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Merge pull request #5240 from edolstra/builtin-help

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nix --help: Display help using lowdown instead of man
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Eelco Dolstra 2021-09-14 11:31:23 +02:00 committed by GitHub
parent 1ca7394a9e 49a932fb18
commit 16d4922dd2
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GPG key ID: 4AEE18F83AFDEB23
10 changed files with 95 additions and 31 deletions
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2
doc/manual/generate-manpage.nix
View file

@ -89,7 +89,7 @@ let
in
let
manpages = processCommand { filename = "nix"; command = "nix"; def = command; };
manpages = processCommand { filename = "nix"; command = "nix"; def = builtins.fromJSON command; };
summary = concatStrings (map (manpage: " - [${manpage.command}](command-ref/new-cli/${manpage.name})\n") manpages);
in
(listToAttrs manpages) // { "SUMMARY.md" = summary; }

2
doc/manual/local.mk
View file

@ -44,7 +44,7 @@ $(d)/src/SUMMARY.md: $(d)/src/SUMMARY.md.in $(d)/src/command-ref/new-cli
$(d)/src/command-ref/new-cli: $(d)/nix.json $(d)/generate-manpage.nix $(bindir)/nix
@rm -rf $@
$(trace-gen) $(nix-eval) --write-to $@ --expr 'import doc/manual/generate-manpage.nix (builtins.fromJSON (builtins.readFile $<))'
$(trace-gen) $(nix-eval) --write-to $@ --expr 'import doc/manual/generate-manpage.nix (builtins.readFile $<)'
$(d)/src/command-ref/conf-file.md: $(d)/conf-file.json $(d)/generate-options.nix $(d)/src/command-ref/conf-file-prefix.md $(bindir)/nix
@cat doc/manual/src/command-ref/conf-file-prefix.md > $@.tmp

8
flake.lock
View file

@ -3,16 +3,16 @@
"lowdown-src": {
"flake": false,
"locked": {
"lastModified": 1617481909,
"narHash": "sha256-SqnfOFuLuVRRNeVJr1yeEPJue/qWoCp5N6o5Kr///p4=",
"lastModified": 1628247802,
"narHash": "sha256-4XSXGYvKqogR7bubyqYNwBHYCtrIn6XRGXj6+u+BXNs=",
"owner": "kristapsdz",
"repo": "lowdown",
"rev": "148f9b2f586c41b7e36e73009db43ea68c7a1a4d",
"rev": "b4483d0ef85990f54b864158ab786b4a5b3904fa",
"type": "github"
},
"original": {
"owner": "kristapsdz",
"ref": "VERSION_0_8_4",
"ref": "VERSION_0_8_6",
"repo": "lowdown",
"type": "github"
}

4
flake.nix
View file

@ -2,7 +2,7 @@
description = "The purely functional package manager";
inputs.nixpkgs.url = "nixpkgs/nixos-21.05-small";
inputs.lowdown-src = { url = "github:kristapsdz/lowdown/VERSION_0_8_4"; flake = false; };
inputs.lowdown-src = { url = "github:kristapsdz/lowdown/VERSION_0_8_6"; flake = false; };
outputs = { self, nixpkgs, lowdown-src }:
@ -350,7 +350,7 @@
};
lowdown = with final; stdenv.mkDerivation rec {
name = "lowdown-0.8.4";
name = "lowdown-0.8.6";
/*
src = fetchurl {

43
src/libexpr/eval.cc
View file

@ -895,23 +895,41 @@ void EvalState::evalFile(const Path & path_, Value & v, bool mustBeTrivial)
return;
}
Path path2 = resolveExprPath(path);
if ((i = fileEvalCache.find(path2)) != fileEvalCache.end()) {
Path resolvedPath = resolveExprPath(path);
if ((i = fileEvalCache.find(resolvedPath)) != fileEvalCache.end()) {
v = i->second;
return;
}
printTalkative("evaluating file '%1%'", path2);
printTalkative("evaluating file '%1%'", resolvedPath);
Expr * e = nullptr;
auto j = fileParseCache.find(path2);
auto j = fileParseCache.find(resolvedPath);
if (j != fileParseCache.end())
e = j->second;
if (!e)
e = parseExprFromFile(checkSourcePath(path2));
e = parseExprFromFile(checkSourcePath(resolvedPath));
fileParseCache[path2] = e;
cacheFile(path, resolvedPath, e, v, mustBeTrivial);
}
void EvalState::resetFileCache()
{
fileEvalCache.clear();
fileParseCache.clear();
}
void EvalState::cacheFile(
const Path & path,
const Path & resolvedPath,
Expr * e,
Value & v,
bool mustBeTrivial)
{
fileParseCache[resolvedPath] = e;
try {
// Enforce that 'flake.nix' is a direct attrset, not a
@ -921,19 +939,12 @@ void EvalState::evalFile(const Path & path_, Value & v, bool mustBeTrivial)
throw EvalError("file '%s' must be an attribute set", path);
eval(e, v);
} catch (Error & e) {
addErrorTrace(e, "while evaluating the file '%1%':", path2);
addErrorTrace(e, "while evaluating the file '%1%':", resolvedPath);
throw;
}
fileEvalCache[path2] = v;
if (path != path2) fileEvalCache[path] = v;
}
void EvalState::resetFileCache()
{
fileEvalCache.clear();
fileParseCache.clear();
fileEvalCache[resolvedPath] = v;
if (path != resolvedPath) fileEvalCache[path] = v;
}

8
src/libexpr/eval.hh
View file

@ -172,6 +172,14 @@ public:
trivial (i.e. doesn't require arbitrary computation). */
void evalFile(const Path & path, Value & v, bool mustBeTrivial = false);
/* Like `cacheFile`, but with an already parsed expression. */
void cacheFile(
const Path & path,
const Path & resolvedPath,
Expr * e,
Value & v,
bool mustBeTrivial = false);
void resetFileCache();
/* Look up a file in the search path. */

1
src/libutil/args.cc
View file

@ -331,6 +331,7 @@ MultiCommand::MultiCommand(const Commands & commands_)
if (i == commands.end())
throw UsageError("'%s' is not a recognised command", s);
command = {s, i->second()};
command->second->parent = this;
}}
});

8
src/libutil/args.hh
View file

@ -12,6 +12,8 @@ namespace nix {
enum HashType : char;
class MultiCommand;
class Args
{
public:
@ -169,11 +171,13 @@ public:
virtual nlohmann::json toJSON();
friend class MultiCommand;
MultiCommand * parent = nullptr;
};
/* A command is an argument parser that can be executed by calling its
run() method. */
struct Command : virtual Args
struct Command : virtual public Args
{
friend class MultiCommand;
@ -193,7 +197,7 @@ typedef std::map<std::string, std::function<ref<Command>()>> Commands;
/* An argument parser that supports multiple subcommands,
i.e. ‘<command> <subcommand>’. */
class MultiCommand : virtual Args
class MultiCommand : virtual public Args
{
public:
Commands commands;

4
src/nix/local.mk
View file

@ -14,7 +14,7 @@ nix_SOURCES := \
$(wildcard src/nix-instantiate/*.cc) \
$(wildcard src/nix-store/*.cc) \
nix_CXXFLAGS += -I src/libutil -I src/libstore -I src/libfetchers -I src/libexpr -I src/libmain -I src/libcmd
nix_CXXFLAGS += -I src/libutil -I src/libstore -I src/libfetchers -I src/libexpr -I src/libmain -I src/libcmd -I doc/manual
nix_LIBS = libexpr libmain libfetchers libstore libutil libcmd
@ -30,3 +30,5 @@ src/nix-env/user-env.cc: src/nix-env/buildenv.nix.gen.hh
src/nix/develop.cc: src/nix/get-env.sh.gen.hh
src/nix-channel/nix-channel.cc: src/nix-channel/unpack-channel.nix.gen.hh
src/nix/main.cc: doc/manual/generate-manpage.nix.gen.hh doc/manual/utils.nix.gen.hh

46
src/nix/main.cc
View file

@ -10,6 +10,7 @@
#include "filetransfer.hh"
#include "finally.hh"
#include "loggers.hh"
#include "markdown.hh"
#include <sys/types.h>
#include <sys/socket.h>
@ -163,9 +164,43 @@ struct NixArgs : virtual MultiCommand, virtual MixCommonArgs
}
};
static void showHelp(std::vector<std::string> subcommand)
/* Render the help for the specified subcommand to stdout using
lowdown. */
static void showHelp(std::vector<std::string> subcommand, MultiCommand & toplevel)
{
showManPage(subcommand.empty() ? "nix" : fmt("nix3-%s", concatStringsSep("-", subcommand)));
auto mdName = subcommand.empty() ? "nix" : fmt("nix3-%s", concatStringsSep("-", subcommand));
evalSettings.restrictEval = false;
evalSettings.pureEval = false;
EvalState state({}, openStore("dummy://"));
auto vGenerateManpage = state.allocValue();
state.eval(state.parseExprFromString(
#include "generate-manpage.nix.gen.hh"
, "/"), *vGenerateManpage);
auto vUtils = state.allocValue();
state.cacheFile(
"/utils.nix", "/utils.nix",
state.parseExprFromString(
#include "utils.nix.gen.hh"
, "/"),
*vUtils);
auto vJson = state.allocValue();
mkString(*vJson, toplevel.toJSON().dump());
auto vRes = state.allocValue();
state.callFunction(*vGenerateManpage, *vJson, *vRes, noPos);
auto attr = vRes->attrs->get(state.symbols.create(mdName + ".md"));
if (!attr)
throw UsageError("Nix has no subcommand '%s'", concatStringsSep("", subcommand));
auto markdown = state.forceString(*attr->value);
RunPager pager;
std::cout << renderMarkdownToTerminal(markdown) << "\n";
}
struct CmdHelp : Command
@ -194,7 +229,10 @@ struct CmdHelp : Command
void run() override
{
showHelp(subcommand);
assert(parent);
MultiCommand * toplevel = parent;
while (toplevel->parent) toplevel = toplevel->parent;
showHelp(subcommand, *toplevel);
}
};
@ -277,7 +315,7 @@ void mainWrapped(int argc, char * * argv)
} else
break;
}
showHelp(subcommand);
showHelp(subcommand, args);
return;
} catch (UsageError &) {
if (!completions) throw;