diff options
Diffstat (limited to 'doc/manual.cli')
| -rw-r--r-- | doc/manual.cli | 33 |
1 files changed, 24 insertions, 9 deletions
diff --git a/doc/manual.cli b/doc/manual.cli index dfb77a7..f6d2e75 100644 --- a/doc/manual.cli +++ b/doc/manual.cli @@ -311,6 +311,16 @@ it searches for a target for the \c{cxx{hello\}} prerequisite. During this search, the \c{extension} variable is looked up and its value is used to end up with the \c{hello.cxx} file. +\N|To resolve a rule match ambiguity or to override a default match \c{build2} +uses \i{rule hints}. For example, if we wanted link a C executable using the +C++ link rule: + +\ +[rule_hint=cxx] exe{hello}: c{hello} +\ + +| + Here is our new dependency declaration again: \ @@ -4624,15 +4634,20 @@ cross-compilation (specifically, inability to run tests). As a result, we recommend using \i{expectation-based} configuration where your project assumes a feature to be available if certain conditions are -met. Examples of such conditions at the source code level include feature -test macros, platform macros, runtime library macros, compiler macros, etc., -with the build system modules exposing some of the same information via -variables to allow making similar decisions in \c{buildfiles}. Another -alternative is to automatically adapt to missing features using more advanced -techniques such as C++ SFINAE. And in situations where none of this is -possible, we recommend delegating the decision to the user via a configuration -value. Our experience with \c{build2} as well as those of other large -cross-platform projects such as Boost show that this is a viable strategy. +met. Examples of such conditions at the source code level include feature test +macros, platform macros, runtime library macros, compiler macros, etc., with +the build system modules exposing some of the same information via variables +to allow making similar decisions in \c{buildfiles}. The standard +pre-installed \l{https://github.com/build2/libbuild2-autoconf/ \c{autoconf}} +build system module provides emulation of GNU \c{autoconf} using this +approach. + +Another alternative is to automatically adapt to missing features using more +advanced techniques such as C++ SFINAE. And in situations where none of this +is possible, we recommend delegating the decision to the user via a +configuration value. Our experience with \c{build2} as well as those of other +large cross-platform projects such as Boost show that this is a viable +strategy. Having said that, \c{build2} does provide the ability to extract configuration information from the environment (\c{$getenv()} function) or other tools |