Extern "C" and "cdecl"

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Why does the compiler treat extern "C" and extern "cdecl" as different conventions?

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I’m not familiar with calling conventions and extern in Rust myself, but did you read an over what the various ABI strings mean in the first place? E.g. here is a list in the reference. Fairly concise of course, and I for sure couldn’t tell you in any detail what similarities and differences these entail on which platforms.

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Is the fact that they are not the same a good enough reason? I'm not sure why you would expect that two different calling conventions be the same.

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Can you please explain how these two differ?

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From the document @steffahn linked:

  • extern "C" -- This is the same as extern fn foo(); whatever the default your C compiler supports.
  • extern "cdecl" -- The default for x86_32 C code.

It explicitly says that the former is a different choice for different platforms, while the latter is a calling convention for a specific platform (x86_32). They are separate things with separate meanings.

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