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authorBoris Kolpackov <boris@codesynthesis.com>2022-03-31 13:34:36 +0200
committerBoris Kolpackov <boris@codesynthesis.com>2022-03-31 13:34:36 +0200
commit0a9dd0c7d31cbba2170fdfda4b747a1fe5ce665a (patch)
tree08aaf5b0c9fa06ca2352f1775f2c470841653a93
parenteed93abebc20e59f861c7e8b6322f7ef3681c59e (diff)
Use own type information instead of dynamic_cast in target::is_a()
-rw-r--r--libbuild2/target-type.hxx9
-rw-r--r--libbuild2/target.cxx15
-rw-r--r--libbuild2/target.hxx35
3 files changed, 35 insertions, 24 deletions
diff --git a/libbuild2/target-type.hxx b/libbuild2/target-type.hxx
index 0e24e3a..ef3a3ed 100644
--- a/libbuild2/target-type.hxx
+++ b/libbuild2/target-type.hxx
@@ -102,14 +102,15 @@ namespace build2
bool
is_a (const target_type& tt) const
{
- return this == &tt || (base != nullptr && is_a_base (tt));
+ for (const target_type* b (this); b != nullptr; b = b->base)
+ if (b == &tt)
+ return true;
+
+ return false;
}
bool
is_a (const char*) const; // Defined in target.cxx
-
- bool
- is_a_base (const target_type&) const; // Defined in target.cxx
};
inline bool
diff --git a/libbuild2/target.cxx b/libbuild2/target.cxx
index 5fa3c37..ba1454e 100644
--- a/libbuild2/target.cxx
+++ b/libbuild2/target.cxx
@@ -22,26 +22,13 @@ namespace build2
bool target_type::
is_a (const char* n) const
{
- if (strcmp (name, n) == 0)
- return true;
-
- for (const target_type* b (base); b != nullptr; b = b->base)
+ for (const target_type* b (this); b != nullptr; b = b->base)
if (strcmp (b->name, n) == 0)
return true;
return false;
}
- bool target_type::
- is_a_base (const target_type& tt) const
- {
- for (const target_type* b (base); b != nullptr; b = b->base)
- if (*b == tt)
- return true;
-
- return false;
- }
-
// target_key
//
void target_key::
diff --git a/libbuild2/target.hxx b/libbuild2/target.hxx
index 6b79e1b..2820aa7 100644
--- a/libbuild2/target.hxx
+++ b/libbuild2/target.hxx
@@ -780,20 +780,43 @@ namespace build2
//
public:
const target*
- is_a (const target_type& tt) const {
- return type ().is_a (tt) ? this : nullptr;}
+ is_a (const target_type& tt) const
+ {
+ return type ().is_a (tt) ? this : nullptr;
+ }
template <typename T>
T*
- is_a () {return dynamic_cast<T*> (this);}
+ is_a ()
+ {
+ // At least with GCC we see slightly better and more consistent
+ // performance with our own type information.
+ //
+#if 0
+ return dynamic_cast<T*> (this);
+#else
+ // We can skip dynamically-derived type here (derived_type).
+ //
+ return dynamic_type ().is_a<T> () ? static_cast<T*> (this) : nullptr;
+#endif
+ }
template <typename T>
const T*
- is_a () const {return dynamic_cast<const T*> (this);}
+ is_a () const
+ {
+#if 0
+ return dynamic_cast<const T*> (this);
+#else
+ return dynamic_type ().is_a<T> () ? static_cast<const T*> (this) : nullptr;
+#endif
+ }
const target*
- is_a (const char* n) const {
- return type ().is_a (n) ? this : nullptr;}
+ is_a (const char* n) const
+ {
+ return type ().is_a (n) ? this : nullptr;
+ }
// Unchecked cast.
//