On 9/29/2015 3:05 AM, Vladimir Prus wrote:

On 29-Sep-15 9:57 AM, Vladimir Prus wrote:

On 28-Sep-15 11:25 PM, Vladimir Prus wrote:

The priority order is roughly this:
- default values, here  warnings=on
- properties on the command line, none in your case
- requirements on projects and metatargets

I am surprised you still get -Wall, I'll take look tomorrow.

Edward,

with the patch below, when I run "b2 --debug-building", I see that
<warnigns>off is in build properties. With msvc, I also see /W0, which
is the expected warning option. Could you try exactly same patch and see
whether -Wall is still there?

--- test/Jamfile
+++ test/Jamfile
@@ -15,7 +15,7 @@ project
    ;

  test-suite lambda
-  : [ run algorithm_test.cpp ]
+  : [ run algorithm_test.cpp : : : <warnings>off ]
      [ run bind_tests_simple.cpp ]
      [ run bind_tests_advanced.cpp ]
      [ run bind_tests_simple_f_refs.cpp ]

The same patch also eliminates -Wall on Ubuntu with gcc.

What I see is that I can override the -Wall default if I specify "warnings=off" on the command line. Also if either the jam file has project requirements with "<warnings>off" or individual target has the "<warnings>off" the -Wall default is overridden.

However evidently, as specified in the documentation for the gcc toolset at http://www.boost.org/build/doc/html/bbv2/reference/tools.html#bbv2.reference.tools.compiler.gcc, the end-user can not use "<warnings>off" ( or any "<warnings>" option ) at the toolset level. I am trying to use it for clang, not gcc, but there is no documentation for the clang toolset in the Boost Build docs so I assume the same restriction goes for clang. Is there a reason why general requirements could not be part of the 'using' rule aside from the fact that it was not designed that way ? It would surely be useful to specify any feature, and not just the limited features which are direct compiler options, in the 'using' rule. I think the end-user should be able to specify a general requirement for his toolset which overrides the default requirement. My particular need is that clang outputs an awful lot of detail even when warnings occur, so I would like to limit as an end-user the warnings for that compiler. Doing it on the command line is possible but it is much easier if I could do it at the toolset level and treat the command line generically as to the toolset ( which is what I currently do by invoking 'b2' from batch files ).