diff options
Diffstat (limited to 'libbuild2')
| -rw-r--r-- | libbuild2/parser.cxx | 50 |
1 files changed, 46 insertions, 4 deletions
diff --git a/libbuild2/parser.cxx b/libbuild2/parser.cxx index b76bb18..1e8757a 100644 --- a/libbuild2/parser.cxx +++ b/libbuild2/parser.cxx @@ -2862,18 +2862,23 @@ namespace build2 next_with_attributes (t, tt); // Get variable attributes, if any, and deal with the special config.* - // attributes. Since currently they can only appear in the config - // directive, we handle them in an ad hoc manner. + // attributes as well as null. Since currently they can only appear in the + // config directive, we handle them in an ad hoc manner. // attributes_push (t, tt); attributes& as (attributes_top ()); + bool nullable (false); optional<string> report; string report_var; for (auto i (as.begin ()); i != as.end (); ) { - if (i->name == "config.report") + if (i->name == "null") + { + nullable = true; + } + else if (i->name == "config.report") { try { @@ -2927,7 +2932,7 @@ namespace build2 if (report && *report != "false" && !config) { - if (!as.empty ()) + if (!as.empty () || nullable) fail (as.loc) << "unexpected attributes for report-only variable"; attributes_pop (); @@ -3029,6 +3034,9 @@ namespace build2 peeked ().value != "false") fail (loc) << var << " variable default value must be literal false"; + if (nullable) + fail (loc) << var << " variable must not be nullable"; + sflags |= config::save_false_omitted; } @@ -3047,14 +3055,48 @@ namespace build2 // all. // if (l.defined ()) + { + // Peek at the attributes to detect whether the value is NULL. + // + if (!dev && !nullable) + { + // Essentially a prefix of parse_variable_value(). + // + mode (lexer_mode::value, '@'); + next_with_attributes (t, tt); + attributes_push (t, tt, true); + for (const attribute& a: attributes_pop ()) + { + if (a.name == "null") + { + nullable = true; + break; + } + } + } + skip_line (t, tt); + } else { value lhs, rhs (parse_variable_value (t, tt, !dev /* mode */)); apply_value_attributes (&var, lhs, move (rhs), type::assign); + + if (!nullable) + nullable = lhs.null; + l = config::lookup_config (new_val, *root_, var, move (lhs), sflags); } } + + // If the variable is not nullable, verify the value is not NULL. + // + // Note that undefined is not the same as NULL (if it is undefined, we + // should either see the default value or if there is no default value, + // then the user is expected to handle the undefined case). + // + if (!nullable && l.defined () && l->null) + fail (loc) << "null value in non-nullable variable " << var; } // We will be printing the report at either level 2 (-v) or 3 (-V) |