[PATCH v2 02/16] BaseTools: Use absolute import in GenFds

[Gary Lin <glin@suse.com>]

Based on "futurize -f libfuturize.fixes.fix_absolute_import"

Since circular import is not allowed after adopting absolute import, the
following changes are applied to break the circles.

* BaseTools/Source/Python/GenFds/Capsule.py
  - Delay "from .GenFds import GenFds" until GenCapsule()
  - Delay "from .GenFds import FindExtendTool" until GenFmpCapsule()
  To break the circle:
  AutoGen.AutoGen => GenFds.FdfParser => GenFds.Capsule => GenFds.GenFds =>
  GenFds.FdfParser

* BaseTools/Source/Python/GenFds/Fd.py
  - Delay "from .GenFds import GenFds" until GenFd()
  To break the circle:
  AutoGen.AutoGen => GenFds.FdfParser => GenFds.Fd => GenFds.GenFds =>
  GenFds.FdfParser

* BaseTools/Source/Python/GenFds/Fv.py
  - Delay "from .GenFds import GenFds" until AddToBuffer()
  To break the circle:
  AutoGen.AutoGen => GenFds.FdfParser => GenFds.Fd => GenFds.Fv =>
  GenFds.GenFds => GenFds.FdfParser

* BaseTools/Source/Python/GenFds/GuidSection.py
  - Delay "from .GenFds import FindExtendTool" until GuidSection()
  To break the circle:
  AutoGen.AutoGen => GenFds.FdfParser => GenFds.Fd => GenFds.Fv =>
  GenFds.AprioriSection => GenFds.FfsFileStatement => GenFds.GuidSection =>
  GenFds.GenFds => GenFds.FdfParser

* BaseTools/Source/Python/GenFds/OptRomInfStatement.py
  - Delay "from . import OptionRom" until __GetOptRomParams()
  To break the circle:
  AutoGen.AutoGen => GenFds.FdfParser => GenFds.OptionRom =>
  GenFds.OptRomInfStatement => GenFds.OptionRom

* BaseTools/Source/Python/GenFds/OptionRom.py
  - Remove the unused "from GenFds import GenFds"
  To break the circle:
  AutoGen.AutoGen => GenFds.FdfParser => GenFds.OptionRom =>
  GenFds.GenFds => GenFds.FdfParser

Contributed-under: TianoCore Contribution Agreement 1.1
Cc: Yonghong Zhu <yonghong.zhu@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Signed-off-by: Gary Lin <glin@suse.com>
---
 BaseTools/Source/Python/GenFds/AprioriSection.py      |  5 +-
 BaseTools/Source/Python/GenFds/Capsule.py             |  7 +--
 BaseTools/Source/Python/GenFds/CapsuleData.py         |  5 +-
 BaseTools/Source/Python/GenFds/CompressSection.py     |  7 +--
 BaseTools/Source/Python/GenFds/DataSection.py         |  7 +--
 BaseTools/Source/Python/GenFds/DepexSection.py        |  7 +--
 BaseTools/Source/Python/GenFds/EfiSection.py          |  7 +--
 BaseTools/Source/Python/GenFds/Fd.py                  |  9 ++--
 BaseTools/Source/Python/GenFds/FdfParser.py           | 55 ++++++++++----------
 BaseTools/Source/Python/GenFds/FfsFileStatement.py    | 11 ++--
 BaseTools/Source/Python/GenFds/FfsInfStatement.py     | 19 +++----
 BaseTools/Source/Python/GenFds/Fv.py                  | 11 ++--
 BaseTools/Source/Python/GenFds/FvImageSection.py      |  7 +--
 BaseTools/Source/Python/GenFds/GenFds.py              | 11 ++--
 BaseTools/Source/Python/GenFds/GuidSection.py         | 11 ++--
 BaseTools/Source/Python/GenFds/OptRomFileStatement.py |  3 +-
 BaseTools/Source/Python/GenFds/OptRomInfStatement.py  | 16 +++---
 BaseTools/Source/Python/GenFds/OptionRom.py           |  6 +--
 BaseTools/Source/Python/GenFds/Region.py              |  3 +-
 BaseTools/Source/Python/GenFds/RuleComplexFile.py     |  3 +-
 BaseTools/Source/Python/GenFds/RuleSimpleFile.py      |  3 +-
 BaseTools/Source/Python/GenFds/Section.py             |  3 +-
 BaseTools/Source/Python/GenFds/UiSection.py           |  7 +--
 BaseTools/Source/Python/GenFds/VerSection.py          |  7 +--
 BaseTools/Source/Python/GenFds/Vtf.py                 |  3 +-
 25 files changed, 127 insertions(+), 106 deletions(-)

diff --git a/BaseTools/Source/Python/GenFds/AprioriSection.py b/BaseTools/Source/Python/GenFds/AprioriSection.py
index b3e7b5fc64a3..7196f7f2c753 100644
--- a/BaseTools/Source/Python/GenFds/AprioriSection.py
+++ b/BaseTools/Source/Python/GenFds/AprioriSection.py
@@ -15,11 +15,12 @@
 ##
 # Import Modules
 #
+from __future__ import absolute_import
 from struct import *
 import Common.LongFilePathOs as os
 from io import BytesIO
-import FfsFileStatement
-from GenFdsGlobalVariable import GenFdsGlobalVariable
+from . import FfsFileStatement
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 from CommonDataClass.FdfClass import AprioriSectionClassObject
 from Common.StringUtils import *
 from Common.Misc import SaveFileOnChange, PathClass
diff --git a/BaseTools/Source/Python/GenFds/Capsule.py b/BaseTools/Source/Python/GenFds/Capsule.py
index 35a25bd38037..27932ef0020c 100644
--- a/BaseTools/Source/Python/GenFds/Capsule.py
+++ b/BaseTools/Source/Python/GenFds/Capsule.py
@@ -15,17 +15,16 @@
 ##
 # Import Modules
 #
-from GenFdsGlobalVariable import GenFdsGlobalVariable
+from __future__ import absolute_import
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 from CommonDataClass.FdfClass import CapsuleClassObject
 import Common.LongFilePathOs as os
 import subprocess
 from io import BytesIO
 from Common.Misc import SaveFileOnChange
-from GenFds import GenFds
 from Common.Misc import PackRegistryFormatGuid
 import uuid
 from struct import pack
-from GenFds import FindExtendTool
 from Common import EdkLogger
 from Common.BuildToolError import *
 
@@ -66,6 +65,7 @@ class Capsule (CapsuleClassObject) :
         #     UINT32            CapsuleImageSize;
         # } EFI_CAPSULE_HEADER;
         #
+        from .GenFds import FindExtendTool
         Header = BytesIO()
         #
         # Use FMP capsule GUID: 6DCBD5ED-E82D-4C44-BDA1-7194199AD92A
@@ -201,6 +201,7 @@ class Capsule (CapsuleClassObject) :
     #   @retval string      Generated Capsule file path
     #
     def GenCapsule(self):
+        from .GenFds import GenFds
         if self.UiCapsuleName.upper() + 'cap' in GenFds.ImageBinDict:
             return GenFds.ImageBinDict[self.UiCapsuleName.upper() + 'cap']
 
diff --git a/BaseTools/Source/Python/GenFds/CapsuleData.py b/BaseTools/Source/Python/GenFds/CapsuleData.py
index 9d17bf5afe28..0caba8983d2e 100644
--- a/BaseTools/Source/Python/GenFds/CapsuleData.py
+++ b/BaseTools/Source/Python/GenFds/CapsuleData.py
@@ -15,8 +15,9 @@
 ##
 # Import Modules
 #
-import Ffs
-from GenFdsGlobalVariable import GenFdsGlobalVariable
+from __future__ import absolute_import
+from . import Ffs
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 from io import BytesIO
 from struct import pack
 import os
diff --git a/BaseTools/Source/Python/GenFds/CompressSection.py b/BaseTools/Source/Python/GenFds/CompressSection.py
index 4ae14f27b3e1..aaaabf84dca8 100644
--- a/BaseTools/Source/Python/GenFds/CompressSection.py
+++ b/BaseTools/Source/Python/GenFds/CompressSection.py
@@ -15,11 +15,12 @@
 ##
 # Import Modules
 #
-from Ffs import Ffs
-import Section
+from __future__ import absolute_import
+from .Ffs import Ffs
+from . import Section
 import subprocess
 import Common.LongFilePathOs as os
-from GenFdsGlobalVariable import GenFdsGlobalVariable
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 from CommonDataClass.FdfClass import CompressSectionClassObject
 from Common.DataType import *
 
diff --git a/BaseTools/Source/Python/GenFds/DataSection.py b/BaseTools/Source/Python/GenFds/DataSection.py
index 29caa00c0d8d..a6387b07c582 100644
--- a/BaseTools/Source/Python/GenFds/DataSection.py
+++ b/BaseTools/Source/Python/GenFds/DataSection.py
@@ -15,10 +15,11 @@
 ##
 # Import Modules
 #
-import Section
-from GenFdsGlobalVariable import GenFdsGlobalVariable
+from __future__ import absolute_import
+from . import Section
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 import subprocess
-from Ffs import Ffs
+from .Ffs import Ffs
 import Common.LongFilePathOs as os
 from CommonDataClass.FdfClass import DataSectionClassObject
 from Common.Misc import PeImageClass
diff --git a/BaseTools/Source/Python/GenFds/DepexSection.py b/BaseTools/Source/Python/GenFds/DepexSection.py
index f42162d5a27e..b2d123bfc045 100644
--- a/BaseTools/Source/Python/GenFds/DepexSection.py
+++ b/BaseTools/Source/Python/GenFds/DepexSection.py
@@ -15,10 +15,11 @@
 ##
 # Import Modules
 #
-import Section
-from GenFdsGlobalVariable import GenFdsGlobalVariable
+from __future__ import absolute_import
+from . import Section
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 import subprocess
-from Ffs import Ffs
+from .Ffs import Ffs
 import Common.LongFilePathOs as os
 from CommonDataClass.FdfClass import DepexSectionClassObject
 from AutoGen.GenDepex import DependencyExpression
diff --git a/BaseTools/Source/Python/GenFds/EfiSection.py b/BaseTools/Source/Python/GenFds/EfiSection.py
index 9223268749a1..623b77d27427 100644
--- a/BaseTools/Source/Python/GenFds/EfiSection.py
+++ b/BaseTools/Source/Python/GenFds/EfiSection.py
@@ -15,11 +15,12 @@
 ##
 # Import Modules
 #
+from __future__ import absolute_import
 from struct import *
-import Section
-from GenFdsGlobalVariable import GenFdsGlobalVariable
+from . import Section
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 import subprocess
-from Ffs import Ffs
+from .Ffs import Ffs
 import Common.LongFilePathOs as os
 from CommonDataClass.FdfClass import EfiSectionClassObject
 from Common import EdkLogger
diff --git a/BaseTools/Source/Python/GenFds/Fd.py b/BaseTools/Source/Python/GenFds/Fd.py
index 552719fa3114..53318c9ea5c0 100644
--- a/BaseTools/Source/Python/GenFds/Fd.py
+++ b/BaseTools/Source/Python/GenFds/Fd.py
@@ -15,18 +15,18 @@
 ##
 # Import Modules
 #
-import Region
-import Fv
+from __future__ import absolute_import
+from . import Region
+from . import Fv
 import Common.LongFilePathOs as os
 from io import BytesIO
 import sys
 from struct import *
-from GenFdsGlobalVariable import GenFdsGlobalVariable
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 from CommonDataClass.FdfClass import FDClassObject
 from Common import EdkLogger
 from Common.BuildToolError import *
 from Common.Misc import SaveFileOnChange
-from GenFds import GenFds
 from Common.DataType import BINARY_FILE_TYPE_FV
 
 ## generate FD
@@ -47,6 +47,7 @@ class FD(FDClassObject):
     #   @retval string      Generated FD file name
     #
     def GenFd (self, Flag = False):
+        from .GenFds import GenFds
         if self.FdUiName.upper() + 'fd' in GenFds.ImageBinDict:
             return GenFds.ImageBinDict[self.FdUiName.upper() + 'fd']
 
diff --git a/BaseTools/Source/Python/GenFds/FdfParser.py b/BaseTools/Source/Python/GenFds/FdfParser.py
index 67217c3b89e3..c890f2d3afb6 100644
--- a/BaseTools/Source/Python/GenFds/FdfParser.py
+++ b/BaseTools/Source/Python/GenFds/FdfParser.py
@@ -17,35 +17,36 @@
 # Import Modules
 #
 from __future__ import print_function
+from __future__ import absolute_import
 import re
 
-import Fd
-import Region
-import Fv
-import AprioriSection
-import FfsInfStatement
-import FfsFileStatement
-import VerSection
-import UiSection
-import FvImageSection
-import DataSection
-import DepexSection
-import CompressSection
-import GuidSection
-import Capsule
-import CapsuleData
-import Rule
-import RuleComplexFile
-import RuleSimpleFile
-import EfiSection
-import Vtf
-import ComponentStatement
-import OptionRom
-import OptRomInfStatement
-import OptRomFileStatement
+from . import Fd
+from . import Region
+from . import Fv
+from . import AprioriSection
+from . import FfsInfStatement
+from . import FfsFileStatement
+from . import VerSection
+from . import UiSection
+from . import FvImageSection
+from . import DataSection
+from . import DepexSection
+from . import CompressSection
+from . import GuidSection
+from . import Capsule
+from . import CapsuleData
+from . import Rule
+from . import RuleComplexFile
+from . import RuleSimpleFile
+from . import EfiSection
+from . import Vtf
+from . import ComponentStatement
+from . import OptionRom
+from . import OptRomInfStatement
+from . import OptRomFileStatement
 import string
 
-from GenFdsGlobalVariable import GenFdsGlobalVariable
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 from Common.BuildToolError import *
 from Common import EdkLogger
 from Common.Misc import PathClass
@@ -60,8 +61,8 @@ from Common.Misc import tdict
 from Common.MultipleWorkspace import MultipleWorkspace as mws
 import Common.LongFilePathOs as os
 from Common.LongFilePathSupport import OpenLongFilePath as open
-from Capsule import EFI_CERT_TYPE_PKCS7_GUID
-from Capsule import EFI_CERT_TYPE_RSA2048_SHA256_GUID
+from .Capsule import EFI_CERT_TYPE_PKCS7_GUID
+from .Capsule import EFI_CERT_TYPE_RSA2048_SHA256_GUID
 from Common.RangeExpression import RangeExpression
 
 ##define T_CHAR_SPACE                ' '
diff --git a/BaseTools/Source/Python/GenFds/FfsFileStatement.py b/BaseTools/Source/Python/GenFds/FfsFileStatement.py
index 5f31ac03fcf4..4c35aac76a00 100644
--- a/BaseTools/Source/Python/GenFds/FfsFileStatement.py
+++ b/BaseTools/Source/Python/GenFds/FfsFileStatement.py
@@ -15,19 +15,20 @@
 ##
 # Import Modules
 #
-import Ffs
-import Rule
+from __future__ import absolute_import
+from . import Ffs
+from . import Rule
 import Common.LongFilePathOs as os
 from io import BytesIO
 import subprocess
 
-from GenFdsGlobalVariable import GenFdsGlobalVariable
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 from CommonDataClass.FdfClass import FileStatementClassObject
 from Common import EdkLogger
 from Common.BuildToolError import *
 from Common.Misc import GuidStructureByteArrayToGuidString
-from GuidSection import GuidSection
-from FvImageSection import FvImageSection
+from .GuidSection import GuidSection
+from .FvImageSection import FvImageSection
 from Common.Misc import SaveFileOnChange
 from struct import *
 
diff --git a/BaseTools/Source/Python/GenFds/FfsInfStatement.py b/BaseTools/Source/Python/GenFds/FfsInfStatement.py
index adb9a95bebfa..56bb966698ad 100644
--- a/BaseTools/Source/Python/GenFds/FfsInfStatement.py
+++ b/BaseTools/Source/Python/GenFds/FfsInfStatement.py
@@ -16,17 +16,18 @@
 ##
 # Import Modules
 #
-import Rule
+from __future__ import absolute_import
+from . import Rule
 import Common.LongFilePathOs as os
 from io import BytesIO
 from struct import *
-from GenFdsGlobalVariable import GenFdsGlobalVariable
-import Ffs
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
+from . import Ffs
 import subprocess
 import sys
-import Section
-import RuleSimpleFile
-import RuleComplexFile
+from . import Section
+from . import RuleSimpleFile
+from . import RuleComplexFile
 from CommonDataClass.FdfClass import FfsInfStatementClassObject
 from Common.MultipleWorkspace import MultipleWorkspace as mws
 from Common.StringUtils import *
@@ -36,15 +37,15 @@ from Common.Misc import ProcessDuplicatedInf
 from Common.Misc import GetVariableOffset
 from Common import EdkLogger
 from Common.BuildToolError import *
-from GuidSection import GuidSection
-from FvImageSection import FvImageSection
+from .GuidSection import GuidSection
+from .FvImageSection import FvImageSection
 from Common.Misc import PeImageClass
 from AutoGen.GenDepex import DependencyExpression
 from PatchPcdValue.PatchPcdValue import PatchBinaryFile
 from Common.LongFilePathSupport import CopyLongFilePath
 from Common.LongFilePathSupport import OpenLongFilePath as open
 import Common.GlobalData as GlobalData
-from DepexSection import DepexSection
+from .DepexSection import DepexSection
 from Common.Misc import SaveFileOnChange
 from Common.Expression import *
 from Common.DataType import *
diff --git a/BaseTools/Source/Python/GenFds/Fv.py b/BaseTools/Source/Python/GenFds/Fv.py
index 798c20a0f4ee..097f51f39e27 100644
--- a/BaseTools/Source/Python/GenFds/Fv.py
+++ b/BaseTools/Source/Python/GenFds/Fv.py
@@ -1,3 +1,4 @@
+from __future__ import absolute_import
 ## @file
 # process FV generation
 #
@@ -20,11 +21,10 @@ import subprocess
 from io import BytesIO
 from struct import *
 
-import Ffs
-import AprioriSection
-import FfsFileStatement
-from GenFdsGlobalVariable import GenFdsGlobalVariable
-from GenFds import GenFds
+from . import Ffs
+from . import AprioriSection
+from . import FfsFileStatement
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 from CommonDataClass.FdfClass import FvClassObject
 from Common.Misc import SaveFileOnChange, PackGUID
 from Common.LongFilePathSupport import CopyLongFilePath
@@ -70,6 +70,7 @@ class FV (FvClassObject):
     #
     def AddToBuffer (self, Buffer, BaseAddress=None, BlockSize= None, BlockNum=None, ErasePloarity='1', VtfDict=None, MacroDict = {}, Flag=False) :
 
+        from .GenFds import GenFds
         if BaseAddress is None and self.UiFvName.upper() + 'fv' in GenFds.ImageBinDict:
             return GenFds.ImageBinDict[self.UiFvName.upper() + 'fv']
 
diff --git a/BaseTools/Source/Python/GenFds/FvImageSection.py b/BaseTools/Source/Python/GenFds/FvImageSection.py
index b4f1f3340e99..04556fc87099 100644
--- a/BaseTools/Source/Python/GenFds/FvImageSection.py
+++ b/BaseTools/Source/Python/GenFds/FvImageSection.py
@@ -15,11 +15,12 @@
 ##
 # Import Modules
 #
-import Section
+from __future__ import absolute_import
+from . import Section
 from io import BytesIO
-from Ffs import Ffs
+from .Ffs import Ffs
 import subprocess
-from GenFdsGlobalVariable import GenFdsGlobalVariable
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 import Common.LongFilePathOs as os
 from CommonDataClass.FdfClass import FvImageSectionClassObject
 from Common import EdkLogger
diff --git a/BaseTools/Source/Python/GenFds/GenFds.py b/BaseTools/Source/Python/GenFds/GenFds.py
index b90b50e53967..c0b60b9b3c1f 100644
--- a/BaseTools/Source/Python/GenFds/GenFds.py
+++ b/BaseTools/Source/Python/GenFds/GenFds.py
@@ -16,17 +16,18 @@
 # Import Modules
 #
 from __future__ import print_function
+from __future__ import absolute_import
 from optparse import OptionParser
 import sys
 import Common.LongFilePathOs as os
 import linecache
-import FdfParser
+from . import FdfParser
 import Common.BuildToolError as BuildToolError
-from GenFdsGlobalVariable import GenFdsGlobalVariable
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 from Workspace.WorkspaceDatabase import WorkspaceDatabase
 from Workspace.BuildClassObject import PcdClassObject
-import RuleComplexFile
-from EfiSection import EfiSection
+from . import RuleComplexFile
+from .EfiSection import EfiSection
 from io import BytesIO
 import Common.TargetTxtClassObject as TargetTxtClassObject
 import Common.ToolDefClassObject as ToolDefClassObject
@@ -40,7 +41,7 @@ from Common.Misc import ClearDuplicatedInf
 from Common.Misc import GuidStructureStringToGuidString
 from Common.BuildVersion import gBUILD_VERSION
 from Common.MultipleWorkspace import MultipleWorkspace as mws
-import FfsFileStatement
+from . import FfsFileStatement
 import glob
 from struct import unpack
 
diff --git a/BaseTools/Source/Python/GenFds/GuidSection.py b/BaseTools/Source/Python/GenFds/GuidSection.py
index c55fb34f2b74..e41c2fd31e6c 100644
--- a/BaseTools/Source/Python/GenFds/GuidSection.py
+++ b/BaseTools/Source/Python/GenFds/GuidSection.py
@@ -16,19 +16,19 @@
 ##
 # Import Modules
 #
-import Section
+from __future__ import absolute_import
+from . import Section
 import subprocess
-from Ffs import Ffs
+from .Ffs import Ffs
 import Common.LongFilePathOs as os
-from GenFdsGlobalVariable import GenFdsGlobalVariable
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 from CommonDataClass.FdfClass import GuidSectionClassObject
 from Common import ToolDefClassObject
 import sys
 from Common import EdkLogger
 from Common.BuildToolError import *
-from FvImageSection import FvImageSection
+from .FvImageSection import FvImageSection
 from Common.LongFilePathSupport import OpenLongFilePath as open
-from GenFds import FindExtendTool
 from Common.DataType import *
 
 ## generate GUIDed section
@@ -131,6 +131,7 @@ class GuidSection(GuidSectionClassObject) :
         ExternalTool = None
         ExternalOption = None
         if self.NameGuid is not None:
+            from .GenFds import FindExtendTool
             ExternalTool, ExternalOption = FindExtendTool(self.KeyStringList, self.CurrentArchList, self.NameGuid)
 
         #
diff --git a/BaseTools/Source/Python/GenFds/OptRomFileStatement.py b/BaseTools/Source/Python/GenFds/OptRomFileStatement.py
index 8b6d2a1cb0bd..e56174ec3c86 100644
--- a/BaseTools/Source/Python/GenFds/OptRomFileStatement.py
+++ b/BaseTools/Source/Python/GenFds/OptRomFileStatement.py
@@ -15,9 +15,10 @@
 ##
 # Import Modules
 #
+from __future__ import absolute_import
 import Common.LongFilePathOs as os
 
-from GenFdsGlobalVariable import GenFdsGlobalVariable
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 ##
 #
 #
diff --git a/BaseTools/Source/Python/GenFds/OptRomInfStatement.py b/BaseTools/Source/Python/GenFds/OptRomInfStatement.py
index dff8235ef755..dfeba5d0b140 100644
--- a/BaseTools/Source/Python/GenFds/OptRomInfStatement.py
+++ b/BaseTools/Source/Python/GenFds/OptRomInfStatement.py
@@ -15,16 +15,16 @@
 ##
 # Import Modules
 #
-import RuleSimpleFile
-import RuleComplexFile
-import Section
-import OptionRom
+from __future__ import absolute_import
+from . import RuleSimpleFile
+from . import RuleComplexFile
+from . import Section
 import Common.GlobalData as GlobalData
 
 from Common.DataType import *
 from Common.StringUtils import *
-from FfsInfStatement import FfsInfStatement
-from GenFdsGlobalVariable import GenFdsGlobalVariable
+from .FfsInfStatement import FfsInfStatement
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 
 ##
 #
@@ -45,7 +45,7 @@ class OptRomInfStatement (FfsInfStatement):
     #   @param  self        The object pointer
     #
     def __GetOptRomParams(self):
-
+        from . import OptionRom
         if self.OverrideAttribs is None:
             self.OverrideAttribs = OptionRom.OverrideAttribs()
 
@@ -150,5 +150,3 @@ class OptRomInfStatement (FfsInfStatement):
                     OutputFileList.extend(FileList)
 
         return OutputFileList
-
-
diff --git a/BaseTools/Source/Python/GenFds/OptionRom.py b/BaseTools/Source/Python/GenFds/OptionRom.py
index 18f3fbd0d7a2..bb7071fa7fca 100644
--- a/BaseTools/Source/Python/GenFds/OptionRom.py
+++ b/BaseTools/Source/Python/GenFds/OptionRom.py
@@ -15,12 +15,12 @@
 ##
 # Import Modules
 #
+from __future__ import absolute_import
 import Common.LongFilePathOs as os
 import subprocess
 
-import OptRomInfStatement
-from GenFdsGlobalVariable import GenFdsGlobalVariable
-from GenFds import GenFds
+from . import OptRomInfStatement
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 from CommonDataClass.FdfClass import OptionRomClassObject
 from Common.Misc import SaveFileOnChange
 from Common import EdkLogger
diff --git a/BaseTools/Source/Python/GenFds/Region.py b/BaseTools/Source/Python/GenFds/Region.py
index 33e4ac8d3c37..7f94b3d66b55 100644
--- a/BaseTools/Source/Python/GenFds/Region.py
+++ b/BaseTools/Source/Python/GenFds/Region.py
@@ -15,8 +15,9 @@
 ##
 # Import Modules
 #
+from __future__ import absolute_import
 from struct import *
-from GenFdsGlobalVariable import GenFdsGlobalVariable
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 from io import BytesIO
 import string
 from CommonDataClass.FdfClass import RegionClassObject
diff --git a/BaseTools/Source/Python/GenFds/RuleComplexFile.py b/BaseTools/Source/Python/GenFds/RuleComplexFile.py
index 36c483fbb207..c357fedbd3be 100644
--- a/BaseTools/Source/Python/GenFds/RuleComplexFile.py
+++ b/BaseTools/Source/Python/GenFds/RuleComplexFile.py
@@ -15,7 +15,8 @@
 ##
 # Import Modules
 #
-import Rule
+from __future__ import absolute_import
+from . import Rule
 from  CommonDataClass.FdfClass import RuleComplexFileClassObject
 
 ## complex rule
diff --git a/BaseTools/Source/Python/GenFds/RuleSimpleFile.py b/BaseTools/Source/Python/GenFds/RuleSimpleFile.py
index 061f984e6af4..7aa184e7d8bb 100644
--- a/BaseTools/Source/Python/GenFds/RuleSimpleFile.py
+++ b/BaseTools/Source/Python/GenFds/RuleSimpleFile.py
@@ -15,7 +15,8 @@
 ##
 # Import Modules
 #
-import Rule
+from __future__ import absolute_import
+from . import Rule
 from CommonDataClass.FdfClass import RuleSimpleFileClassObject
 
 ## simple rule
diff --git a/BaseTools/Source/Python/GenFds/Section.py b/BaseTools/Source/Python/GenFds/Section.py
index ca4705a90c95..19a70009dcce 100644
--- a/BaseTools/Source/Python/GenFds/Section.py
+++ b/BaseTools/Source/Python/GenFds/Section.py
@@ -15,8 +15,9 @@
 ##
 # Import Modules
 #
+from __future__ import absolute_import
 from CommonDataClass.FdfClass import SectionClassObject
-from GenFdsGlobalVariable import GenFdsGlobalVariable
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 import Common.LongFilePathOs as os, glob
 from Common import EdkLogger
 from Common.BuildToolError import *
diff --git a/BaseTools/Source/Python/GenFds/UiSection.py b/BaseTools/Source/Python/GenFds/UiSection.py
index 280500952b63..24f2f3ca938d 100644
--- a/BaseTools/Source/Python/GenFds/UiSection.py
+++ b/BaseTools/Source/Python/GenFds/UiSection.py
@@ -15,11 +15,12 @@
 ##
 # Import Modules
 #
-import Section
-from Ffs import Ffs
+from __future__ import absolute_import
+from . import Section
+from .Ffs import Ffs
 import subprocess
 import Common.LongFilePathOs as os
-from GenFdsGlobalVariable import GenFdsGlobalVariable
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 from CommonDataClass.FdfClass import UiSectionClassObject
 from Common.LongFilePathSupport import OpenLongFilePath as open
 from Common.DataType import *
diff --git a/BaseTools/Source/Python/GenFds/VerSection.py b/BaseTools/Source/Python/GenFds/VerSection.py
index 456a430079bb..db71fe9653d4 100644
--- a/BaseTools/Source/Python/GenFds/VerSection.py
+++ b/BaseTools/Source/Python/GenFds/VerSection.py
@@ -15,11 +15,12 @@
 ##
 # Import Modules
 #
-from Ffs import Ffs
-import Section
+from __future__ import absolute_import
+from .Ffs import Ffs
+from . import Section
 import Common.LongFilePathOs as os
 import subprocess
-from GenFdsGlobalVariable import GenFdsGlobalVariable
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 from CommonDataClass.FdfClass import VerSectionClassObject
 from Common.LongFilePathSupport import OpenLongFilePath as open
 from Common.DataType import SUP_MODULE_SEC
diff --git a/BaseTools/Source/Python/GenFds/Vtf.py b/BaseTools/Source/Python/GenFds/Vtf.py
index 83abc98f07c3..5cb2d4acfb1c 100644
--- a/BaseTools/Source/Python/GenFds/Vtf.py
+++ b/BaseTools/Source/Python/GenFds/Vtf.py
@@ -15,7 +15,8 @@
 ##
 # Import Modules
 #
-from GenFdsGlobalVariable import GenFdsGlobalVariable
+from __future__ import absolute_import
+from .GenFdsGlobalVariable import GenFdsGlobalVariable
 import Common.LongFilePathOs as os
 from CommonDataClass.FdfClass import VtfClassObject
 from Common.LongFilePathSupport import OpenLongFilePath as open
-- 
2.18.0