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authorBoris Kolpackov <boris@codesynthesis.com>2017-02-10 17:28:40 +0200
committerBoris Kolpackov <boris@codesynthesis.com>2017-02-13 12:42:42 +0200
commit62f962ec68435f6acade5769335153ffb90aad69 (patch)
tree0c3e95ebca03969faa692d2a5fdb9199f886886c
parent1821a11704143a89581b26e285d968230b86a8ac (diff)
Some ground work for proper variable cache implementation
-rw-r--r--build2/scope.cxx13
-rw-r--r--build2/variable51
2 files changed, 37 insertions, 27 deletions
diff --git a/build2/scope.cxx b/build2/scope.cxx
index aaa0077..6f21636 100644
--- a/build2/scope.cxx
+++ b/build2/scope.cxx
@@ -53,7 +53,8 @@ namespace build2
//
// @@ MT
//
- value& cache (s->target_vars.cache[make_tuple (&v, tt, *tn)]);
+ variable_map::value_data& cache (
+ s->target_vars.cache[make_tuple (&v, tt, *tn)]);
// Un-typify the cache. This can be necessary, for example, if we are
// changing from one value-typed stem to another.
@@ -185,7 +186,7 @@ namespace build2
//
// We also keep track of the root scope of the project from which this
// innermost value comes. This is used to decide whether a non-recursive
- // project-wise override applies.
+ // project-wise override applies. And also where our variable cache is.
//
const variable_map* inner_vars (nullptr);
const scope* inner_proj (nullptr);
@@ -303,7 +304,7 @@ namespace build2
if (inner_vars == nullptr)
{
inner_vars = l.vars;
- inner_proj = s->root_scope (); // Not actually used.
+ inner_proj = s->root_scope ();
}
apply = true;
@@ -322,6 +323,12 @@ namespace build2
assert (inner_vars != nullptr);
+ // If for some reason we are not in a project, use the cache from the
+ // global scope.
+ //
+ if (inner_proj == nullptr)
+ inner_proj = global_scope;
+
// Implementing proper caching is tricky so for now we are going to re-
// calculate the value every time. Later, the plan is to use value
// versioning (incremented on every update) to detect stem value changes.
diff --git a/build2/variable b/build2/variable
index 40470fa..6c579dd 100644
--- a/build2/variable
+++ b/build2/variable
@@ -330,7 +330,7 @@ namespace build2
using value_type = build2::value;
const value_type* value; // NULL if undefined.
- const variable_map* vars;
+ const variable_map* vars; // value is variable_map::value_data if not NULL.
bool
defined () const {return value != nullptr;}
@@ -355,11 +355,11 @@ namespace build2
template <typename T>
lookup (const value_type& v, const T& x): lookup (&v, &x.vars) {}
- lookup (const value_type& v, const variable_map& vs)
- : value (&v), vars (&vs) {}
+ lookup (const value_type& v, const variable_map& vm)
+ : value (&v), vars (&vm) {}
- lookup (const value_type* v, const variable_map* vs)
- : value (v), vars (v != nullptr ? vs : nullptr) {}
+ lookup (const value_type* v, const variable_map* vm)
+ : value (v), vars (v != nullptr ? vm : nullptr) {}
};
// Two lookups are equal if they point to the same variable.
@@ -757,18 +757,6 @@ namespace build2
static const value_type_ex value_type;
};
- // Variable override cache.
- //
- struct variable_override_value
- {
- build2::value value;
- const variable_map* stem_vars = nullptr; // NULL means there is no stem.
- };
-
- using variable_override_cache = std::map<pair<const variable_map*,
- const variable*>,
- variable_override_value>;
-
// Project-wide (as opposed to global) variable overrides. Returned by
// context.cxx:reset().
//
@@ -1046,6 +1034,7 @@ namespace build2
struct value_data: value
{
using value::value;
+ using value::operator=;
size_t version = 0; // Incremented on each modification (override cache).
size_t generation; // load_generation of this value (global state only).
@@ -1223,9 +1212,9 @@ namespace build2
return map_.emplace (t, variable_pattern_map (global_)).first->second;
}
- const_iterator begin () const {return map_.begin ();}
- const_iterator end () const {return map_.end ();}
- bool empty () const {return map_.empty ();}
+ const_iterator begin () const {return map_.begin ();}
+ const_iterator end () const {return map_.end ();}
+ bool empty () const {return map_.empty ();}
lookup
find (const target_type&, const string& tname, const variable&) const;
@@ -1237,18 +1226,32 @@ namespace build2
// guarantee the references remain valid).
//
// The key is the combination of the "original value identity" (as a
- // pointer to the value in variable_pattern_map) and the "target identity"
- // (as target type and target name).
+ // pointer to the value in one of the variable_pattern_map's) and the
+ // "target identity" (as target type and target name). Note that while at
+ // first it may seem like we don't need the target identity, we actually
+ // do since the stem may itself be target-type/pattern-specific.
//
// @@ MT
//
- mutable
- std::map<tuple<const value*, const target_type*, string>, value> cache;
+ mutable std::map<tuple<const value*, const target_type*, string>,
+ variable_map::value_data> cache;
private:
bool global_;
map_type map_;
};
+
+ // Variable override cache.
+ //
+ struct variable_override_value
+ {
+ variable_map::value_data value;
+ const variable_map* stem_vars = nullptr; // NULL means there is no stem.
+ };
+
+ using variable_override_cache = std::map<pair<const variable_map*,
+ const variable*>,
+ variable_override_value>;
}
#include <build2/variable.ixx>