llvm-project/lldb/source/Commands/CommandObjectHelp.h

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//===-- CommandObjectHelp.h -------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef liblldb_CommandObjectHelp_h_
#define liblldb_CommandObjectHelp_h_
#include "lldb/Host/OptionParser.h"
#include "lldb/Interpreter/CommandObject.h"
#include "lldb/Interpreter/Options.h"
namespace lldb_private {
//-------------------------------------------------------------------------
// CommandObjectHelp
//-------------------------------------------------------------------------
class CommandObjectHelp : public CommandObjectParsed {
public:
CommandObjectHelp(CommandInterpreter &interpreter);
~CommandObjectHelp() override;
Refactoring for for the internal command line completion API (NFC) Summary: This patch refactors the internal completion API. It now takes (as far as possible) a single CompletionRequest object instead o half a dozen in/out/in-out parameters. The CompletionRequest contains a common superset of the different parameters as far as it makes sense. This includes the raw command line string and raw cursor position, which should make the `expr` command possible to implement (at least without hacks that reconstruct the command line from the args). This patch is not intended to change the observable behavior of lldb in any way. It's also as minimal as possible and doesn't attempt to fix all the problems the API has. Some Q&A: Q: Why is this not fixing all the problems in the completion API? A: Because is a blocker for the expr command completion which I want to get in ASAP. This is the smallest patch that unblocks the expr completion patch and which allows trivial refactoring in the future. The patch also doesn't really change the internal information flow in the API, so that hopefully saves us from ever having to revert and resubmit this humongous patch. Q: Can we merge all the copy-pasted code in the completion methods (like computing the current incomplete arg) into CompletionRequest class? A: Yes, but it's out of scope for this patch. Q: Why the `word_complete = request.GetWordComplete(); ... ` pattern? A: I don't want to add a getter that returns a reference to the internal integer. So we have to use a temporary variable and the Getter/Setter instead. We don't throw exceptions from what I can tell, so the behavior doesn't change. Q: Why are we not owning the list of matches? A: Because that's how the previous API works. But that should be fixed too (in another patch). Q: Can we make the constructor simpler and compute some of the values from the plain command? A: I think this works, but I rather want to have this in a follow up commit. Especially when making nested request it's a bit awkward that the parsed arguments behave as both input/output (as we should in theory propagate the changes on the nested request back to the parent request if we don't want to change the behavior too much). Q: Can't we pass one const request object and then just return another result object instead of mixing them together in one in/out parameter? A: It's hard to get keep the same behavior with that pattern, but I think we can also get a nice API with just a single request object. If we make all input parameters read-only, we have a clear separation between what is actually an input and what an output parameter (and hopefully we get rid of the in-out parameters). Q: Can we throw out the 'match' variables that are not implemented according to the comment? A: We currently just forward them as in the old code to the different methods, even though I think they are really not used. We can easily remove and readd them once every single completion method just takes a CompletionRequest, but for now I prefer NFC behavior from the perspective of the API user. Reviewers: davide, jingham, labath Reviewed By: jingham Subscribers: mgorny, friss, lldb-commits Differential Revision: https://reviews.llvm.org/D48796 llvm-svn: 336146
2018-07-03 05:29:56 +08:00
int HandleCompletion(CompletionRequest &request) override;
static void GenerateAdditionalHelpAvenuesMessage(
Stream *s, llvm::StringRef command, llvm::StringRef prefix,
llvm::StringRef subcommand, bool include_apropos = true,
bool include_type_lookup = true);
class CommandOptions : public Options {
public:
CommandOptions() : Options() {}
~CommandOptions() override {}
Status SetOptionValue(uint32_t option_idx, llvm::StringRef option_arg,
ExecutionContext *execution_context) override {
Status error;
const int short_option = m_getopt_table[option_idx].val;
switch (short_option) {
case 'a':
m_show_aliases = false;
break;
case 'u':
m_show_user_defined = false;
break;
case 'h':
m_show_hidden = true;
break;
default:
error.SetErrorStringWithFormat("unrecognized option '%c'",
short_option);
break;
}
return error;
}
void OptionParsingStarting(ExecutionContext *execution_context) override {
m_show_aliases = true;
m_show_user_defined = true;
m_show_hidden = false;
}
llvm::ArrayRef<OptionDefinition> GetDefinitions() override;
// Instance variables to hold the values for command options.
bool m_show_aliases;
bool m_show_user_defined;
bool m_show_hidden;
};
Options *GetOptions() override { return &m_options; }
protected:
bool DoExecute(Args &command, CommandReturnObject &result) override;
private:
CommandOptions m_options;
};
} // namespace lldb_private
#endif // liblldb_CommandObjectHelp_h_