SERVER-27497 Scope SCons Environment changes narrowly

SConstruct

@@ -2949,9 +2949,9 @@ module_sconscripts = moduleconfig.get_module_sconscripts(mongo_modules)
 # Currently, however, the SConscript files do need some predicates for
 # conditional decision making that hasn't been moved up to this SConstruct file,
 # and they are exported here, as well.
-Export("env")
 Export("get_option")
-Export("has_option use_system_version_of_library")
+Export("has_option")
+Export("use_system_version_of_library")
 Export("serverJs")
 Export("usemozjs")
 Export('module_sconscripts')
@@ -2982,7 +2982,16 @@ env.Alias("distsrc-tgz", env.GZip(
 env.Alias("distsrc-zip", env.DistSrc("mongodb-src-${MONGO_VERSION}.zip"))
 env.Alias("distsrc", "distsrc-tgz")
 
-env.SConscript('src/SConscript', variant_dir='$BUILD_DIR', duplicate=False)
+env.SConscript(
+    dirs=[
+        'src',
+    ],
+    duplicate=False,
+    exports=[
+        'env',
+    ],
+    variant_dir='$BUILD_DIR',
+)
 
 all = env.Alias('all', ['core', 'tools', 'dbtest', 'unittests', 'integration_tests'])
 

src/SConscript

@@ -3,13 +3,25 @@
 # This is the principle SConscript file, invoked by the SConstruct.  Its job is
 # to delegate to any and all per-module SConscript files.
 
-Import('env module_sconscripts')
-
-env.SConscript(
-    [
-        # NOTE: We must do third_party first as it adds methods to the environment
-        # that we need in the mongo sconscript
-        'third_party/SConscript',
-        'mongo/SConscript',
-    ] + module_sconscripts
-)
+Import('env')
+Import('module_sconscripts')
+
+# NOTE: We must do third_party first as it adds methods to the environment
+# that we need in the mongo sconscript
+env = env.Clone()
+env.SConscript('third_party/SConscript', exports=['env'])
+
+# Inject boost and pcre from third_party globally for all core mongo code
+# and modules. Ideally, pcre wouldn't be here, but enough things require it
+# now that it seems hopeless to remove it now.
+env = env.Clone()
+env.InjectThirdPartyIncludePaths(libraries=[
+    'boost',
+    'pcre',
+])
+
+# Run the core mongodb SConscript.
+env.SConscript('mongo/SConscript', exports=['env'])
+
+# Run SConscripts for any modules in play
+env.SConscript(module_sconscripts, exports=['env'])

src/mongo/SConscript

@@ -14,13 +14,8 @@ Import("get_option")
 Import("usemozjs")
 Import("use_system_version_of_library")
 
-# Boost we need everywhere. 's2' is spammed in all over the place by
-# db/geo unfortunately. pcre is also used many places.
-env.InjectThirdPartyIncludePaths(libraries=[
-    'boost',
-    'pcre',
-    's2',
-])
+env = env.Clone()
+
 env.InjectMongoIncludePaths()
 
 env.SConscript(
@@ -44,6 +39,9 @@ env.SConscript(
         'unittest',
         'util',
     ],
+    exports=[
+        'env',
+    ],
 )
 
 # NOTE: This library does not really belong here. Its presence here is

src/mongo/base/SConscript

@@ -2,6 +2,8 @@
 
 Import("env")
 
+env = env.Clone()
+
 generateErrorCodes = env.Command(
     target=['error_codes.h', 'error_codes.cpp'],
     source=['generate_error_codes.py', 'error_codes.err'],

src/mongo/bson/SConscript

@@ -2,11 +2,16 @@
 
 Import('env')
 
+env = env.Clone()
+
 env.SConscript(
     dirs=[
         'mutable',
         'util',
     ],
+    exports=[
+        'env',
+    ],
 )
 
 env.CppUnitTest(

src/mongo/bson/mutable/SConscript

@@ -2,6 +2,8 @@
 
 Import('env')
 
+env = env.Clone()
+
 env.Library(
     target='mutable_bson',
     source=[

src/mongo/bson/util/SConscript

@@ -2,6 +2,8 @@
 
 Import('env')
 
+env = env.Clone()
+
 env.Library(
     target='bson_extract',
     source=[

src/mongo/client/SConscript

@@ -2,6 +2,8 @@
 
 Import('env')
 
+env = env.Clone()
+
 # Contains only the core ConnectionString functionality, *not* the ability to call connect()
 # and return a DBClientBase* back. For that you need to link against the 'clientdriver' library.
 env.Library(
@@ -129,8 +131,10 @@ env.Library(
     ],
 )
 
+clientDriverEnv = env.Clone()
+clientDriverEnv.InjectThirdPartyIncludePaths('asio')
 
-env.Library(
+clientDriverEnv.Library(
     target='clientdriver',
     source=[
         'connection_string_connect.cpp',

src/mongo/crypto/SConscript

@@ -2,10 +2,15 @@
 
 Import("env")
 
+env = env.Clone()
+
 env.SConscript(
     dirs=[
         'tom',
     ],
+    exports=[
+        'env',
+    ],
 )
 
 env.Library('crypto_tom',

src/mongo/crypto/tom/SConscript

@@ -2,6 +2,8 @@
 
 Import("env")
 
+env = env.Clone()
+
 env.Library('tomcrypt',
            ['crypt_argchk.c',
            'crypt_find_hash.c',

src/mongo/db/SConscript

@@ -4,6 +4,14 @@ Import("env")
 Import("has_option")
 Import("wiredtiger")
 
+env = env.Clone()
+
+# Ideally 's2' would be scoped narrowly but it is spammed in all over the place by
+# db/geo unfortunately.
+env.InjectThirdPartyIncludePaths(libraries=[
+    's2',
+])
+
 env.SConscript(
     dirs=[
         'auth',
@@ -27,6 +35,9 @@ env.SConscript(
         'storage',
         'views',
     ],
+    exports=[
+        'env',
+    ],
 )
 
 #

src/mongo/db/auth/SConscript

@@ -2,6 +2,8 @@
 
 Import("env")
 
+env = env.Clone()
+
 env.Library('serverauth', ['mongo_authentication_session.cpp'])
 
 generateActionTypes = env.Command(

src/mongo/db/bson/SConscript

@@ -2,6 +2,8 @@
 
 Import("env")
 
+env = env.Clone()
+
 env.Library(
     target="dotted_path_support",
     source=[

src/mongo/db/catalog/SConscript

@@ -2,6 +2,8 @@
 
 Import("env")
 
+env = env.Clone()
+
 env.Library('collection_options', ['collection_options.cpp'], LIBDEPS=['$BUILD_DIR/mongo/base'])
 
 env.CppUnitTest('collection_options_test', ['collection_options_test.cpp'],

src/mongo/db/commands/SConscript

@@ -3,6 +3,8 @@
 Import("env")
 Import("has_option")
 
+env = env.Clone()
+
 env.Library(
     target="test_commands_enabled",
     source=[

src/mongo/db/concurrency/SConscript

@@ -2,6 +2,8 @@
 
 Import("env")
 
+env = env.Clone()
+
 env.Library(
     target='write_conflict_exception',
     source=[

src/mongo/db/exec/SConscript

@@ -2,6 +2,8 @@
 
 Import("env")
 
+env = env.Clone()
+
 # WorkingSet target and associated test
 env.Library(
     target = "working_set",

src/mongo/db/ftdc/SConscript

@@ -1,6 +1,8 @@
 # -*- mode: python -*-
 Import("env")
 
+env = env.Clone()
+
 ftdcEnv = env.Clone()
 ftdcEnv.InjectThirdPartyIncludePaths(libraries=['zlib'])
 

src/mongo/db/fts/SConscript

@@ -2,10 +2,15 @@
 
 Import("env")
 
+env = env.Clone()
+
 env.SConscript(
     dirs=[
         'unicode',
     ],
+    exports=[
+        'env',
+    ],
 )
 
 stop_word_languages = [

src/mongo/db/fts/unicode/SConscript

@@ -2,6 +2,8 @@
 
 Import("env")
 
+env = env.Clone()
+
 env.Command( 
     target="codepoints_casefold.cpp",
     source=[

src/mongo/db/geo/SConscript

@@ -2,6 +2,8 @@
 
 Import("env")
 
+env = env.Clone()
+
 # Core geometry shape libraries
 env.Library("geometry", [ "hash.cpp",
                           "shapes.cpp",
@@ -34,4 +36,4 @@ env.CppUnitTest("r2_region_coverer_test", [ "r2_region_coverer_test.cpp" ],
 
 env.CppUnitTest("big_polygon_test", [ "big_polygon_test.cpp" ],
                 LIBDEPS = [ "geometry",
-                            "$BUILD_DIR/mongo/db/common" ]) # db/common needed for field parsing
+                            "$BUILD_DIR/mongo/db/common" ]) # db/common needed for field parsing

src/mongo/db/index/SConscript

@@ -2,6 +2,8 @@
 
 Import("env")
 
+env = env.Clone()
+
 env.Library(
         target='index_descriptor',
         source=[

src/mongo/db/matcher/SConscript

@@ -2,6 +2,8 @@
 
 Import('env')
 
+env = env.Clone()
+
 env.Library(
     target='path',
     source=[

src/mongo/db/ops/SConscript

@@ -2,6 +2,8 @@
 
 Import("env")
 
+env = env.Clone()
+
 env.Library(
     target='update_common',
     source=[

src/mongo/db/pipeline/SConscript

@@ -2,6 +2,8 @@
 
 Import('env')
 
+env = env.Clone()
+
 env.Library(
     target='aggregation',
     source=[

src/mongo/db/query/SConscript

@@ -2,10 +2,15 @@
 
 Import("env")
 
+env = env.Clone()
+
 env.SConscript(
     dirs=[
         "collation",
     ],
+    exports=[
+        'env'
+    ],
 )
 
 env.Library(

src/mongo/db/repl/SConscript

@@ -2,6 +2,8 @@
 
 Import("env")
 
+env = env.Clone()
+
 env.Library(
     target='bgsync',
     source=[

src/mongo/db/s/SConscript

@@ -2,6 +2,8 @@
 
 Import("env")
 
+env = env.Clone()
+
 env.Library(
     target='metadata',
     source=[

src/mongo/db/sorter/SConscript

@@ -1,5 +1,7 @@
 Import("env")
 
+env = env.Clone()
+
 sorterEnv = env.Clone()
 sorterEnv.InjectThirdPartyIncludePaths(libraries=['snappy'])
 sorterEnv.CppUnitTest('sorter_test',

src/mongo/db/stats/SConscript

@@ -2,6 +2,8 @@
 
 Import("env")
 
+env = env.Clone()
+
 env.Library(
     target='timer_stats',
     source=[