Обсуждение: Re: 7.5 beta version]

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Re: 7.5 beta version]

От
"Dann Corbit"
Дата:
> -----Original Message-----
> From: Jürgen Cappel [mailto:email@juergen-cappel.de]
> Sent: Monday, April 12, 2004 12:33 PM
> To: Dann Corbit
> Cc: pgsql-hackers@postgresql.org
> Subject: Re: [HACKERS] 7.5 beta version]
>
>
>
> Point 1 I completely agree on: byte order, alignment,
> padding, etc. is different for each platform and data cannot
> directly be exchanged.
>
> Point 2: who really needs C++ ??
C++ programmers do.  I was responding to a suggestion that PostgreSQL was being compiled as C++.  Perhaps I
misunderstood.

> -------- Ursprüngliche Nachricht --------
> Betreff: Re: [HACKERS] 7.5 beta version
> Datum: Mon, 12 Apr 2004 11:55:45 -0700
> Von: "Dann Corbit" <DCorbit@connx.com>
> An: "Jeroen T. Vermeulen" <jtv@xs4all.nl>,    "Bruce Momjian"
> <pgman@candle.pha.pa.us>
> CC: <pgsql-hackers@postgresql.org>
>
> > -----Original Message-----
> > From: Jeroen T. Vermeulen [mailto:jtv@xs4all.nl]
> > Sent: Sunday, April 11, 2004 7:28 AM
> > To: Bruce Momjian
> > Cc: Dann Corbit; pgsql-hackers@postgresql.org
> > Subject: Re: [HACKERS] 7.5 beta version
> >
> >
> > On Mon, Apr 05, 2004 at 09:38:13PM -0400, Bruce Momjian wrote:
> > >
> > > I don't think you can mix libs/binaries from different compilers.
> >
> > As long as it's plain old C, and the compilers adhere to the
> > platform's ABI standards, why not?  Even if you compile the C code
> > using a C++ compiler, as in this case, any C structs will
> be PODs and
> > so should be compiled according to the C layout rules.
>
> 1.
> The C language does not define alignment of structs.
>
> The C language does not specify that an integer shall be the
> same size on two different platforms.
>
> The C language does not specify a portable way even to read
> and write structs to disk and preserve alignment across platforms.
>
> The C language does not specify that IEEE arithmetic must be
> used or even that a double shall be able to represent a value
> larger than a float.
>
> 2.
> It is a mistake to use a C++ compiler to compile C code,
> because the languages are different.  Stroustrup's statement
> that good C code tends to be valid C++ code is not correct.
>
> Mingw GCC is both a C and a C++ compiler.  Fortunately, the C
> compiler is used, because there is no way that the code base
> would compile as C code.  A trivial example to show why not
> is the frequent use of the C++ keyword 'new' in the code
> base.  Here is an example: regc_color.c (225):  struct
> colordesc *new; regc_color.c (251):  new = (struct colordesc
> *) MALLOC(n * regc_color.c (253):  if (new != NULL)
> regc_color.c (254):  memcpy(VS(new), VS(cm->cdspace),
> cm->ncds * regc_color.c (258):  new = (struct colordesc *)
> REALLOC(cm->cd, regc_color.c (260):  if (new == NULL)
> regc_color.c (265):  cm->cd = new;
>
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