diff options
Diffstat (limited to 'libbuild2/variable.cxx')
| -rw-r--r-- | libbuild2/variable.cxx | 926 |
1 files changed, 926 insertions, 0 deletions
diff --git a/libbuild2/variable.cxx b/libbuild2/variable.cxx index 0ad63b1..b0fe32a 100644 --- a/libbuild2/variable.cxx +++ b/libbuild2/variable.cxx @@ -3,10 +3,16 @@ #include <libbuild2/variable.hxx> +#include <cstdio> // snprintf() #include <cstring> // memcmp(), memcpy() #include <libbutl/path-pattern.hxx> +#ifndef BUILD2_BOOTSTRAP +# include <libbutl/json/parser.hxx> +# include <libbutl/json/serializer.hxx> +#endif + #include <libbuild2/target.hxx> #include <libbuild2/diagnostics.hxx> @@ -584,6 +590,8 @@ namespace build2 if (!wspace (v[0])) { + // Note: see also similar code in to_json_value(). + // int b (v[0] == '0' && (v[1] == 'x' || v[1] == 'X') ? 16 : 10); // May throw invalid_argument or out_of_range. @@ -1501,6 +1509,924 @@ namespace build2 nullptr // Iterate. }; + // json + // + static string + to_string_value (name& n, const char* what) + { + if (n.typed () || n.qualified () || n.pattern) + throw_invalid_argument (n, nullptr, what); + + string s; + + if (n.simple ()) + s.swap (n.value); + else + { + // Note that here we cannot assume what's in dir is really a path (think + // s/foo/bar/) so we have to reverse it exactly. + // + s = move (n.dir).representation (); // Move out of path. + + if (!n.value.empty ()) + s += n.value; // Separator is already there. + } + + return s; + } + + static json_value + to_json_value (name& n, const char* what) + { + if (n.typed () || n.qualified () || n.pattern) + throw_invalid_argument (n, nullptr, what); + + string s; + + if (n.simple ()) + s.swap (n.value); + else + { + // Note that here we cannot assume what's in dir is really a path (think + // s/foo/bar/) so we have to reverse it exactly. + // + s = move (n.dir).representation (); // Move out of path. + + if (!n.value.empty ()) + s += n.value; // Separator is already there. + + // A path is always interpreted as a JSON string. + // + return json_value (move (s)); + } + + bool f; + if (s.empty ()) + return json_value (string ()); + if (s == "null") + return json_value (); + else if ((f = (s == "true")) || s == "false") + return json_value (f); + else if (s.find_first_not_of ( + "0123456789", (f = (s[0] == '-')) ? 1 : 0) == string::npos) + { + name n (move (s)); + return f + ? json_value (value_traits<int64_t>::convert (n, nullptr)) + : json_value (value_traits<uint64_t>::convert (n, nullptr)); + } + // + // Handle the hex notation similar to <uint64_t>::convert() (and JSON5). + // + else if (s[0] == '0' && + (s[1] == 'x' || s[1] == 'X') && + s.size () > 2 && + s.find_first_not_of ("0123456789aAbBcCdDeEfF", 2) == string::npos) + { + return json_value ( + value_traits<uint64_t>::convert (name (move (s)), nullptr), + true /* hex */); + } + else + { + // If this is not a JSON representation of string, array, or object, + // then treat it as a string. + // + // Note that the special `"`, `{`, and `[` characters could be preceded + // with whitespaces. Note: see similar test in json_object below. + // + size_t p (s.find_first_not_of (" \t\n\r")); + + if (p == string::npos || (s[p] != '"' && s[p] != '{' && s[p] != '[')) + return json_value (move (s)); + + // Parse as valid JSON input text. + // +#ifndef BUILD2_BOOTSTRAP + try + { + json_parser p (s, nullptr /* name */); + return json_value (p); + } + catch (const invalid_json_input& e) + { + // Turned out printing line/column/offset can be misleading since we + // could be parsing a single name from a potential list of names. + // feels like without also printing the value this is of not much use. + // +#if 0 + string m ("invalid json input at line "); + m += to_string (e.line); + m += ", column "; + m += to_string (e.column); + m += ", byte offset "; + m += to_string (e.position); + m += ": "; + m += e.what (); +#else + string m ("invalid json input: "); + m += e.what (); +#endif + throw invalid_argument (move (m)); + } +#else + throw invalid_argument ("json parsing requested during bootstrap"); +#endif + } + } + + json_value value_traits<json_value>:: + convert (names&& ns) + { + size_t n (ns.size ()); + + if (n == 0) + { + // Note: this is the ([json] ) case, not ([json] ""). See also the + // relevant note in json_reverse() below. + // + return json_value (); // null + } + else if (n == 1) + { + return to_json_value (ns.front (), "json"); + } + else + { + if (ns.front ().pair) // object + { + json_value r (json_type::object); + r.object.reserve (n / 2); + + for (auto i (ns.begin ()); i != ns.end (); ++i) + { + if (!i->pair) + throw invalid_argument ( + "expected pair in json member value '" + to_string (*i) + '\''); + + // Note that we could support JSON-quoted member names but it's + // unclear why would someone want that (and if they do, they can + // always specify JSON text instead). + // + // @@ The empty pair value ([json] one@ ) which is currently empty + // string is inconsistent with empty value ([json] ) above which + // is null. Maybe we could distinguish the one@ and one@"" cases + // via type hints? + // + string n (to_string_value (*i, "json member name")); + json_value v (to_json_value (*++i, "json member")); + + // Check for duplicates. One can use append/prepend to merge. + // + if (find_if (r.object.begin (), r.object.end (), + [&n] (const json_member& m) + { + return m.name == n; + }) != r.object.end ()) + { + throw invalid_argument ( + "duplicate json object member '" + n + '\''); + } + + r.object.push_back (json_member {move (n), move (v)}); + } + + return r; + } + else // array + { + json_value r (json_type::array); + r.array.reserve (n); + + for (name& n: ns) + { + if (n.pair) + throw invalid_argument ( + "unexpected pair in json array element value '" + + to_string (n) + '\''); + + r.array.push_back (to_json_value (n, "json array element")); + } + + return r; + } + } + } + + static void + json_assign (value& v, names&& ns, const variable* var) + { + using traits = value_traits<json_value>; + + try + { + traits::assign (v, traits::convert (move (ns))); + } + catch (const invalid_argument& e) + { + // Note: ns is not guaranteed to be valid. + // + diag_record dr (fail); + dr << "invalid json value"; + + if (var != nullptr) + dr << " in variable " << var->name; + + dr << ": " << e; + } + } + + static void + json_append (value& v, names&& ns, const variable* var) + { + using traits = value_traits<json_value>; + + try + { + traits::append (v, traits::convert (move (ns))); + } + catch (const invalid_argument& e) + { + // Note: ns is not guaranteed to be valid. + // + diag_record dr (fail); + dr << "invalid json value"; + + if (var != nullptr) + dr << " in variable " << var->name; + + dr << ": " << e; + } + } + + static void + json_prepend (value& v, names&& ns, const variable* var) + { + using traits = value_traits<json_value>; + + try + { + traits::prepend (v, traits::convert (move (ns))); + } + catch (const invalid_argument& e) + { + // Note: ns is not guaranteed to be valid. + // + diag_record dr (fail); + dr << "invalid json value"; + + if (var != nullptr) + dr << " in variable " << var->name; + + dr << ": " << e; + } + } + + static names_view + json_reverse (const value& x, names& ns, bool) + { + const json_value& v (x.as<json_value> ()); + + switch (v.type) + { + case json_type::null: + { + // @@ Hm, it would be nice if this somehow got mapped to [null]/empty + // but still be round-trippable to JSON null. Perhaps via type + // hint? + // + // But won't `print ([json] null)` printing nothing be + // surprising. Also, it's not clear that mapping JSON null to out + // [null] is a good idea since our [null] means "no value" while + // JSON null means "null value". + // + // Maybe the current semantics is the best: we map our [null] and + // empty names to JSON null (naturally) but we always reverse JSON + // null to the JSON "null" literal. Or maybe we could reverse it to + // null but type-hint it that it's a spelling or [null]/empty. + // Quite fuzzy, admittedly. In our model null values decay to empty + // so JSON null decaying to "null" literal is strange. Let's try + // and see how it goes. See also json_subscript_impl() below. + // +#if 0 + ns.push_back (name ("null")); +#endif + break; + } + case json_type::boolean: + { + ns.push_back (name (v.boolean ? "true" : "false")); + break; + } + case json_type::signed_number: + { + ns.push_back (value_traits<int64_t>::reverse (v.signed_number)); + break; + } + case json_type::unsigned_number: + { + ns.push_back (value_traits<uint64_t>::reverse (v.unsigned_number)); + break; + } + case json_type::hexadecimal_number: + { + // Hexadecimal representation of 64-bit integers requires a maximum of + // 10 character (plus '\0'): 0xffffffff. + // + char buf[11]; + snprintf (buf, sizeof (buf), + "0x%llx", + static_cast<unsigned long long> (v.unsigned_number)); + + ns.push_back (name (string (buf))); + break; + } + case json_type::string: + // + // @@ Hm, it would be nice if this somehow got mapped to unquoted + // string but still be round-trippable to JSON value. Perhaps via + // the type hint idea? This is pretty bad. See also subscript we + // hacked around this somewhat. + // + // Note that it may be tempting to fix this by only quoting strings + // that would otherwise be mis-interpreted (null, true, all digits, + // etc). But that would be worse: things would seem to work but + // fall apart in the perhaps unlikely event of encountering one of + // the problematic values. It is better to produce a consistent + // result. + // + case json_type::array: + case json_type::object: + { + // Serialize as JSON output text. + // + string o; + +#ifndef BUILD2_BOOTSTRAP + try + { + // Disable pretty-printing so that the output is all on the same + // line. While it's not going to be easy to read for larger JSON + // outputs, it will fit better into the existing model where none of + // the value representations use formatting newlines. If a pretty- + // printed representation is required, then the $json.serialize() + // function can be used to obtain it. + // + json_buffer_serializer s (o, 0 /* indentation */); + v.serialize (s); + } + catch (const invalid_json_output& e) + { + // Note: the same diagnostics as in $json.serialize(). + // + diag_record dr; + dr << fail << "invalid json value: " << e; + + if (e.event) + dr << info << "while serializing " << to_string (*e.event); + + if (e.offset != string::npos) + dr << info << "offending byte offset " << e.offset; + } +#else + fail << "json serialization requested during bootstrap"; +#endif + ns.push_back (name (move (o))); + break; + } + } + + return ns; + } + + static int + json_compare (const value& l, const value& r) + { + return l.as<json_value> ().compare (r.as<json_value> ()); + } + + // Return null value if the index/name is out of range. + // + static value + json_subscript_impl (const value& val, value* val_data, + uint64_t i, const string& n, bool index) + { + const json_value& jv (val.as<json_value> ()); + + json_value jr; + + if (index) + { + if (i >= (jv.type == json_type::array ? jv.array.size () : + jv.type == json_type::object ? jv.object.size () : 1)) + return value (); + + switch (jv.type) + { + case json_type::null: + return value (); // JSON null has no elements. + case json_type::boolean: + case json_type::signed_number: + case json_type::unsigned_number: + case json_type::hexadecimal_number: + case json_type::string: + { + // Steal the value if possible. + // + jr = (&val == val_data + ? json_value (move (const_cast<json_value&> (jv))) + : json_value (jv)); + break; + } + case json_type::array: + { + // Steal the value if possible. + // + const json_value& r (jv.array[i]); + jr = (&val == val_data + ? json_value (move (const_cast<json_value&> (r))) + : json_value (r)); + break; + } + case json_type::object: + { + // Represent as an object with one member. + // + new (&jr.object) json_value::object_type (); + jr.type = json_type::object; + + // Steal the member if possible. + // + const json_member& m (jv.object[i]); + jr.object.push_back (&val == val_data + ? json_member (move (const_cast<json_member&> (m))) + : json_member (m)); + break; + } + } + } + else + { + auto i (find_if (jv.object.begin (), + jv.object.end (), + [&n] (const json_member& m) + { + return m.name == n; + })); + + if (i == jv.object.end ()) + return value (); + + // Steal the member value if possible. + // + jr = (&val == val_data + ? json_value (move (const_cast<json_value&> (i->value))) + : json_value (i->value)); + } + + // @@ As a temporary work around for the lack of type hints (see + // json_reverse() for background), reverse simple JSON values to the + // corresponding fundamental type values. The thinking here is that + // subscript (and iteration) is primarily meant for consumption (as + // opposed to reverse() where it is used to build up values and thus + // needs things to be fully reversible). Once we add type hints, then + // this should become unnecessary and we should be able to just always + // return json_value. + // + // @@ TODO: split this function into two (index/name) once get rid of this. + // +#if 1 + switch (jr.type) + { + case json_type::null: return value (names {}); + case json_type::boolean: return value (jr.boolean); + case json_type::signed_number: return value (jr.signed_number); + case json_type::unsigned_number: + case json_type::hexadecimal_number: return value (jr.unsigned_number); + case json_type::string: return value (move (jr.string)); + case json_type::array: + case json_type::object: break; + } +#endif + + return value (move (jr)); + } + + static value + json_subscript (const value& val, value* val_data, + value&& sub, + const location& sloc, + const location& bloc) + { + const json_value* jv (val.null ? nullptr : &val.as<json_value> ()); + + // For consistency with other places treat JSON null value as maybe + // missing array/object. In particular, we don't want to fail trying to + // lookup by-name on a null value which could have been an object. + // + if (jv != nullptr && jv->type == json_type::null) + jv = nullptr; + + // Process subscript even if the value is null to make sure it is valid. + // + bool index; + uint64_t i (0); + string n; + + // Always interpret uint64-typed subscript as index even for objects. + // This can be used to, for example, to iterate with an index over object + // members. + // + if (!sub.null && sub.type == &value_traits<uint64_t>::value_type) + { + i = sub.as<uint64_t> (); + index = true; + } + else + { + // How we interpret the subscript depends on the JSON value type. For + // objects we treat it as a string (member name) and for everything else + // as an index. + // + // What if the value is null and we don't have a JSON type? In this case + // we treat as a string since a valid number is also a valid string. + // + try + { + if (jv == nullptr || jv->type == json_type::object) + { + n = convert<string> (move (sub)); + index = false; + } + else + { + i = convert<uint64_t> (move (sub)); + index = true; + } + } + catch (const invalid_argument& e) + { + // We will likely be trying to interpret a member name as an integer + // due to the incorrect value type so issue appropriate diagnostics. + // + diag_record dr; + dr << fail (sloc) << "invalid json value subscript: " << e; + + if (jv != nullptr && jv->type != json_type::object) + dr << info << "json value type is " << jv->type; + + dr << info (bloc) << "use the '\\[' escape sequence if this is a " + << "wildcard pattern" << endf; + } + } + + return (jv != nullptr + ? json_subscript_impl (val, val_data, i, n, index) + : value ()); + } + + void json_iterate (const value& val, + const function<void (value&&, bool first)>& f) + { + // Implement in terms of subscript for consistency (in particular, + // iterating over simple values like number, string). + // + for (uint64_t i (0);; ++i) + { + value e (json_subscript_impl (val, nullptr, i, {}, true)); + + if (e.null) + break; + + f (move (e), i == 0); + } + } + + const json_value value_traits<json_value>::empty_instance; + const char* const value_traits<json_value>::type_name = "json"; + + // Note that whether the json value is a container or not depends on its + // payload type. However, for our purposes it feels correct to assume it is + // a container rather than not with itself as the element type (see + // value_traits::{container, element_type} usage for details). + // + const value_type value_traits<json_value>::value_type + { + type_name, + sizeof (json_value), + nullptr, // No base. + true, // Container. + &value_traits<json_value>::value_type, // Element (itself). + &default_dtor<json_value>, + &default_copy_ctor<json_value>, + &default_copy_assign<json_value>, + &json_assign, + json_append, + json_prepend, + &json_reverse, + nullptr, // No cast (cast data_ directly). + &json_compare, + &default_empty<json_value>, + &json_subscript, + &json_iterate + }; + + // json_array + // + json_array value_traits<json_array>:: + convert (names&& ns) + { + json_array r; + + size_t n (ns.size ()); + if (n == 0) + ; // Empty. + else if (n == 1) + { + // Tricky: this can still be JSON input text that is an array. And if + // it's not, then make it an element of an array. + // + json_value v (to_json_value (ns.front (), "json")); + + if (v.type == json_type::array) + r.array = move (v.array); + else + r.array.push_back (move (v)); + } + else + { + r.array.reserve (n); + + for (name& n: ns) + { + if (n.pair) + throw invalid_argument ( + "unexpected pair in json array element value '" + + to_string (n) + '\''); + + r.array.push_back (to_json_value (n, "json array element")); + } + } + + return r; + } + + static void + json_array_assign (value& v, names&& ns, const variable* var) + { + using traits = value_traits<json_array>; + + try + { + traits::assign (v, traits::convert (move (ns))); + } + catch (const invalid_argument& e) + { + // Note: ns is not guaranteed to be valid. + // + diag_record dr (fail); + dr << "invalid json array"; + + if (var != nullptr) + dr << " in variable " << var->name; + + dr << ": " << e; + } + } + + static void + json_array_append (value& v, names&& ns, const variable* var) + { + using val_traits = value_traits<json_value>; + using arr_traits = value_traits<json_array>; + + try + { + arr_traits::append (v, val_traits::convert (move (ns))); + } + catch (const invalid_argument& e) + { + // Note: ns is not guaranteed to be valid. + // + diag_record dr (fail); + dr << "invalid json array"; + + if (var != nullptr) + dr << " in variable " << var->name; + + dr << ": " << e; + } + } + + static void + json_array_prepend (value& v, names&& ns, const variable* var) + { + using val_traits = value_traits<json_value>; + using arr_traits = value_traits<json_array>; + + try + { + arr_traits::prepend (v, val_traits::convert (move (ns))); + } + catch (const invalid_argument& e) + { + // Note: ns is not guaranteed to be valid. + // + diag_record dr (fail); + dr << "invalid json array"; + + if (var != nullptr) + dr << " in variable " << var->name; + + dr << ": " << e; + } + } + + const json_array value_traits<json_array>::empty_instance; + const char* const value_traits<json_array>::type_name = "json_array"; + + const value_type value_traits<json_array>::value_type + { + type_name, + sizeof (json_array), + &value_traits<json_value>::value_type, // Base (assuming direct cast works + // for both). + true, // Container. + &value_traits<json_value>::value_type, // Element (json_value). + &default_dtor<json_array>, + &default_copy_ctor<json_array>, + &default_copy_assign<json_array>, + &json_array_assign, + &json_array_append, + &json_array_prepend, + &json_reverse, + nullptr, // No cast (cast data_ directly). + &json_compare, + &default_empty<json_array>, + &json_subscript, + &json_iterate + }; + + // json_object + // + json_object value_traits<json_object>:: + convert (names&& ns) + { + json_object r; + + size_t n (ns.size ()); + if (n == 0) + ; // Empty. + else if (n == 1) + { + // Tricky: this can still be JSON input text that is an object. So do + // a similar check as in to_json_value() above. + // + name& n (ns.front ()); + + if (!n.simple () || n.pattern) + throw_invalid_argument (n, nullptr, "json object"); + + string& s (n.value); + size_t p (s.find_first_not_of (" \t\n\r")); + + if (p == string::npos || s[p] != '{') + { + // Unlike for array above, we cannot turn any value into a member. + // + throw invalid_argument ("expected json object instead of '" + s + '\''); + } + + json_value v (to_json_value (ns.front (), "json object")); + assert (v.type == json_type::object); + r.object = move (v.object); + } + else + { + r.object.reserve (n / 2); + + for (auto i (ns.begin ()); i != ns.end (); ++i) + { + if (!i->pair) + throw invalid_argument ( + "expected pair in json member value '" + to_string (*i) + '\''); + + string n (to_string_value (*i, "json member name")); + json_value v (to_json_value (*++i, "json member")); + + if (find_if (r.object.begin (), r.object.end (), + [&n] (const json_member& m) + { + return m.name == n; + }) != r.object.end ()) + { + throw invalid_argument ( + "duplicate json object member '" + n + '\''); + } + + r.object.push_back (json_member {move (n), move (v)}); + } + } + + return r; + } + + static void + json_object_assign (value& v, names&& ns, const variable* var) + { + using traits = value_traits<json_object>; + + try + { + traits::assign (v, traits::convert (move (ns))); + } + catch (const invalid_argument& e) + { + // Note: ns is not guaranteed to be valid. + // + diag_record dr (fail); + dr << "invalid json object"; + + if (var != nullptr) + dr << " in variable " << var->name; + + dr << ": " << e; + } + } + + static void + json_object_append (value& v, names&& ns, const variable* var) + { + using val_traits = value_traits<json_value>; + using obj_traits = value_traits<json_object>; + + try + { + obj_traits::append (v, val_traits::convert (move (ns))); + } + catch (const invalid_argument& e) + { + // Note: ns is not guaranteed to be valid. + // + diag_record dr (fail); + dr << "invalid json object"; + + if (var != nullptr) + dr << " in variable " << var->name; + + dr << ": " << e; + } + } + + static void + json_object_prepend (value& v, names&& ns, const variable* var) + { + using val_traits = value_traits<json_value>; + using obj_traits = value_traits<json_object>; + + try + { + obj_traits::prepend (v, val_traits::convert (move (ns))); + } + catch (const invalid_argument& e) + { + // Note: ns is not guaranteed to be valid. + // + diag_record dr (fail); + dr << "invalid json object"; + + if (var != nullptr) + dr << " in variable " << var->name; + + dr << ": " << e; + } + } + + const json_object value_traits<json_object>::empty_instance; + const char* const value_traits<json_object>::type_name = "json_object"; + + const value_type value_traits<json_object>::value_type + { + type_name, + sizeof (json_object), + &value_traits<json_value>::value_type, // Base (assuming direct cast works + // for both). + true, // Container. + &value_traits<json_value>::value_type, // Element (json_value). + &default_dtor<json_object>, + &default_copy_ctor<json_object>, + &default_copy_assign<json_object>, + &json_object_assign, + &json_object_append, + &json_object_prepend, + &json_reverse, + nullptr, // No cast (cast data_ directly). + &json_compare, + &default_empty<json_object>, + &json_subscript, + &json_iterate + }; + // cmdline // cmdline value_traits<cmdline>:: |