diff options
| -rw-r--r-- | build/cli/module.cxx | 138 | ||||
| -rw-r--r-- | build/variable | 10 |
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+=(). |