Compiler and Vendor Documentation

Major compiler docs

• Microsoft C++ documentation: MSVC options, language notes, diagnostics, debugging, and Windows-focused workflows.
• GCC online docs: GNU compiler options, extensions, and libstdc++ documentation.
• Clang documentation: compiler flags, diagnostics, sanitizers, static analysis, and LLVM/Clang tooling.

When to use these

• Use vendor docs when warnings, flags, ABI notes, extension behavior, or standard-library implementation details differ across toolchains.
• Use them alongside Compiler Explorer when you want to compare observed behavior against documented options.

When to start here

• a program behaves differently across compilers
• you need the exact meaning of a warning, flag, extension, or library implementation note
• you are debugging platform-specific behavior or toolchain-specific diagnostics

Quick decision guide

1. Use MSVC docs when the issue is Windows-focused, MSVC-flag-specific, or tied to the Microsoft standard library/runtime.
2. Use GCC docs when the issue is about GNU extensions, libstdc++ behavior, or GNU toolchain flags.
3. Use Clang docs when the issue involves sanitizers, diagnostics tuning, static analysis, or LLVM/Clang-specific behavior.

Cross-toolchain workflow

1. Reproduce the behavior with the smallest possible source file.
2. Build it with at least two compilers using strict warnings and the same language mode.
3. Check vendor docs for the exact warning, flag, or extension involved.
4. If behavior still differs, confirm whether the issue is standard wording, implementation choice, or undefined behavior in the program.

Practical comparison habits

• look up warning identifiers exactly as emitted by the compiler
• keep notes about which standard library implementation was in use, not just the compiler front end
• when testing portability, compare both compile diagnostics and runtime behavior