Auto merge of #35340 - michaelwoerister:incr-comp-cli-args, r=nikomatsakis

Take commandline arguments into account for incr. comp.

Implements the conservative strategy described in https://github.com/rust-lang/rust/issues/33727.

From now one, every time a new commandline option is added, one has to specify if it influences the incremental compilation cache. I've tried to implement this as automatic as possible: One just has to added either the `[TRACKED]` or the `[UNTRACKED]` marker next to the field. The `Options`, `CodegenOptions`, and `DebuggingOptions` definitions in `session::config` show plenty of examples.

The PR removes some cruft from `session::config::Options`, mostly unnecessary copies of flags also present in `DebuggingOptions` or `CodeGenOptions` in the same struct.

One notable removal is the `cfg` field that contained the values passed via `--cfg` commandline arguments. I chose to remove it because (1) its content is only a subset of what later is stored in `hir::Crate::config` and it's pretty likely that reading the cfgs from `Options` would not be what you wanted, and (2) we could not incorporate it into the dep-tracking hash of the `Options` struct because of how the test framework works, leaving us with a piece of untracked but vital data.

It is now recommended (just as before) to access the crate config via the `krate()` method in the HIR map.

Because the `cfg` field is not present in the `Options` struct any more, some methods in the `CompilerCalls` trait now take the crate config as an explicit parameter -- which might constitute a breaking change for plugin authors.

src/librustdoc/core.rs

@@ -45,7 +45,6 @@ pub enum MaybeTyped<'a, 'tcx: 'a> {
     NotTyped(&'a session::Session)
 }
 
-pub type Externs = HashMap<String, Vec<String>>;
 pub type ExternalPaths = HashMap<DefId, (Vec<String>, clean::TypeKind)>;
 
 pub struct DocContext<'a, 'tcx: 'a> {
@@ -99,7 +98,7 @@ impl DocAccessLevels for AccessLevels<DefId> {
 
 pub fn run_core(search_paths: SearchPaths,
                 cfgs: Vec<String>,
-                externs: Externs,
+                externs: config::Externs,
                 input: Input,
                 triple: Option<String>) -> (clean::Crate, RenderInfo)
 {
@@ -120,7 +119,6 @@ pub fn run_core(search_paths: SearchPaths,
         lint_cap: Some(lint::Allow),
         externs: externs,
         target_triple: triple.unwrap_or(config::host_triple().to_string()),
-        cfg: config::parse_cfgspecs(cfgs),
         // Ensure that rustdoc works even if rustc is feature-staged
         unstable_features: UnstableFeatures::Allow,
         ..config::basic_options().clone()
@@ -139,7 +137,7 @@ pub fn run_core(search_paths: SearchPaths,
                                        codemap, cstore.clone());
     rustc_lint::register_builtins(&mut sess.lint_store.borrow_mut(), Some(&sess));
 
-    let mut cfg = config::build_configuration(&sess);
+    let mut cfg = config::build_configuration(&sess, config::parse_cfgspecs(cfgs));
     target_features::add_configuration(&mut cfg, &sess);
 
     let krate = panictry!(driver::phase_1_parse_input(&sess, cfg, &input));

src/librustdoc/lib.rs

@@ -51,7 +51,7 @@ extern crate rustc_errors as errors;
 
 extern crate serialize as rustc_serialize; // used by deriving
 
-use std::collections::HashMap;
+use std::collections::{BTreeMap, BTreeSet};
 use std::default::Default;
 use std::env;
 use std::path::PathBuf;
@@ -60,7 +60,8 @@ use std::sync::mpsc::channel;
 
 use externalfiles::ExternalHtml;
 use rustc::session::search_paths::SearchPaths;
-use rustc::session::config::{ErrorOutputType, RustcOptGroup, nightly_options};
+use rustc::session::config::{ErrorOutputType, RustcOptGroup, nightly_options,
+                             Externs};
 
 #[macro_use]
 pub mod externalfiles;
@@ -323,7 +324,7 @@ pub fn main_args(args: &[String]) -> isize {
 /// Looks inside the command line arguments to extract the relevant input format
 /// and files and then generates the necessary rustdoc output for formatting.
 fn acquire_input(input: &str,
-                 externs: core::Externs,
+                 externs: Externs,
                  matches: &getopts::Matches) -> Result<Output, String> {
     match matches.opt_str("r").as_ref().map(|s| &**s) {
         Some("rust") => Ok(rust_input(input, externs, matches)),
@@ -335,10 +336,10 @@ fn acquire_input(input: &str,
 }
 
 /// Extracts `--extern CRATE=PATH` arguments from `matches` and
-/// returns a `HashMap` mapping crate names to their paths or else an
+/// returns a map mapping crate names to their paths or else an
 /// error message.
-fn parse_externs(matches: &getopts::Matches) -> Result<core::Externs, String> {
-    let mut externs = HashMap::new();
+fn parse_externs(matches: &getopts::Matches) -> Result<Externs, String> {
+    let mut externs = BTreeMap::new();
     for arg in &matches.opt_strs("extern") {
         let mut parts = arg.splitn(2, '=');
         let name = parts.next().ok_or("--extern value must not be empty".to_string())?;
@@ -346,9 +347,9 @@ fn parse_externs(matches: &getopts::Matches) -> Result<core::Externs, String> {
                                  .ok_or("--extern value must be of the format `foo=bar`"
                                     .to_string())?;
         let name = name.to_string();
-        externs.entry(name).or_insert(vec![]).push(location.to_string());
+        externs.entry(name).or_insert_with(BTreeSet::new).insert(location.to_string());
     }
-    Ok(externs)
+    Ok(Externs::new(externs))
 }
 
 /// Interprets the input file as a rust source file, passing it through the
@@ -356,7 +357,7 @@ fn parse_externs(matches: &getopts::Matches) -> Result<core::Externs, String> {
 /// generated from the cleaned AST of the crate.
 ///
 /// This form of input will run all of the plug/cleaning passes
-fn rust_input(cratefile: &str, externs: core::Externs, matches: &getopts::Matches) -> Output {
+fn rust_input(cratefile: &str, externs: Externs, matches: &getopts::Matches) -> Output {
     let mut default_passes = !matches.opt_present("no-defaults");
     let mut passes = matches.opt_strs("passes");
     let mut plugins = matches.opt_strs("plugins");

src/librustdoc/markdown.rs

@@ -14,10 +14,10 @@ use std::io::prelude::*;
 use std::io;
 use std::path::{PathBuf, Path};
 
-use core;
 use getopts;
 use testing;
 use rustc::session::search_paths::SearchPaths;
+use rustc::session::config::Externs;
 
 use externalfiles::ExternalHtml;
 
@@ -142,7 +142,7 @@ pub fn render(input: &str, mut output: PathBuf, matches: &getopts::Matches,
 }
 
 /// Run any tests/code examples in the markdown file `input`.
-pub fn test(input: &str, cfgs: Vec<String>, libs: SearchPaths, externs: core::Externs,
+pub fn test(input: &str, cfgs: Vec<String>, libs: SearchPaths, externs: Externs,
             mut test_args: Vec<String>) -> isize {
     let input_str = load_or_return!(input, 1, 2);
 

src/librustdoc/test.rs

@@ -26,7 +26,8 @@ use rustc_lint;
 use rustc::dep_graph::DepGraph;
 use rustc::hir::map as hir_map;
 use rustc::session::{self, config};
-use rustc::session::config::{get_unstable_features_setting, OutputType};
+use rustc::session::config::{get_unstable_features_setting, OutputType,
+                             OutputTypes, Externs};
 use rustc::session::search_paths::{SearchPaths, PathKind};
 use rustc_back::dynamic_lib::DynamicLibrary;
 use rustc_back::tempdir::TempDir;
@@ -55,7 +56,7 @@ pub struct TestOptions {
 pub fn run(input: &str,
            cfgs: Vec<String>,
            libs: SearchPaths,
-           externs: core::Externs,
+           externs: Externs,
            mut test_args: Vec<String>,
            crate_name: Option<String>)
            -> isize {
@@ -89,8 +90,7 @@ pub fn run(input: &str,
                                        cstore.clone());
     rustc_lint::register_builtins(&mut sess.lint_store.borrow_mut(), Some(&sess));
 
-    let mut cfg = config::build_configuration(&sess);
-    cfg.extend(config::parse_cfgspecs(cfgs.clone()));
+    let cfg = config::build_configuration(&sess, config::parse_cfgspecs(cfgs.clone()));
     let krate = panictry!(driver::phase_1_parse_input(&sess, cfg, &input));
     let driver::ExpansionResult { defs, mut hir_forest, .. } = {
         phase_2_configure_and_expand(
@@ -172,7 +172,7 @@ fn scrape_test_config(krate: &::rustc::hir::Crate) -> TestOptions {
 }
 
 fn runtest(test: &str, cratename: &str, cfgs: Vec<String>, libs: SearchPaths,
-           externs: core::Externs,
+           externs: Externs,
            should_panic: bool, no_run: bool, as_test_harness: bool,
            compile_fail: bool, mut error_codes: Vec<String>, opts: &TestOptions) {
     // the test harness wants its own `main` & top level functions, so
@@ -182,8 +182,7 @@ fn runtest(test: &str, cratename: &str, cfgs: Vec<String>, libs: SearchPaths,
         name: driver::anon_src(),
         input: test.to_owned(),
     };
-    let mut outputs = HashMap::new();
-    outputs.insert(OutputType::Exe, None);
+    let outputs = OutputTypes::new(&[(OutputType::Exe, None)]);
 
     let sessopts = config::Options {
         maybe_sysroot: Some(env::current_exe().unwrap().parent().unwrap()
@@ -247,8 +246,7 @@ fn runtest(test: &str, cratename: &str, cfgs: Vec<String>, libs: SearchPaths,
     let outdir = Mutex::new(TempDir::new("rustdoctest").ok().expect("rustdoc needs a tempdir"));
     let libdir = sess.target_filesearch(PathKind::All).get_lib_path();
     let mut control = driver::CompileController::basic();
-    let mut cfg = config::build_configuration(&sess);
-    cfg.extend(config::parse_cfgspecs(cfgs.clone()));
+    let cfg = config::build_configuration(&sess, config::parse_cfgspecs(cfgs.clone()));
     let out = Some(outdir.lock().unwrap().path().to_path_buf());
 
     if no_run {
@@ -396,7 +394,7 @@ pub struct Collector {
     names: Vec<String>,
     cfgs: Vec<String>,
     libs: SearchPaths,
-    externs: core::Externs,
+    externs: Externs,
     cnt: usize,
     use_headers: bool,
     current_header: Option<String>,
@@ -405,7 +403,7 @@ pub struct Collector {
 }
 
 impl Collector {
-    pub fn new(cratename: String, cfgs: Vec<String>, libs: SearchPaths, externs: core::Externs,
+    pub fn new(cratename: String, cfgs: Vec<String>, libs: SearchPaths, externs: Externs,
                use_headers: bool, opts: TestOptions) -> Collector {
         Collector {
             tests: Vec::new(),