Rust: load files from disk ourselves

This avoids problems with files containing invalid utf-8 data, which may cause
panic's like:
```
 thread 'main' panicked at external/rules_rust~~_crate~ql~~r~r__ra_ap_salsa-0.0.232/src/input.rs:91:32:
   no value set for CompressedFileTextQuery(FileId(2429))
   stack backtrace:
      0: rust_begin_unwind
                at /rustc/eeb90cda1969383f56a2637cbd3037bdf598841c/library/std/src/panicking.rs:665:5
      1: core::panicking::panic_fmt
                at /rustc/eeb90cda1969383f56a2637cbd3037bdf598841c/library/core/src/panicking.rs:74:14
      2: <salsa::input::InputStorage<Q> as salsa::plumbing::QueryStorageOps<Q>>::fetch
      3: <DB as ra_ap_base_db::SourceDatabase>::compressed_file_text::__shim
      4: <ra_ap_base_db::FileTextQuery as salsa::plumbing::QueryFunction>::execute
      5: salsa::Cycle::catch
      6: salsa::derived_lru::slot::Slot<Q,MP>::execute
      7: salsa::derived_lru::slot::Slot<Q,MP>::read
      8: <salsa::derived_lru::DerivedStorage<Q,MP> as salsa::plumbing::QueryStorageOps<Q>>::fetch
      9: <DB as ra_ap_base_db::SourceDatabase>::file_text::__shim
     10: <DB as ra_ap_base_db::SourceDatabase>::file_text
     11: <ra_ap_base_db::ParseQuery as salsa::plumbing::QueryFunction>::execute
     12: salsa::Cycle::catch
     13: salsa::derived_lru::slot::Slot<Q,MP>::execute
     14: salsa::derived_lru::slot::Slot<Q,MP>::read
     15: <salsa::derived_lru::DerivedStorage<Q,MP> as salsa::plumbing::QueryStorageOps<Q>>::fetch
     16: <DB as ra_ap_base_db::SourceDatabase>::parse::__shim
     17: <DB as ra_ap_base_db::SourceDatabase>::parse
     18: ra_ap_hir::semantics::SemanticsImpl::parse
     19: single_arch_extractor::main
```

rust/extractor/src/main.rs

@@ -8,7 +8,7 @@ mod translate;
 pub mod trap;
 
 fn extract(
-    rust_analyzer: &rust_analyzer::RustAnalyzer,
+    rust_analyzer: &mut rust_analyzer::RustAnalyzer,
     traps: &trap::TrapFileProvider,
     file: std::path::PathBuf,
 ) -> anyhow::Result<()> {
@@ -49,7 +49,7 @@ fn main() -> anyhow::Result<()> {
         .module(module_path!())
         .verbosity(2 + cfg.verbose as usize)
         .init()?;
-    let rust_analyzer = rust_analyzer::RustAnalyzer::new(&cfg)?;
+    let mut rust_analyzer = rust_analyzer::RustAnalyzer::new(&cfg)?;
 
     let traps = trap::TrapFileProvider::new(&cfg).context("failed to set up trap files")?;
     let archiver = archive::Archiver {
@@ -59,7 +59,7 @@ fn main() -> anyhow::Result<()> {
         let file = std::path::absolute(&file).unwrap_or(file);
         let file = std::fs::canonicalize(&file).unwrap_or(file);
         archiver.archive(&file);
-        extract(&rust_analyzer, &traps, file)?;
+        extract(&mut rust_analyzer, &traps, file)?;
     }
 
     Ok(())

rust/extractor/src/rust_analyzer.rs

@@ -3,6 +3,7 @@ use anyhow::Context;
 use itertools::Itertools;
 use log::info;
 use ra_ap_base_db::SourceDatabase;
+use ra_ap_base_db::SourceDatabaseFileInputExt;
 use ra_ap_hir::Semantics;
 use ra_ap_ide_db::RootDatabase;
 use ra_ap_load_cargo::{load_workspace_at, LoadCargoConfig, ProcMacroServerChoice};
@@ -59,7 +60,7 @@ impl RustAnalyzer {
         Ok(RustAnalyzer { workspace })
     }
     pub fn parse(
-        &self,
+        &mut self,
         path: &PathBuf,
     ) -> (
         SourceFile,
@@ -68,31 +69,6 @@ impl RustAnalyzer {
         Option<EditionedFileId>,
         Option<Semantics<'_, RootDatabase>>,
     ) {
-        let mut p = path.as_path();
-        while let Some(parent) = p.parent() {
-            p = parent;
-            if let Some((vfs, db)) = self.workspace.get(parent) {
-                if let Some(file_id) = Utf8PathBuf::from_path_buf(path.to_path_buf())
-                    .ok()
-                    .and_then(|x| AbsPathBuf::try_from(x).ok())
-                    .map(VfsPath::from)
-                    .and_then(|x| vfs.file_id(&x))
-                {
-                    let semi = Semantics::new(db);
-                    let file_id = EditionedFileId::current_edition(file_id);
-
-                    return (
-                        semi.parse(file_id),
-                        db.file_text(file_id.into()),
-                        db.parse_errors(file_id)
-                            .map(|x| x.to_vec())
-                            .unwrap_or_default(),
-                        Some(file_id),
-                        Some(semi),
-                    );
-                }
-            }
-        }
         let mut errors = Vec::new();
         let input = match std::fs::read(path) {
             Ok(data) => data,
@@ -105,6 +81,40 @@ impl RustAnalyzer {
             }
         };
         let (input, err) = from_utf8_lossy(&input);
+
+        let mut p = path.as_path();
+        while let Some(parent) = p.parent() {
+            p = parent;
+            if self.workspace.contains_key(parent) {
+                let (vfs, db) = self.workspace.get_mut(parent).unwrap();
+                if let Some(file_id) = Utf8PathBuf::from_path_buf(path.to_path_buf())
+                    .ok()
+                    .and_then(|x| AbsPathBuf::try_from(x).ok())
+                    .map(VfsPath::from)
+                    .and_then(|x| vfs.file_id(&x))
+                {
+                    db.set_file_text(file_id, &input);
+                    let semi = Semantics::new(db);
+
+                    let file_id = EditionedFileId::current_edition(file_id);
+                    let source_file = semi.parse(file_id);
+                    errors.extend(
+                        db.parse_errors(file_id)
+                            .into_iter()
+                            .flat_map(|x| x.to_vec()),
+                    );
+                    return (
+                        source_file,
+                        input.as_ref().into(),
+                        errors,
+                        Some(file_id),
+                        Some(semi),
+                    );
+                } else {
+                    break;
+                }
+            }
+        }
         let parse = ra_ap_syntax::ast::SourceFile::parse(&input, Edition::CURRENT);
         errors.extend(parse.errors());
         errors.extend(err);