Calling conventions for C++ compilers and OS

In the complex ecosystem of C++ development, binary compatibility across different compilers and operating systems remains one of the most challenging aspects of software engineering. This authoritative manual, "Calling Conventions for C++ Compilers and Operating Systems," provides an exhaustive reference for developers grappling with interoperability issues between compilers like GCC, Clang, MSVC, and ICC. By detailing how each compiler handles function calling conventions, name mangling, and data representation, the guide serves as an indispensable resource for anyone working on cross-platform libraries, mixed-language projects, or performance-critical assembly integrations.

Learning the Calling conventions for C++ compilers and OS

The manual begins by dissecting calling conventions—the critical low-level protocols that govern how functions pass arguments, return values, and manage stack frames across different compilers and platforms. You'll learn the key differences between __cdecl, __stdcall, __fastcall, and __vectorcall on Windows, as well as the System V AMD64 ABI dominant on Linux and macOS. These conventions directly impact binary compatibility, affecting everything from simple function calls to complex callback systems. The guide provides practical examples of how to explicitly specify calling conventions in your code to ensure consistent behavior across compiler boundaries, particularly important when creating DLLs or interfacing with assembly code.

A core focus of the manual is name mangling—the compiler-specific technique for encoding function names with type information in object files. The document compares the mangling schemes of major compilers, explaining why a function compiled with MSVC might be completely unrecognizable to GCC linker, and how to work around these issues using extern "C" and careful API design. This knowledge becomes crucial when building cross-platform libraries or debugging mysterious linker errors in mixed-compiler environments. The guide also covers vendor extensions like MSVC's __declspec attributes and GCC's visibility pragmas that affect symbol export behavior.

For developers working with binary data interoperability, the manual provides essential guidance on data type representation across compilers and platforms. You'll learn about structure padding differences, alignment requirements, and endianness considerations that can cause subtle bugs when reading binary files or sharing memory between processes. The document explains how to use #pragma pack and alignas to control layout explicitly, ensuring consistent data representation regardless of compiler used. These techniques prove invaluable when dealing with network protocols, file formats, or inter-process communication where binary compatibility is mandatory.

The manual's practical applications extend to several advanced scenarios: creating assembly routines that interface safely with multiple compilers, building polyglot projects combining C++ with other languages like Rust or Fortran, and developing tools like debuggers or disassemblers that need to understand multiple compiler outputs. Special attention is given to exception handling differences and stack unwinding implementations, which vary significantly between compilers and can cause crashes if not properly accounted for in mixed environments.

As part of a comprehensive optimization series, this calling conventions manual completes the picture for developers needing full control over their software's binary footprint. By understanding these low-level details, you'll be equipped to solve some of the most stubborn compatibility issues in C++ development—whether you're maintaining legacy codebases, developing cross-platform middleware, or pushing the boundaries of performance through careful compiler-specific optimizations. The knowledge contained herein not only helps work within the current compiler landscape but also informs better design decisions that make future interoperability challenges easier to solve.