diff options
Diffstat (limited to 'build2/algorithm.hxx')
| -rw-r--r-- | build2/algorithm.hxx | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/build2/algorithm.hxx b/build2/algorithm.hxx index 4d6c4ff..c7839d1 100644 --- a/build2/algorithm.hxx +++ b/build2/algorithm.hxx @@ -463,6 +463,12 @@ namespace build2 // prerequisite_targets to NULL. If count is not 0, then only the first // count prerequisites are executed beginning from start. // + // Note that because after the call the ad hoc prerequisites are no longer + // easily accessible, this function shouldn't be used in rules that make a + // timestamp-based out-of-date'ness determination (which must take into + // account such prerequisites). Instead, consider the below versions that + // incorporate the timestamp check and do the right thing. + // target_state straight_execute_prerequisites (action, const target&, size_t count = 0, size_t start = 0); @@ -491,12 +497,13 @@ namespace build2 execute_prerequisites_inner (action, const target&, size_t count = 0); // A version of the above that also determines whether the action needs to - // be executed on the target based on the passed timestamp and filter. + // be executed on the target based on the passed timestamp and filter. If + // count is not 0, then only the first count prerequisites are executed. // // The filter is passed each prerequisite target and is expected to signal // which ones should be used for timestamp comparison. If the filter is - // NULL, then all the prerequisites are used. If count is not 0, then only - // the first count prerequisites are executed. + // NULL, then all the prerequisites are used. Note that ad hoc prerequisites + // are always used. // // Note that the return value is an optional target state. If the target // needs updating, then the value is absent. Otherwise it is the state that @@ -524,7 +531,7 @@ namespace build2 // on the passed timestamp and finds a prerequisite of the specified type // (e.g., a source file). If there are multiple prerequisites of this type, // then the first is returned (this can become important if additional - // prerequisites of the same type may get injected). + // prerequisites of the same type get injected). // template <typename T> pair<optional<target_state>, const T&> @@ -552,7 +559,8 @@ namespace build2 // Similar in semantics to execute_prerequisites(). // // T can only be const target* or prerequisite_target. If it is the latter, - // the ad hoc semantics described in execute_prerequsites() is in effect. + // the ad hoc blank out semantics described in execute_prerequsites() is in + // effect. // template <typename T> target_state |