Changing compiler in IDAPython

Question

I've been trying to use the IDAPython API to adjust the compiler setting in a script, but I can't seem to get any function to work properly. Some of the things I've attempted:

1.

Python>SetLongPrm(INF_COMPILER, COMP_MS)

This leaves me with the compiler id set to the right value, but for some reason it sets all the other compiler related values to 0 or something similar. Giving me an error about the Pointer Size not being right and int size not being a valid value.

2.

Python>idaapi.set_compiler_id(2)
False

This just straight up doesn't work, but this would probably end up the same as the first command.

3.

class compiler_info_t(object):
    id = COMP_MS
    cm = 0x3 | 0x00 | 0x30
    size_i = 4
    size_b = 1
    size_e = 4
    defalign = 0
    size_s = 2
    size_l = 4
    size_ll = 8
    def __init__(self, *args):
        """
        __init__(self) -> compiler_info_t
        """
        this = _idaapi.new_compiler_info_t(*args)
        try: self.this.append(this)
        except: self.this = this

My last attempt was to try and make my own compiler_info_t object to pass to idaapi.set_compiler(), but since "_idaapi" isn't a module i can import normally it won't let me call new_compiler_info_t().

Question: Is there a way to, perhaps, individually set/fix the compiler values for pointer size, memory model, and calling convention? If not, is there a different way to completely adjust the compiler, analogous to how it would function if you changed it by hand in the compiler settings window?

Answer 1

Here is my example: "Set Compiler defaults for Visual C++"

def print_compiler(id):
    print '-'*(80)
    abbr = ida_typeinf.get_compiler_abbr(id)
    name = ida_typeinf.get_compiler_name(id)
    print "id: %d (%s)" % (id,abbr)
    print "Compiler: '%s'" % name
    im = idc.get_inf_attr(INF_COMPILER)
    print "Calling model: %02X" % im.cm
    print "Defauil alignments: %d" % im.defalign
    print "sizeof(int): %d\tsizeof(short): %d" % (im.size_i,im.size_s)
    print "sizeof(bool): %d\tsizeof(long): %d" % (im.size_b,im.size_l)
    print "sizeof(enum): %d\tsizeof(longlong): %d" % (im.size_e,im.size_ll)
    print "sizeof(long double): %d" % (im.size_ldbl)
    print "Predefined macros: '%s'" % ida_idp.cfg_get_cc_predefined_macros(id)
    print "Included directories: '%s'" % ida_idp.cfg_get_cc_header_path(id)
    print '-'*(80)

# Print Old Compiler settings by ID
print_compiler(idc.get_inf_attr(INF_COMPILER).id)

# Set Compiler defaults for Visual C++
im = idc.get_inf_attr(INF_COMPILER) # Get current settings
im.id = ida_typeinf.COMP_MS
im.cm = 0x03 | 0x00 | 0x30
im.defalign = 0
im.size_i = 4
im.size_b = 1
im.size_e = 4
im.size_s = 2
im.size_l = 4
im.size_ll = 8
im.size_ldbl = 8
# Replace predefined macros and included directories by id
# from IDA.CFG (see 'CC_PARMS' in Built-in C parser parameters)
ida_typeinf.set_c_macros(ida_idp.cfg_get_cc_predefined_macros(im.id))
ida_typeinf.set_c_header_path(ida_idp.cfg_get_cc_header_path(im.id))
# Resetting new settings :)
idc.set_inf_attr(INF_COMPILER, im.id)

# Print New Compiler settings by ID
print_compiler(im.id)