[BUG] Broader Regression: Go-to-Def, Rename, and References broken in macro attribute blocks (Large Workspace)

[xusd320]

Description

I am experiencing a severe regression in rust-analyzer where symbol resolution seems to be completely broken for code wrapped in macros like #[turbo_tasks::value_impl].

Affected Features:

1. Go to Definition: Jumps to the #[turbo_tasks::value_impl] macro attribute instead of the function definition.
2. Rename Symbol: Fails to rename the symbol correctly (often effectively doing nothing or erroring).
3. Find References: Returns incomplete or zero results for symbols defined inside the macro block.

Reproduction Attempts (Important)

I have tried multiple times to create a minimal reproduction repository, and bisection debugging, but I was unable to stably reproduce it in a small, isolated environment.

1. I created a minimal repo with a macro identical to value_impl structure -> Works correctly.
2. I created a small repo importing the actual turbo-tasks crate -> Works correctly.
3. The issue only reliably reproduces in the full vercel/next.js repository.

This suggests the issue implies interaction with:

• The sheer size of the workspace (Next.js is a very large monorepo).
• Interaction with complex dependency graphs or caching in large projects.

Steps to Reproduce (in Next.js)

Since I cannot minimize it effectively, here is how to reproduce it using the Next.js repo as the test case:

1. Clone vercel/next.js@6dfcffe
2. Open the folder in VS Code with rust-analyzer installed.
3. Open crates/next-api/src/project.rs.
4. Locate a function call inside a #[turbo_tasks::value_impl] block (e.g., https://github.com/vercel/next.js/blob/6dfcffe1cfb375363674723182b1a5d5c2894ea9/crates/next-api/src/project.rs#L1008).
5. Try to:
   • Go to Definition on a usage -> Jumps to macro attribute.
   • Rename the function definition -> Fails or behaves inconsistently.
   • Find References -> Returns incorrect results.

Expected Behavior:
All IDE features should resolve to the specific function definition inside the impl block, ignoring the macro wrapper.

Actual Behavior:
IDE features treat the symbols as if they originate from the macro attribute itself, losing the mapping to the inner source code.

Environment & Bisect

• OS: macOS
• Known Regression Window:
  • Good: 2025-12-01 (Nightly)
  • Bad: 2025-12-08 (Nightly)

Update: I am currently attempting to git bisect the rust-analyzer repository locally to pinpoint the exact commit. I will update this issue if I find the specific PR, but any pointers on what changed in macro expansion/span mapping during this window would be appreciated.

[xusd320]

I've narrowed down the "Go to Definition" regression to PR #21178 (tracked-modules) through bisection on rust-analyzer commits:

• Good Baseline: 41f0d80622 (just before the merge)
• Regression Introduced: e059280fbb (merge commit of internal: Make ModuleId a tracked struct #21178)

In large projects like Next.js, "Go to Definition" on code generated by attribute macros (e.g., #[turbo_tasks::value_impl]) incorrectly jumps into the macro attribute instead of the actual method definition. This navigation worked correctly in 41f0d80622 but broke immediately after merging PR #21178.

@Veykril Could u help to take a look ?

[Veykril]

Thank you so much for tracking this down, I've noticed this issue as well but haven't had the time to look into it. I'll try to figure out whats going wrong there