[Patch 1/3] BaseTools: Improve GetDependencyList function

["Bob Feng" <bob.c.feng@intel.com>]

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2102

GetDependencyList get the header file via
re.findall in the whole header file.

This patch is to pre-process the header file and
to feed the shorter string to re.findall.

This patch is to improve GetDependencyList() efficiency

Cc: Liming Gao <liming.gao@intel.com>
Signed-off-by: Bob Feng <bob.c.feng@intel.com>
---
 BaseTools/Source/Python/AutoGen/GenMake.py | 29 ++++++++++++----------
 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/BaseTools/Source/Python/AutoGen/GenMake.py b/BaseTools/Source/Python/AutoGen/GenMake.py
index 47dae82e1aeb..5d02d9a05694 100755
--- a/BaseTools/Source/Python/AutoGen/GenMake.py
+++ b/BaseTools/Source/Python/AutoGen/GenMake.py
@@ -1690,26 +1690,29 @@ def GetDependencyList(AutoGenObject, FileCache, File, ForceList, SearchPathList)
         CurrentFileDependencyList = []
         if F in DepDb:
             CurrentFileDependencyList = DepDb[F]
         else:
             try:
-                Fd = open(F.Path, 'rb')
-                FileContent = Fd.read()
-                Fd.close()
+                with open(F.Path, 'rb') as Fd:
+                    FileContent = Fd.read(1)
+                    Fd.seek(0)
+                    if not FileContent:
+                        continue
+                    if FileContent[0] == 0xff or FileContent[0] == 0xfe:
+                        FileContent2 = Fd.read()
+                        FileContent2 = FileContent2.decode('utf-16')
+                        IncludedFileList = gIncludePattern.findall(FileContent2)
+                    else:
+                        FileLines = Fd.readlines()
+                        FileContent2 = [line for line in FileLines if str(line).lstrip("#\t ")[:8] == "include "]
+                        simpleFileContent="".join(FileContent2)
+
+                        IncludedFileList = gIncludePattern.findall(simpleFileContent)
             except BaseException as X:
                 EdkLogger.error("build", FILE_OPEN_FAILURE, ExtraData=F.Path + "\n\t" + str(X))
-            if len(FileContent) == 0:
+            if not FileContent:
                 continue
-            try:
-                if FileContent[0] == 0xff or FileContent[0] == 0xfe:
-                    FileContent = FileContent.decode('utf-16')
-                else:
-                    FileContent = FileContent.decode()
-            except:
-                # The file is not txt file. for example .mcb file
-                continue
-            IncludedFileList = gIncludePattern.findall(FileContent)
 
             for Inc in IncludedFileList:
                 Inc = Inc.strip()
                 # if there's macro used to reference header file, expand it
                 HeaderList = gMacroPattern.findall(Inc)
-- 
2.20.1.windows.1