cdecl and stdcall Calling Conventions, Stack Clearing and the EAX Register

Two key calling conventions are:

1. cdecl
2. stdcall

In cdecl parameters are pushed from right to left and the caller of the function is responsible for clearing the arguments from the stack. Used by most C systems on the x86 architecture.
Example of a cdecl call in C:
 int python_rocks(reason_one, reason_two, reason_three); 
In x86 Assembly:

push reason_three
push reason_two
push reason_one
call python_rocks
add esp, 12

The last line above increments the stack pointer 12 bytes (there are 3 parameters to the function and each stack parameter is 4 bytes and thus 12 bytes) which essentially clears those parameters.
cdecl
Example of a stdcall call in C:

int my_socks(color_one, color_two, color_three);

In x86 Assembly:

push color_three
push color_two
push color_one
call my_socks
The order of the parameters in stdcall is the same but the stack clearing is not done by the caller, but by the my_socks function.
For both stdcall and cdecl calling conventions it’s important to note that return values are stored in the EAX register.