diff options
Diffstat (limited to 'libbuild2/config/utility.hxx')
| -rw-r--r-- | libbuild2/config/utility.hxx | 55 |
1 files changed, 48 insertions, 7 deletions
diff --git a/libbuild2/config/utility.hxx b/libbuild2/config/utility.hxx index bafcafa..1e2ff53 100644 --- a/libbuild2/config/utility.hxx +++ b/libbuild2/config/utility.hxx @@ -11,6 +11,8 @@ #include <libbuild2/scope.hxx> #include <libbuild2/variable.hxx> +#include <libbuild2/config/types.hxx> + #include <libbuild2/export.hxx> namespace build2 @@ -58,6 +60,15 @@ namespace build2 { // Mark a variable to be saved during configuration. // + // Note: the save_*_omitted flags work best when undefined or (one of) the + // omitted value(s) is the default (see a note in lookup_config() + // documentation for details). + // + // The below lookup_*() functions mark the default value by setting + // value::extra to 1. Note that it's exactly 1 and not "not 0" since other + // values could have other meaning (see, for example, package skeleton + // in bpkg). + // const uint64_t save_default_commented = 0x01; // Based on value::extra. const uint64_t save_null_omitted = 0x02; // Treat NULL as undefined. const uint64_t save_empty_omitted = 0x04; // Treat empty as undefined. @@ -242,9 +253,6 @@ namespace build2 // expensive. It is also ok to call both versions multiple times provided // the flags are the same. // - // @@ Should save_null_omitted be interpreted to treat null as undefined? - // Sounds logical. - // lookup lookup_config (scope& rs, const variable&, @@ -263,6 +271,8 @@ namespace build2 const string& var, uint64_t save_flags = 0) { + // Note: go straight for the public variable pool. + // return lookup_config (rs, rs.ctx.var_pool[var], save_flags); } @@ -272,6 +282,8 @@ namespace build2 const string& var, uint64_t save_flags = 0) { + // Note: go straight for the public variable pool. + // return lookup_config (new_value, rs, rs.ctx.var_pool[var], save_flags); } @@ -300,8 +312,14 @@ namespace build2 // or from the command line (i.e., it is inherited from the amalgamation), // then its value is "overridden" to the default value on this root scope. // - // @@ Should save_null_omitted be interpreted to treat null as undefined? - // Sounds logical. + // Note that while it may seem logical, these functions do not + // "reinterpret" defined values according to the save_*_omitted flags (for + // example, by returning the default value if the defined value is NULL + // and the save_null_omitted flag is specified). This is because such a + // reinterpretation may cause a diversion between the returned value and + // the re-queried config.* variable value if the defined value came from + // an override. To put another way, the save_*_omitted flags are purely to + // reduce the noise in config.build. // template <typename T> lookup @@ -353,6 +371,8 @@ namespace build2 uint64_t save_flags = 0, bool override = false) { + // Note: go straight for the public variable pool. + // return lookup_config (rs, rs.ctx.var_pool[var], std::forward<T> (default_value), // VC14 @@ -369,6 +389,8 @@ namespace build2 uint64_t save_flags = 0, bool override = false) { + // Note: go straight for the public variable pool. + // return lookup_config (new_value, rs, rs.ctx.var_pool[var], @@ -413,7 +435,7 @@ namespace build2 const V* cv ( cast_null<V> ( lookup_config (rs, - rs.var_pool ().insert<V> ("config." + var), + rs.var_pool (true).insert<V> ("config." + var), std::forward<T> (default_value)))); // VC14 value& v (bs.assign<V> (move (var))); @@ -431,7 +453,7 @@ namespace build2 const V* cv ( cast_null<V> ( lookup_config (rs, - rs.var_pool ().insert<V> ("config." + var), + rs.var_pool (true).insert<V> ("config." + var), std::forward<T> (default_value)))); // VC14 value& v (bs.append<V> (move (var))); @@ -494,6 +516,25 @@ namespace build2 // LIBBUILD2_SYMEXPORT bool unconfigured (scope& rs, const string& var, bool value); + + // Return the origin of the value of the specified configuration variable + // plus the value itself. See $config.origin() for details. + // + // Throws invalid_argument if the passed variable is not config.*. + // + LIBBUILD2_SYMEXPORT pair<variable_origin, lookup> + origin (const scope& rs, const string& name); + + LIBBUILD2_SYMEXPORT pair<variable_origin, lookup> + origin (const scope& rs, const variable&); + + // As above but using the result of scope::lookup_original() or + // semantically equivalent (e.g., lookup_namespace()). + // + // Note that this version does not check that the variable is config.*. + // + LIBBUILD2_SYMEXPORT pair<variable_origin, lookup> + origin (const scope& rs, const variable&, pair<lookup, size_t> original); } } |