rustdoc: port the -C option from rustc

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

@@ -141,6 +141,31 @@ Similar to `--library-path`, `--extern` is about specifying the location
 of a dependency. `--library-path` provides directories to search in, `--extern`
 instead lets you specify exactly which dependency is located where.
 
+## `-C`/`--codegen`: pass codegen options to rustc
+
+Using this flag looks like this:
+
+```bash
+$ rustdoc src/lib.rs -C target_feature=+avx
+$ rustdoc src/lib.rs --codegen target_feature=+avx
+
+$ rustdoc --test src/lib.rs -C target_feature=+avx
+$ rustdoc --test src/lib.rs --codegen target_feature=+avx
+
+$ rustdoc --test README.md -C target_feature=+avx
+$ rustdoc --test README.md --codegen target_feature=+avx
+```
+
+When rustdoc generates documentation, looks for documentation tests, or executes documentation
+tests, it needs to compile some rust code, at least part-way. This flag allows you to tell rustdoc
+to provide some extra codegen options to rustc when it runs these compilations. Most of the time,
+these options won't affect a regular documentation run, but if something depends on target features
+to be enabled, or documentation tests need to use some additional options, this flag allows you to
+affect that.
+
+The arguments to this flag are the same as those for the `-C` flag on rustc. Run `rustc -C help` to
+get the full list.
+
 ## `--passes`: add more rustdoc passes
 
 Using this flag looks like this:

src/librustdoc/core.rs

@@ -42,7 +42,7 @@ use clean;
 use clean::Clean;
 use html::render::RenderInfo;
 
-pub use rustc::session::config::Input;
+pub use rustc::session::config::{Input, CodegenOptions};
 pub use rustc::session::search_paths::SearchPaths;
 
 pub type ExternalPaths = FxHashMap<DefId, (Vec<String>, clean::TypeKind)>;
@@ -125,7 +125,8 @@ pub fn run_core(search_paths: SearchPaths,
                 allow_warnings: bool,
                 crate_name: Option<String>,
                 force_unstable_if_unmarked: bool,
-                edition: Edition) -> (clean::Crate, RenderInfo)
+                edition: Edition,
+                cg: CodegenOptions) -> (clean::Crate, RenderInfo)
 {
     // Parse, resolve, and typecheck the given crate.
 
@@ -143,6 +144,7 @@ pub fn run_core(search_paths: SearchPaths,
         crate_types: vec![config::CrateTypeRlib],
         lint_opts: if !allow_warnings { vec![(warning_lint, lint::Allow)] } else { vec![] },
         lint_cap: Some(lint::Allow),
+        cg,
         externs,
         target_triple: triple.unwrap_or(host_triple),
         // Ensure that rustdoc works even if rustc is feature-staged

src/librustdoc/lib.rs

@@ -63,7 +63,8 @@ use std::sync::mpsc::channel;
 use syntax::edition::Edition;
 use externalfiles::ExternalHtml;
 use rustc::session::search_paths::SearchPaths;
-use rustc::session::config::{ErrorOutputType, RustcOptGroup, nightly_options, Externs};
+use rustc::session::config::{ErrorOutputType, RustcOptGroup, Externs, CodegenOptions};
+use rustc::session::config::{nightly_options, build_codegen_options};
 use rustc_back::target::TargetTriple;
 
 #[macro_use]
@@ -157,6 +158,9 @@ pub fn opts() -> Vec<RustcOptGroup> {
         stable("plugin-path", |o| {
             o.optmulti("", "plugin-path", "directory to load plugins from", "DIR")
         }),
+        stable("C", |o| {
+            o.optmulti("C", "codegen", "pass a codegen option to rustc", "OPT[=VALUE]")
+        }),
         stable("passes", |o| {
             o.optmulti("", "passes",
                        "list of passes to also run, you might want \
@@ -443,14 +447,16 @@ pub fn main_args(args: &[String]) -> isize {
         }
     };
 
+    let cg = build_codegen_options(&matches, ErrorOutputType::default());
+
     match (should_test, markdown_input) {
         (true, true) => {
             return markdown::test(input, cfgs, libs, externs, test_args, maybe_sysroot,
-                                  display_warnings, linker, edition)
+                                  display_warnings, linker, edition, cg)
         }
         (true, false) => {
             return test::run(Path::new(input), cfgs, libs, externs, test_args, crate_name,
-                             maybe_sysroot, display_warnings, linker, edition)
+                             maybe_sysroot, display_warnings, linker, edition, cg)
         }
         (false, true) => return markdown::render(Path::new(input),
                                                  output.unwrap_or(PathBuf::from("doc")),
@@ -460,7 +466,7 @@ pub fn main_args(args: &[String]) -> isize {
     }
 
     let output_format = matches.opt_str("w");
-    let res = acquire_input(PathBuf::from(input), externs, edition, &matches, move |out| {
+    let res = acquire_input(PathBuf::from(input), externs, edition, cg, &matches, move |out| {
         let Output { krate, passes, renderinfo } = out;
         info!("going to format");
         match output_format.as_ref().map(|s| &**s) {
@@ -502,14 +508,15 @@ fn print_error<T>(error_message: T) where T: Display {
 fn acquire_input<R, F>(input: PathBuf,
                        externs: Externs,
                        edition: Edition,
+                       cg: CodegenOptions,
                        matches: &getopts::Matches,
                        f: F)
                        -> Result<R, String>
 where R: 'static + Send, F: 'static + Send + FnOnce(Output) -> R {
     match matches.opt_str("r").as_ref().map(|s| &**s) {
-        Some("rust") => Ok(rust_input(input, externs, edition, matches, f)),
+        Some("rust") => Ok(rust_input(input, externs, edition, cg, matches, f)),
         Some(s) => Err(format!("unknown input format: {}", s)),
-        None => Ok(rust_input(input, externs, edition, matches, f))
+        None => Ok(rust_input(input, externs, edition, cg, matches, f))
     }
 }
 
@@ -538,6 +545,7 @@ fn parse_externs(matches: &getopts::Matches) -> Result<Externs, String> {
 fn rust_input<R, F>(cratefile: PathBuf,
                     externs: Externs,
                     edition: Edition,
+                    cg: CodegenOptions,
                     matches: &getopts::Matches,
                     f: F) -> R
 where R: 'static + Send,
@@ -591,7 +599,7 @@ where R: 'static + Send,
         let (mut krate, renderinfo) =
             core::run_core(paths, cfgs, externs, Input::File(cratefile), triple, maybe_sysroot,
                            display_warnings, crate_name.clone(),
-                           force_unstable_if_unmarked, edition);
+                           force_unstable_if_unmarked, edition, cg);
 
         info!("finished with rustc");
 

src/librustdoc/markdown.rs

@@ -16,7 +16,7 @@ use std::path::{PathBuf, Path};
 use getopts;
 use testing;
 use rustc::session::search_paths::SearchPaths;
-use rustc::session::config::Externs;
+use rustc::session::config::{Externs, CodegenOptions};
 use syntax::codemap::DUMMY_SP;
 use syntax::edition::Edition;
 
@@ -140,7 +140,8 @@ pub fn render(input: &Path, 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: Externs,
             mut test_args: Vec<String>, maybe_sysroot: Option<PathBuf>,
-            display_warnings: bool, linker: Option<PathBuf>, edition: Edition) -> isize {
+            display_warnings: bool, linker: Option<PathBuf>, edition: Edition,
+            cg: CodegenOptions) -> isize {
     let input_str = match load_string(input) {
         Ok(s) => s,
         Err(LoadStringError::ReadFail) => return 1,
@@ -150,7 +151,7 @@ pub fn test(input: &str, cfgs: Vec<String>, libs: SearchPaths, externs: Externs,
     let mut opts = TestOptions::default();
     opts.no_crate_inject = true;
     opts.display_warnings = display_warnings;
-    let mut collector = Collector::new(input.to_owned(), cfgs, libs, externs,
+    let mut collector = Collector::new(input.to_owned(), cfgs, libs, cg, externs,
                                        true, opts, maybe_sysroot, None,
                                        Some(PathBuf::from(input)),
                                        linker, edition);

src/librustdoc/test.rs

@@ -24,11 +24,11 @@ use rustc_lint;
 use rustc::hir;
 use rustc::hir::intravisit;
 use rustc::session::{self, CompileIncomplete, config};
-use rustc::session::config::{OutputType, OutputTypes, Externs};
+use rustc::session::config::{OutputType, OutputTypes, Externs, CodegenOptions};
 use rustc::session::search_paths::{SearchPaths, PathKind};
 use rustc_metadata::dynamic_lib::DynamicLibrary;
 use tempdir::TempDir;
-use rustc_driver::{self, driver, Compilation};
+use rustc_driver::{self, driver, target_features, Compilation};
 use rustc_driver::driver::phase_2_configure_and_expand;
 use rustc_metadata::cstore::CStore;
 use rustc_resolve::MakeGlobMap;
@@ -64,7 +64,8 @@ pub fn run(input_path: &Path,
            maybe_sysroot: Option<PathBuf>,
            display_warnings: bool,
            linker: Option<PathBuf>,
-           edition: Edition)
+           edition: Edition,
+           cg: CodegenOptions)
            -> isize {
     let input = config::Input::File(input_path.to_owned());
 
@@ -73,6 +74,7 @@ pub fn run(input_path: &Path,
             || Some(env::current_exe().unwrap().parent().unwrap().parent().unwrap().to_path_buf())),
         search_paths: libs.clone(),
         crate_types: vec![config::CrateTypeDylib],
+        cg: cg.clone(),
         externs: externs.clone(),
         unstable_features: UnstableFeatures::from_environment(),
         lint_cap: Some(::rustc::lint::Level::Allow),
@@ -96,8 +98,10 @@ pub fn run(input_path: &Path,
     let trans = rustc_driver::get_trans(&sess);
     let cstore = CStore::new(trans.metadata_loader());
     rustc_lint::register_builtins(&mut sess.lint_store.borrow_mut(), Some(&sess));
-    sess.parse_sess.config =
-        config::build_configuration(&sess, config::parse_cfgspecs(cfgs.clone()));
+
+    let mut cfg = config::build_configuration(&sess, config::parse_cfgspecs(cfgs.clone()));
+    target_features::add_configuration(&mut cfg, &sess, &*trans);
+    sess.parse_sess.config = cfg;
 
     let krate = panictry!(driver::phase_1_parse_input(&driver::CompileController::basic(),
                                                       &sess,
@@ -123,6 +127,7 @@ pub fn run(input_path: &Path,
     let mut collector = Collector::new(crate_name,
                                        cfgs,
                                        libs,
+                                       cg,
                                        externs,
                                        false,
                                        opts,
@@ -188,7 +193,7 @@ fn scrape_test_config(krate: &::rustc::hir::Crate) -> TestOptions {
 
 fn run_test(test: &str, cratename: &str, filename: &FileName, line: usize,
             cfgs: Vec<String>, libs: SearchPaths,
-            externs: Externs,
+            cg: CodegenOptions, externs: Externs,
             should_panic: bool, no_run: bool, as_test_harness: bool,
             compile_fail: bool, mut error_codes: Vec<String>, opts: &TestOptions,
             maybe_sysroot: Option<PathBuf>, linker: Option<PathBuf>, edition: Edition) {
@@ -213,7 +218,7 @@ fn run_test(test: &str, cratename: &str, filename: &FileName, line: usize,
         cg: config::CodegenOptions {
             prefer_dynamic: true,
             linker,
-            .. config::basic_codegen_options()
+            ..cg
         },
         test: as_test_harness,
         unstable_features: UnstableFeatures::from_environment(),
@@ -271,8 +276,11 @@ fn run_test(test: &str, cratename: &str, filename: &FileName, line: usize,
     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();
-    sess.parse_sess.config =
-        config::build_configuration(&sess, config::parse_cfgspecs(cfgs.clone()));
+
+    let mut cfg = config::build_configuration(&sess, config::parse_cfgspecs(cfgs.clone()));
+    target_features::add_configuration(&mut cfg, &sess, &*trans);
+    sess.parse_sess.config = cfg;
+
     let out = Some(outdir.lock().unwrap().path().to_path_buf());
 
     if no_run {
@@ -473,6 +481,7 @@ pub struct Collector {
 
     cfgs: Vec<String>,
     libs: SearchPaths,
+    cg: CodegenOptions,
     externs: Externs,
     use_headers: bool,
     cratename: String,
@@ -486,15 +495,16 @@ pub struct Collector {
 }
 
 impl Collector {
-    pub fn new(cratename: String, cfgs: Vec<String>, libs: SearchPaths, externs: Externs,
-               use_headers: bool, opts: TestOptions, maybe_sysroot: Option<PathBuf>,
-               codemap: Option<Lrc<CodeMap>>, filename: Option<PathBuf>,
-               linker: Option<PathBuf>, edition: Edition) -> Collector {
+    pub fn new(cratename: String, cfgs: Vec<String>, libs: SearchPaths, cg: CodegenOptions,
+               externs: Externs, use_headers: bool, opts: TestOptions,
+               maybe_sysroot: Option<PathBuf>, codemap: Option<Lrc<CodeMap>>,
+               filename: Option<PathBuf>, linker: Option<PathBuf>, edition: Edition) -> Collector {
         Collector {
             tests: Vec::new(),
             names: Vec::new(),
             cfgs,
             libs,
+            cg,
             externs,
             use_headers,
             cratename,
@@ -519,6 +529,7 @@ impl Collector {
         let name = self.generate_name(line, &filename);
         let cfgs = self.cfgs.clone();
         let libs = self.libs.clone();
+        let cg = self.cg.clone();
         let externs = self.externs.clone();
         let cratename = self.cratename.to_string();
         let opts = self.opts.clone();
@@ -547,6 +558,7 @@ impl Collector {
                                  line,
                                  cfgs,
                                  libs,
+                                 cg,
                                  externs,
                                  should_panic,
                                  no_run,

src/test/rustdoc/doc-cfg-target-feature.rs

@@ -0,0 +1,31 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// only-x86_64
+// compile-flags:--test
+// should-fail
+// no-system-llvm
+
+// #49723: rustdoc didn't add target features when extracting or running doctests
+
+#![feature(doc_cfg)]
+
+/// Foo
+///
+/// # Examples
+///
+/// ```
+/// #![feature(cfg_target_feature)]
+///
+/// #[cfg(target_feature = "sse")]
+/// assert!(false);
+/// ```
+#[doc(cfg(target_feature = "sse"))]
+pub unsafe fn foo() {}

src/test/rustdoc/force-target-feature.rs

@@ -0,0 +1,21 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// only-x86_64
+// compile-flags:--test -C target-feature=+avx
+// should-fail
+
+/// (written on a spider's web) Some Struct
+///
+/// ```
+/// panic!("oh no");
+/// ```
+#[doc(cfg(target_feature = "avx"))]
+pub struct SomeStruct;