build: fix Windows build settings

Author: SYMSCAE

SConstruct

@@ -70,7 +70,11 @@ if env['PLATFORM'] == "win32":
     lib_path = pjoin(env['prefix'], 'Library', 'lib')
     shared_path = pjoin(env['prefix'], 'Library', 'share')
 
-    env['ENV']['TMP'] = os.environ['TMP']
+    # Windows programs started by SCons, such as python for cxxtestgen,
+    # fail without these system variables.
+    for k in ('SYSTEMROOT', 'SYSTEMDRIVE', 'COMSPEC', 'PATHEXT', 'TEMP', 'TMP'):
+        if k in os.environ:
+            env['ENV'][k] = os.environ[k]
 else:
     include_path = pjoin(env['prefix'], 'include')
     lib_path = pjoin(env['prefix'], 'lib')

news/windows.rst

@@ -3,7 +3,6 @@
 * Support building libdiffpy on Windows with MSVC, clang or MinGW, merged from the upstream ``windows`` branch.
 * Export the public API from the Windows DLL with the ``DLL_EXPORT`` macro in ``diffpy/Export.hpp``.
 * Install headers, libraries and data under ``$PREFIX`` or ``$CONDA_PREFIX`` by default, using the ``Library/`` layout on Windows.
-* Add a Windows build and test job to the pull request CI.
 * Add a clang-format pre-commit hook and ``.git-blame-ignore-revs`` for the reformat commits.
 
 **Changed:**

src/SConscript

@@ -48,8 +48,7 @@ if env['PLATFORM'] == 'darwin':
 
 # Compiler specific options
 if env['PLATFORM'] == 'win32':
-    # BUILD_DLL makes DLL_EXPORT export symbols, see diffpy/Export.hpp.
-    env.AppendUnique(CPPDEFINES=['BUILD_DLL', '_USE_MATH_DEFINES'])
+    env.AppendUnique(CPPDEFINES=['_USE_MATH_DEFINES'])
     if env['tool'] == 'clang':
         # clang++ on Windows
         env['CC'] = 'clang'
@@ -63,7 +62,10 @@ if env['PLATFORM'] == 'win32':
         env.AppendUnique(LINKFLAGS='-m64')
     else:
         # Visual C++
-        env.PrependUnique(CCFLAGS=['/Ox', '/EHsc', '/MD', '/Wall'])
+        # /W3 rather than /Wall, which floods the log with warnings from the
+        # standard library and boost headers.  /bigobj is needed for the
+        # boost serialization code.
+        env.PrependUnique(CCFLAGS=['/Ox', '/EHsc', '/MD', '/W3', '/bigobj'])
         env.AppendUnique(CXXFLAGS='/std:c++latest')
         env.AppendUnique(CPPDEFINES={'NDEBUG': None})
         env.AppendUnique(LINKFLAGS=['/OPT:NOREF', '/OPT:NOICF'])
@@ -167,6 +169,10 @@ if 'sdist' in COMMAND_LINE_TARGETS:
 
 # use new environment with extra libraries needed for libdiffpy.
 env_lib = env.Clone()
+if env['PLATFORM'] == 'win32':
+    # Export the API from the DLL, see diffpy/Export.hpp.  Code that uses
+    # the library, including the unit tests, imports it instead.
+    env_lib.AppendUnique(CPPDEFINES=['BUILD_DLL'])
 # The dladdr call in runtimepath.cpp requires the dl library.
 # Windows uses GetModuleHandleEx instead.
 if env['PLATFORM'] != 'win32':

src/diffpy/SConscript

@@ -12,6 +12,9 @@ if env['PLATFORM'] == "win32":
 
 env_rt = env.Clone()
 env_rt.AppendUnique(CPPDEFINES=dict(DIFFPYRUNTIMERELPATH=rtrp))
+if env['PLATFORM'] == "win32":
+    # runtimepath is part of the DLL, see BUILD_DLL in src/SConscript.
+    env_rt.AppendUnique(CPPDEFINES=['BUILD_DLL'])
 rtso = env_rt.SharedObject('runtimepath', 'runtimepath.cpp')
 env['lib_sources'] += rtso
 

src/tests/SConscript

@@ -15,7 +15,11 @@ else:
 use_our_library = not env['test_installed']
 
 env_test.PrependUnique(LIBS='diffpy', LIBPATH=lib_dir, delete_existing=1)
-env_test.PrependUnique(LINKFLAGS="-Wl,-rpath,%r" % lib_dir)
+if env['PLATFORM'] == 'win32':
+    # Windows has no rpath.  Let the test program find diffpy.dll on PATH.
+    env_test.PrependENVPath('PATH', lib_dir)
+else:
+    env_test.PrependUnique(LINKFLAGS="-Wl,-rpath,%r" % lib_dir)
 
 # Targets --------------------------------------------------------------------