Re: [PATCH 3/3] trace: add GIT_TRACE_STDIN
flat view
From: Jeff King <hidden>
Date: 2016-06-15 23:05:20
Subsystem:
the rest · Maintainer:
Linus Torvalds
Possibly related (same subject, not in this thread)
- 2016-06-15 · Re: [PATCH 3/3] trace: add GIT_TRACE_STDIN · Junio C Hamano <hidden>
On Tue, Jun 16, 2015 at 03:49:07PM -0400, Jeff King wrote:
Another option would be to stop trying to intercept stdin in git.c, and instead make this a feature of run-command.c. That is, right before we exec a process, tee its stdin there. That means that you cannot do: GIT_TRACE_STDIN=/tmp/foo.out git foo to collect the stdin of foo. But that is not really an interesting case anyway. You can run "tee" yourself if you want. The interesting cases are the ones where git is spawning a sub-process, and you want to intercept the data moving between the git processes.
Hmm. I guess we do not actually have to move the stdin interception there. We can just move the config-checking there, like the patch below. It basically just converts trace.foo.bar into GIT_TRACE_BAR when we are running "foo" as a git command. This does work, but is perhaps potentially confusing to the user, because it only kicks in when _git_ runs "foo". IOW, this works: git config trace.upload-pack.foo /path/to/foo.out git daemon and will trace as you expect. But then running: git upload-pack yourself will do nothing. I dunno. --- run-command.c | 17 +++++++++++++++++ trace.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ trace.h | 9 +++++++++ 3 files changed, 70 insertions(+)
diff --git a/run-command.c b/run-command.c
index 4d73e90..2febbb5 100644
--- a/run-command.c
+++ b/run-command.c@@ -284,6 +284,23 @@ int start_command(struct child_process *cmd) if (!cmd->argv) cmd->argv = cmd->args.argv; + if (cmd->git_cmd) { + /* + * Load any extra variables into env_array. But + * if we weren't going to use it (in favor of "env"), + * then consolidate the two. Make sure the original "env" + * goes after what we add, so that it can override. + * + * We cannot just keep two lists, because we may hand off the + * single list to a spawn() implementation. + */ + trace_config_for(cmd->argv[0], &cmd->env_array); + if (cmd->env_array.argc && cmd->env) { + for (; *cmd->env; cmd->env++) + argv_array_push(&cmd->env_array, *cmd->env); + cmd->env = NULL; + } + } if (!cmd->env) cmd->env = cmd->env_array.argv;
diff --git a/trace.c b/trace.c
index a7ec484..86c988e 100644
--- a/trace.c
+++ b/trace.c@@ -24,6 +24,7 @@ #include "cache.h" #include "quote.h" +#include "argv-array.h" static size_t expand_trace_name(struct strbuf *out, const char *fmt, void *data)
@@ -449,3 +450,46 @@ void trace_command_performance(const char **argv) sq_quote_argv(&command_line, argv, 0); command_start_time = getnanotime(); } + +struct trace_config_data { + const char *want_cmd; + struct argv_array *out; +}; + +static int trace_config_cb(const char *var, const char *value, void *vdata) +{ + struct trace_config_data *data = vdata; + const char *have_cmd, *key; + int have_len; + + if (!parse_config_key(var, "trace", &have_cmd, &have_len, &key) && + have_cmd && + !strncmp(data->want_cmd, have_cmd, have_len) && + data->want_cmd[have_len] == '\0') { + struct strbuf buf = STRBUF_INIT; + + strbuf_addstr(&buf, "GIT_TRACE_"); + while (*key) + strbuf_addch(&buf, toupper(*key++)); + + /* + * Environment always takes precedence over config, so do not + * override existing variables. We cannot rely on setenv()'s + * overwrite flag here, because we may pass the list off to + * a spawn() implementation, which always overwrites. + */ + if (!getenv(buf.buf)) + argv_array_pushf(data->out, "%s=%s", buf.buf, value); + + strbuf_release(&buf); + } + return 0; +} + +void trace_config_for(const char *cmd, struct argv_array *out) +{ + struct trace_config_data data; + data.want_cmd = cmd; + data.out = out; + git_config(trace_config_cb, &data); +}
diff --git a/trace.h b/trace.h
index 179b249..83618e9 100644
--- a/trace.h
+++ b/trace.h@@ -4,6 +4,8 @@ #include "git-compat-util.h" #include "strbuf.h" +struct argv_array; + struct trace_key { const char * const key; int fd;
@@ -20,6 +22,13 @@ extern uint64_t getnanotime(void); extern void trace_command_performance(const char **argv); extern void trace_verbatim(struct trace_key *key, const void *buf, unsigned len); +/** + * Load any trace-related config for git command "cmd", and insert the matching + * environment variables into "out", which is suitable for use by run-command + * and friends. + */ +void trace_config_for(const char *cmd, struct argv_array *out); + #ifndef HAVE_VARIADIC_MACROS __attribute__((format (printf, 1, 2)))
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2.4.3.699.g84b4da7