cogu / cfile

A python C code generator

cfile

A C code generator written in Python 3.

Usage

import cfile

C = cfile.CFactory()
code = C.sequence()
code.append(C.sysinclude("stdio.h"))
code.append(C.blank())
char_ptr_type = C.type("char", pointer=True)
code.append(C.declaration(C.function("main", "int",
                                     params=[C.variable("argc", "int"),
                                             C.variable("argv", char_ptr_type, pointer=True)
                                             ])))
main_body = C.block()
main_body.append(C.statement(C.func_call("printf", C.str_literal(r"Hello World\n"))))
main_body.append(C.statement(C.func_return(0)))
code.append(main_body)
writer = cfile.Writer(cfile.StyleOptions())
print(writer.write_str(code))

Output

   #include <stdio.h>

   int main(int argc, char** argv)
   {
      printf("Hello World!\n");
      return 0;
   }

Here's the same example again but this time we change the formatting style of the output:

• Opening brace on same line
• Pointer alignment to the right

import cfile

C = cfile.CFactory()
code = C.sequence()
code.append(C.sysinclude("stdio.h"))
code.append(C.blank())
char_ptr_type = C.type("char", pointer=True)
code.append(C.declaration(C.function("main", "int",
                                     params=[C.variable("argc", "int"),
                                             C.variable("argv", char_ptr_type, pointer=True)
                                             ])))
main_body = C.block()
main_body.append(C.statement(C.func_call("printf", C.str_literal(r"Hello World\n"))))
main_body.append(C.statement(C.func_return(0)))
code.append(main_body)
style = cfile.StyleOptions(break_before_braces=cfile.BreakBeforeBraces.ATTACH,
                           pointer_alignment=cfile.Alignment.RIGHT)
writer = cfile.Writer(style)
print(writer.write_str(code))

Output

   #include <stdio.h>

   int main(int argc, char **argv) {
      printf("Hello World!\n");
      return 0;
   }

Important update about declarations

Starting from version 0.3.2 you need to wrap functions, variables, structs and typedefs inside C.declaraton to actually declare them. Before v0.3.2 these elements were implicitly declared when encountered in the code sequence.

Not using C.declaration will only print the name when used on variables, functions or typedefs.

For structs it will have the following meaning:

• without declaration: Will only forward declare the struct type.
• With declaration: Will fully declare the struct and its members.

Example

import cfile

C = cfile.CFactory()

code = C.sequence()
mystruct = C.struct("mystruct",
                    members=[C.struct_member("field_1", "int"),
                             C.struct_member("field_2", "int")])
code.append(C.statement(mystruct))  # Forward declaration
code.append(C.blank())
code.append(C.statement(C.declaration(mystruct)))  # Struct declaration
writer = cfile.Writer(cfile.StyleOptions())
print(writer.write_str(code))

Output

struct mystruct;

struct mystruct
{
    int field_1;
    int field_2;
};

When declaring typedefs of structs you can wrap the struct declaration inside the declaration of the typedef.

Example

import cfile

C = cfile.CFactory()

code = C.sequence()
mystruct = C.struct("mystruct",
                    members=[C.struct_member("field_1", "int"),
                             C.struct_member("field_2", "int")])
code.append(C.statement(C.declaration(C.typedef("mystruct_t", C.declaration(mystruct)))))
writer = cfile.Writer(cfile.StyleOptions(break_before_braces=cfile.BreakBeforeBraces.ATTACH))
print(writer.write_str(code))

Output

typedef struct mystruct {
    int field_1;
    int field_2;
} mystruct_t;

There's some basic support for struct initializers. By rearranging the code from the example above we can declare a new struct variable named instance with initializer.

import cfile

C = cfile.CFactory()
code = C.sequence()
struct = C.struct("mystruct",
                  members=[C.struct_member("field_1", "int"),
                           C.struct_member("field_2", "int")])
struct_type = C.typedef("my_struct_t", C.declaration(struct))
code.append(C.statement(C.declaration(struct_type)))
code.append(C.blank())
code.append(C.statement(C.declaration(C.variable("instance", struct_type), [0, 0])))

writer = cfile.Writer(cfile.StyleOptions(break_before_braces=cfile.BreakBeforeBraces.ATTACH))
print(writer.write_str(code))

Output

typedef struct mystruct {
    int field_1;
    int field_2;
} my_struct_t;

my_struct_t instance = {0, 0};

Requires

Python 3.10+ (Needed for modern type hinting support).

Documentation

Documentation will be written at a later date.

For currently supported style options see class StyleOptions in cfile.style module.

Changelog

See Changelog document.

About versions

v0.2: No longer maintained.

v0.4: Stable version (bug-fixes only).

v0.5: Development track.