diff options
Diffstat (limited to 'libbuild2/script/run.hxx')
| -rw-r--r-- | libbuild2/script/run.hxx | 80 |
1 files changed, 29 insertions, 51 deletions
diff --git a/libbuild2/script/run.hxx b/libbuild2/script/run.hxx index 5d46d21..c4c2aa2 100644 --- a/libbuild2/script/run.hxx +++ b/libbuild2/script/run.hxx @@ -83,61 +83,39 @@ namespace build2 string diag_path (const dir_name_view&); - // Read out the stream content into a string, optionally splitting the - // input data at whitespaces or newlines in which case return one - // sub-string at a time (see the set builtin options for the splitting - // semantics). Throw io_error on the underlying OS error. + // Read the stream content, optionally splitting the input data at + // whitespaces or newlines and calling the specified callback function for + // each substring (see the set builtin options for the splitting + // semantics). Throw failed on io_error. // - // If the execution deadline is specified, then turn the stream into the - // non-blocking mode. If the specified deadline is reached while reading - // the stream, then bail out for the successful deadline and fail - // otherwise. Note that in the former case the result will be incomplete, - // but we leave it to the caller to handle that. + // If the stream is a pipeline's output, then the pipeline argument must + // also be specified. Normally called from a custom command function (see + // command_function for details) which is provided with the pipeline + // information. // - // Note that on Windows we can only turn pipe file descriptors into the - // non-blocking mode. Thus, we have no choice but to read from descriptors - // of other types synchronously there. That implies that we can - // potentially block indefinitely reading a file and missing the deadline - // on Windows. Note though, that the user can normally rewrite the - // command, for example, `set foo <<<file` with `cat file | set foo` to - // avoid this problem. + // Turn the stream into the non-blocking mode and, if the pipeline is + // specified, read out its buffered stderr streams while waiting for the + // input stream data. If a deadline is specified and is reached, then + // terminate the whole pipeline, if specified, and bail out. Otherwise + // issue diagnostics and fail. The thinking here is that in the former + // case the caller first needs to dump the buffered stderr streams, issue + // the appropriate diagnostics for the pipeline processes/builtins, and + // only throw failed afterwards. // - class stream_reader - { - public: - stream_reader (auto_fd&&, - bool pipe, - bool whitespace, bool newline, bool exact, - const optional<deadline>&, - const command& deadline_cmd, - const location&); - - // Return nullopt if eos is reached. - // - optional<string> - next (); - - private: - ifdstream is_; - bool whitespace_; - bool newline_; - bool exact_; - optional<deadline> deadline_; - const command& deadline_cmd_; - const location& location_; - - bool empty_ = true; // Set to false after the first character is read. - }; - - // Read the stream content using the stream reader in the no-split exact - // mode. + // Note that on Windows we can only turn file descriptors of the pipe type + // into the non-blocking mode. Thus, a non-pipe descriptor is read in the + // blocking manner (and the deadline is checked less accurately). This is + // fine since there are no pipeline stderr streams to read out in this + // case. // - string - stream_read (auto_fd&&, - bool pipe, - const optional<deadline>&, - const command& deadline_cmd, - const location&); + void + read (auto_fd&&, + bool whitespace, bool newline, bool exact, + const function<void (string&&)>&, + pipe_command* pipeline, + const optional<deadline>&, + const location&, + const char* what); } } |