BaseTools: Reset FdsGlobalVariable

https://bugzilla.tianocore.org/show_bug.cgi?id=1418
This patch is going to fix a regression issue that is introduced
by commit b3497bad12.

Before commit b3497b, build launched a external GenFds.py to generate
Fd, so the global variable in GenFds.py was reset in each execution.

After commit b3497b, each GenFds run in the same python interpeter, so
we need to explicitly reset global variable in each GenFdsApi call.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Bob Feng <bob.c.feng@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

BaseTools/Source/Python/GenFds/GenFds.py

@@ -41,6 +41,8 @@ from Workspace.WorkspaceDatabase import WorkspaceDatabase
 from .FdfParser import FdfParser, Warning
 from .GenFdsGlobalVariable import GenFdsGlobalVariable
 from .FfsFileStatement import FileStatement
+import Common.DataType as DataType
+from struct import Struct
 
 ## Version and Copyright
 versionNumber = "1.0" + ' ' + gBUILD_VERSION
@@ -62,11 +64,60 @@ def main():
     EdkLogger.Initialize()
     return GenFdsApi(OptionsToCommandDict(Options))
 
+def resetFdsGlobalVariable():
+    GenFdsGlobalVariable.FvDir = ''
+    GenFdsGlobalVariable.OutputDirDict = {}
+    GenFdsGlobalVariable.BinDir = ''
+    # will be FvDir + os.sep + 'Ffs'
+    GenFdsGlobalVariable.FfsDir = ''
+    GenFdsGlobalVariable.FdfParser = None
+    GenFdsGlobalVariable.LibDir = ''
+    GenFdsGlobalVariable.WorkSpace = None
+    GenFdsGlobalVariable.WorkSpaceDir = ''
+    GenFdsGlobalVariable.ConfDir = ''
+    GenFdsGlobalVariable.EdkSourceDir = ''
+    GenFdsGlobalVariable.OutputDirFromDscDict = {}
+    GenFdsGlobalVariable.TargetName = ''
+    GenFdsGlobalVariable.ToolChainTag = ''
+    GenFdsGlobalVariable.RuleDict = {}
+    GenFdsGlobalVariable.ArchList = None
+    GenFdsGlobalVariable.VtfDict = {}
+    GenFdsGlobalVariable.ActivePlatform = None
+    GenFdsGlobalVariable.FvAddressFileName = ''
+    GenFdsGlobalVariable.VerboseMode = False
+    GenFdsGlobalVariable.DebugLevel = -1
+    GenFdsGlobalVariable.SharpCounter = 0
+    GenFdsGlobalVariable.SharpNumberPerLine = 40
+    GenFdsGlobalVariable.FdfFile = ''
+    GenFdsGlobalVariable.FdfFileTimeStamp = 0
+    GenFdsGlobalVariable.FixedLoadAddress = False
+    GenFdsGlobalVariable.PlatformName = ''
+
+    GenFdsGlobalVariable.BuildRuleFamily = DataType.TAB_COMPILER_MSFT
+    GenFdsGlobalVariable.ToolChainFamily = DataType.TAB_COMPILER_MSFT
+    GenFdsGlobalVariable.__BuildRuleDatabase = None
+    GenFdsGlobalVariable.GuidToolDefinition = {}
+    GenFdsGlobalVariable.FfsCmdDict = {}
+    GenFdsGlobalVariable.SecCmdList = []
+    GenFdsGlobalVariable.CopyList   = []
+    GenFdsGlobalVariable.ModuleFile = ''
+    GenFdsGlobalVariable.EnableGenfdsMultiThread = False
+
+    GenFdsGlobalVariable.LargeFileInFvFlags = []
+    GenFdsGlobalVariable.EFI_FIRMWARE_FILE_SYSTEM3_GUID = '5473C07A-3DCB-4dca-BD6F-1E9689E7349A'
+    GenFdsGlobalVariable.LARGE_FILE_SIZE = 0x1000000
+
+    GenFdsGlobalVariable.SectionHeader = Struct("3B 1B")
+
+    # FvName, FdName, CapName in FDF, Image file name
+    GenFdsGlobalVariable.ImageBinDict = {}
+
 def GenFdsApi(FdsCommandDict, WorkSpaceDataBase=None):
     global Workspace
     Workspace = ""
     ArchList = None
     ReturnCode = 0
+    resetFdsGlobalVariable()
 
     try:
         if FdsCommandDict.get("verbose"):