rustc: Stabilize options for pipelined compilation

src/bootstrap/test.rs

@@ -229,6 +229,9 @@ impl Step for Cargo {
         cargo.env("CFG_DISABLE_CROSS_TESTS", "1");
         // Disable a test that has issues with mingw.
         cargo.env("CARGO_TEST_DISABLE_GIT_CLI", "1");
+        // Forcibly disable tests using nightly features since any changes to
+        // those features won't be able to land.
+        cargo.env("CARGO_TEST_DISABLE_NIGHTLY", "1");
 
         try_run(
             builder,

src/doc/rustc/src/command-line-arguments.md

@@ -271,3 +271,36 @@ current directory out of pathnames emitted into the object files. The
 replacement is purely textual, with no consideration of the current system's
 pathname syntax. For example `--remap-path-prefix foo=bar` will match
 `foo/lib.rs` but not `./foo/lib.rs`.
+
+## `--json`: configure json messages printed by the compiler
+
+When the `--error-format=json` option is passed to rustc then all of the
+compiler's diagnostic output will be emitted in the form of JSON blobs. The
+`--json` argument can be used in conjunction with `--error-format=json` to
+configure what the JSON blobs contain as well as which ones are emitted.
+
+With `--error-format=json` the compiler will always emit any compiler errors as
+a JSON blob, but the following options are also available to the `--json` flag
+to customize the output:
+
+- `diagnostic-short` - json blobs for diagnostic messages should use the "short"
+  rendering instead of the normal "human" default. This means that the output of
+  `--error-format=short` will be embedded into the JSON diagnostics instead of
+  the default `--error-format=human`.
+
+- `diagnostic-rendered-ansi` - by default JSON blobs in their `rendered` field
+  will contain a plain text rendering of the diagnostic. This option instead
+  indicates that the diagnostic should have embedded ANSI color codes intended
+  to be used to colorize the message in the manner rustc typically already does
+  for terminal outputs. Note that this is usefully combined with crates like
+  `fwdansi` to translate these ANSI codes on Windows to console commands or
+  `strip-ansi-escapes` if you'd like to optionally remove the ansi colors
+  afterwards.
+
+- `artifacts` - this instructs rustc to emit a JSON blob for each artifact that
+  is emitted. An artifact corresponds to a request from the `--emit` CLI
+  argument, and as soon as the artifact is available on the filesystem a
+  notification will be emitted.
+
+Note that it is invalid to combine the `--json` argument with the `--color`
+argument, and it is required to combine `--json` with `--error-format=json`.

src/librustc/session/config.rs

@@ -438,6 +438,10 @@ top_level_options!(
         remap_path_prefix: Vec<(PathBuf, PathBuf)> [UNTRACKED],
 
         edition: Edition [TRACKED],
+
+        // Whether or not we're emitting JSON blobs about each artifact produced
+        // by the compiler.
+        json_artifact_notifications: bool [TRACKED],
     }
 );
 
@@ -625,6 +629,7 @@ impl Default for Options {
             cli_forced_thinlto_off: false,
             remap_path_prefix: Vec::new(),
             edition: DEFAULT_EDITION,
+            json_artifact_notifications: false,
         }
     }
 }
@@ -1463,8 +1468,6 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
          the same values as the target option of the same name"),
     allow_features: Option<Vec<String>> = (None, parse_opt_comma_list, [TRACKED],
         "only allow the listed language features to be enabled in code (space separated)"),
-    emit_artifact_notifications: bool = (false, parse_bool, [UNTRACKED],
-        "emit notifications after each artifact has been output (only in the JSON format)"),
     symbol_mangling_version: SymbolManglingVersion = (SymbolManglingVersion::Legacy,
         parse_symbol_mangling_version, [TRACKED],
         "which mangling version to use for symbol names"),
@@ -1822,11 +1825,11 @@ pub fn rustc_optgroups() -> Vec<RustcOptGroup> {
             "How errors and other messages are produced",
             "human|json|short",
         ),
-        opt::opt(
+        opt::multi_s(
             "",
-            "json-rendered",
-            "Choose `rendered` field of json diagnostics render scheme",
-            "plain|termcolor",
+            "json",
+            "Configure the JSON output of the compiler",
+            "CONFIG",
         ),
         opt::opt_s(
             "",
@@ -1922,10 +1925,9 @@ pub fn get_cmd_lint_options(matches: &getopts::Matches,
     (lint_opts, describe_lints, lint_cap)
 }
 
-pub fn build_session_options_and_crate_config(
-    matches: &getopts::Matches,
-) -> (Options, FxHashSet<(String, Option<String>)>) {
-    let color = match matches.opt_str("color").as_ref().map(|s| &s[..]) {
+/// Parse the `--color` flag
+pub fn parse_color(matches: &getopts::Matches) -> ColorConfig {
+    match matches.opt_str("color").as_ref().map(|s| &s[..]) {
         Some("auto") => ColorConfig::Auto,
         Some("always") => ColorConfig::Always,
         Some("never") => ColorConfig::Never,
@@ -1940,46 +1942,52 @@ pub fn build_session_options_and_crate_config(
                 arg
             ),
         ),
-    };
+    }
+}
 
-    let edition = match matches.opt_str("edition") {
-        Some(arg) => Edition::from_str(&arg).unwrap_or_else(|_|
+/// Parse the `--json` flag.
+///
+/// The first value returned is how to render JSON diagnostics, and the second
+/// is whether or not artifact notifications are enabled.
+pub fn parse_json(matches: &getopts::Matches) -> (HumanReadableErrorType, bool) {
+    let mut json_rendered: fn(ColorConfig) -> HumanReadableErrorType =
+        HumanReadableErrorType::Default;
+    let mut json_color = ColorConfig::Never;
+    let mut json_artifact_notifications = false;
+    for option in matches.opt_strs("json") {
+        // For now conservatively forbid `--color` with `--json` since `--json`
+        // won't actually be emitting any colors and anything colorized is
+        // embedded in a diagnostic message anyway.
+        if matches.opt_str("color").is_some() {
             early_error(
                 ErrorOutputType::default(),
-                &format!(
-                    "argument for --edition must be one of: \
-                     {}. (instead was `{}`)",
-                    EDITION_NAME_LIST,
-                    arg
-                ),
-            ),
-        ),
-        None => DEFAULT_EDITION,
-    };
+                "cannot specify the `--color` option with `--json`",
+            );
+        }
 
-    if !edition.is_stable() && !nightly_options::is_nightly_build() {
-        early_error(
-                ErrorOutputType::default(),
-                &format!(
-                    "Edition {} is unstable and only \
-                     available for nightly builds of rustc.",
-                    edition,
-                )
-        )
+        for sub_option in option.split(',') {
+            match sub_option {
+                "diagnostic-short" => json_rendered = HumanReadableErrorType::Short,
+                "diagnostic-rendered-ansi" => json_color = ColorConfig::Always,
+                "artifacts" => json_artifact_notifications = true,
+                s => {
+                    early_error(
+                        ErrorOutputType::default(),
+                        &format!("unknown `--json` option `{}`", s),
+                    )
+                }
+            }
+        }
     }
+    (json_rendered(json_color), json_artifact_notifications)
+}
 
-    let json_rendered = matches.opt_str("json-rendered").and_then(|s| match s.as_str() {
-        "plain" => None,
-        "termcolor" => Some(HumanReadableErrorType::Default(ColorConfig::Always)),
-        _ => early_error(
-            ErrorOutputType::default(),
-            &format!(
-                "argument for --json-rendered must be `plain` or `termcolor` (instead was `{}`)",
-                s,
-            ),
-        ),
-    }).unwrap_or(HumanReadableErrorType::Default(ColorConfig::Never));
-
+/// Parse the `--error-format` flag
+pub fn parse_error_format(
+    matches: &getopts::Matches,
+    color: ColorConfig,
+    json_rendered: HumanReadableErrorType,
+) -> ErrorOutputType {
     // We need the opts_present check because the driver will send us Matches
     // with only stable options if no unstable options are used. Since error-format
     // is unstable, it will not be present. We have to use opts_present not
@@ -2008,6 +2016,60 @@ pub fn build_session_options_and_crate_config(
         ErrorOutputType::HumanReadable(HumanReadableErrorType::Default(color))
     };
 
+    match error_format {
+        ErrorOutputType::Json { .. } => {}
+
+        // Conservatively require that the `--json` argument is coupled with
+        // `--error-format=json`. This means that `--json` is specified we
+        // should actually be emitting JSON blobs.
+        _ if matches.opt_strs("json").len() > 0 => {
+            early_error(
+                ErrorOutputType::default(),
+                "using `--json` requires also using `--error-format=json`",
+            );
+        }
+
+        _ => {}
+    }
+
+    return error_format;
+}
+
+pub fn build_session_options_and_crate_config(
+    matches: &getopts::Matches,
+) -> (Options, FxHashSet<(String, Option<String>)>) {
+    let color = parse_color(matches);
+
+    let edition = match matches.opt_str("edition") {
+        Some(arg) => Edition::from_str(&arg).unwrap_or_else(|_|
+            early_error(
+                ErrorOutputType::default(),
+                &format!(
+                    "argument for --edition must be one of: \
+                     {}. (instead was `{}`)",
+                    EDITION_NAME_LIST,
+                    arg
+                ),
+            ),
+        ),
+        None => DEFAULT_EDITION,
+    };
+
+    if !edition.is_stable() && !nightly_options::is_nightly_build() {
+        early_error(
+                ErrorOutputType::default(),
+                &format!(
+                    "Edition {} is unstable and only \
+                     available for nightly builds of rustc.",
+                    edition,
+                )
+        )
+    }
+
+    let (json_rendered, json_artifact_notifications) = parse_json(matches);
+
+    let error_format = parse_error_format(matches, color, json_rendered);
+
     let unparsed_crate_types = matches.opt_strs("crate-type");
     let crate_types = parse_crate_types_from_list(unparsed_crate_types)
         .unwrap_or_else(|e| early_error(error_format, &e[..]));
@@ -2018,9 +2080,6 @@ pub fn build_session_options_and_crate_config(
     let mut debugging_opts = build_debugging_options(matches, error_format);
 
     if !debugging_opts.unstable_options {
-        if matches.opt_str("json-rendered").is_some() {
-            early_error(error_format, "`--json-rendered=x` is unstable");
-        }
         if let ErrorOutputType::Json { pretty: true, json_rendered } = error_format {
             early_error(
                 ErrorOutputType::Json { pretty: false, json_rendered },
@@ -2445,6 +2504,7 @@ pub fn build_session_options_and_crate_config(
             cli_forced_thinlto_off: disable_thinlto,
             remap_path_prefix,
             edition,
+            json_artifact_notifications,
         },
         cfg,
     )

src/librustc_codegen_ssa/back/link.rs

@@ -95,7 +95,7 @@ pub fn link_binary<'a, B: ArchiveBuilder<'a>>(sess: &'a Session,
                     );
                 }
             }
-            if sess.opts.debugging_opts.emit_artifact_notifications {
+            if sess.opts.json_artifact_notifications {
                 sess.parse_sess.span_diagnostic.emit_artifact_notification(&out_filename, "link");
             }
         }

src/librustc_interface/passes.rs

@@ -696,7 +696,7 @@ fn write_out_deps(compiler: &Compiler, outputs: &OutputFilenames, out_filenames:
 
     match result {
         Ok(_) => {
-            if sess.opts.debugging_opts.emit_artifact_notifications {
+            if sess.opts.json_artifact_notifications {
                  sess.parse_sess.span_diagnostic
                     .emit_artifact_notification(&deps_filename, "dep-info");
             }
@@ -1059,7 +1059,7 @@ fn encode_and_write_metadata(
         if let Err(e) = fs::rename(&metadata_filename, &out_filename) {
             tcx.sess.fatal(&format!("failed to write {}: {}", out_filename.display(), e));
         }
-        if tcx.sess.opts.debugging_opts.emit_artifact_notifications {
+        if tcx.sess.opts.json_artifact_notifications {
             tcx.sess.parse_sess.span_diagnostic
                 .emit_artifact_notification(&out_filename, "metadata");
         }

src/librustc_save_analysis/lib.rs

@@ -1087,7 +1087,7 @@ impl<'a> SaveHandler for DumpHandler<'a> {
             file_name
         };
 
-        if sess.opts.debugging_opts.emit_artifact_notifications {
+        if sess.opts.json_artifact_notifications {
             sess.parse_sess.span_diagnostic
                 .emit_artifact_notification(&file_name, "save-analysis");
         }

src/librustdoc/config.rs

@@ -3,10 +3,9 @@ use std::fmt;
 use std::path::PathBuf;
 
 use errors;
-use errors::emitter::{ColorConfig, HumanReadableErrorType};
 use getopts;
 use rustc::lint::Level;
-use rustc::session::early_error;
+use rustc::session;
 use rustc::session::config::{CodegenOptions, DebuggingOptions, ErrorOutputType, Externs};
 use rustc::session::config::{nightly_options, build_codegen_options, build_debugging_options,
                              get_cmd_lint_options, ExternEntry};
@@ -243,36 +242,9 @@ impl Options {
             return Err(0);
         }
 
-        let color = match matches.opt_str("color").as_ref().map(|s| &s[..]) {
-            Some("auto") => ColorConfig::Auto,
-            Some("always") => ColorConfig::Always,
-            Some("never") => ColorConfig::Never,
-            None => ColorConfig::Auto,
-            Some(arg) => {
-                early_error(ErrorOutputType::default(),
-                            &format!("argument for `--color` must be `auto`, `always` or `never` \
-                                      (instead was `{}`)", arg));
-            }
-        };
-        // FIXME: deduplicate this code from the identical code in librustc/session/config.rs
-        let error_format = match matches.opt_str("error-format").as_ref().map(|s| &s[..]) {
-            None |
-            Some("human") => ErrorOutputType::HumanReadable(HumanReadableErrorType::Default(color)),
-            Some("json") => ErrorOutputType::Json {
-                pretty: false,
-                json_rendered: HumanReadableErrorType::Default(ColorConfig::Never),
-            },
-            Some("pretty-json") => ErrorOutputType::Json {
-                pretty: true,
-                json_rendered: HumanReadableErrorType::Default(ColorConfig::Never),
-            },
-            Some("short") => ErrorOutputType::HumanReadable(HumanReadableErrorType::Short(color)),
-            Some(arg) => {
-                early_error(ErrorOutputType::default(),
-                            &format!("argument for `--error-format` must be `human`, `json` or \
-                                      `short` (instead was `{}`)", arg));
-            }
-        };
+        let color = session::config::parse_color(&matches);
+        let (json_rendered, _artifacts) = session::config::parse_json(&matches);
+        let error_format = session::config::parse_error_format(&matches, color, json_rendered);
 
         let codegen_options = build_codegen_options(matches, error_format);
         let debugging_options = build_debugging_options(matches, error_format);

src/librustdoc/lib.rs

@@ -289,6 +289,12 @@ fn opts() -> Vec<RustcOptGroup> {
                      "How errors and other messages are produced",
                      "human|json|short")
         }),
+        stable("json", |o| {
+            o.optopt("",
+                     "json",
+                     "Configure the structure of JSON diagnostics",
+                     "CONFIG")
+        }),
         unstable("disable-minification", |o| {
              o.optflag("",
                        "disable-minification",

src/test/ui/emit-artifact-notifications.rs

@@ -1,4 +1,4 @@
-// compile-flags:--emit=metadata --error-format=json -Z emit-artifact-notifications
+// compile-flags:--emit=metadata --error-format=json --json artifacts
 // build-pass (FIXME(62277): could be check-pass?)
 // ignore-pass
 // ^-- needed because `--pass check` does not emit the output needed.

src/test/ui/json-and-color.rs

@@ -0,0 +1,4 @@
+// build-fail
+// compile-flags: --json=artifacts --error-format=json --color never
+
+fn main() {}

src/test/ui/json-and-color.stderr

@@ -0,0 +1,2 @@
+error: cannot specify the `--color` option with `--json`
+

src/test/ui/json-and-error-format.rs

@@ -0,0 +1,4 @@
+// build-fail
+// compile-flags: --json=artifacts --error-format=short
+
+fn main() {}

src/test/ui/json-and-error-format.stderr

@@ -0,0 +1,2 @@
+error: using `--json` requires also using `--error-format=json`
+

src/test/ui/json-invalid.rs

@@ -0,0 +1,4 @@
+// build-fail
+// compile-flags: --json=foo --error-format=json
+
+fn main() {}