CA written test, MS interview Vender test, unfortunately, I didn't make it again :(
The Visual C / C compiler provides several ways to call internal and external functions. Understanding these different approaches can help you debug your program and link your code with assembly-language routines.The following will explain the differences between the calling conventions, how arguments are passed, and how values are returned by functions __cdecl:. the default calling convention for C and C programs Because the stack is cleaned up by the caller, it can do vararg functions The __cdecl calling convention creates larger executables than __stdcall, because it.. Requires Each Function Call to include Stack Cleanup Code.
ElementImplementationArgument-passing orderRight to leftStack-maintenance responsibilityCalling function pops the arguments from the stackName-decoration conventionUnderscore character (_) is prefixed to namesCase-translation conventionNo case translation performed
__stdcall:
THE
__stdcall calling convention is used to call win32 API functions. The Callee Cleans The Stack, So The Compiler Makes
Vararg functions
__cdecl. Functions That Use this Calling Convention Require a Function Prototype.
ElementImplementationArgument-passing orderRight to left.Argument-passing conventionBy value, unless a pointer or reference type is passed.Stack-maintenance responsibilityCalled function pops its own arguments from the stack.Name-decoration conventionAn underscore (_) is prefixed to the name. The name is followed by the at sign (@) followed by the number of bytes (in decimal) in the argument list Therefore, the function declared as int func (int a, double b) is decorated as follows:. _func @ 12Case-translation Conventionnone__fastcall:
THE __FASTCALL CALLING CONVENTION SPECIFIES THAT ARGUMENTS TO Functions Are To Be Passed in Registers, When Possible.
ElementImplementationArgument-passing orderThe first two DWORD or smaller arguments are passed in ECX and EDX registers; all other arguments are passed right to left.Stack-maintenance responsibilityCalled function pops the arguments from the stack.Name-decoration conventionAt sign (@) is prefixed to Names; an at Sign Followed by the number of bytes (in decimal) in the parameter list is enough. ..case-translation convention.
