Merge pull request #21465 from owen-mc/go/small-tweaks

Go: improve detection of type expressions when database is missing some type information

Author: owen-mc

go/ql/lib/semmle/go/Expr.qll

@@ -829,7 +829,7 @@ class ConversionExpr extends CallOrConversionExpr {
 /**
  * A function call expression.
  *
- * On snapshots with incomplete type information, type conversions may be misclassified
+ * On databases with incomplete type information, type conversions may be misclassified
  * as function call expressions.
  *
  * Examples:
@@ -2096,7 +2096,7 @@ class LabelName extends Name {
  * Holds if `e` is a type expression, as determined by a bottom-up syntactic
  * analysis starting with `TypeName`s.
  *
- * On a snapshot with full type information, this predicate covers all type
+ * On a database with full type information, this predicate covers all type
  * expressions. However, if type information is missing then not all type names
  * may be identified as such, so not all type expressions can be determined by
  * a bottom-up analysis. In such cases, `isTypeExprTopDown` below is useful.
@@ -2134,11 +2134,12 @@ private predicate isTypeExprBottomUp(Expr e) {
  * Holds if `e` must be a type expression because it either occurs in a syntactic
  * position where a type is expected, or it is part of a larger type expression.
  *
- * This predicate is only needed on snapshots for which type information is
- * incomplete. It is an underapproximation; in cases where it is syntactically ambiguous
- * whether an expression refers to a type or a value, we conservatively assume that
- * it may be the latter and so this predicate does not consider the expression to be
- * a type expression.
+ * This predicate is only needed on databases for which type information is
+ * incomplete - for example, when some dependencies could not be reached during
+ * extraction. It is an underapproximation; in cases where it is syntactically
+ * ambiguous whether an expression refers to a type or a value, we conservatively
+ * assume that it may be the latter and so this predicate does not consider the
+ * expression to be a type expression.
  */
 pragma[nomagic]
 private predicate isTypeExprTopDown(Expr e) {
@@ -2148,20 +2149,12 @@ private predicate isTypeExprTopDown(Expr e) {
   or
   e = any(ArrayTypeExpr ae).getElement()
   or
-  e = any(FieldDecl f).getTypeExpr()
-  or
-  e = any(ParameterDecl pd).getTypeExpr()
+  e = any(FieldBase fb).getTypeExpr()
   or
   e = any(TypeParamDecl tpd).getTypeConstraintExpr()
   or
   e = any(TypeParamDecl tpd).getNameExpr(_)
   or
-  e = any(ReceiverDecl rd).getTypeExpr()
-  or
-  e = any(ResultVariableDecl rvd).getTypeExpr()
-  or
-  e = any(MethodSpec md).getTypeExpr()
-  or
   e = any(MapTypeExpr mt).getKeyTypeExpr()
   or
   e = any(MapTypeExpr mt).getValueTypeExpr()

go/ql/lib/semmle/go/controlflow/IR.qll

@@ -294,7 +294,7 @@ module IR {
   /**
    * An IR instruction that reads the value of a field.
    *
-   * On snapshots with incomplete type information, method expressions may sometimes be
+   * On databases with incomplete type information, method expressions may sometimes be
    * misclassified as field reads.
    */
   class FieldReadInstruction extends ComponentReadInstruction {

go/ql/src/filters/ClassifyFiles.ql

@@ -1,6 +1,6 @@
 /**
  * @name Classify files
- * @description This query produces a list of all files in a snapshot that are classified as
+ * @description This query produces a list of all files in a database that are classified as
  *              generated code, test code or vendored-in library code.
  * @kind file-classifier
  * @id go/file-classifier