本頁面說明輸出目錄的需求和版面配置。
需求條件
輸出目錄版面配置的需求：
- 如果多位使用者在同一個方塊中建構應用程式，則不會發生衝突。
- 支援同時在多個工作區中建立。
- 支援在相同工作區中建構多種目標設定。
- 不會與其他工具衝突。
- 易於使用
- 易於清理，甚至可選擇性使用。
- 不夠明確，即使使用者在變更至用戶端目錄時使用符號連結也一樣。
- 每位使用者的所有建構狀態都應位於同一個目錄之下 (「我要從所有用戶端清理所有 .o 檔案)。
目前版面配置
目前實作的解決方案：
- 您必須從包含存放區邊界檔案的目錄或子目錄中叫用 Bazel。換句話說，您必須從存放區內部叫用 Bazel。否則，系統會回報錯誤。
- 在 Linux 上，outputRoot 目錄預設為
${XDG_CACHE_HOME}/bazel(如未設定XDG_CACHE_HOME環境變數，則為~/.cache/bazel)；在 macOS 上，若未設定/private/var/tmp，則預設為%HOME%；如已設定%USERPROFILE%，則在已設定FOLDERID_Profile旗標的情況下呼叫SHGetKnownFolderPath()的結果。如果環境變數$TEST_TMPDIR已經設定 (例如在 Bazel 本身的測試中)，則該值會覆寫預設值。 - Bazel 使用者的建構狀態位於
outputRoot/_bazel_$USER下方。這就是 outputUserRoot 目錄。 outputUserRoot目錄下方有一個install目錄，installBase目錄的名稱為 Bazel 安裝資訊清單的 MD5 雜湊。- 在
outputUserRoot目錄下方，系統也會建立outputBase目錄，其名稱為工作區根目錄的 MD5 雜湊。舉例來說，如果 Bazel 在工作區根目錄/home/user/src/my-project(或連結至該工作區的目錄) 中執行，系統會建立名為/home/user/.cache/bazel/_bazel_user/7ffd56a6e4cb724ea575aba15733d113的輸出基本目錄。您也可以在工作區根目錄中執行echo -n $(pwd) | md5sum，以取得 MD5。 - 您可以使用 Bazel 的
--output_base啟動選項覆寫預設輸出基本目錄。例如bazel --output_base=/tmp/bazel/output build x/y:z。 - 您也可以使用 Bazel 的
--output_user_root啟動選項覆寫預設安裝數和輸出基本目錄。例如：bazel --output_user_root=/tmp/bazel build x/y:z。
「bazel-<workspace-name>」、「bazel-out」、「bazel-testlogs」和「bazel-bin」的符號連結會放在工作區目錄中；這些符號連結會指向輸出目錄內目標目錄中的某些目錄。這些符號連結只是為了使用者方便起見，因為 Bazel 本身不會使用這類連結。此外，只有在工作區根層級可寫入時，系統才會執行這項作業。
版面配置圖表
目錄如下所示：
<workspace-name>/ <== The workspace root
bazel-my-project => <..._main> <== Symlink to execRoot
bazel-out => <...bazel-out> <== Convenience symlink to outputPath
bazel-bin => <...bin> <== Convenience symlink to most recent written bin dir $(BINDIR)
bazel-testlogs => <...testlogs> <== Convenience symlink to the test logs directory
/home/user/.cache/bazel/ <== Root for all Bazel output on a machine: outputRoot
_bazel_$USER/ <== Top level directory for a given user depends on the user name:
outputUserRoot
install/
fba9a2c87ee9589d72889caf082f1029/ <== Hash of the Bazel install manifest: installBase
_embedded_binaries/ <== Contains binaries and scripts unpacked from the data section of
the bazel executable on first run (such as helper scripts and the
main Java file BazelServer_deploy.jar)
7ffd56a6e4cb724ea575aba15733d113/ <== Hash of the client's workspace root (such as
/home/user/src/my-project): outputBase
action_cache/ <== Action cache directory hierarchy
This contains the persistent record of the file
metadata (timestamps, and perhaps eventually also MD5
sums) used by the FilesystemValueChecker.
command.log <== A copy of the stdout/stderr output from the most
recent bazel command.
external/ <== The directory that remote repositories are
downloaded/symlinked into.
server/ <== The Bazel server puts all server-related files (such
as socket file, logs, etc) here.
jvm.out <== The debugging output for the server.
execroot/ <== The working directory for all actions. For special
cases such as sandboxing and remote execution, the
actions run in a directory that mimics execroot.
Implementation details, such as where the directories
are created, are intentionally hidden from the action.
Every action can access its inputs and outputs relative
to the execroot directory.
_main/ <== Working tree for the Bazel build & root of symlink forest: execRoot
_bin/ <== Helper tools are linked from or copied to here.
bazel-out/ <== All actual output of the build is under here: outputPath
_tmp/actions/ <== Action output directory. This contains a file with the
stdout/stderr for every action from the most recent
bazel run that produced output.
local_linux-fastbuild/ <== one subdirectory per unique target BuildConfiguration instance;
this is currently encoded
bin/ <== Bazel outputs binaries for target configuration here: $(BINDIR)
foo/bar/_objs/baz/ <== Object files for a cc_* rule named //foo/bar:baz
foo/bar/baz1.o <== Object files from source //foo/bar:baz1.cc
other_package/other.o <== Object files from source //other_package:other.cc
foo/bar/baz <== foo/bar/baz might be the artifact generated by a cc_binary named
//foo/bar:baz
foo/bar/baz.runfiles/ <== The runfiles symlink farm for the //foo/bar:baz executable.
MANIFEST
_main/
...
genfiles/ <== Bazel puts generated source for the target configuration here:
$(GENDIR)
foo/bar.h such as foo/bar.h might be a headerfile generated by //foo:bargen
testlogs/ <== Bazel internal test runner puts test log files here
foo/bartest.log such as foo/bar.log might be an output of the //foo:bartest test with
foo/bartest.status foo/bartest.status containing exit status of the test (such as
PASSED or FAILED (Exit 1), etc)
include/ <== a tree with include symlinks, generated as needed. The
bazel-include symlinks point to here. This is used for
linkstamp stuff, etc.
host/ <== BuildConfiguration for build host (user's workstation), for
building prerequisite tools, that will be used in later stages
of the build (ex: Protocol Compiler)
<packages>/ <== Packages referenced in the build appear as if under a regular workspace
RunfilesSupport 指向的位置會詳細說明 *.runfiles 目錄的版面配置。
bazel clean
bazel clean 會對 outputPath 和 action_cache 目錄執行 rm -rf。系統也會移除工作區符號連結。--expunge 選項會清除整個 outputBase。