Merge pull request #520 from sauyon/add-diagnosticfile

Add a new diagnostics file class and use it for errors

Author: smowton

ql/src/semmle/go/Errors.qll

@@ -19,7 +19,7 @@ class Error extends @error {
   int getIndex() { errors(this, _, _, _, _, _, _, _, result) }
 
   /** Gets the file in which this error was reported, if it can be determined. */
-  File getFile() { hasLocationInfo(result.getAbsolutePath(), _, _, _, _) }
+  ExtractedOrExternalFile getFile() { hasLocationInfo(result.getAbsolutePath(), _, _, _, _) }
 
   /**
    * Holds if this element is at the specified location.

ql/src/semmle/go/Files.qll

@@ -177,25 +177,12 @@ class Folder extends Container, @folder {
   override string getURL() { result = "folder://" + getAbsolutePath() }
 }
 
-/** A file. */
-class File extends Container, @file, Documentable, ExprParent, GoModExprParent, DeclParent,
-  ScopeNode {
-  string path;
-
-  File() {
-    files(this, path, _, _, _) and
-    (
-      // Exclude `.go` files that have not been extracted. Non-extracted files only exist in the `files`
-      // table if we are reporting compilation errors relating to them in the `diagnostics` table.
-      not path.matches("%.go")
-      or
-      exists(this.getAChild())
-    )
-  }
-
+/** Any file, including files that have not been extracted but are referred to as locations for errors. */
+class ExtractedOrExternalFile extends Container, @file, Documentable, ExprParent, GoModExprParent,
+  DeclParent, ScopeNode {
   override Location getLocation() { has_location(this, result) }
 
-  override string getAbsolutePath() { result = path }
+  override string getAbsolutePath() { files(this, result, _, _, _) }
 
   /** Gets the number of lines in this file. */
   int getNumberOfLines() { numlines(this, result, _, _) }
@@ -266,3 +253,14 @@ class File extends Container, @file, Documentable, ExprParent, GoModExprParent,
 
   override string getAPrimaryQlClass() { result = "File" }
 }
+
+/** A file that has been extracted. */
+class File extends ExtractedOrExternalFile {
+  File() {
+    // getAChild is specifically for the Go AST and so does not apply to non-go files
+    // we care about all non-go extracted files, as only go files can have `@file` entries due to requiring a file entry for diagnostic errors
+    not this.getExtension() = "go"
+    or
+    exists(this.getAChild())
+  }
+}