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authorBoris Kolpackov <boris@codesynthesis.com>2015-12-02 11:37:15 +0200
committerBoris Kolpackov <boris@codesynthesis.com>2015-12-02 11:37:15 +0200
commit9891b20350021ce41a950645dd76df20a45c92cc (patch)
tree0cd27041b0c3413e17b9319ae99e87c5e745b1ff /build/variable
parent74212589a797ca75e55f92a522e198915c0dbaf6 (diff)
Implement optional module loading
The syntax is: using? cli Now each module use results in two bool variables: <module>.loaded and <module>.configured. Also implement variable visibility (the above two variables are limited to project).
Diffstat (limited to 'build/variable')
-rw-r--r--build/variable82
1 files changed, 61 insertions, 21 deletions
diff --git a/build/variable b/build/variable
index 7976ab9..061004c 100644
--- a/build/variable
+++ b/build/variable
@@ -7,10 +7,8 @@
#include <map>
#include <vector>
-#include <string>
#include <cstddef> // nullptr_t
-#include <utility> // move(), pair, make_pair()
-#include <cassert>
+#include <utility> // pair, make_pair()
#include <iterator>
#include <functional> // hash, reference_wrapper
#include <type_traits> // conditional, is_reference, remove_reference, etc.
@@ -19,6 +17,8 @@
#include <butl/prefix-map>
#include <build/types>
+#include <build/utility>
+
#include <build/target-type>
namespace build
@@ -37,19 +37,23 @@ namespace build
bool (*const append) (names&, names, const variable&);
};
+ enum class variable_visibility
+ {
+ scope, // This scope (no outer scopes).
+ project, // This project (no outer projects).
+ normal // All outer scopes.
+ };
+
// variable
//
// The two variables are considered the same if they have the same name.
//
struct variable
{
- explicit
- variable (std::string n, const value_type* t = nullptr, char p = '\0')
- : name (std::move (n)), pairs (p), type (t) {}
-
std::string name;
- char pairs;
- const value_type* type; // If NULL, then not (yet) typed.
+ const value_type* type; // If NULL, then not (yet) typed.
+ variable_visibility visibility;
+ char pairs; // Pair symbold or '\0' if not used.
};
inline bool
@@ -616,13 +620,40 @@ namespace build
{
// variable_pool
//
- using variable_set_base = std::unordered_set<variable>;
- struct variable_set: private variable_set_base
+ using variable_pool_base = std::unordered_set<variable>;
+ struct variable_pool: private variable_pool_base
{
const variable&
- find (std::string name, const build::value_type* t = nullptr, char p = '\0')
+ find (string name, const build::value_type* t = nullptr, char p = '\0')
{
- auto r (emplace (std::move (name), t, p));
+ return find (name, nullptr, t, p);
+ }
+
+ const variable&
+ find (string name,
+ variable_visibility v,
+ const build::value_type* t = nullptr,
+ char p = '\0')
+ {
+ return find (name, &v, t, p);
+ }
+
+ using variable_pool_base::clear;
+
+ private:
+ const variable&
+ find (string name,
+ const variable_visibility* vv,
+ const build::value_type* t,
+ char p)
+ {
+ auto r (
+ insert (
+ variable {
+ std::move (name),
+ t,
+ vv != nullptr ? *vv : variable_visibility::normal,
+ p}));
const variable& v (*r.first);
// Update type?
@@ -630,16 +661,25 @@ namespace build
if (!r.second && t != nullptr && v.type != t)
{
assert (v.type == nullptr);
- const_cast<variable&> (v).type = t; // Ok, not changing the key.
+ const_cast<variable&> (v).type = t; // Not changing the key.
+ }
+
+ // Change visibility? While this might at first seem like a bad idea,
+ // it can happen that the variable lookup happens before any values
+ // were set, in which case the variable will be entered with the
+ // default visibility.
+ //
+ if (!r.second && vv != nullptr && v.visibility != *vv)
+ {
+ assert (v.visibility == variable_visibility::normal); // Default.
+ const_cast<variable&> (v).visibility = *vv; // Not changing the key.
}
return v;
}
-
- using variable_set_base::clear;
};
- extern variable_set variable_pool;
+ extern variable_pool var_pool;
// variable_map
//
@@ -696,7 +736,7 @@ namespace build
lookup<const value>
operator[] (const std::string& name) const
{
- return operator[] (variable_pool.find (name));
+ return operator[] (var_pool.find (name));
}
// Non-const lookup. Only exposed on the map directly.
@@ -710,7 +750,7 @@ namespace build
lookup<value>
operator[] (const std::string& name)
{
- return operator[] (variable_pool.find (name));
+ return operator[] (var_pool.find (name));
}
// The second member in the pair indicates whether the new
@@ -733,13 +773,13 @@ namespace build
std::pair<std::reference_wrapper<value>, bool>
assign (const std::string& name)
{
- return assign (variable_pool.find (name));
+ return assign (var_pool.find (name));
}
std::pair<const_iterator, const_iterator>
find_namespace (const std::string& ns) const
{
- auto r (m_.find_prefix (variable_pool.find (ns)));
+ auto r (m_.find_prefix (var_pool.find (ns)));
return std::make_pair (const_iterator (r.first),
const_iterator (r.second));
}