Fix rustfmt silently skipping symlinked sources

rust/private/rustfmt.bzl

@@ -47,7 +47,19 @@ def _find_rustfmtable_srcs(crate_info, aspect_ctx = None):
             if tag.replace("-", "_").lower() in ignore_tags:
                 return []
 
-    # Filter out any generated files
+    # Filter out generated files, but recover hand-written sources that were
+    # symlinked into bazel-out by transform_sources() (which happens when any
+    # compile_data entry is generated). Return the original source File objects
+    # so that exec_path and short_path remain correct for manifests and runfiles.
+    if aspect_ctx and hasattr(aspect_ctx.rule.attr, "srcs"):
+        original_srcs = []
+        for target in aspect_ctx.rule.attr.srcs:
+            for f in target.files.to_list():
+                if f.is_source:
+                    original_srcs.append(f)
+        if original_srcs:
+            return original_srcs
+
     srcs = [src for src in crate_info.srcs.to_list() if src.is_source]
 
     return srcs
@@ -219,7 +231,7 @@ def _rustfmt_test_impl(ctx):
     )
 
     crate_infos = [_get_rustfmt_ready_crate_info(target) for target in ctx.attr.targets]
-    srcs = [depset(_find_rustfmtable_srcs(crate_info)) for crate_info in crate_infos if crate_info]
+    srcs = [crate_info.srcs for crate_info in crate_infos if crate_info]
 
     # Some targets may be included in tests but tagged as "no-format". In this
     # case, there will be no manifest.

test/rustfmt/rustfmt_integration_test_suite.bzl

@@ -1,5 +1,6 @@
 """Test definitions for rustfmt test rules"""
 
+load("@bazel_skylib//rules:write_file.bzl", "write_file")
 load(
     "@rules_rust//rust:defs.bzl",
     "rust_binary",
@@ -101,12 +102,35 @@ def rustfmt_integration_test_suite(name, **kwargs):
             targets = [":{}_generated".format(variant)],
         )
 
+        #
+        # Test targets with generated compile_data (triggers transform_sources
+        # to symlink hand-written sources into bazel-out)
+        #
+        write_file(
+            name = "{}_compile_data_gen".format(variant),
+            out = "{}_generated_data.txt".format(variant),
+            content = ["generated"],
+        )
+
+        rust_rule(
+            name = "{}_compile_data_generated".format(variant),
+            srcs = ["srcs/compile_data_generated/lib.rs"],
+            compile_data = [":{}_compile_data_gen".format(variant)],
+            edition = "2021",
+        )
+
+        rustfmt_test(
+            name = "{}_compile_data_generated_test".format(variant),
+            targets = [":{}_compile_data_generated".format(variant)],
+        )
+
         tests.extend([
             "{}_formatted_2015_test".format(variant),
             "{}_formatted_2018_test".format(variant),
             "{}_unformatted_2015_test".format(variant),
             "{}_unformatted_2018_test".format(variant),
             "{}_generated_test".format(variant),
+            "{}_compile_data_generated_test".format(variant),
         ])
 
     native.test_suite(

test/rustfmt/srcs/compile_data_generated/lib.rs

@@ -0,0 +1,3 @@
+pub fn main() {
+    println!("compile_data_generated");
+}