Re: [boost] test_main.cpp (was Review: Function library)

From: Beman Dawes (bdawes_at_[hidden])
Date: 2001-06-13 20:55:06

At 04:47 PM 6/13/2001, Darin Adler wrote:
 >On Wednesday, June 13, 2001, at 07:47  AM, Beman Dawes wrote:
 >
 >>> 5) In test_main.cpp I made report_error() and report_critical_error()
 >>> static.
 >>
 >> Uh, run that one by me again.  What does making a function static 
inside
 >> a
 >> namespace do, anyhow?
 >
 >Marking a function static makes it have internal linkage. This is a
 >separate issue from whether the function is in a namespace or not. It's
 >true that there's no need for internal linkage for things that are inside 

 >an anonymous namespace, but for things that are in a non-anonymous
 >namespace it still makes sense to either nest an anonymous namespace or
 >use static to hide the function.

That's what I thought.  But what is confusing about the request is that the 
two functions in question are declared in a header (test_tools.hpp) so they 
shouldn't be hidden.

 > The idea is to make certain that there
 >are no references to the function in other files. If there were 
references
 >in other files, you'd want to have a header with the declaration in it, 
so
 >all the files share the same declaration.
 >
 >Metrowerks CodeWarrior has a nice warning that warns about functions that 

 >are defined without a previous declaration. This is to help you remember
 >to put declarations into header files. To avoid these warnings every
 >function definition must either:
 >
 >	1) Have a separate declaration before the definition, or
 >	2) be inside an anonymous namespace, or
 >	3) have internal linkage, or
 >	4) be marked inline.
 >
 >Case 1 is typical for header files, 2 is the modern way of hiding things
 >that are private to a single file, 3 is the old-fashioned C way of hiding 

 >things that are private to a single file, and 4 there because it's normal 

 >to have external linkage inlines in header files without separate
 >declarations. (Don't get me started on internal vs. external linkage
 >inlines unless you are really interested.)
 >
 >An appropriate fix for test_main.cpp is to put report_error and
 >report_critical_error into an anonymous namespace nested inside namespace 

 >boost.
 >
 >A side note: I'd like to see the cpp_main function's declaration in a
 >cpp_main.hpp header and the test_main function's declaration in a
 >test_main.hpp header.

Ullrich Koethe and I have been working on getting his unit test library 
ready for review.  That will involve a lot of internal implementation 
changes to the Boost Test Library, so I'm planning to ask for a formal 
review of the whole package.  That would be the time to make those 
changes.  I'll add 'em to the to-do list.

--Beman