Could dmd/ldc/gdc produce user defined attributes embedded (eg as json string) embedded in some section of the object file/static/shared library, eg:

```

{"compiler" : "dmd", "version" : "2.072", "flags" : "-O -debug"}

```

with some way to write and read those attributes, so that tooling can give informative warnings or errors when attempting to link together several libraries whose attributes don't match (user defined function can decide what matches based on those attributes), or to select which libraries to link if there are several choices

NOTE: posted a more general question here [1] beyond just D usage

[1] http://stackoverflow.com/questions/41240093/how-to-annotate-a-compilation-output-object-library-file-with-compiler-annotat

quote from that question:

----

Use cases:

either the linker ld or some other user defined tool could use this metadata to give informative warnings or errors when attempting to link together several libraries whose attributes don't match (eg when linking libraries compiles with -std=c++11 with others compiled without this)
this would provide much more user friendly error messages compared to the usual hard to debug undefined symbol errors, eg: undefined reference to llvm::Twine::str[abi:cxx11]() https://github.com/ldc-developers/ldc/issues/1928 or other errors that are due to compilation flag mismatches (eg missing -debug from https://github.com/rejectedsoftware/vibe.d/issues/740#issuecomment-268039416)
make it possible for tools to read the embedded metadata and find the most appropriate matching libraries to link when multiple ones are available

NOTE: the only thing I could find was https://gcc.gnu.org/onlinedocs/gccint/LTO-object-file-layout.html but not sure if that's relevant or how I would write (and later read) such user defined attributes:

Command line options (.gnu.lto_.opts): This section contains the command line options used to generate the object files