What is the equivalent in GCC to MSVC's '#pragma message'?

Question

On MSVC I can issue compilation-time message like so:

#pragma message("...some compilation-time message...")

Is there an equivalent in GCC?

Answer 1

You can just use #pragma in gcc too. Otherwise there is warning and error:

#pragma message("...some compilation-time message...")
#warning I warn you.
#error I mean it.

results in

$ g++ -O2 -W -Wall -g -c foo.cc
foo.cc:2:2: warning: #warning I warn you. [-Wcpp]
    2 | #warning I warn you.
      |  ^~~~~~~
foo.cc:3:2: error: #error I mean it.
    3 | #error I mean it.
      |  ^~~~~
foo.cc:1:54: note: ‘#pragma message: ...some compilation-time message...’
    1 | #pragma message("...some compilation-time message...")
      |                                                      ^