[libclang] Expose record layout info via new libclang functions:

clang_Type_getAlignOf
clang_Type_getSizeOf
clang_Type_getOffsetOf
clang_Cursor_isBitField

Patch by Loïc Jaquemet!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179251 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 115 insertions, 2 deletions

diff --git a/bindings/python/clang/cindex.py b/bindings/python/clang/cindex.py
index 70f4f36a2c..36761bd859 100644
--- a/bindings/python/clang/cindex.py
+++ b/bindings/python/clang/cindex.py
@@ -1314,6 +1314,18 @@ class Cursor(Structure):
         """
         return TokenGroup.get_tokens(self._tu, self.extent)
 
+    def is_bitfield(self):
+        """
+        Check if the field is a bitfield.
+        """
+        return conf.lib.clang_Cursor_isBitField(self)
+
+    def get_bitfield_width(self):
+        """
+        Retrieve the width of a bitfield.
+        """
+        return conf.lib.clang_getFieldDeclBitWidth(self)
+
     @staticmethod
     def from_result(res, fn, args):
         assert isinstance(res, Cursor)
@@ -1613,6 +1625,24 @@ class Type(Structure):
         """
         return conf.lib.clang_getArraySize(self)
 
+    def get_align(self):
+        """
+        Retrieve the alignment of the record.
+        """
+        return conf.lib.clang_Type_getAlignOf(self)
+
+    def get_size(self):
+        """
+        Retrieve the size of the record.
+        """
+        return conf.lib.clang_Type_getSizeOf(self)
+
+    def get_offset(self, fieldname):
+        """
+        Retrieve the offset of a field in the record.
+        """
+        return conf.lib.clang_Type_getOffsetOf(self, c_char_p(fieldname))
+
     def __eq__(self, other):
         if type(other) != type(self):
             return False
@@ -2623,6 +2653,10 @@ functionList = [
    [Type],
    c_longlong),
 
+  ("clang_getFieldDeclBitWidth",
+   [Cursor],
+   c_int),
+
   ("clang_getCanonicalCursor",
    [Cursor],
    Cursor,
@@ -3038,6 +3072,22 @@ functionList = [
    [Cursor, c_uint],
    Cursor,
    Cursor.from_result),
+
+  ("clang_Cursor_isBitField",
+   [Cursor],
+   c_long),
+
+  ("clang_Type_getAlignOf",
+   [Type],
+   c_longlong),
+
+  ("clang_Type_getOffsetOf",
+   [Type, c_char_p],
+   c_longlong),
+
+  ("clang_Type_getSizeOf",
+   [Type],
+   c_ulonglong),
 ]
 
 class LibclangError(Exception):
diff --git a/bindings/python/tests/cindex/test_type.py b/bindings/python/tests/cindex/test_type.py
index 28e4411c77..9bbed5aa94 100644
--- a/bindings/python/tests/cindex/test_type.py
+++ b/bindings/python/tests/cindex/test_type.py
@@ -298,3 +298,66 @@ def test_is_restrict_qualified():
     assert isinstance(i.type.is_restrict_qualified(), bool)
     assert i.type.is_restrict_qualified()
     assert not j.type.is_restrict_qualified()
+
+def test_record_layout():
+    """Ensure Cursor.type.get_size, Cursor.type.get_align and
+    Cursor.type.get_offset works."""
+
+    source ="""
+struct a {
+    long a1;
+    long a2:3;
+    long a3:4;
+    long long a4;
+};
+"""
+    tries=[(['-target','i386-linux-gnu'],(4,16,0,32,35,64)),
+           (['-target','nvptx64-unknown-unknown'],(8,24,0,64,67,128)),
+           (['-target','i386-pc-win32'],(8,16,0,32,35,64)),
+           (['-target','msp430-none-none'],(2,14,0,32,35,48))]
+    for flags, values in tries:
+        align,total,a1,a2,a3,a4 = values
+
+        tu = get_tu(source, flags=flags)
+        teststruct = get_cursor(tu, 'a')
+        fields = list(teststruct.get_children())
+
+        assert teststruct.type.get_align() == align
+        assert teststruct.type.get_size() == total
+        assert teststruct.type.get_offset(fields[0].spelling) == a1
+        assert teststruct.type.get_offset(fields[1].spelling) == a2
+        assert teststruct.type.get_offset(fields[2].spelling) == a3
+        assert teststruct.type.get_offset(fields[3].spelling) == a4
+        assert fields[0].is_bitfield() == False
+        assert fields[1].is_bitfield() == True
+        assert fields[1].get_bitfield_width() == 3
+        assert fields[2].is_bitfield() == True
+        assert fields[2].get_bitfield_width() == 4
+        assert fields[3].is_bitfield() == False
+
+def test_offset():
+    """Ensure Cursor.get_record_field_offset works in anonymous records"""
+    source="""
+struct Test {
+  struct {
+    int bariton;
+    union {
+      int foo;
+    };
+  };
+  int bar;
+};"""
+    tries=[(['-target','i386-linux-gnu'],(4,16,0,32,64)),
+           (['-target','nvptx64-unknown-unknown'],(8,24,0,32,64)),
+           (['-target','i386-pc-win32'],(8,16,0,32,64)),
+           (['-target','msp430-none-none'],(2,14,0,32,64))]
+    for flags, values in tries:
+        align,total,bariton,foo,bar = values
+        tu = get_tu(source)
+        teststruct = get_cursor(tu, 'Test')
+        fields = list(teststruct.get_children())
+        assert teststruct.type.get_offset("bariton") == bariton
+        assert teststruct.type.get_offset("foo") == foo
+        assert teststruct.type.get_offset("bar") == bar
+
+
diff --git a/bindings/python/tests/cindex/util.py b/bindings/python/tests/cindex/util.py
index 2323839306..8614b02ad2 100644
--- a/bindings/python/tests/cindex/util.py
+++ b/bindings/python/tests/cindex/util.py
@@ -3,7 +3,7 @@
 from clang.cindex import Cursor
 from clang.cindex import TranslationUnit
 
-def get_tu(source, lang='c', all_warnings=False):
+def get_tu(source, lang='c', all_warnings=False, flags=[]):
     """Obtain a translation unit from source and language.
 
     By default, the translation unit is created from source file "t.<ext>"
@@ -14,8 +14,8 @@ def get_tu(source, lang='c', all_warnings=False):
 
     all_warnings is a convenience argument to enable all compiler warnings.
     """
+    args = list(flags)
     name = 't.c'
-    args = []
     if lang == 'cpp':
         name = 't.cpp'
         args.append('-std=c++11')