1 files changed, 41 insertions, 41 deletions

diff --git a/meta/lib/oe/qa.py b/meta/lib/oe/qa.py
index fbe719d8ec..22d76dcbcd 100644
--- a/meta/lib/oe/qa.py
+++ b/meta/lib/oe/qa.py
@@ -1,4 +1,4 @@
-import os, struct
+import os, struct, mmap
 
 class NotELFFileError(Exception):
     pass
@@ -23,9 +23,9 @@ class ELFFile:
     EV_CURRENT   = 1
 
     # possible values for EI_DATA
-    ELFDATANONE  = 0
-    ELFDATA2LSB  = 1
-    ELFDATA2MSB  = 2
+    EI_DATA_NONE  = 0
+    EI_DATA_LSB  = 1
+    EI_DATA_MSB  = 2
 
     PT_INTERP = 3
 
@@ -34,51 +34,46 @@ class ELFFile:
             #print "'%x','%x' %s" % (ord(expectation), ord(result), self.name)
             raise NotELFFileError("%s is not an ELF" % self.name)
 
-    def __init__(self, name, bits = 0):
+    def __init__(self, name):
         self.name = name
-        self.bits = bits
         self.objdump_output = {}
 
-    def open(self):
-        if not os.path.isfile(self.name):
-            raise NotELFFileError("%s is not a normal file" % self.name)
+    # Context Manager functions to close the mmap explicitly
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        self.data.close()
 
+    def open(self):
         with open(self.name, "rb") as f:
-            # Read 4k which should cover most of the headers we're after
-            self.data = f.read(4096)
+            try:
+                self.data = mmap.mmap(f.fileno(), 0, access=mmap.ACCESS_READ)
+            except ValueError:
+                # This means the file is empty
+                raise NotELFFileError("%s is empty" % self.name)
 
+        # Check the file has the minimum number of ELF table entries
         if len(self.data) < ELFFile.EI_NIDENT + 4:
             raise NotELFFileError("%s is not an ELF" % self.name)
 
+        # ELF header
         self.my_assert(self.data[0], 0x7f)
         self.my_assert(self.data[1], ord('E'))
         self.my_assert(self.data[2], ord('L'))
         self.my_assert(self.data[3], ord('F'))
-        if self.bits == 0:
-            if self.data[ELFFile.EI_CLASS] == ELFFile.ELFCLASS32:
-                self.bits = 32
-            elif self.data[ELFFile.EI_CLASS] == ELFFile.ELFCLASS64:
-                self.bits = 64
-            else:
-                # Not 32-bit or 64.. lets assert
-                raise NotELFFileError("ELF but not 32 or 64 bit.")
-        elif self.bits == 32:
-            self.my_assert(self.data[ELFFile.EI_CLASS], ELFFile.ELFCLASS32)
-        elif self.bits == 64:
-            self.my_assert(self.data[ELFFile.EI_CLASS], ELFFile.ELFCLASS64)
+        if self.data[ELFFile.EI_CLASS] == ELFFile.ELFCLASS32:
+            self.bits = 32
+        elif self.data[ELFFile.EI_CLASS] == ELFFile.ELFCLASS64:
+            self.bits = 64
         else:
-            raise NotELFFileError("Must specify unknown, 32 or 64 bit size.")
+            # Not 32-bit or 64.. lets assert
+            raise NotELFFileError("ELF but not 32 or 64 bit.")
         self.my_assert(self.data[ELFFile.EI_VERSION], ELFFile.EV_CURRENT)
 
-        self.sex = self.data[ELFFile.EI_DATA]
-        if self.sex == ELFFile.ELFDATANONE:
-            raise NotELFFileError("self.sex == ELFDATANONE")
-        elif self.sex == ELFFile.ELFDATA2LSB:
-            self.sex = "<"
-        elif self.sex == ELFFile.ELFDATA2MSB:
-            self.sex = ">"
-        else:
-            raise NotELFFileError("Unknown self.sex")
+        self.endian = self.data[ELFFile.EI_DATA]
+        if self.endian not in (ELFFile.EI_DATA_LSB, ELFFile.EI_DATA_MSB):
+            raise NotELFFileError("Unexpected EI_DATA %x" % self.endian)
 
     def osAbi(self):
         return self.data[ELFFile.EI_OSABI]
@@ -90,16 +85,20 @@ class ELFFile:
         return self.bits
 
     def isLittleEndian(self):
-        return self.sex == "<"
+        return self.endian == ELFFile.EI_DATA_LSB
 
     def isBigEndian(self):
-        return self.sex == ">"
+        return self.endian == ELFFile.EI_DATA_MSB
+
+    def getStructEndian(self):
+        return {ELFFile.EI_DATA_LSB: "<",
+                ELFFile.EI_DATA_MSB: ">"}[self.endian]
 
     def getShort(self, offset):
-        return struct.unpack_from(self.sex+"H", self.data, offset)[0]
+        return struct.unpack_from(self.getStructEndian() + "H", self.data, offset)[0]
 
     def getWord(self, offset):
-        return struct.unpack_from(self.sex+"i", self.data, offset)[0]
+        return struct.unpack_from(self.getStructEndian() + "i", self.data, offset)[0]
 
     def isDynamic(self):
         """
@@ -118,7 +117,7 @@ class ELFFile:
 
     def machine(self):
         """
-        We know the sex stored in self.sex and we
+        We know the endian stored in self.endian and we
         know the position
         """
         return self.getShort(ELFFile.E_MACHINE)
@@ -166,6 +165,7 @@ def elf_machine_to_string(machine):
 
 if __name__ == "__main__":
     import sys
-    elf = ELFFile(sys.argv[1])
-    elf.open()
-    print(elf.isDynamic())
+
+    with ELFFile(sys.argv[1]) as elf:
+        elf.open()
+        print(elf.isDynamic())