authorbors <bors@rust-lang.org> 2026-05-21 22:46:41 UTC
committerbors <bors@rust-lang.org> 2026-05-21 22:46:41 UTC
log4d276d7fdba2a24c73dbca3027461bb202e83436
treee95f0cc3a6c1f1af54f2b90c5f5c24a5af0ad563
parente96c36b6f76833388c519561d145492d2c08db4e
parentd3bdea115d929178e0a3189fb4fdf0e827529ed3

Auto merge of #155307 - Urgau:rustdoc-stabilize-remap-path-prefix, r=GuillaumeGomez

Stabilize `--remap-path-prefix` in rustdoc # Stabilization report of `--remap-path-prefix` in rustdoc ## Summary `rustc` supports remapping source paths prefixes as a best effort in all compiler generated output, including compiler diagnostics, debugging information, macro expansions, documentation, doctests, etc. This is useful for normalizing build products, for example, by removing the current directory out of the paths emitted into object files. This stabilization stabilize the same flag used by `rustc` in `rustdoc`. There are no tracking issue. Stabilization was discussed at the last meeting, [#t-rustdoc/meetings > 2026-04-13 @ 💬](https://rust-lang.zulipchat.com/#narrow/channel/393423-t-rustdoc.2Fmeetings/topic/2026-04-13/near/585264347). ### What is stabilized The rustdoc `--remap-path-prefix` flag is being stabilized by this PR. (It's equivalent to rustc flag) It permits remapping (as a best effort) source path prefixes in all output, including diagnostics, debug information, macro expansions, generated documentation, etc. It takes a value of the form `FROM=TO` where a path prefix equal to `FROM` is rewritten to the value `TO`. #### Example ```sh rustdoc src/lib.rs --remap-path-prefix="$PWD=/foo" ``` ### What isn't stabilized Neither `--remap-path-scope` (~~soon to be added as unstable in `rustdoc`~~ https://github.com/rust-lang/rust/issues/155451) or the already unstable in `rustc` `documentation` scope are being stabilized or added here. ## Design ### Implementation history - rust-lang/rust#107099 ### Unresolved questions There are no unresolved questions. ### Post-implementation changes The implementation has evolved with `rustc`, but no changes to the flag it-self have been made. ### Nightly extensions The `documentation` scope, which currently can only be set from `rustc`, as we need to add an equivalent to the `--remap-path-scope` flag, ~~which is planned~~ (EDIT: https://github.com/rust-lang/rust/issues/155451), but not required, the current `--remap-path-prefix` defaults to the `all` scope, like `rustc`. ### Doors closed We are committing to having to having a flag that permits remapping paths. The compiler team already made the same commitment. ## Feedback ### Call for testing No call for testing has been done. ### Nightly use Unable to determine. A [GitHub search](https://github.com/search?q=%20%2F--remap-path-prefix%2F&type=code) only seems to only reveals the `rustc` usage (over 6k though). Rust-for-Linux is using the [flag](https://github.com/torvalds/linux/blob/e80d033851b3bc94c3d254ac66660ddd0a49d72c/Makefile#L1151-L1153). ## Implementation ### Major parts - rust-lang/rust#107099 - rust-lang/rust#149709 - rust-lang/rust#150172 - rust-lang/rust#151589 ### Coverage - [`tests/rustdoc-ui/remap-path-prefix-failed-doctest-output.rs`](https://github.com/rust-lang/rust/blob/12f35ad39ed3e39df4d953c46d4f6cc6c82adc96/tests/rustdoc-ui/remap-path-prefix-failed-doctest-output.rs) - [`tests/rustdoc-ui/remap-path-prefix-invalid-doctest.rs`](https://github.com/rust-lang/rust/blob/12f35ad39ed3e39df4d953c46d4f6cc6c82adc96/tests/rustdoc-ui/remap-path-prefix-invalid-doctest.rs) - [`tests/rustdoc-ui/remap-path-prefix-macro.rs`](https://github.com/rust-lang/rust/blob/12f35ad39ed3e39df4d953c46d4f6cc6c82adc96/tests/rustdoc-ui/remap-path-prefix-macro.rs) - [`tests/rustdoc-ui/remap-path-prefix-passed-doctest-output.rs`](https://github.com/rust-lang/rust/blob/12f35ad39ed3e39df4d953c46d4f6cc6c82adc96/tests/rustdoc-ui/remap-path-prefix-passed-doctest-output.rs) - [`tests/rustdoc-ui/lints/remap-path-prefix-lint.rs`](https://github.com/rust-lang/rust/blob/12f35ad39ed3e39df4d953c46d4f6cc6c82adc96/tests/rustdoc-ui/lints/remap-path-prefix-lint.rs) - [`tests/rustdoc-html/import-remapped-paths.rs`](https://github.com/rust-lang/rust/blob/12f35ad39ed3e39df4d953c46d4f6cc6c82adc96/tests/rustdoc-html/import-remapped-paths.rs) - [`tests/rustdoc-html/macro/external-macro-src.rs`](https://github.com/rust-lang/rust/blob/12f35ad39ed3e39df4d953c46d4f6cc6c82adc96/tests/rustdoc-html/macro/external-macro-src.rs) ### Outstanding bugs There are no outstanding bugs regarding `--remap-path-prefix` in `rustdoc`. There are [caveats and limitation](https://doc.rust-lang.org/nightly/rustc/remap-source-paths.html#caveats-and-limitations) in `rustc`, but they mostly concern generated object files, which we don't really have. ### Outstanding FIXMEs There are no FIXME regarding `--remap-path-prefix`. ## Acknowledgments - @edward-shen - @Urgau

12 files changed, 34 insertions(+), 30 deletions(-)

src/doc/rustdoc/src/command-line-arguments.md+12
...@@ -183,6 +183,18 @@ affect that....@@ -183,6 +183,18 @@ affect that.
183The arguments to this flag are the same as those for the `-C` flag on rustc. Run `rustc -C help` to183The arguments to this flag are the same as those for the `-C` flag on rustc. Run `rustc -C help` to
184get the full list.184get the full list.
185185
186## `--remap-path-prefix`: remap source paths in output
187
188This flag is the equivalent flag from `rustc`: `--remap-path-prefix`.
189
190```bash
191$ rustdoc src/lib.rs --remap-path-prefix="$PWD=/foo"
192```
193
194It permits remapping (as a best effort) source path prefixes in all output, including diagnostics,
195debug information, macro expansions, generated documentation, etc. It takes a value of the
196form `FROM=TO` where a path prefix equal to `FROM` is rewritten to the value `TO`.
197
186## `--test`: run code examples as tests198## `--test`: run code examples as tests
187199
188Using this flag looks like this:200Using this flag looks like this:
src/doc/rustdoc/src/unstable-features.md-8
...@@ -760,14 +760,6 @@ pass `--doctest-build-arg ARG` for each argument `ARG`....@@ -760,14 +760,6 @@ pass `--doctest-build-arg ARG` for each argument `ARG`.
760760
761This flag enables the generation of toggles to expand macros in the HTML source code pages.761This flag enables the generation of toggles to expand macros in the HTML source code pages.
762762
763## `--remap-path-prefix`: Remap source code paths in output
764
765This flag is the equivalent flag from `rustc` `--remap-path-prefix`.
766
767it permits remapping source path prefixes in all output, including compiler diagnostics,
768debug information, macro expansions, etc. It takes a value of the form `FROM=TO`
769where a path prefix equal to `FROM` is rewritten to the value `TO`.
770
771## `--remap-path-scope`: Scopes to which the source remapping should be done763## `--remap-path-scope`: Scopes to which the source remapping should be done
772764
773This flag is the equivalent flag from `rustc` `--remap-path-scope`.765This flag is the equivalent flag from `rustc` `--remap-path-scope`.
src/librustdoc/lib.rs+8-8
...@@ -458,6 +458,14 @@ fn opts() -> Vec<RustcOptGroup> {...@@ -458,6 +458,14 @@ fn opts() -> Vec<RustcOptGroup> {
458 By default, it is at `forbid` level.",458 By default, it is at `forbid` level.",
459 "LEVEL",459 "LEVEL",
460 ),460 ),
461 opt(
462 Stable,
463 Multi,
464 "",
465 "remap-path-prefix",
466 "Remap source names in compiler messages",
467 "FROM=TO",
468 ),
461 opt(Unstable, Opt, "", "index-page", "Markdown file to be used as index page", "PATH"),469 opt(Unstable, Opt, "", "index-page", "Markdown file to be used as index page", "PATH"),
462 opt(470 opt(
463 Unstable,471 Unstable,
...@@ -550,14 +558,6 @@ fn opts() -> Vec<RustcOptGroup> {...@@ -550,14 +558,6 @@ fn opts() -> Vec<RustcOptGroup> {
550 "Force all doctests to be compiled as a single binary, instead of one binary per test. If merging fails, rustdoc will emit a hard error.",558 "Force all doctests to be compiled as a single binary, instead of one binary per test. If merging fails, rustdoc will emit a hard error.",
551 "yes|no|auto",559 "yes|no|auto",
552 ),560 ),
553 opt(
554 Unstable,
555 Multi,
556 "",
557 "remap-path-prefix",
558 "Remap source names in compiler messages",
559 "FROM=TO",
560 ),
561 opt(561 opt(
562 Unstable,562 Unstable,
563 Opt,563 Opt,
tests/run-make/rustdoc-default-output/output-default.stdout+2-2
...@@ -125,6 +125,8 @@ Options:...@@ -125,6 +125,8 @@ Options:
125 Set the most restrictive lint level. More restrictive125 Set the most restrictive lint level. More restrictive
126 lints are capped at this level. By default, it is at126 lints are capped at this level. By default, it is at
127 `forbid` level.127 `forbid` level.
128 --remap-path-prefix FROM=TO
129 Remap source names in compiler messages
128 --index-page PATH130 --index-page PATH
129 Markdown file to be used as index page131 Markdown file to be used as index page
130 --enable-index-page 132 --enable-index-page
...@@ -158,8 +160,6 @@ Options:...@@ -158,8 +160,6 @@ Options:
158 Force all doctests to be compiled as a single binary,160 Force all doctests to be compiled as a single binary,
159 instead of one binary per test. If merging fails,161 instead of one binary per test. If merging fails,
160 rustdoc will emit a hard error.162 rustdoc will emit a hard error.
161 --remap-path-prefix FROM=TO
162 Remap source names in compiler messages
163 --remap-path-scope [macro,diagnostics,debuginfo,coverage,object,all]163 --remap-path-scope [macro,diagnostics,debuginfo,coverage,object,all]
164 Defines which scopes of paths should be remapped by164 Defines which scopes of paths should be remapped by
165 `--remap-path-prefix`165 `--remap-path-prefix`
tests/rustdoc-html/auxiliary/remapped-paths.rs+1-1
...@@ -1,4 +1,4 @@...@@ -1,4 +1,4 @@
1//@ compile-flags:-Zunstable-options --remap-path-prefix={{src-base}}=1//@ compile-flags:--remap-path-prefix={{src-base}}=
22
3pub struct MyStruct {3pub struct MyStruct {
4 field: u32,4 field: u32,
tests/rustdoc-ui/lints/remap-path-prefix-lint.rs+1-1
...@@ -1,7 +1,7 @@...@@ -1,7 +1,7 @@
1// Regression test for remapped paths in rustdoc errors1// Regression test for remapped paths in rustdoc errors
2// <https://github.com/rust-lang/rust/issues/69264>.2// <https://github.com/rust-lang/rust/issues/69264>.
33
4//@ compile-flags:-Z unstable-options --remap-path-prefix={{src-base}}=remapped_path4//@ compile-flags:--remap-path-prefix={{src-base}}=remapped_path
5//@ rustc-env:RUST_BACKTRACE=05//@ rustc-env:RUST_BACKTRACE=0
66
7#![deny(rustdoc::invalid_html_tags)]7#![deny(rustdoc::invalid_html_tags)]
tests/rustdoc-ui/remap-path-prefix-doctest.rs+1-1
...@@ -9,7 +9,7 @@...@@ -9,7 +9,7 @@
9//@ revisions: without-scope9//@ revisions: without-scope
1010
11//@ compile-flags:--test --test-args --test-threads=111//@ compile-flags:--test --test-args --test-threads=1
12//@ compile-flags:-Z unstable-options --remap-path-prefix={{src-base}}=remapped_path12//@ compile-flags:--remap-path-prefix={{src-base}}=remapped_path
1313
14//@[with-diag-scope] compile-flags: -Zunstable-options --remap-path-scope=diagnostics14//@[with-diag-scope] compile-flags: -Zunstable-options --remap-path-scope=diagnostics
15//@[with-macro-scope] compile-flags: -Zunstable-options --remap-path-scope=macro15//@[with-macro-scope] compile-flags: -Zunstable-options --remap-path-scope=macro
tests/rustdoc-ui/remap-path-prefix-failed-doctest-output.rs+1-1
...@@ -2,7 +2,7 @@...@@ -2,7 +2,7 @@
2// adapted to use that, and that normalize line can go away2// adapted to use that, and that normalize line can go away
33
4//@ failure-status: 1014//@ failure-status: 101
5//@ compile-flags:--test -Z unstable-options --remap-path-prefix={{src-base}}=remapped_path --test-args --test-threads=15//@ compile-flags:--test --remap-path-prefix={{src-base}}=remapped_path --test-args --test-threads=1
6//@ rustc-env:RUST_BACKTRACE=06//@ rustc-env:RUST_BACKTRACE=0
7//@ normalize-stdout: "finished in \d+\.\d+s" -> "finished in $$TIME"7//@ normalize-stdout: "finished in \d+\.\d+s" -> "finished in $$TIME"
8//@ normalize-stdout: "exit (status|code): 101" -> "exit status: 101"8//@ normalize-stdout: "exit (status|code): 101" -> "exit status: 101"
tests/rustdoc-ui/remap-path-prefix-invalid-doctest.rs+1-1
...@@ -2,7 +2,7 @@...@@ -2,7 +2,7 @@
2// adapted to use that, and that normalize line can go away2// adapted to use that, and that normalize line can go away
33
4//@ failure-status: 1014//@ failure-status: 101
5//@ compile-flags:--test -Z unstable-options --remap-path-prefix={{src-base}}=remapped_path --test-args --test-threads=15//@ compile-flags:--test --remap-path-prefix={{src-base}}=remapped_path --test-args --test-threads=1
6//@ rustc-env:RUST_BACKTRACE=06//@ rustc-env:RUST_BACKTRACE=0
7//@ normalize-stdout: "finished in \d+\.\d+s" -> "finished in $$TIME"7//@ normalize-stdout: "finished in \d+\.\d+s" -> "finished in $$TIME"
88
tests/rustdoc-ui/remap-path-prefix-macro-138520.rs+1-1
...@@ -2,7 +2,7 @@...@@ -2,7 +2,7 @@
2// when using --remap-path-prefix with macro rendering.2// when using --remap-path-prefix with macro rendering.
3// <https://github.com/rust-lang/rust/issues/138520>3// <https://github.com/rust-lang/rust/issues/138520>
44
5//@ compile-flags:-Z unstable-options --remap-path-prefix={{src-base}}=remapped_path5//@ compile-flags:--remap-path-prefix={{src-base}}=remapped_path
6//@ rustc-env:RUST_BACKTRACE=06//@ rustc-env:RUST_BACKTRACE=0
7//@ build-pass7//@ build-pass
88
tests/rustdoc-ui/remap-path-prefix-passed-doctest-output.rs+1-1
...@@ -4,7 +4,7 @@...@@ -4,7 +4,7 @@
4// FIXME: if/when the output of the test harness can be tested on its own, this test should be4// FIXME: if/when the output of the test harness can be tested on its own, this test should be
5// adapted to use that, and that normalize line can go away5// adapted to use that, and that normalize line can go away
66
7//@ compile-flags:--test -Z unstable-options --remap-path-prefix={{src-base}}=remapped_path --test-args --test-threads=17//@ compile-flags:--test --remap-path-prefix={{src-base}}=remapped_path --test-args --test-threads=1
8//@ normalize-stdout: "finished in \d+\.\d+s" -> "finished in $$TIME"8//@ normalize-stdout: "finished in \d+\.\d+s" -> "finished in $$TIME"
99
10// doctest passes at runtime10// doctest passes at runtime
tests/rustdoc-ui/remap-path-prefix.rs+5-5
...@@ -7,11 +7,11 @@...@@ -7,11 +7,11 @@
7//@ revisions: with-diag-scope with-macro-scope with-debuginfo-scope with-doc-scope7//@ revisions: with-diag-scope with-macro-scope with-debuginfo-scope with-doc-scope
8//@ revisions: without-scopes without-remap8//@ revisions: without-scopes without-remap
99
10//@[with-diag-scope] compile-flags: -Zunstable-options --remap-path-prefix={{src-base}}=remapped10//@[with-diag-scope] compile-flags: --remap-path-prefix={{src-base}}=remapped
11//@[with-macro-scope] compile-flags: -Zunstable-options --remap-path-prefix={{src-base}}=remapped11//@[with-macro-scope] compile-flags: --remap-path-prefix={{src-base}}=remapped
12//@[with-debuginfo-scope] compile-flags: -Zunstable-options --remap-path-prefix={{src-base}}=remapped12//@[with-debuginfo-scope] compile-flags: --remap-path-prefix={{src-base}}=remapped
13//@[with-doc-scope] compile-flags: -Zunstable-options --remap-path-prefix={{src-base}}=remapped13//@[with-doc-scope] compile-flags: --remap-path-prefix={{src-base}}=remapped
14//@[without-scopes] compile-flags: -Zunstable-options --remap-path-prefix={{src-base}}=remapped14//@[without-scopes] compile-flags: --remap-path-prefix={{src-base}}=remapped
1515
16//@[with-diag-scope] compile-flags: -Zunstable-options --remap-path-scope=diagnostics16//@[with-diag-scope] compile-flags: -Zunstable-options --remap-path-scope=diagnostics
17//@[with-macro-scope] compile-flags: -Zunstable-options --remap-path-scope=macro17//@[with-macro-scope] compile-flags: -Zunstable-options --remap-path-scope=macro