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From: jeffa@hpmwtd.HP.COM (Jeff Aguilera)
Newsgroups: comp.lang.c++
Subject: incorrect inline translation in 1.2 and 2.0
Message-ID: <1520004@hpmwjaa.HP.COM>
Date: 26 Oct 89 22:43:35 GMT
Organization: HP Microwave Tech. - Santa Rosa, Ca.
Lines: 53

C++ generates incorrect code for the following program.  The problem exists
under versions 1.2, 2.0 beta, and 2.0.  Correct code is emitted when the inline 
specifier is deleted.

    /*********************************************************************/
    //inlinebug.c
    const char* null(const char* p) {
        if (p) while(*p) ++p;
        return p;
    }

    inline int length(const char* p) { return null(p)-p; }

    int snafu() { return length("oops"); }
    /*********************************************************************/

C++ translates this as follows:

    /* @(#)<<AT&T C++ Translator 2.00 06/30/89>> */
    /* < inlinebug.c > */
    ...

    char* null__FPCc(__0p) char* __0p; {
        if (__0p) while ((*__0p)) ++__0p;
        return __0p;
    }

    int snafu__Fv() { return ((null__FPCc(((char*)"oops"))-((char*)"oops"))); }

Although ANSI C permits the two instances of "oops" to share the same read-only
address, this is not required, nor is it traditional:

A2.6 Strings (Kernighan and Ritchie 2nd ed, p.194)
    A string literal, also called a string constant, is a sequence of characters 
    surrounded by double quotes, as in "...".  A string has type ``array of 
    characters'' and storage class static, and is initialized with the given 
    characters.  Whether identical string literals are distinct is
    implementation-defined, and the behavior of a program that attempts to 
    alter a string literal is undefined.

2.5 Strings (Stroustrup, p.247):
    A string is a sequence of characters surrounded by double quotes, as in
    "...".  A string has type ``array of characters'' and storage class
    static, and is initialized with the given characters.  All strings, even
    when written identically, are distinct.

2.5 Strings (Kernighan and Ritchie, p.181)
    A string is a sequence of characters surrounded by double quotes, as in
    "...".  A string has type ``array of characters'' and storage class
    static, and is initialized with the given characters.  All strings, even
    when written identically, are distinct.
---
  jaa