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-rw-r--r--libbuild2/function.cxx9
-rw-r--r--libbuild2/function.hxx11
-rw-r--r--libbuild2/functions-builtin.cxx46
3 files changed, 35 insertions, 31 deletions
diff --git a/libbuild2/function.cxx b/libbuild2/function.cxx
index 79e7a81..25dacf9 100644
--- a/libbuild2/function.cxx
+++ b/libbuild2/function.cxx
@@ -117,13 +117,8 @@ namespace build2
// Overload resolution.
//
- // Ours is pretty simple: we sort all the overloads into three ranks:
- //
- // 0 -- all the arguments match exactly (perfect match)
- // 1 -- one or more arguments match via the derived-to-base conversion
- // 2 -- one or more arguments match via the reversal to untyped
- //
- // More than one match of the same rank is ambiguous.
+ // See the overall function machinery description for the ranking
+ // semantics.
//
auto ip (map_.equal_range (name));
diff --git a/libbuild2/function.hxx b/libbuild2/function.hxx
index ce47bd9..b745173 100644
--- a/libbuild2/function.hxx
+++ b/libbuild2/function.hxx
@@ -32,7 +32,7 @@ namespace build2
// as arguments. There is also higher-level, more convenient support for
// defining functions as pointers to functions (including capture-less
// lambdas), pointers to member functions (e.g., string::size()), or
- // pointers to data members (e.g., name::type). In this case the build2
+ // pointers to data members (e.g., name::type). In this case the buildfile
// function types are automatically matched to C++ function types according
// to these rules:
//
@@ -43,6 +43,15 @@ namespace build2
// value* - NULL-able any type (never NULL itself, use value::null)
// optional<T> - optional argument (here T can be T*, names, value)
//
+ // The overload resolution is pretty simple: we sort all the candidates into
+ // three ranks:
+ //
+ // 0 -- all the arguments match exactly (perfect match)
+ // 1 -- one or more arguments match via the derived-to-base conversion
+ // 2 -- one or more arguments match via the reversal to untyped
+ //
+ // More than one match of the same rank is ambiguous.
+ //
// Optional arguments must be last. In case of a failure the function is
// expected to issue diagnostics and throw failed. Note that the arguments
// are conceptually "moved" and can be reused by the implementation.
diff --git a/libbuild2/functions-builtin.cxx b/libbuild2/functions-builtin.cxx
index 4c5929b..c4f0314 100644
--- a/libbuild2/functions-builtin.cxx
+++ b/libbuild2/functions-builtin.cxx
@@ -3,6 +3,7 @@
#include <sstream>
+#include <libbuild2/scope.hxx>
#include <libbuild2/function.hxx>
#include <libbuild2/variable.hxx>
@@ -10,29 +11,23 @@ using namespace std;
namespace build2
{
- // Return NULL value if an environment variable is not set, untyped value
- // otherwise.
- //
- static inline value
- getenvvar (const string& name)
- {
- optional<string> v (getenv (name));
-
- if (!v)
- return value ();
-
- names r;
- r.emplace_back (to_name (move (*v)));
- return value (move (r));
- }
-
void
builtin_functions (function_map& m)
{
function_family f (m, "builtin");
- f["type"] = [](value* v) {return v->type != nullptr ? v->type->name : "";};
+ // Note that we may want to extend the scope argument to a more general
+ // notion of "lookup context" (scope, target, prerequisite).
+ //
+ f["defined"] = [](const scope* s, names name)
+ {
+ if (s == nullptr)
+ fail << "defined() called out of scope" << endf;
+ return (*s)[convert<string> (move (name))].defined ();
+ };
+
+ f["type"] = [](value* v) {return v->type != nullptr ? v->type->name : "";};
f["null"] = [](value* v) {return v->null;};
f["empty"] = [](value* v) {return v->null || v->empty ();};
@@ -67,14 +62,19 @@ namespace build2
// getenv
//
- f["getenv"] = [](string name)
- {
- return getenvvar (name);
- };
-
+ // Return NULL if the environment variable is not set, untyped value
+ // otherwise.
+ //
f["getenv"] = [](names name)
{
- return getenvvar (convert<string> (move (name)));
+ optional<string> v (getenv (convert<string> (move (name))));
+
+ if (!v)
+ return value ();
+
+ names r;
+ r.emplace_back (to_name (move (*v)));
+ return value (move (r));
};
}
}