🚀 go-pugleaf

In <48190c$bak@nyx10.cs.du.edu> colin@nyx10.cs.du.edu (Colin Plumb) writes:

>I noticed that a DEC's Alpha compiler breaks on
>
>host% cat > foo.f <<EOF
>#ifndef HAVE_FOO
>#define HAVE_FOO defined(FOO)
>#endif
>
>#if HAVE_FOO
>#error No, we have FOO
>#else
>#error Yes, we have no FOO
>#endif
>EOF
>host% cc -migrate foo.c

Hey, you created foo.f, but you attempt to compile foo.c :-)

>cc: Warning: foo.c, line 5: Spurious token(s) ignored on preprocessor directive line.
>#if HAVE_FOO
>----^
>cc: Error: foo.c, line 8: #error Yes, we have no FOO
>#error Yes, we have no FOO
>-^
>cc: Warning: foo.c, line 9: Source file does not contain any declarations.
>#endif
>------^
>
>Now, the second two diagnostics are fine, but is the compiler allowed to
>not recognize "defined(FOO)" when it appears as part of a macro expansion?

Yes, it is, because you didn't invoke the compiler in ANSI mode.
Try to add the -std1 option, which makes it ANSI compliant.  Anyway, the
compiler is free to emit as many diagnostics as it likes, as long as it
translates the source file correctly.

Dan
--
Dan Pop
CERN, CN Division
Email: danpop@mail.cern.ch 
Mail:  CERN - PPE, Bat. 31 R-004, CH-1211 Geneve 23, Switzerland