in the build directory instead of the source directory.  The placeholder solution file is now generated in the build directory and the solution file is generated in the source folder similar to the handling of project files.
* Add project dsp nodes to the dsw source node list.  This appears to always cause the project files to be generated before the solution files which is necessary to retrieve the project GUIDs for use in the solution file.  This does change the behavior of clean for a project generated with auto_build_solution disabled and explicit solution generation: when the solution file is cleaned, the project files are also cleaned.  The tests for vs 6.0-7.1 were changed accordingly.

testing/framework/TestSConsMSVS.py:
* Add known project GUID for single project tests and two known project GUIDs for dual project tests.
* Add projectguid to MSVSProject arguments for single project test SConstruct/SConscript files.
* Add PROJECT_BASENAME replaceable field to expected generated project file templates.
* Add dual project and single solution templates.

Tests:
* Use known project guid for most tests which prevents have to hard-code generated GUIDs.
* Add 4 (2x2) tests using two projects for combinations of auto_build_solutions settings (2) and variant directories (2).
* Add 2 tests using two projects which use default GUID generation with and without variant directories.

2 files changed, 76 insertions, 26 deletions

diff --git a/SCons/Tool/msvs.py b/SCons/Tool/msvs.py
index eff1c8e..e26ec11 100644
--- a/SCons/Tool/msvs.py
+++ b/SCons/Tool/msvs.py
@@ -124,6 +124,24 @@ def _generateGUID(slnfile, name, namespace=external_makefile_guid):
     return '{' + str(solution).upper() + '}'
 
 
+def _projectGUID(env, dspfile):
+    """Generates a GUID for the project file to use.
+
+    In order of preference:
+    * MSVSProject projectguid argument
+    * MSVS_PROJECT_GUID in environment
+    * Generated from the project file name (dspfile)
+
+    Returns (str)
+    """
+    project_guid = env.get('projectguid')
+    if not project_guid:
+        project_guid = env.get('MSVS_PROJECT_GUID')
+    if not project_guid:
+        project_guid = _generateGUID(dspfile, '')
+    return project_guid
+
+
 version_re = re.compile(r'(\d+\.\d+)(.*)')
 
 
@@ -428,6 +446,9 @@ class _DSPGenerator:
         'misc']
 
     def __init__(self, dspfile, source, env) -> None:
+        dspnode = env.File(dspfile)
+        self.project_guid = _projectGUID(env, dspfile)
+        dspnode.Tag('project_guid', self.project_guid)
         self.dspfile = str(dspfile)
         try:
             get_abspath = dspfile.get_abspath
@@ -912,8 +933,9 @@ class _GenerateV7DSP(_DSPGenerator, _GenerateV7User):
 
     def PrintHeader(self) -> None:
         env = self.env
-        versionstr = self.versionstr
         name = self.name
+        versionstr = self.versionstr
+        project_guid = self.project_guid
         encoding = self.env.subst('$MSVSENCODING')
         scc_provider = env.get('MSVS_SCC_PROVIDER', '')
         scc_project_name = env.get('MSVS_SCC_PROJECT_NAME', '')
@@ -923,9 +945,6 @@ class _GenerateV7DSP(_DSPGenerator, _GenerateV7User):
         scc_local_path_legacy = env.get('MSVS_SCC_LOCAL_PATH', '')
         scc_connection_root = env.get('MSVS_SCC_CONNECTION_ROOT', os.curdir)
         scc_local_path = os.path.relpath(scc_connection_root, os.path.dirname(self.dspabs))
-        project_guid = env.get('MSVS_PROJECT_GUID', '')
-        if not project_guid:
-            project_guid = _generateGUID(self.dspfile, '')
         if scc_provider != '':
             scc_attrs = '\tSccProjectName="%s"\n' % scc_project_name
             if scc_aux_path != '':
@@ -1209,8 +1228,8 @@ class _GenerateV10DSP(_DSPGenerator, _GenerateV10User):
         env = self.env
         name = self.name
         versionstr = self.versionstr
+        project_guid = self.project_guid
         encoding = env.subst('$MSVSENCODING')
-        project_guid = env.get('MSVS_PROJECT_GUID', '')
         scc_provider = env.get('MSVS_SCC_PROVIDER', '')
         scc_project_name = env.get('MSVS_SCC_PROJECT_NAME', '')
         scc_aux_path = env.get('MSVS_SCC_AUX_PATH', '')
@@ -1219,8 +1238,6 @@ class _GenerateV10DSP(_DSPGenerator, _GenerateV10User):
         scc_local_path_legacy = env.get('MSVS_SCC_LOCAL_PATH', '')
         scc_connection_root = env.get('MSVS_SCC_CONNECTION_ROOT', os.curdir)
         scc_local_path = os.path.relpath(scc_connection_root, os.path.dirname(self.dspabs))
-        if not project_guid:
-            project_guid = _generateGUID(self.dspfile, '')
         if scc_provider != '':
             scc_attrs = '\t\t<SccProjectName>%s</SccProjectName>\n' % scc_project_name
             if scc_aux_path != '':
@@ -1465,6 +1482,26 @@ class _GenerateV10DSP(_DSPGenerator, _GenerateV10User):
 
         _GenerateV10User.Build(self)
 
+def _projectDSPNodes(env):
+    if 'projects' not in env:
+        raise SCons.Errors.UserError("You must specify a 'projects' argument to create an MSVSSolution.")
+    projects = env['projects']
+    if not SCons.Util.is_List(projects):
+        raise SCons.Errors.InternalError("The 'projects' argument must be a list of nodes.")
+    projects = SCons.Util.flatten(projects)
+    if len(projects) < 1:
+        raise SCons.Errors.UserError("You must specify at least one project to create an MSVSSolution.")
+    sln_suffix = env.subst('$MSVSSOLUTIONSUFFIX')
+    dspnodes = []
+    for p in projects:
+        node = env.File(p)
+        if str(node).endswith(sln_suffix):
+            continue
+        dspnodes.append(node)
+    if len(dspnodes) < 1:
+        raise SCons.Errors.UserError("You must specify at least one project node to create an MSVSSolution.")
+    return dspnodes
+
 class _DSWGenerator:
     """ Base class for DSW generators """
     def __init__(self, dswfile, source, env) -> None:
@@ -1472,15 +1509,8 @@ class _DSWGenerator:
         self.dsw_folder_path = os.path.dirname(os.path.abspath(self.dswfile))
         self.env = env
 
-        if 'projects' not in env:
-            raise SCons.Errors.UserError("You must specify a 'projects' argument to create an MSVSSolution.")
-        projects = env['projects']
-        if not SCons.Util.is_List(projects):
-            raise SCons.Errors.InternalError("The 'projects' argument must be a list of nodes.")
-        projects = SCons.Util.flatten(projects)
-        if len(projects) < 1:
-            raise SCons.Errors.UserError("You must specify at least one project to create an MSVSSolution.")
-        self.dspfiles = list(map(str, projects))
+        dspnodes = _projectDSPNodes(env)
+        self.dsp_srcnodes = [dspnode.srcnode() for dspnode in dspnodes]
 
         if 'name' in self.env:
             self.name = self.env['name']
@@ -1554,8 +1584,9 @@ class _GenerateV7DSW(_DSWGenerator):
                           if not (p.platform in seen or seen.add(p.platform))]
 
         def GenerateProjectFilesInfo(self) -> None:
-            project_guid = self.env.get('MSVS_PROJECT_GUID', '')
-            for dspfile in self.dspfiles:
+            for dspnode in self.dsp_srcnodes:
+                project_guid = dspnode.GetTag('project_guid')
+                dspfile = str(dspnode)
                 dsp_folder_path, name = os.path.split(dspfile)
                 dsp_folder_path = os.path.abspath(dsp_folder_path)
                 if SCons.Util.splitext(name)[1] == '.filters':
@@ -1567,11 +1598,9 @@ class _GenerateV7DSW(_DSWGenerator):
                 else:
                     dsp_relative_file_path = os.path.join(dsp_relative_folder_path, name)
                 if not project_guid:
-                    guid = _generateGUID(dspfile, '')
-                else:
-                    guid = project_guid
+                    project_guid = _generateGUID(dspfile, '')
                 dspfile_info = {'NAME': name,
-                                'GUID': guid,
+                                'GUID': project_guid,
                                 'FOLDER_PATH': dsp_folder_path,
                                 'FILE_PATH': dspfile,
                                 'SLN_RELATIVE_FOLDER_PATH': dsp_relative_folder_path,
@@ -1650,7 +1679,7 @@ class _GenerateV7DSW(_DSWGenerator):
 
         env = self.env
         if 'MSVS_SCC_PROVIDER' in env:
-            scc_number_of_projects = len(self.dspfiles) + 1
+            scc_number_of_projects = len(self.dsp_srcnodes) + 1
             slnguid = self.slnguid
             scc_provider = env.get('MSVS_SCC_PROVIDER', '').replace(' ', r'\u0020')
             scc_project_name = env.get('MSVS_SCC_PROJECT_NAME', '').replace(' ', r'\u0020')
@@ -1782,7 +1811,7 @@ class _GenerateV6DSW(_DSWGenerator):
     def PrintWorkspace(self) -> None:
         """ writes a DSW file """
         name = self.name
-        dspfile = os.path.relpath(self.dspfiles[0], self.dsw_folder_path)
+        dspfile = os.path.relpath(str(self.dsp_srcnodes[0]), self.dsw_folder_path)
         self.file.write(V6DSWHeader % locals())
 
     def Build(self):
@@ -1872,7 +1901,22 @@ def GenerateProject(target, source, env):
         GenerateDSW(dswfile, source, env)
 
 def GenerateSolution(target, source, env) -> None:
-    GenerateDSW(target[0], source, env)
+
+    builddswfile = target[0]
+    dswfile = builddswfile.srcnode()
+
+    if dswfile is not builddswfile:
+
+        try:
+            bdsw = open(str(builddswfile), "w+")
+        except OSError as detail:
+            print('Unable to open "' + str(dspfile) + '" for writing:',detail,'\n')
+            raise
+
+        bdsw.write("This is just a placeholder file.\nThe real workspace file is here:\n%s\n" % dswfile.get_abspath())
+        bdsw.close()
+
+    GenerateDSW(dswfile, source, env)
 
 def projectEmitter(target, source, env):
     """Sets up the DSP dependencies."""
@@ -1966,7 +2010,7 @@ def projectEmitter(target, source, env):
     sourcelist = source
 
     if env.get('auto_build_solution', 1):
-        env['projects'] = [env.File(t).srcnode() for t in targetlist]
+        env['projects'] = [env.File(t) for t in targetlist]
         t, s = solutionEmitter(target, target, env)
         targetlist = targetlist + t
 
@@ -2033,6 +2077,9 @@ def solutionEmitter(target, source, env):
         source = source + ' "%s"' % str(target[0])
         source = [SCons.Node.Python.Value(source)]
 
+    dsp_nodes = _projectDSPNodes(env)
+    source.extend(dsp_nodes)
+
     return ([target[0]], source)
 
 projectAction = SCons.Action.Action(GenerateProject, None)
diff --git a/SCons/Tool/msvsTests.py b/SCons/Tool/msvsTests.py
index 7893caf..dd423d4 100644
--- a/SCons/Tool/msvsTests.py
+++ b/SCons/Tool/msvsTests.py
@@ -420,6 +420,9 @@ class DummyEnv:
     def Dir(self, name):
         return self.fs.Dir(name)
 
+    def File(self, name):
+        return self.fs.File(name)
+
     def subst(self, key):
         if key[0] == '$':
             key = key[1:]