From ReactOS

A list of features we'd really like to see in MinGW

Contents 1 gcc 1.1 g++ 2 binutils 2.1 ld 2.2 dlltool

gcc

• SEH. Really.
  • patenting issues: see this and this.
• __uuidof and __declspec(uuid)
• native support for __int8, __int16, __int32 and __int64
• __ptr32 and __ptr64
• Microsoft-compatible string pooling (give each string a special decorated name and a COMDAT)

g++

• SEH-compatible unwinding. Also SEH
• Microsoft-compatible ABI
  • ktietz of mingw-w64 is already working on compatible symbol name decoration

binutils

• recognize the libraryname.lib pattern as equivalent to liblibraryname.a
• don't store debugging information in sections, because COFF doesn't support non-loadable sections, and debugging information incorrectly takes up address space
• support for the CodeView Program Database (CV/PDB) debugging information format
  • information on the format

ld

• COMDATs and identical COMDAT folding
• alias __image_base__ to __ImageBase
• honor linker directives embedded in object files (.drectve), especially /EXPORT and /DEFAULTLIB

dlltool