Merge pull request #8036 from jketema/remove-legacy-relations-2

C++: Remove some unused legacy relations from the DB scheme - Take 2

cpp/downgrades/2cd420191e5f782589b4e4efb70127de265390dd/upgrade.properties

@@ -0,0 +1,2 @@
+description: Remove unused legacy relations
+compatibility: backwards

cpp/ql/lib/semmlecode.cpp.dbscheme

@@ -135,52 +135,11 @@ externalData(
     string value : string ref
 );
 
-/**
- * The date of the snapshot.
- */
-snapshotDate(unique date snapshotDate : date ref);
-
 /**
  * The source location of the snapshot.
  */
 sourceLocationPrefix(string prefix : string ref);
 
-/**
- * Data used by the 'duplicate code' detection.
- */
-duplicateCode(
-    unique int id : @duplication,
-    string relativePath : string ref,
-    int equivClass : int ref
-);
-
-/**
- * Data used by the 'similar code' detection.
- */
-similarCode(
-    unique int id : @similarity,
-    string relativePath : string ref,
-    int equivClass : int ref
-);
-
-/**
- * Data used by the 'duplicate code' and 'similar code' detection.
- */
-@duplication_or_similarity = @duplication | @similarity
-
-/**
- * Data used by the 'duplicate code' and 'similar code' detection.
- */
-#keyset[id, offset]
-tokens(
-    int id : @duplication_or_similarity ref,
-    int offset : int ref,
-    int beginLine : int ref,
-    int beginColumn : int ref,
-    int endLine : int ref,
-    int endColumn : int ref
-);
-
 /**
  * Information about packages that provide code used during compilation.
  * The `id` is just a unique identifier.

cpp/ql/lib/upgrades/018f430097e80bcf4b2786c989dae94b7d82b819/upgrade.properties

@@ -0,0 +1,6 @@
+description: Remove unused legacy relations
+compatibility: full
+snapshotDate.rel: delete
+duplicateCode.rel: delete
+similarCode.rel: delete
+tokens.rel: delete

cpp/ql/src/change-notes/2022-02-11-code-duplication.md

@@ -0,0 +1,4 @@
+---
+category: deprecated
+---
+* The `CodeDuplication.Copy`, `CodeDuplication.DuplicateBlock`, and `CodeDuplication.SimilarBlock` classes have been deprecated.

cpp/ql/src/external/CodeDuplication.qll

@@ -2,59 +2,40 @@
 
 import cpp
 
-private string relativePath(File file) { result = file.getRelativePath().replaceAll("\\", "/") }
-
-cached
-private predicate tokenLocation(string path, int sl, int sc, int ec, int el, Copy copy, int index) {
-  path = copy.sourceFile().getAbsolutePath() and
-  tokens(copy, index, sl, sc, ec, el)
-}
-
-/** A token block used for detection of duplicate and similar code. */
-class Copy extends @duplication_or_similarity {
-  /** Gets the index of the last token in this block. */
-  private int lastToken() { result = max(int i | tokens(this, i, _, _, _, _) | i) }
+private newtype TDuplicationOrSimilarity = MKDuplicationOrSimilarity()
 
+/**
+ * DEPRECATED: This class is no longer used.
+ *
+ * A token block used for detection of duplicate and similar code.
+ */
+class Copy extends TDuplicationOrSimilarity {
   /** Gets the index of the token in this block starting at the location `loc`, if any. */
-  int tokenStartingAt(Location loc) {
-    exists(string filepath, int startline, int startcol |
-      loc.hasLocationInfo(filepath, startline, startcol, _, _) and
-      tokenLocation(filepath, startline, startcol, _, _, this, result)
-    )
-  }
+  int tokenStartingAt(Location loc) { none() }
 
   /** Gets the index of the token in this block ending at the location `loc`, if any. */
-  int tokenEndingAt(Location loc) {
-    exists(string filepath, int endline, int endcol |
-      loc.hasLocationInfo(filepath, _, _, endline, endcol) and
-      tokenLocation(filepath, _, _, endline, endcol, this, result)
-    )
-  }
+  int tokenEndingAt(Location loc) { none() }
 
   /** Gets the line on which the first token in this block starts. */
-  int sourceStartLine() { tokens(this, 0, result, _, _, _) }
+  int sourceStartLine() { none() }
 
   /** Gets the column on which the first token in this block starts. */
-  int sourceStartColumn() { tokens(this, 0, _, result, _, _) }
+  int sourceStartColumn() { none() }
 
   /** Gets the line on which the last token in this block ends. */
-  int sourceEndLine() { tokens(this, this.lastToken(), _, _, result, _) }
+  int sourceEndLine() { none() }
 
   /** Gets the column on which the last token in this block ends. */
-  int sourceEndColumn() { tokens(this, this.lastToken(), _, _, _, result) }
+  int sourceEndColumn() { none() }
 
   /** Gets the number of lines containing at least (part of) one token in this block. */
   int sourceLines() { result = this.sourceEndLine() + 1 - this.sourceStartLine() }
 
   /** Gets an opaque identifier for the equivalence class of this block. */
-  int getEquivalenceClass() { duplicateCode(this, _, result) or similarCode(this, _, result) }
+  int getEquivalenceClass() { none() }
 
   /** Gets the source file in which this block appears. */
-  File sourceFile() {
-    exists(string name | duplicateCode(this, name, _) or similarCode(this, name, _) |
-      name.replaceAll("\\", "/") = relativePath(result)
-    )
-  }
+  File sourceFile() { none() }
 
   /**
    * Holds if this element is at the specified location.
@@ -77,15 +58,23 @@ class Copy extends @duplication_or_similarity {
   string toString() { none() }
 }
 
-/** A block of duplicated code. */
-class DuplicateBlock extends Copy, @duplication {
+/**
+ * DEPRECATED: This class is no longer used.
+ *
+ * A block of duplicated code.
+ */
+class DuplicateBlock extends Copy {
   override string toString() {
     result = "Duplicate code: " + this.sourceLines() + " duplicated lines."
   }
 }
 
-/** A block of similar code. */
-class SimilarBlock extends Copy, @similarity {
+/**
+ * DEPRECATED: This class is no longer used.
+ *
+ * A block of similar code.
+ */
+class SimilarBlock extends Copy {
   override string toString() {
     result = "Similar code: " + this.sourceLines() + " almost duplicated lines."
   }