Type-based search does not work for primitives since March

[jyn514]

searched nightlies: from nightly-2019-05-02 to nightly-2020-07-17
regressed nightly: nightly-2020-03-20
searched commits: from f509b26 to f4c675c
regressed commit: f4c675c

bisected with cargo-bisect-rustc v0.5.2

Host triple: x86_64-unknown-linux-gnu
Reproduce with:

cargo bisect-rustc --script ./search_works.sh --start 2019-05-02 --preserve 

search_works.sh:

#!/bin/sh
set -eu
rustdoc search_function_type.rs
node ~/rustc/src/tools/rustdoc-js/tester.js --doc-folder doc --crate-name search_function_type --test-file ~/rustc/src/test/rustdoc-js/tmp/search-function-type.js

search_function_type.rs:

/// f
pub fn f(u: usize) -> usize {
    u
}

search-function-type.js:

const QUERY = 'usize -> usize';

const EXPECTED = {
    'in_args': [
        { 'path': 'search_function_type', 'name': 'f' },
    ],
};

This requires a git clone of rustc as well as the following modification to tester.js:

diff --git a/src/tools/rustdoc-js/tester.js b/src/tools/rustdoc-js/tester.js
index 139e6f73f42..8a3ab056f80 100644
--- a/src/tools/rustdoc-js/tester.js
+++ b/src/tools/rustdoc-js/tester.js
@@ -182,7 +182,7 @@ function loadThings(thingsToLoad, kindOfLoad, funcToCall, fileContent) {
         var tmp = funcToCall(fileContent, thingsToLoad[i]);
         if (tmp === null) {
             console.log('unable to find ' + kindOfLoad + ' "' + thingsToLoad[i] + '"');
-            process.exit(1);
+            continue;
         }
         content += tmp;
         content += 'exports.' + thingsToLoad[i] + ' = ' + thingsToLoad[i] + ';';

Originally reported in #60485 (comment).

[jyn514]

Relevant PR: #69402

[jyn514]

The function is missing from the search index after that PR. Before:

var N=null,E="",T="t",U="u",searchIndex={};

searchIndex["search_function_type"]={"doc":E,"i":[[5,"f","search_function_type","f",N,[[["usize"]],["usize"]]],[0,"m",E,E,N,N]],"p":[]};
initSearch(searchIndex);addSearchOptions(searchIndex);

After:

searchIndex["search_function_type"] = {"doc":"","i":[[5,"f","search_function_type","f",null,[[]]],[0,"m","","",null,null]],"p":[]};
addSearchOptions(searchIndex);initSearch(searchIndex);

[jyn514]

Actually it looks like the function is still there, it's just missing the types for the arguments and return type.

[jyn514]

Maybe this bit of code is skipping it when it wasn't before? https://github.com/rust-lang/rust/pull/69402/files?file-filters%5B%5D=.rs#diff-2b73a40b29f966df2a77a3bbaf34a9f1L234-R246

[jyn514]

Yeah, I don't think arguments have def ids.

[GuillaumeGomez]

To be exact, the problem seems to come from:

Primitive(p) => crate::html::render::cache().primitive_locations.get(&p).cloned(),

coming from:

impl GetDefId for Type {
    fn def_id(&self) -> Option<DefId> {
        ...
    }
}

in the librustdoc/clean/types.rs file.

[Manishearth]

Through some chats in discord it seems like a good approach to this would be to:

• compute a separate list of primitives before starting the whole cleaning rigmarole. For efficiency it might be worth tagging std as doc(has_primitives) or something if we'd like, but this wouldn't be a perf loss since this work is being done anyway.
• use that list in GetDefId for Type

Eventually I'd like to stop having the cache be a global parameter and instead passing it around as much as possible so that such problems are easier to avoid.