diff options
Diffstat (limited to 'build2/variable')
| -rw-r--r-- | build2/variable | 33 |
1 files changed, 22 insertions, 11 deletions
diff --git a/build2/variable b/build2/variable index 5b9189c..cc99dc6 100644 --- a/build2/variable +++ b/build2/variable @@ -712,11 +712,13 @@ namespace build2 return operator[] (var_pool.find (name)); } + // If typed is false, leave the value untyped even if the variable is. + // const value* - find (const variable&) const; + find (const variable&, bool typed = true) const; value* - find (const variable&); + find (const variable&, bool typed = true); // Return a value suitable for assignment. See scope for details. // @@ -737,15 +739,16 @@ namespace build2 } // As above but also return an indication of whether the new value (which - // will be NULL) was actually inserted. + // will be NULL) was actually inserted. Similar to find(), if typed is + // false, leave the value untyped even if the variable is. // pair<reference_wrapper<value>, bool> - insert (const variable&); + insert (const variable&, bool typed = true); pair<reference_wrapper<value>, bool> - insert (const string& name) + insert (const string& name, bool typed = true) { - return insert (var_pool.find (name)); + return insert (var_pool.find (name), typed); } pair<const_iterator, const_iterator> @@ -773,11 +776,6 @@ namespace build2 // Target type/pattern-specific variables. // - // @@ In quite a few places we assume that we can store a reference - // to the returned value (e.g., install::lookup_install()). If - // we "instantiate" the value on the fly, then we will need to - // consider its lifetime. - // using variable_pattern_map = std::map<string, variable_map>; using variable_type_map_base = std::map<reference_wrapper<const target_type>, variable_pattern_map>; @@ -786,6 +784,19 @@ namespace build2 { lookup find (const target_type&, const string& tname, const variable&) const; + + // In many places we assume that we can store a reference to the returned + // variable value (e.g., install::lookup_install()). As a result, in case + // of append/prepent where we calculate the value dynamically, we have to + // cache it. + // + // The key is the combination of the "original value idenity" (as a + // pointer to the value in variable_pattern_map) and the "target identity" + // (as target type and target name). The target name, unfortunately, has + // to be stored by value (maybe will pool them at some point). + // + mutable + std::map<tuple<const value*, const target_type*, string>, value> cache; }; // Override cache. |