Rust: introduce File::hasSemantics and File::isSkippedByCompilation

Author: redsun82

rust/ql/lib/change-notes/2025-10-16-new-extracted-file-methods.md

@@ -0,0 +1,4 @@
+---
+category: minorAnalysis
+---
+* Added `ExtractedFile::hasSemantics` and `ExtractedFile::isSkippedByCompilation` predicates.

rust/ql/lib/codeql/files/FileSystem.qll

@@ -71,6 +71,25 @@ class File extends Container, Impl::File {
  */
 class ExtractedFile extends File {
   ExtractedFile() { this.fromSource() }
+
+  private Diagnostic getNoSemanticsDiagnostic() {
+    result.getTag() = "semantics" and result.getLocation().getFile() = this
+  }
+
+  /**
+   * Holds if we have semantical information about this file, which means
+   * we should be able to
+   * * expand any macros
+   * * skip any blocks that are conditionally compiled out
+   */
+  predicate hasSemantics() { not exists(Diagnostic d | d = this.getNoSemanticsDiagnostic()) }
+
+  /**
+   * Holds if we know this file was skipped by conditional compilation.
+   * This is not the same as `not this.hasSemantics()`, as a file
+   * might not have semantics because of some error.
+   */
+  predicate isSkippedByCompilation() { this.getNoSemanticsDiagnostic().getSeverityText() = "Info" }
 }
 
 /**

rust/ql/test/extractor-tests/File/File.expected

@@ -1,6 +1,9 @@
-| Cargo.toml:0:0:0:0 | Cargo.toml | fromSource: no |
-| a_file.rs:0:0:0:0 | a_file.rs | fromSource: yes |
-| another_file.rs:0:0:0:0 | another_file.rs | fromSource: yes |
-| lib.rs:0:0:0:0 | lib.rs | fromSource: yes |
-| nested.rs:0:0:0:0 | nested.rs | fromSource: yes |
-| nested/file.rs:0:0:0:0 | nested/file.rs | fromSource: yes |
+| Cargo.toml:0:0:0:0 | Cargo.toml | fromSource: no | hasSemantics: no | isSkippedByCompilation: no |
+| a_file.rs:0:0:0:0 | a_file.rs | fromSource: yes | hasSemantics: yes | isSkippedByCompilation: no |
+| another_file.rs:0:0:0:0 | another_file.rs | fromSource: yes | hasSemantics: yes | isSkippedByCompilation: no |
+| bad_cargo/Cargo.toml:0:0:0:0 | bad_cargo/Cargo.toml | fromSource: no | hasSemantics: no | isSkippedByCompilation: no |
+| bad_cargo/src/no_semantics.rs:0:0:0:0 | bad_cargo/src/no_semantics.rs | fromSource: yes | hasSemantics: no | isSkippedByCompilation: no |
+| lib.rs:0:0:0:0 | lib.rs | fromSource: yes | hasSemantics: yes | isSkippedByCompilation: no |
+| nested.rs:0:0:0:0 | nested.rs | fromSource: yes | hasSemantics: yes | isSkippedByCompilation: no |
+| nested/file.rs:0:0:0:0 | nested/file.rs | fromSource: yes | hasSemantics: yes | isSkippedByCompilation: no |
+| nested/not_compiled.rs:0:0:0:0 | nested/not_compiled.rs | fromSource: yes | hasSemantics: no | isSkippedByCompilation: yes |

rust/ql/test/extractor-tests/File/File.ql

@@ -1,7 +1,15 @@
 import rust
 
-from File f, string fromSource
+from File f, string fromSource, string hasSemantics, string isSkippedByCompilation
 where
   exists(f.getRelativePath()) and
-  if f.fromSource() then fromSource = "fromSource: yes" else fromSource = "fromSource: no"
-select f, fromSource
+  (if f.fromSource() then fromSource = "fromSource: yes" else fromSource = "fromSource: no") and
+  (
+    if f.(ExtractedFile).hasSemantics()
+    then hasSemantics = "hasSemantics: yes"
+    else hasSemantics = "hasSemantics: no"
+  ) and
+  if f.(ExtractedFile).isSkippedByCompilation()
+  then isSkippedByCompilation = "isSkippedByCompilation: yes"
+  else isSkippedByCompilation = "isSkippedByCompilation: no"
+select f, fromSource, hasSemantics, isSkippedByCompilation

rust/ql/test/extractor-tests/File/bad_cargo/.gitignore

@@ -0,0 +1 @@
+!/Cargo.toml

rust/ql/test/extractor-tests/File/bad_cargo/Cargo.toml

@@ -0,0 +1 @@
+wrong