_is: info for specific symbols and vspace option

shell/i.cpp

@@ -246,17 +246,125 @@ void _isc(Session &session, std::string vspace_name, bool sort,
 // is
 //---
 
-static void parse_is(Session &, Parser &parser)
+struct _is_args
 {
+    std::string vspace_name;
+    FxOS::Symbol symbol;
+};
+
+static struct _is_args parse_is(Session &session, Parser &parser)
+{
+    _is_args args;
+
+    parser.option("vspace",
+        [&args](std::string const &value) { args.vspace_name = value; });
+
+    parser.accept_options();
+
+    FxOS::Symbol s;
+
+    if(!parser.at_end()) {
+        if(parser.lookahead().type == T::SYSCALL) {
+            s.type = FxOS::Symbol::Syscall;
+            s.value = parser.expect(T::SYSCALL).value.NUM;
+        }
+        else {
+            s.type = FxOS::Symbol::Address;
+            s.value = parser.expr(session.current_space);
+        }
+    }
+    else {
+        s.type = FxOS::Symbol::Address;
+        s.value = 0;
+    }
+
+    args.symbol = s;
+
+
+    VirtualSpace *space = session.current_space;
+    if(!args.vspace_name.empty()) {
+        space = session.get_space(args.vspace_name);
+        if(!space) {
+            std::string msg
+                = format("virtual space '%s' does not exist", args.vspace_name);
+            if(parser.completing())
+                throw Parser::CompletionRequest("_error", msg);
+            else
+                FxOS_log(ERR, "%s", msg);
+        }
+    }
+
     parser.end();
+    return args;
 }
 
-void _is(Session &session)
+void _is(Session &session, std::string vspace_name, FxOS::Symbol symbol)
 {
-    if(!session.current_space)
+    VirtualSpace *space = session.current_space;
+    if(!space) {
+        FxOS_log(ERR, "no virtual space selected");
         return;
+    }
 
-    for(auto const &s: session.current_space->symbols.symbols) {
+    if(!vspace_name.empty())
+        space = session.get_space(vspace_name);
+
+    if(!space) {
+        FxOS_log(ERR, "virtual space '%s' does not exist", vspace_name);
+        return;
+    }
+
+    std::vector<FxOS::Symbol> symbols;
+
+    if(symbol.type == FxOS::Symbol::Address && symbol.value == 0)
+        symbols = space->symbols.symbols;
+    else {
+        std::optional<std::string> name
+            = space->symbols.query(symbol.type, symbol.value);
+
+        if(name.has_value())
+            symbol.name = name.value();
+        else if(symbol.type == FxOS::Symbol::Address) {
+            if(vspace_name.empty())
+                fmt::print(stderr,
+                    "\x1b[31;1merror:\x1b[0m no symbol exists for address 0x{:08x} in current virtual space\n",
+                    symbol.value);
+            else
+                fmt::print(stderr,
+                    "\x1b[31;1merror:\x1b[0m no symbol exists for address 0x{:08x} in virtual space '{}'\n",
+                    symbol.value, vspace_name);
+
+            return;
+        }
+        else if(symbol.type == FxOS::Symbol::Syscall) {
+            if(vspace_name.empty()) {
+                if(symbol.value < 0x1000)
+                    fmt::print(stderr,
+                        "\x1b[31;1merror:\x1b[0m no symbol exists for syscall %{:03x} in current virtual space\n",
+                        symbol.value);
+                else
+                    fmt::print(stderr,
+                        "\x1b[31;1merror:\x1b[0m no symbol exists for syscall %{:04x} in current virtual space\n",
+                        symbol.value);
+            }
+            else {
+                if(symbol.value < 0x1000)
+                    fmt::print(stderr,
+                        "\x1b[31;1merror:\x1b[0m no symbol exists for syscall %{:03x} in virtual space '{}'\n",
+                        symbol.value, vspace_name);
+                else
+                    fmt::print(stderr,
+                        "\x1b[31;1merror:\x1b[0m no symbol exists for syscall %{:04x} in virtual space '{}'\n",
+                        symbol.value, vspace_name);
+            }
+
+            return;
+        }
+
+        symbols = {symbol};
+    }
+
+    for(auto const &s: symbols) {
         if(s.type == FxOS::Symbol::Syscall && s.value < 0x1000) {
             fmt::print(theme(10), "        %{:03x}", s.value);
         }
@@ -311,11 +419,13 @@ sort=true is specified, they are instead sorted by address.
 static ShellCommand _is_cmd(
     "is",
     [](Session &s, Parser &p) {
-        parse_is(s, p);
-        _is(s);
+        auto args = parse_is(s, p);
+        _is(s, args.vspace_name, args.symbol);
     },
     [](Session &s, Parser &p) { parse_is(s, p); }, "Info Symbols", R"(
-is
+is [vspace=<virtual_space>] [<address|syscall>]
 
-Lists all symbols in the current virtual space.
+Lists symbols in the specified virtual space (defaults to the current
+one). By default, all symbols are listed, but if an address or syscall is
+provided, the symbol associated with it will be printed instead.
 )");