Rollup merge of rust-lang#50541 - QuietMisdreavus:rustdoc-errors, r=G…

…uillaumeGomez

rustdoc: replace most (e)println! statements with structured warnings/errors

Turns out, the rustc diagnostic handler doesn't need a whole lot of setup that we weren't already doing. For errors that occur outside a "dealing with source code" context, we can just use the format/color config we were already parsing and make up a `Handler` that we can emit structured warnings/errors from. So i did that. This will make it way easier to test things with `rustdoc-ui` tests, since those require the JSON error output. (In fact, this PR is a yak shave for a different one where i was trying to do just that. `>_>`)

src/librustdoc/core.rs

@@ -117,6 +117,57 @@ impl DocAccessLevels for AccessLevels<DefId> {
  }
 }
 
+/// Creates a new diagnostic `Handler` that can be used to emit warnings and errors.
+///
+/// If the given `error_format` is `ErrorOutputType::Json` and no `CodeMap` is given, a new one
+/// will be created for the handler.
+pub fn new_handler(error_format: ErrorOutputType, codemap: Option<Lrc<codemap::CodeMap>>)
+ -> errors::Handler
+{
+ // rustdoc doesn't override (or allow to override) anything from this that is relevant here, so
+ // stick to the defaults
+ let sessopts = config::basic_options();
+ let emitter: Box<dyn Emitter + sync::Send> = match error_format {
+ ErrorOutputType::HumanReadable(color_config) => Box::new(
+ EmitterWriter::stderr(
+ color_config,
+ codemap.map(|cm| cm as _),
+ false,
+ sessopts.debugging_opts.teach,
+ ).ui_testing(sessopts.debugging_opts.ui_testing)
+ ),
+ ErrorOutputType::Json(pretty) => {
+ let codemap = codemap.unwrap_or_else(
+ || Lrc::new(codemap::CodeMap::new(sessopts.file_path_mapping())));
+ Box::new(
+ JsonEmitter::stderr(
+ None,
+ codemap,
+ pretty,
+ sessopts.debugging_opts.suggestion_applicability,
+ ).ui_testing(sessopts.debugging_opts.ui_testing)
+ )
+ },
+ ErrorOutputType::Short(color_config) => Box::new(
+ EmitterWriter::stderr(
+ color_config,
+ codemap.map(|cm| cm as _),
+ true,
+ false)
+ ),
+ };
+
+ errors::Handler::with_emitter_and_flags(
+ emitter,
+ errors::HandlerFlags {
+ can_emit_warnings: true,
+ treat_err_as_bug: false,
+ external_macro_backtrace: false,
+ ..Default::default()
+ },
+ )
+}
+
 pub fn run_core(search_paths: SearchPaths,
  cfgs: Vec<String>,
  externs: config::Externs,
@@ -159,41 +210,11 @@ pub fn run_core(search_paths: SearchPaths,
  },
  error_format,
  edition,
- ..config::basic_options().clone()
+ ..config::basic_options()
  };
  driver::spawn_thread_pool(sessopts, move |sessopts| {
  let codemap = Lrc::new(codemap::CodeMap::new(sessopts.file_path_mapping()));
- let emitter: Box<dyn Emitter + sync::Send> = match error_format {
- ErrorOutputType::HumanReadable(color_config) => Box::new(
- EmitterWriter::stderr(
- color_config,
- Some(codemap.clone()),
- false,
- sessopts.debugging_opts.teach,
- ).ui_testing(sessopts.debugging_opts.ui_testing)
- ),
- ErrorOutputType::Json(pretty) => Box::new(
- JsonEmitter::stderr(
- None,
- codemap.clone(),
- pretty,
- sessopts.debugging_opts.suggestion_applicability,
- ).ui_testing(sessopts.debugging_opts.ui_testing)
- ),
- ErrorOutputType::Short(color_config) => Box::new(
- EmitterWriter::stderr(color_config, Some(codemap.clone()), true, false)
- ),
- };
-
- let diagnostic_handler = errors::Handler::with_emitter_and_flags(
- emitter,
- errors::HandlerFlags {
- can_emit_warnings: true,
- treat_err_as_bug: false,
- external_macro_backtrace: false,
- ..Default::default()
- },
- );
+ let diagnostic_handler = new_handler(error_format, Some(codemap.clone()));
 
  let mut sess = session::build_session_(
  sessopts, cpath, diagnostic_handler, codemap,

src/librustdoc/externalfiles.rs

@@ -11,6 +11,7 @@
 use std::fs;
 use std::path::Path;
 use std::str;
+use errors;
 use html::markdown::Markdown;
 
 #[derive(Clone)]
@@ -28,23 +29,23 @@ pub struct ExternalHtml {
 
 impl ExternalHtml {
  pub fn load(in_header: &[String], before_content: &[String], after_content: &[String],
- md_before_content: &[String], md_after_content: &[String])
+ md_before_content: &[String], md_after_content: &[String], diag: &errors::Handler)
  -> Option<ExternalHtml> {
- load_external_files(in_header)
+ load_external_files(in_header, diag)
  .and_then(|ih|
- load_external_files(before_content)
+ load_external_files(before_content, diag)
  .map(|bc| (ih, bc))
  )
  .and_then(|(ih, bc)|
- load_external_files(md_before_content)
+ load_external_files(md_before_content, diag)
  .map(|m_bc| (ih, format!("{}{}", bc, Markdown(&m_bc, &[]))))
  )
  .and_then(|(ih, bc)|
- load_external_files(after_content)
+ load_external_files(after_content, diag)
  .map(|ac| (ih, bc, ac))
  )
  .and_then(|(ih, bc, ac)|
- load_external_files(md_after_content)
+ load_external_files(md_after_content, diag)
  .map(|m_ac| (ih, bc, format!("{}{}", ac, Markdown(&m_ac, &[]))))
  )
  .map(|(ih, bc, ac)|
@@ -62,28 +63,30 @@ pub enum LoadStringError {
  BadUtf8,
 }
 
-pub fn load_string<P: AsRef<Path>>(file_path: P) -> Result<String, LoadStringError> {
+pub fn load_string<P: AsRef<Path>>(file_path: P, diag: &errors::Handler)
+ -> Result<String, LoadStringError>
+{
  let file_path = file_path.as_ref();
  let contents = match fs::read(file_path) {
  Ok(bytes) => bytes,
  Err(e) => {
- eprintln!("error reading `{}`: {}", file_path.display(), e);
+ diag.struct_err(&format!("error reading `{}`: {}", file_path.display(), e)).emit();
  return Err(LoadStringError::ReadFail);
  }
  };
  match str::from_utf8(&contents) {
  Ok(s) => Ok(s.to_string()),
  Err(_) => {
- eprintln!("error reading `{}`: not UTF-8", file_path.display());
+ diag.struct_err(&format!("error reading `{}`: not UTF-8", file_path.display())).emit();
  Err(LoadStringError::BadUtf8)
  }
  }
 }
 
-fn load_external_files(names: &[String]) -> Option<String> {
+fn load_external_files(names: &[String], diag: &errors::Handler) -> Option<String> {
  let mut out = String::new();
  for name in names {
- let s = match load_string(name) {
+ let s = match load_string(name, diag) {
  Ok(s) => s,
  Err(_) => return None,
  };