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// file : libbuild2/config/utility.cxx -*- C++ -*-
// license : MIT; see accompanying LICENSE file
#include <libbuild2/config/utility.hxx>
using namespace std;
namespace build2
{
void (*config_save_variable) (scope&, const variable&, optional<uint64_t>);
void (*config_save_environment) (scope&, const char*);
void (*config_save_module) (scope&, const char*, int);
const string& (*config_preprocess_create) (context&,
values&,
vector_view<opspec>&,
bool,
const location&);
bool (*config_configure_post) (scope&, bool (*)(action, const scope&));
bool (*config_disfigure_pre) (scope&, bool (*)(action, const scope&));
namespace config
{
pair<lookup, bool>
lookup_config_impl (scope& rs, const variable& var, uint64_t sflags)
{
// This is a stripped-down version of the default value case.
pair<lookup, size_t> org (rs.lookup_original (var));
bool n (false); // New flag.
lookup l (org.first);
// Treat an inherited value that was set to default as new.
//
if (l.defined () && l->extra)
n = true;
if (var.overrides != nullptr)
{
// This is tricky: if we didn't find the original, pretend we have set
// the default value for the purpose of override lookup in order to
// have consistent semantics with the default value case (see notes in
// that implementation for background).
//
// In particular, this makes sure we can first do the lookup without
// the default value and then, if there is no value, call the version
// with the default value and end up with the same result if we called
// the default value version straight away.
//
// Note that we need to detect both when the default value is not
// overridden as well as when the override is based on it (e.g., via
// append; think config.cxx+=-m32).
//
// @@ Maybe a callback that computes the default value on demand is a
// better way?
//
variable_map::value_data v; // NULL value, but must be with version.
if (!l.defined ())
org = make_pair (lookup (v, var, rs), 1); // As default value case.
scope::override_info li (rs.lookup_override_info (var, move (org)));
pair<lookup, size_t>& ovr (li.lookup);
if (l.defined () ? l != ovr.first : !li.original) // Overriden?
{
// Override is always treated as new.
//
n = true;
l = move (ovr.first);
}
}
if (l.defined ())
save_variable (rs, var, sflags);
return pair<lookup, bool> (l, n);
}
bool
specified_config (scope& rs,
const string& n,
initializer_list<const char*> ig)
{
auto& vp (rs.var_pool ());
// Search all outer scopes for any value in this namespace.
//
// What about "pure" overrides, i.e., those without any original values?
// Well, they will also be found since their names have the original
// variable as a prefix. But do they apply? Yes, since we haven't found
// any original values, they will be "visible"; see find_override() for
// details.
//
const string ns ("config." + n);
for (scope* s (&rs); s != nullptr; s = s->parent_scope ())
{
for (auto p (s->vars.lookup_namespace (ns));
p.first != p.second;
++p.first)
{
const variable* v (&p.first->first.get ());
// This can be one of the overrides (__override, __prefix, etc).
//
if (size_t n = v->override ())
v = vp.find (string (v->name, 0, n));
auto match_tail = [&ns, v] (const char* t)
{
return v->name.compare (ns.size () + 1, string::npos, t) == 0;
};
// Ignore config.*.configured and user-supplied names.
//
if (v->name.size () <= ns.size () ||
(!match_tail ("configured") &&
find_if (ig.begin (), ig.end (), match_tail) == ig.end ()))
return true;
}
}
return false;
}
bool
unconfigured (scope& rs, const string& n)
{
// Pattern-typed as bool.
//
const variable& var (
rs.var_pool ().insert ("config." + n + ".configured"));
save_variable (rs, var);
auto l (rs[var]); // Include inherited values.
return l && !cast<bool> (l);
}
bool
unconfigured (scope& rs, const string& n, bool v)
{
// Pattern-typed as bool.
//
const variable& var (
rs.var_pool ().insert ("config." + n + ".configured"));
save_variable (rs, var);
value& x (rs.assign (var));
if (x.null || cast<bool> (x) != !v)
{
x = !v;
return true;
}
else
return false;
}
pair<variable_origin, lookup>
origin (const scope& rs, const string& n)
{
// Make sure this is a config.* variable. This could matter since we
// reply on the semantics of value::extra. We could also detect
// special variables like config.booted, some config.config.*, etc.,
// (see config_save() for details) but that seems harmless.
//
if (n.compare (0, 7, "config.") != 0)
throw invalid_argument ("config.* variable expected");
const variable* var (rs.ctx.var_pool.find (n));
if (var == nullptr)
return make_pair (variable_origin::undefined, lookup ());
pair<lookup, size_t> org (rs.lookup_original (*var));
pair<lookup, size_t> ovr (var->overrides == nullptr
? org
: rs.lookup_override (*var, org));
if (!ovr.first.defined ())
return make_pair (variable_origin::undefined, lookup ());
if (org.first != ovr.first)
return make_pair (variable_origin::override_, ovr.first);
return make_pair (org.first->extra
? variable_origin::default_
: variable_origin::buildfile,
org.first);
}
}
}
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