Implement new --ninja-outputs-file option.
The CL adds a new option to the `gen` command to
write a file listing all Ninja output paths that
appear in the generated build plan for any GN target
in the graph.
This can be used by GN clients to quickly convert between
GN labels and Ninja target paths. In particular, the Fuchsia
team will use this to improve developer workflows, by allowing
the `fx build` command to support GN labels directly.
The generated output includes all Ninja paths, including stamp
files for completeness. It can be processed by an external
tool, for example to convert it into a more efficient binary
format.
On a large Fuchsia build plan, this adds about 400ms
of generation time, on top of a total of 13s. Which is
drastically faster than generating a project.json file
(which is also significantly larger, and doesn't contain
all Ninja outputs).
Change-Id: I78318809f4000416689857ec4c676975ddb18061
Reviewed-on: https://gn-review.googlesource.com/c/gn/+/16000
Reviewed-by: Takuto Ikuta <tikuta@google.com>
Commit-Queue: David Turner <digit@google.com>
Reviewed-by: Dirk Pranke <dpranke@google.com>
diff --git a/docs/reference.md b/docs/reference.md
index feabe8e..24036dc 100644
--- a/docs/reference.md
+++ b/docs/reference.md
@@ -910,7 +910,35 @@
generated JSON file will be first argument when invoking script.
--json-ide-script-args=<argument>
- Optional second argument that will passed to executed script.
+ Optional second argument that will be passed to executed script.
+```
+
+#### **Ninja Outputs**
+
+```
+ The --ninja-outputs-file=<FILE> option dumps a JSON file that maps GN labels
+ to their Ninja output paths. This can be later processed to build an index
+ to convert between Ninja targets and GN ones before or after the build itself.
+ It looks like:
+
+ {
+ "label1": [
+ "path1",
+ "path2"
+ ],
+ "label2": [
+ "path3"
+ ]
+ }
+
+ --ninja-outputs-script=<path_to_python_script>
+ Executes python script after the outputs file is generated or updated
+ with new content. Path can be project absolute (//), system absolute (/) or
+ relative, in which case the output directory will be base. Path to
+ generated file will be first argument when invoking script.
+
+ --ninja-outputs-script-args=<argument>
+ Optional second argument that will be passed to executed script.
```
#### **Compilation Database**
diff --git a/src/gn/command_gen.cc b/src/gn/command_gen.cc
index 0a2d7b8..891ba91 100644
--- a/src/gn/command_gen.cc
+++ b/src/gn/command_gen.cc
@@ -2,6 +2,8 @@
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
+#include <inttypes.h>
+
#include <mutex>
#include <thread>
#include <unordered_map>
@@ -17,6 +19,7 @@
#include "gn/filesystem_utils.h"
#include "gn/json_project_writer.h"
#include "gn/label_pattern.h"
+#include "gn/ninja_outputs_writer.h"
#include "gn/ninja_target_writer.h"
#include "gn/ninja_tools.h"
#include "gn/ninja_writer.h"
@@ -53,6 +56,9 @@
const char kSwitchIdeRootTarget[] = "ide-root-target";
const char kSwitchNinjaExecutable[] = "ninja-executable";
const char kSwitchNinjaExtraArgs[] = "ninja-extra-args";
+const char kSwitchNinjaOutputsFile[] = "ninja-outputs-file";
+const char kSwitchNinjaOutputsScript[] = "ninja-outputs-script";
+const char kSwitchNinjaOutputsScriptArgs[] = "ninja-outputs-script-args";
const char kSwitchNoDeps[] = "no-deps";
const char kSwitchSln[] = "sln";
const char kSwitchXcodeProject[] = "xcode-project";
@@ -70,11 +76,19 @@
const char kSwitchExportCompileCommands[] = "export-compile-commands";
const char kSwitchExportRustProject[] = "export-rust-project";
-// Collects Ninja rules for each toolchain. The lock protectes the rules.
+// A map type used to implement --ide=ninja_outputs
+using NinjaOutputsMap = NinjaOutputsWriter::MapType;
+
+// Collects Ninja rules for each toolchain. The lock protects the rules
struct TargetWriteInfo {
+ // Set this to true to populate |ninja_outputs_map| below.
+ bool want_ninja_outputs = false;
+
std::mutex lock;
NinjaWriter::PerToolchainRules rules;
+ NinjaOutputsMap ninja_outputs_map;
+
using ResolvedMap = std::unordered_map<std::thread::id, ResolvedTargetData>;
std::unique_ptr<ResolvedMap> resolved_map = std::make_unique<ResolvedMap>();
@@ -84,17 +98,28 @@
// Called on worker thread to write the ninja file.
void BackgroundDoWrite(TargetWriteInfo* write_info, const Target* target) {
ResolvedTargetData* resolved;
+ std::vector<OutputFile> target_ninja_outputs;
+ std::vector<OutputFile>* ninja_outputs =
+ write_info->want_ninja_outputs ? &target_ninja_outputs : nullptr;
+
{
std::lock_guard<std::mutex> lock(write_info->lock);
resolved = &((*write_info->resolved_map)[std::this_thread::get_id()]);
}
- std::string rule = NinjaTargetWriter::RunAndWriteFile(target, resolved);
+ std::string rule =
+ NinjaTargetWriter::RunAndWriteFile(target, resolved, ninja_outputs);
+
DCHECK(!rule.empty());
{
std::lock_guard<std::mutex> lock(write_info->lock);
write_info->rules[target->toolchain()].emplace_back(target,
std::move(rule));
+
+ if (write_info->want_ninja_outputs) {
+ write_info->ninja_outputs_map.emplace(target,
+ std::move(target_ninja_outputs));
+ }
}
}
@@ -632,7 +657,33 @@
generated JSON file will be first argument when invoking script.
--json-ide-script-args=<argument>
- Optional second argument that will passed to executed script.
+ Optional second argument that will be passed to executed script.
+
+Ninja Outputs
+
+ The --ninja-outputs-file=<FILE> option dumps a JSON file that maps GN labels
+ to their Ninja output paths. This can be later processed to build an index
+ to convert between Ninja targets and GN ones before or after the build itself.
+ It looks like:
+
+ {
+ "label1": [
+ "path1",
+ "path2"
+ ],
+ "label2": [
+ "path3"
+ ]
+ }
+
+ --ninja-outputs-script=<path_to_python_script>
+ Executes python script after the outputs file is generated or updated
+ with new content. Path can be project absolute (//), system absolute (/) or
+ relative, in which case the output directory will be base. Path to
+ generated file will be first argument when invoking script.
+
+ --ninja-outputs-script-args=<argument>
+ Optional second argument that will be passed to executed script.
Compilation Database
@@ -715,6 +766,9 @@
// Cause the load to also generate the ninja files for each target.
TargetWriteInfo write_info;
+ write_info.want_ninja_outputs =
+ command_line->HasSwitch(kSwitchNinjaOutputsFile);
+
setup->builder().set_resolved_and_generated_callback(
[&write_info](const BuilderRecord* record) {
ItemResolvedAndGeneratedCallback(&write_info, record);
@@ -756,6 +810,38 @@
return 1;
}
+ if (write_info.want_ninja_outputs) {
+ ElapsedTimer outputs_timer;
+ std::string file_name =
+ command_line->GetSwitchValueString(kSwitchNinjaOutputsFile);
+ if (file_name.empty()) {
+ Err(Location(), "The --ninja-outputs-file argument cannot be empty!")
+ .PrintToStdout();
+ return 1;
+ }
+
+ bool quiet = command_line->HasSwitch(switches::kQuiet);
+
+ std::string exec_script =
+ command_line->GetSwitchValueString(kSwitchNinjaOutputsScript);
+
+ std::string exec_script_extra_args =
+ command_line->GetSwitchValueString(kSwitchNinjaOutputsScriptArgs);
+
+ bool res = NinjaOutputsWriter::RunAndWriteFiles(
+ write_info.ninja_outputs_map, &setup->build_settings(), file_name,
+ exec_script, exec_script_extra_args, quiet, &err);
+ if (!res) {
+ err.PrintToStdout();
+ return 1;
+ }
+ if (!command_line->HasSwitch(switches::kQuiet)) {
+ OutputString(base::StringPrintf(
+ "Generating Ninja outputs file took %" PRId64 "ms\n",
+ outputs_timer.Elapsed().InMilliseconds()));
+ }
+ }
+
if (!WriteRuntimeDepsFilesIfNecessary(&setup->build_settings(),
setup->builder(), &err)) {
err.PrintToStdout();
