c/594: cpp errs when one macro calls another

[mcartoaj@mat.ulaval.ca]

>Number:         594
>Category:       c
>Synopsis:       cpp errs when one macro calls another
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Oct 03 10:06:00 PDT 2000
>Closed-Date:
>Last-Modified:
>Originator:     Mihai Cartoaje
>Release:        2.8.1
>Organization:
>Environment:
Linux & Solaris
>Description:
In cpp, the code,

#define __T_TYPE float
#define __T_ADD __T_ADD_(__T_TYPE)

__T_ADD

gives,

__T_ADD_(float )

and the code,

#define __T_ADD_(name) name##_float

__T_ADD_(float )

gives,

float_add

However, the code,

#define __T_TYPE float
#define __T_ADD_(name) name##_float
#define __T_ADD __T_ADD(__T_TYPE)

__T_ADD

gives,

__T_TYPE_add

So if we write the output of a first macro explicitly, 
it will work correctly, otherwise, cpp will err when one 
macro calls another.
>How-To-Repeat:
gcc test.c -E
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted:
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