BZ:https://bugzilla.tianocore.org/show_bug.cgi?id=2400

In Dsc Parser, included dsc file is parsed always no matter
if its condition is False

  gUefiOvmfPkgTokenSpaceGuid.test1|FALSE
!if gUefiOvmfPkgTokenSpaceGuid.test1 == FALSE
  !include OvmfPkg/test1.dsc
!else
  !include OvmfPkg/test2.dsc
!endif

In the above case, since the conditional result is FALSE,
"test2.dsc" is not parsed.
The patch avoids processing redundant dsc files and improves
the way Tool handles them.

Cc: Liming Gao <liming.gao@intel.com>
Cc: Bob Feng <bob.c.feng@intel.com>
Signed-off-by: Zhiju.Fan <zhijux.fan@intel.com>
---
 .../Source/Python/Workspace/MetaFileParser.py      | 79 +++++++++++-----------
 1 file changed, 40 insertions(+), 39 deletions(-)

diff --git a/BaseTools/Source/Python/Workspace/MetaFileParser.py b/BaseTools/Source/Python/Workspace/MetaFileParser.py
index 8a665b118e..a3b6edbd15 100644
--- a/BaseTools/Source/Python/Workspace/MetaFileParser.py
+++ b/BaseTools/Source/Python/Workspace/MetaFileParser.py
@@ -1612,46 +1612,47 @@ class DscParser(MetaFileParser):
             # First search the include file under the same directory as DSC file
             #
             IncludedFile1 = PathClass(IncludedFile, self.MetaFile.Dir)
-            ErrorCode, ErrorInfo1 = IncludedFile1.Validate()
-            if ErrorCode != 0:
-                #
-                # Also search file under the WORKSPACE directory
-                #
-                IncludedFile1 = PathClass(IncludedFile, GlobalData.gWorkspace)
-                ErrorCode, ErrorInfo2 = IncludedFile1.Validate()
+            if self._Enabled:
+                ErrorCode, ErrorInfo1 = IncludedFile1.Validate()
                 if ErrorCode != 0:
-                    EdkLogger.error('parser', ErrorCode, File=self._FileWithError,
-                                    Line=self._LineIndex + 1, ExtraData=ErrorInfo1 + "\n" + ErrorInfo2)
-
-            self._FileWithError = IncludedFile1
-
-            FromItem = self._Content[self._ContentIndex - 1][0]
-            if self._InSubsection:
-                Owner = self._Content[self._ContentIndex - 1][8]
-            else:
-                Owner = self._Content[self._ContentIndex - 1][0]
-            IncludedFileTable = MetaFileStorage(self._RawTable.DB, IncludedFile1, MODEL_FILE_DSC, False, FromItem=FromItem)
-            Parser = DscParser(IncludedFile1, self._FileType, self._Arch, IncludedFileTable,
-                               Owner=Owner, From=FromItem)
-
-            self.IncludedFiles.add (IncludedFile1)
-
-            # set the parser status with current status
-            Parser._SectionName = self._SectionName
-            Parser._SubsectionType = self._SubsectionType
-            Parser._InSubsection = self._InSubsection
-            Parser._SectionType = self._SectionType
-            Parser._Scope = self._Scope
-            Parser._Enabled = self._Enabled
-            # Parse the included file
-            Parser.StartParse()
-            # Insert all records in the table for the included file into dsc file table
-            Records = IncludedFileTable.GetAll()
-            if Records:
-                self._Content[self._ContentIndex:self._ContentIndex] = Records
-                self._Content.pop(self._ContentIndex - 1)
-                self._ValueList = None
-                self._ContentIndex -= 1
+                    #
+                    # Also search file under the WORKSPACE directory
+                    #
+                    IncludedFile1 = PathClass(IncludedFile, GlobalData.gWorkspace)
+                    ErrorCode, ErrorInfo2 = IncludedFile1.Validate()
+                    if ErrorCode != 0:
+                        EdkLogger.error('parser', ErrorCode, File=self._FileWithError,
+                                        Line=self._LineIndex + 1, ExtraData=ErrorInfo1 + "\n" + ErrorInfo2)
+
+                self._FileWithError = IncludedFile1
+
+                FromItem = self._Content[self._ContentIndex - 1][0]
+                if self._InSubsection:
+                    Owner = self._Content[self._ContentIndex - 1][8]
+                else:
+                    Owner = self._Content[self._ContentIndex - 1][0]
+                IncludedFileTable = MetaFileStorage(self._RawTable.DB, IncludedFile1, MODEL_FILE_DSC, False, FromItem=FromItem)
+                Parser = DscParser(IncludedFile1, self._FileType, self._Arch, IncludedFileTable,
+                                   Owner=Owner, From=FromItem)
+
+                self.IncludedFiles.add (IncludedFile1)
+
+                # set the parser status with current status
+                Parser._SectionName = self._SectionName
+                Parser._SubsectionType = self._SubsectionType
+                Parser._InSubsection = self._InSubsection
+                Parser._SectionType = self._SectionType
+                Parser._Scope = self._Scope
+                Parser._Enabled = self._Enabled
+                # Parse the included file
+                Parser.StartParse()
+                # Insert all records in the table for the included file into dsc file table
+                Records = IncludedFileTable.GetAll()
+                if Records:
+                    self._Content[self._ContentIndex:self._ContentIndex] = Records
+                    self._Content.pop(self._ContentIndex - 1)
+                    self._ValueList = None
+                    self._ContentIndex -= 1
 
     def __ProcessPackages(self):
         self._ValueList[0] = ReplaceMacro(self._ValueList[0], self._Macros)
-- 
2.14.1.windows.1