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// Copyright 2020 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "gn/rust_project_writer.h"
#include <fstream>
#include <optional>
#include <sstream>
#include <tuple>
#include "base/json/string_escape.h"
#include "gn/builder.h"
#include "gn/deps_iterator.h"
#include "gn/filesystem_utils.h"
#include "gn/ninja_target_command_util.h"
#include "gn/rust_project_writer_helpers.h"
#include "gn/rust_tool.h"
#include "gn/source_file.h"
#include "gn/string_output_buffer.h"
#include "gn/tool.h"
#if defined(OS_WINDOWS)
#define NEWLINE "\r\n"
#else
#define NEWLINE "\n"
#endif
// Current structure of rust-project.json output file
//
// {
// "roots": [
// "some/source/root" // each crate's source root
// ],
// "crates": [
// {
// "deps": [
// {
// "crate": 1, // index into crate array
// "name": "alloc" // extern name of dependency
// },
// ],
// "edition": "2018", // edition of crate
// "cfg": [
// "unix", // "atomic" value config options
// "rust_panic=\"abort\""", // key="value" config options
// ]
// "root_module": "absolute path to crate",
// "label": "//path/target:value", // GN target for the crate
// "target": "x86_64-unknown-linux" // optional rustc target
// },
// }
//
bool RustProjectWriter::RunAndWriteFiles(const BuildSettings* build_settings,
const Builder& builder,
const std::string& file_name,
bool quiet,
Err* err) {
SourceFile output_file = build_settings->build_dir().ResolveRelativeFile(
Value(nullptr, file_name), err);
if (output_file.is_null())
return false;
base::FilePath output_path = build_settings->GetFullPath(output_file);
std::vector<const Target*> all_targets = builder.GetAllResolvedTargets();
StringOutputBuffer out_buffer;
std::ostream out(&out_buffer);
RenderJSON(build_settings, all_targets, out);
if (out_buffer.ContentsEqual(output_path)) {
return true;
}
return out_buffer.WriteToFile(output_path, err);
}
// Map of Targets to their index in the crates list (for linking dependencies to
// their indexes).
using TargetIndexMap = std::unordered_map<const Target*, uint32_t>;
// A collection of Targets.
using TargetsVector = UniqueVector<const Target*>;
// Get the Rust deps for a target, recursively expanding OutputType::GROUPS
// that are present in the GN structure. This will return a flattened list of
// deps from the groups, but will not expand a Rust lib dependency to find any
// transitive Rust dependencies.
void GetRustDeps(const Target* target, TargetsVector* rust_deps) {
for (const auto& pair : target->GetDeps(Target::DEPS_LINKED)) {
const Target* dep = pair.ptr;
if (dep->source_types_used().RustSourceUsed()) {
// Include any Rust dep.
rust_deps->push_back(dep);
} else if (dep->output_type() == Target::OutputType::GROUP) {
// Inspect (recursively) any group to see if it contains Rust deps.
GetRustDeps(dep, rust_deps);
}
}
}
TargetsVector GetRustDeps(const Target* target) {
TargetsVector deps;
GetRustDeps(target, &deps);
return deps;
}
std::vector<std::string> ExtractCompilerArgs(const Target* target) {
std::vector<std::string> args;
for (ConfigValuesIterator iter(target); !iter.done(); iter.Next()) {
auto rustflags = iter.cur().rustflags();
for (auto flag_iter = rustflags.begin(); flag_iter != rustflags.end();
flag_iter++) {
args.push_back(*flag_iter);
}
}
return args;
}
std::optional<std::string> FindArgValue(const char* arg,
const std::vector<std::string>& args) {
for (auto current = args.begin(); current != args.end();) {
// capture the current value
auto previous = *current;
// and increment
current++;
// if the previous argument matches `arg`, and after the above increment the
// end hasn't been reached, this current argument is the desired value.
if (previous == arg && current != args.end()) {
return std::make_optional(*current);
}
}
return std::nullopt;
}
std::optional<std::string> FindArgValueAfterPrefix(
const std::string& prefix,
const std::vector<std::string>& args) {
for (auto arg : args) {
if (!arg.compare(0, prefix.size(), prefix)) {
auto value = arg.substr(prefix.size());
return std::make_optional(value);
}
}
return std::nullopt;
}
std::vector<std::string> FindAllArgValuesAfterPrefix(
const std::string& prefix,
const std::vector<std::string>& args) {
std::vector<std::string> values;
for (auto arg : args) {
if (!arg.compare(0, prefix.size(), prefix)) {
auto value = arg.substr(prefix.size());
values.push_back(value);
}
}
return values;
}
// TODO(bwb) Parse sysroot structure from toml files. This is fragile and
// might break if upstream changes the dependency structure.
const std::string_view sysroot_crates[] = {"std",
"core",
"alloc",
"panic_unwind",
"proc_macro",
"test",
"panic_abort",
"unwind"};
// Multiple sysroot crates have dependenices on each other. This provides a
// mechanism for specifying that in an extendible manner.
const std::unordered_map<std::string_view, std::vector<std::string_view>>
sysroot_deps_map = {{"alloc", {"core"}},
{"std", {"alloc", "core", "panic_abort", "unwind"}}};
// Add each of the crates a sysroot has, including their dependencies.
void AddSysrootCrate(const BuildSettings* build_settings,
std::string_view crate,
std::string_view current_sysroot,
SysrootCrateIndexMap& sysroot_crate_lookup,
CrateList& crate_list) {
if (sysroot_crate_lookup.find(crate) != sysroot_crate_lookup.end()) {
// If this sysroot crate is already in the lookup, we don't add it again.
return;
}
// Add any crates that this sysroot crate depends on.
auto deps_lookup = sysroot_deps_map.find(crate);
if (deps_lookup != sysroot_deps_map.end()) {
auto deps = (*deps_lookup).second;
for (auto dep : deps) {
AddSysrootCrate(build_settings, dep, current_sysroot,
sysroot_crate_lookup, crate_list);
}
}
size_t crate_index = crate_list.size();
sysroot_crate_lookup.insert(std::make_pair(crate, crate_index));
base::FilePath rebased_out_dir =
build_settings->GetFullPath(build_settings->build_dir());
auto crate_path =
FilePathToUTF8(rebased_out_dir) + std::string(current_sysroot) +
"/lib/rustlib/src/rust/library/" + std::string(crate) + "/src/lib.rs";
Crate sysroot_crate =
Crate(SourceFile(crate_path), crate_index, std::string(crate), "2018");
sysroot_crate.AddConfigItem("debug_assertions");
if (deps_lookup != sysroot_deps_map.end()) {
auto deps = (*deps_lookup).second;
for (auto dep : deps) {
auto idx = sysroot_crate_lookup[dep];
sysroot_crate.AddDependency(idx, std::string(dep));
}
}
crate_list.push_back(sysroot_crate);
}
// Add the given sysroot to the project, if it hasn't already been added.
void AddSysroot(const BuildSettings* build_settings,
std::string_view sysroot,
SysrootIndexMap& sysroot_lookup,
CrateList& crate_list) {
// If this sysroot is already in the lookup, we don't add it again.
if (sysroot_lookup.find(sysroot) != sysroot_lookup.end()) {
return;
}
// Otherwise, add all of its crates
for (auto crate : sysroot_crates) {
AddSysrootCrate(build_settings, crate, sysroot, sysroot_lookup[sysroot],
crate_list);
}
}
void AddSysrootDependencyToCrate(Crate* crate,
const SysrootCrateIndexMap& sysroot,
std::string_view crate_name) {
if (const auto crate_idx = sysroot.find(crate_name);
crate_idx != sysroot.end()) {
crate->AddDependency(crate_idx->second, std::string(crate_name));
}
}
void AddTarget(const BuildSettings* build_settings,
const Target* target,
TargetIndexMap& lookup,
SysrootIndexMap& sysroot_lookup,
CrateList& crate_list) {
if (lookup.find(target) != lookup.end()) {
// If target is already in the lookup, we don't add it again.
return;
}
auto compiler_args = ExtractCompilerArgs(target);
auto compiler_target = FindArgValue("--target", compiler_args);
// Check what sysroot this target needs. Add it to the crate list if it
// hasn't already been added.
auto rust_tool =
target->toolchain()->GetToolForTargetFinalOutputAsRust(target);
auto current_sysroot = rust_tool->GetSysroot();
if (current_sysroot != "" && sysroot_lookup.count(current_sysroot) == 0) {
AddSysroot(build_settings, current_sysroot, sysroot_lookup, crate_list);
}
auto crate_deps = GetRustDeps(target);
// Add all dependencies of this crate, before this crate.
for (const auto& dep : crate_deps) {
AddTarget(build_settings, dep, lookup, sysroot_lookup, crate_list);
}
// The index of a crate is its position (0-based) in the list of crates.
size_t crate_id = crate_list.size();
// Add the target to the crate lookup.
lookup.insert(std::make_pair(target, crate_id));
SourceFile crate_root = target->rust_values().crate_root();
std::string crate_label = target->label().GetUserVisibleName(false);
auto edition =
FindArgValueAfterPrefix(std::string("--edition="), compiler_args);
if (!edition.has_value()) {
edition = FindArgValue("--edition", compiler_args);
}
Crate crate =
Crate(crate_root, crate_id, crate_label, edition.value_or("2015"));
crate.SetCompilerArgs(compiler_args);
if (compiler_target.has_value())
crate.SetCompilerTarget(compiler_target.value());
ConfigList cfgs =
FindAllArgValuesAfterPrefix(std::string("--cfg="), compiler_args);
crate.AddConfigItem("test");
crate.AddConfigItem("debug_assertions");
for (auto& cfg : cfgs) {
crate.AddConfigItem(cfg);
}
// Add the sysroot dependencies, if there is one.
if (current_sysroot != "") {
const auto& sysroot = sysroot_lookup[current_sysroot];
AddSysrootDependencyToCrate(&crate, sysroot, "core");
AddSysrootDependencyToCrate(&crate, sysroot, "alloc");
AddSysrootDependencyToCrate(&crate, sysroot, "std");
// Proc macros have the proc_macro crate as a direct dependency
if (std::string_view(rust_tool->name()) ==
std::string_view(RustTool::kRsToolMacro)) {
AddSysrootDependencyToCrate(&crate, sysroot, "proc_macro");
}
}
// Add the rest of the crate dependencies.
for (const auto& dep : crate_deps) {
auto idx = lookup[dep];
crate.AddDependency(idx, dep->rust_values().crate_name());
}
crate_list.push_back(crate);
}
void WriteCrates(const BuildSettings* build_settings,
CrateList& crate_list,
std::ostream& rust_project) {
// produce a de-duplicated set of source roots:
std::set<std::string> roots;
for (auto& crate : crate_list) {
roots.insert(
FilePathToUTF8(build_settings->GetFullPath(crate.root().GetDir())));
}
rust_project << "{" NEWLINE;
rust_project << " \"roots\": [";
bool first_root = true;
for (auto& root : roots) {
if (!first_root)
rust_project << ",";
first_root = false;
rust_project << NEWLINE " \"" << root << "\"";
}
rust_project << NEWLINE " ]," NEWLINE;
rust_project << " \"crates\": [";
bool first_crate = true;
for (auto& crate : crate_list) {
if (!first_crate)
rust_project << ",";
first_crate = false;
auto crate_module =
FilePathToUTF8(build_settings->GetFullPath(crate.root()));
rust_project << NEWLINE << " {" NEWLINE
<< " \"crate_id\": " << crate.index() << "," NEWLINE
<< " \"root_module\": \"" << crate_module << "\"," NEWLINE
<< " \"label\": \"" << crate.label() << "\"," NEWLINE;
auto compiler_target = crate.CompilerTarget();
if (compiler_target.has_value()) {
rust_project << " \"target\": \"" << compiler_target.value()
<< "\"," NEWLINE;
}
auto compiler_args = crate.CompilerArgs();
if (!compiler_args.empty()) {
rust_project << " \"compiler_args\": [";
bool first_arg = true;
for (auto& arg : crate.CompilerArgs()) {
if (!first_arg)
rust_project << ", ";
first_arg = false;
std::string escaped_arg;
base::EscapeJSONString(arg, false, &escaped_arg);
rust_project << "\"" << escaped_arg << "\"";
}
rust_project << "]," << NEWLINE;
}
rust_project << " \"deps\": [";
bool first_dep = true;
for (auto& dep : crate.dependencies()) {
if (!first_dep)
rust_project << ",";
first_dep = false;
rust_project << NEWLINE << " {" NEWLINE
<< " \"crate\": " << dep.first << "," NEWLINE
<< " \"name\": \"" << dep.second << "\"" NEWLINE
<< " }";
}
rust_project << NEWLINE " ]," NEWLINE; // end dep list
rust_project << " \"edition\": \"" << crate.edition() << "\"," NEWLINE;
rust_project << " \"cfg\": [";
bool first_cfg = true;
for (const auto& cfg : crate.configs()) {
if (!first_cfg)
rust_project << ",";
first_cfg = false;
std::string escaped_config;
base::EscapeJSONString(cfg, false, &escaped_config);
rust_project << NEWLINE;
rust_project << " \"" << escaped_config << "\"";
}
rust_project << NEWLINE;
rust_project << " ]" NEWLINE; // end cfgs
rust_project << " }"; // end crate
}
rust_project << NEWLINE " ]" NEWLINE; // end crate list
rust_project << "}" NEWLINE;
}
void RustProjectWriter::RenderJSON(const BuildSettings* build_settings,
std::vector<const Target*>& all_targets,
std::ostream& rust_project) {
TargetIndexMap lookup;
SysrootIndexMap sysroot_lookup;
CrateList crate_list;
// All the crates defined in the project.
for (const auto* target : all_targets) {
if (!target->IsBinary() || !target->source_types_used().RustSourceUsed())
continue;
AddTarget(build_settings, target, lookup, sysroot_lookup, crate_list);
}
WriteCrates(build_settings, crate_list, rust_project);
}