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authorBoris Kolpackov <boris@codesynthesis.com>2015-12-02 13:08:16 +0200
committerBoris Kolpackov <boris@codesynthesis.com>2015-12-02 13:08:16 +0200
commit685fe65f6b26b9e57c3d10cfe68c66d8baff8a68 (patch)
tree27b83b16118241956a9cfdcc9249347f4da3b606
parentc5fc14f302a4080ad0c6469e78582abb8e9b113f (diff)
Add support for optional configuration for cli module
-rw-r--r--build/cli/module.cxx138
-rw-r--r--build/variable10
2 files changed, 101 insertions, 47 deletions
diff --git a/build/cli/module.cxx b/build/cli/module.cxx
index 081980b..7ce4235 100644
--- a/build/cli/module.cxx
+++ b/build/cli/module.cxx
@@ -34,7 +34,7 @@ namespace build
const location& loc,
std::unique_ptr<module>&,
bool first,
- bool)
+ bool optional)
{
tracer trace ("cli::init");
level5 ([&]{trace << "for " << base.out_path ();});
@@ -61,30 +61,6 @@ namespace build
tts.insert<cli_cxx> ();
}
- // Register our rules.
- //
- {
- auto& rs (base.rules);
-
- rs.insert<cli_cxx> (perform_id, update_id, "cli", compile_);
- rs.insert<cli_cxx> (perform_id, clean_id, "cli", compile_);
-
- rs.insert<cxx::hxx> (perform_id, update_id, "cli", compile_);
- rs.insert<cxx::hxx> (perform_id, clean_id, "cli", compile_);
-
- rs.insert<cxx::cxx> (perform_id, update_id, "cli", compile_);
- rs.insert<cxx::cxx> (perform_id, clean_id, "cli", compile_);
-
- rs.insert<cxx::ixx> (perform_id, update_id, "cli", compile_);
- rs.insert<cxx::ixx> (perform_id, clean_id, "cli", compile_);
-
- // Other rules (e.g., cxx::compile) may need to have the group
- // members resolved. Looks like a general pattern: groups should
- // resolve on configure(update).
- //
- rs.insert<cli_cxx> (configure_id, update_id, "cli", compile_);
- }
-
// Enter module variables.
//
if (first)
@@ -97,19 +73,27 @@ namespace build
// Configure.
//
+ // The plan is as follows: try to configure the module. If this
+ // fails with the default values and the module is optional,
+ // leave it unconfigured.
+ //
+ bool r (true);
+
+ // We will only honor optional if the user didn't specify any cli
+ // configuration explicitly.
+ //
+ optional = optional && !config::specified (root, "config.cli");
// config.cli
//
if (first)
{
- auto p (config::required (root, "config.cli", "cli"));
-
- // If we actually set a new value, test it by trying to execute.
+ // Return version or empty string if unable to execute (e.g.,
+ // the cli executable is not found).
//
- if (p.second)
+ auto test = [optional] (const char* cli) -> string
{
- const string& cli (as<string> (p.first));
- const char* args[] = {cli.c_str (), "--version", nullptr};
+ const char* args[] = {cli, "--version", nullptr};
if (verb >= 2)
print_process (args);
@@ -124,33 +108,75 @@ namespace build
// The version should be the last word on the first line.
//
- string l;
- getline (is, l);
- auto p (l.rfind (' '));
+ getline (is, ver);
+ auto p (ver.rfind (' '));
if (p != string::npos)
- ver = string (l, p + 1);
+ ver = string (ver, p + 1);
is.close (); // Don't block the other end.
if (!pr.wait ())
- throw failed ();
+ return string (); // Not found.
if (ver.empty ())
fail << "unexpected output from " << cli;
+
+ return ver;
}
catch (const process_error& e)
{
- error << "unable to execute " << cli << ": " << e.what ();
+ if (!optional)
+ error << "unable to execute " << cli << ": " << e.what ();
if (e.child ())
exit (1);
throw failed ();
}
+ };
- if (verb >= 2)
- text << cli << " " << ver;
+ string ver;
+ const char* cli ("cli"); // Default.
+
+ if (optional)
+ {
+ // Test the default value before setting any config.cli.* values
+ // so that if we fail to configure, nothing will be written to
+ // config.build.
+ //
+ ver = test (cli);
+
+ if (ver.empty ())
+ {
+ r = false;
+
+ if (verb >= 2)
+ text << cli << " not found, leaving cli module unconfigured";
+ }
+ else
+ {
+ auto p (config::required (root, "config.cli", cli));
+ assert (p.second && as<string> (p.first) == cli);
+ }
+ }
+ else
+ {
+ auto p (config::required (root, "config.cli", cli));
+
+ // If we actually set a new value, test it by trying to execute.
+ //
+ if (p.second)
+ {
+ cli = as<string> (p.first).c_str ();
+ ver = test (cli);
+
+ if (ver.empty ())
+ throw failed ();
+ }
}
+
+ if (!ver.empty () && verb >= 2)
+ text << cli << " " << ver;
}
// config.cli.options
@@ -159,10 +185,38 @@ namespace build
// cli.* variables. See the cxx module for more information on
// this merging semantics and some of its tricky aspects.
//
- if (const value& v = config::optional (root, "config.cli.options"))
- base.assign ("cli.options") += as<strings> (v);
+ if (r)
+ {
+ if (const value& v = config::optional (root, "config.cli.options"))
+ base.assign ("cli.options") += as<strings> (v);
+ }
+
+ // Register our rules.
+ //
+ if (r)
+ {
+ auto& rs (base.rules);
+
+ rs.insert<cli_cxx> (perform_id, update_id, "cli", compile_);
+ rs.insert<cli_cxx> (perform_id, clean_id, "cli", compile_);
+
+ rs.insert<cxx::hxx> (perform_id, update_id, "cli", compile_);
+ rs.insert<cxx::hxx> (perform_id, clean_id, "cli", compile_);
+
+ rs.insert<cxx::cxx> (perform_id, update_id, "cli", compile_);
+ rs.insert<cxx::cxx> (perform_id, clean_id, "cli", compile_);
+
+ rs.insert<cxx::ixx> (perform_id, update_id, "cli", compile_);
+ rs.insert<cxx::ixx> (perform_id, clean_id, "cli", compile_);
+
+ // Other rules (e.g., cxx::compile) may need to have the group
+ // members resolved. Looks like a general pattern: groups should
+ // resolve on configure(update).
+ //
+ rs.insert<cli_cxx> (configure_id, update_id, "cli", compile_);
+ }
- return true;
+ return r;
}
}
}
diff --git a/build/variable b/build/variable
index 061004c..5d0b175 100644
--- a/build/variable
+++ b/build/variable
@@ -10,7 +10,7 @@
#include <cstddef> // nullptr_t
#include <utility> // pair, make_pair()
#include <iterator>
-#include <functional> // hash, reference_wrapper
+#include <functional> // hash
#include <type_traits> // conditional, is_reference, remove_reference, etc.
#include <unordered_set>
@@ -93,10 +93,10 @@ namespace build
}
value&
- operator= (std::reference_wrapper<const value> v)
- {
- return *this = v.get ();
- }
+ operator= (reference_wrapper<value> v) {return *this = v.get ();}
+
+ value&
+ operator= (reference_wrapper<const value> v) {return *this = v.get ();}
value&
append (value, const variable&); // Aka operator+=().