compiler: Include span of too huge array with `-Cdebuginfo=2` #146025

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Enselic wants to merge 1 commit into rust-lang:master

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compiler: Include span of too huge array with `-Cdebuginfo=2` #146025

Enselic wants to merge 1 commit into rust-lang:master from Enselic:big-array-debuginfo-span

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@Enselic Enselic commented Aug 30, 2025 •

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We have a few ui tests to ensure we emit an error if we encounter too big arrays. Before this fix, compiling the tests with -Cdebuginfo=2 would not include the spans of the instantiation sites, because the error is then emitted from a different code path that does not include the span.

Propagate the span to the error also in the debuginfo case, so the tests passes regardless of debuginfo level.

r? @wesleywiser since this is a natural continuation of #145967 that you approved (thanks!).

cc #61117 since this takes is one step closer to increasing rust.debuginfo-level-tests to 2 in the x86_64-gnu-debug CI job.

Test failure output without the fix

Here is what the test failures look like if you run the tests without the fix. (Click to expand.)

$ ./x test --set rust.debuginfo-level-tests=2 tests/ui/limits/huge-array-simple-64.rs tests/ui/limits/huge-array.rs tests/ui/limits/issue-15919-64.rs
Building bootstrap
 Finished `dev` profile [unoptimized] target(s) in 0.16s
/home/martin/src/rust/build/x86_64-unknown-linux-gnu/ci-llvm/bin/llvm-strip does not exist; skipping copy
Building stage1 compiler artifacts (stage0 -> stage1, x86_64-unknown-linux-gnu)
 Finished `release` profile [optimized + debuginfo] target(s) in 0.40s
Creating a sysroot for stage1 compiler (use `rustup toolchain link 'name' build/host/stage1`)
Building stage1 lld-wrapper (stage0 -> stage1, x86_64-unknown-linux-gnu)
 Finished `release` profile [optimized + debuginfo] target(s) in 0.08s
Building stage1 library artifacts (stage1 -> stage1, x86_64-unknown-linux-gnu)
 Compiling addr2line v0.25.0
 Compiling std v0.0.0 (/home/martin/src/rust/library/std)
 Compiling rustc-std-workspace-std v1.99.0 (/home/martin/src/rust/library/rustc-std-workspace-std)
 Compiling unicode-width v0.2.1
 Compiling rustc-literal-escaper v0.0.5
 Compiling proc_macro v0.0.0 (/home/martin/src/rust/library/proc_macro)
 Compiling getopts v0.2.23
 Compiling test v0.0.0 (/home/martin/src/rust/library/test)
 Compiling sysroot v0.0.0 (/home/martin/src/rust/library/sysroot)
 Finished `release` profile [optimized + debuginfo] target(s) in 14.43s
Building stage1 compiletest (stage0 -> stage1, x86_64-unknown-linux-gnu)
 Finished `release` profile [optimized + debuginfo] target(s) in 0.14s
Testing stage2 compiletest suite=ui mode=ui (stage1 -> stage2, x86_64-unknown-linux-gnu)
running 6 tests
[ui] tests/ui/limits/huge-array.rs#full-debuginfo ... F
[ui] tests/ui/limits/issue-15919-64.rs#full-debuginfo ... F
[ui] tests/ui/limits/huge-array-simple-64.rs#full-debuginfo ... F
...
failures:
---- [ui] tests/ui/limits/huge-array.rs#full-debuginfo stdout ----
Saved the actual stderr to `/home/martin/src/rust/build/x86_64-unknown-linux-gnu/test/ui/limits/huge-array.full-debuginfo/huge-array.full-debuginfo.stderr`
diff of stderr:
1 error: values of the type `[[u8; 1518599999]; 1518600000]` are too big for the target architecture
- --> $DIR/huge-array.rs:9:9
- |
- LL | let s: [T; 1518600000] = [t; 1518600000];
- | ^
6
7 error: aborting due to 1 previous error
8
The actual stderr differed from the expected stderr
To update references, rerun the tests and pass the `--bless` flag
To only update this specific test, also pass `--test-args limits/huge-array.rs`
error in revision `full-debuginfo`: 1 errors occurred comparing output.
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/home/martin/src/rust/build/x86_64-unknown-linux-gnu/stage1/bin/rustc" "/home/martin/src/rust/tests/ui/limits/huge-array.rs" "-Zthreads=1" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/home/martin/.cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/home/martin/src/rust/vendor" "--sysroot" "/home/martin/src/rust/build/x86_64-unknown-linux-gnu/stage1" "--target=x86_64-unknown-linux-gnu" "--cfg" "full_debuginfo" "--check-cfg" "cfg(test,FALSE,no_debuginfo,full_debuginfo)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "-C" "prefer-dynamic" "--out-dir" "/home/martin/src/rust/build/x86_64-unknown-linux-gnu/test/ui/limits/huge-array.full-debuginfo" "-A" "unused" "-A" "internal_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Lnative=/home/martin/src/rust/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-Cdebuginfo=2"
stdout: none
--- stderr -------------------------------
error: values of the type `[[u8; 1518599999]; 1518600000]` are too big for the target architecture
error: aborting due to 1 previous error
------------------------------------------
---- [ui] tests/ui/limits/huge-array.rs#full-debuginfo stdout end ----
---- [ui] tests/ui/limits/issue-15919-64.rs#full-debuginfo stdout ----
Saved the actual stderr to `/home/martin/src/rust/build/x86_64-unknown-linux-gnu/test/ui/limits/issue-15919-64.full-debuginfo/issue-15919-64.full-debuginfo.stderr`
diff of stderr:
1 error: values of the type `[usize; usize::MAX]` are too big for the target architecture
- --> $DIR/issue-15919-64.rs:10:9
- |
- LL | let x = [0usize; 0xffff_ffff_ffff_ffff];
- | ^
6
7 error: aborting due to 1 previous error
8
The actual stderr differed from the expected stderr
To update references, rerun the tests and pass the `--bless` flag
To only update this specific test, also pass `--test-args limits/issue-15919-64.rs`
error in revision `full-debuginfo`: 1 errors occurred comparing output.
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/home/martin/src/rust/build/x86_64-unknown-linux-gnu/stage1/bin/rustc" "/home/martin/src/rust/tests/ui/limits/issue-15919-64.rs" "-Zthreads=1" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/home/martin/.cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/home/martin/src/rust/vendor" "--sysroot" "/home/martin/src/rust/build/x86_64-unknown-linux-gnu/stage1" "--target=x86_64-unknown-linux-gnu" "--cfg" "full_debuginfo" "--check-cfg" "cfg(test,FALSE,no_debuginfo,full_debuginfo)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "-C" "prefer-dynamic" "--out-dir" "/home/martin/src/rust/build/x86_64-unknown-linux-gnu/test/ui/limits/issue-15919-64.full-debuginfo" "-A" "unused" "-A" "internal_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Lnative=/home/martin/src/rust/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-Cdebuginfo=2"
stdout: none
--- stderr -------------------------------
error: values of the type `[usize; usize::MAX]` are too big for the target architecture
error: aborting due to 1 previous error
------------------------------------------
---- [ui] tests/ui/limits/issue-15919-64.rs#full-debuginfo stdout end ----
---- [ui] tests/ui/limits/huge-array-simple-64.rs#full-debuginfo stdout ----
Saved the actual stderr to `/home/martin/src/rust/build/x86_64-unknown-linux-gnu/test/ui/limits/huge-array-simple-64.full-debuginfo/huge-array-simple-64.full-debuginfo.stderr`
diff of stderr:
1 error: values of the type `[u8; 2305843011361177600]` are too big for the target architecture
- --> $DIR/huge-array-simple-64.rs:12:9
- |
- LL | let _fat: [u8; (1<<61)+(1<<31)] =
- | ^^^^
6
7 error: aborting due to 1 previous error
8
The actual stderr differed from the expected stderr
To update references, rerun the tests and pass the `--bless` flag
To only update this specific test, also pass `--test-args limits/huge-array-simple-64.rs`
error in revision `full-debuginfo`: 1 errors occurred comparing output.
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/home/martin/src/rust/build/x86_64-unknown-linux-gnu/stage1/bin/rustc" "/home/martin/src/rust/tests/ui/limits/huge-array-simple-64.rs" "-Zthreads=1" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/home/martin/.cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/home/martin/src/rust/vendor" "--sysroot" "/home/martin/src/rust/build/x86_64-unknown-linux-gnu/stage1" "--target=x86_64-unknown-linux-gnu" "--cfg" "full_debuginfo" "--check-cfg" "cfg(test,FALSE,no_debuginfo,full_debuginfo)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "-C" "prefer-dynamic" "--out-dir" "/home/martin/src/rust/build/x86_64-unknown-linux-gnu/test/ui/limits/huge-array-simple-64.full-debuginfo" "-A" "unused" "-A" "internal_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Lnative=/home/martin/src/rust/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-Cdebuginfo=2"
stdout: none
--- stderr -------------------------------
error: values of the type `[u8; 2305843011361177600]` are too big for the target architecture
error: aborting due to 1 previous error
------------------------------------------
---- [ui] tests/ui/limits/huge-array-simple-64.rs#full-debuginfo stdout end ----
failures:
 [ui] tests/ui/limits/huge-array.rs#full-debuginfo
 [ui] tests/ui/limits/issue-15919-64.rs#full-debuginfo
 [ui] tests/ui/limits/huge-array-simple-64.rs#full-debuginfo
test result: FAILED. 3 passed; 3 failed; 0 ignored; 0 measured; 19720 filtered out; finished in 117.18ms
Some tests failed in compiletest suite=ui mode=ui host=x86_64-unknown-linux-gnu target=x86_64-unknown-linux-gnu
Build completed unsuccessfully in 0:00:17

As can be seen, the span info is missing with debuginfo=2 without the fix.

@Enselic


 compiler: Include span of too huge array with -Cdebuginfo=2

2ce6154

We have a few ui tests to ensure we emit an error if we encounter too
big arrays. Before this fix, compiling the tests with `-Cdebuginfo=2`
would not include the spans of the instantiation sites, because the
error is then emitted from a different code path that does not include
the span.
Propagate the span to the error also in the debuginfo case, so the tests
passes regardless of debuginfo level.

@rustbot rustbot assigned wesleywiser

Aug 30, 2025