Swift: canonicalize all VarDecls

Author: redsun82

swift/extractor/infra/SwiftDispatcher.h

@@ -138,6 +138,12 @@ class SwiftDispatcher {
       // this will be treated on emission
       return undefined_label;
     }
+    if constexpr (std::derived_from<swift::VarDecl, E>) {
+      // canonicalize all VarDecls. For details, see doc of getCanonicalVarDecl
+      if (auto var = llvm::dyn_cast<const swift::VarDecl>(e)) {
+        e = var->getCanonicalVarDecl();
+      }
+    }
     auto& stored = store[e];
     if (!stored.valid()) {
       auto inserted = fetching.insert(e);

swift/extractor/translators/StmtTranslator.cpp

@@ -136,15 +136,7 @@ codeql::CaseStmt StmtTranslator::translateCaseStmt(const swift::CaseStmt& stmt)
   auto labels = stmt.getCaseLabelItems();
   entry.body = dispatcher.fetchLabel(stmt.getBody());
   entry.labels = dispatcher.fetchRepeatedLabels(labels);
-  // we don't use stmt.getCaseBodyVariables() because it's actually filled with copies of the
-  // variable declarations, which would lead to duplicate `DeclVar` entities.
-  // Instead we follow the same logic that's used to fill getCaseBodyVariables, looking at the first
-  // pattern and collecting variables from it. See
-  // https://github.com/apple/swift/blob/71fff6649b3ce57cc22954f141cf8b567be6de88/lib/Parse/ParseStmt.cpp#L2210
-  if (!labels.empty() && labels.front().getPattern()) {
-    labels.front().getPattern()->forEachVariable(
-        [&](const swift::VarDecl* var) { entry.variables.push_back(dispatcher.fetchLabel(var)); });
-  }
+  entry.variables = dispatcher.fetchRepeatedLabels(stmt.getCaseBodyVariablesOrEmptyArray());
   return entry;
 }
 

swift/ql/test/extractor-tests/generated/decl/ConcreteVarDecl/ConcreteVarDecl.expected

@@ -23,7 +23,6 @@
 | var_decls.swift:57:36:57:36 | _w4 | getModule: | file://:0:0:0:0 | var_decls | getNumberOfMembers: | 0 | getInterfaceType: | WrapperWithProjectedAndInit | getNumberOfAccessors: | 0 | getName: | _w4 | getType: | WrapperWithProjectedAndInit | hasAttachedPropertyWrapperType: | no | hasParentPattern: | yes | hasParentInitializer: | yes | hasPropertyWrapperBackingVarBinding: | no | hasPropertyWrapperBackingVar: | no | hasPropertyWrapperProjectionVarBinding: | no | hasPropertyWrapperProjectionVar: | no | getIntroducerInt: | 1 |
 | var_decls.swift:57:36:57:36 | w4 | getModule: | file://:0:0:0:0 | var_decls | getNumberOfMembers: | 0 | getInterfaceType: | Int | getNumberOfAccessors: | 2 | getName: | w4 | getType: | Int | hasAttachedPropertyWrapperType: | yes | hasParentPattern: | yes | hasParentInitializer: | yes | hasPropertyWrapperBackingVarBinding: | yes | hasPropertyWrapperBackingVar: | yes | hasPropertyWrapperProjectionVarBinding: | yes | hasPropertyWrapperProjectionVar: | yes | getIntroducerInt: | 1 |
 | var_decls.swift:65:19:65:19 | case_variable | getModule: | file://:0:0:0:0 | var_decls | getNumberOfMembers: | 0 | getInterfaceType: | Int | getNumberOfAccessors: | 0 | getName: | case_variable | getType: | Int | hasAttachedPropertyWrapperType: | no | hasParentPattern: | yes | hasParentInitializer: | no | hasPropertyWrapperBackingVarBinding: | no | hasPropertyWrapperBackingVar: | no | hasPropertyWrapperProjectionVarBinding: | no | hasPropertyWrapperProjectionVar: | no | getIntroducerInt: | 0 |
-| var_decls.swift:65:19:65:19 | case_variable | getModule: | file://:0:0:0:0 | var_decls | getNumberOfMembers: | 0 | getInterfaceType: | Int | getNumberOfAccessors: | 0 | getName: | case_variable | getType: | Int | hasAttachedPropertyWrapperType: | no | hasParentPattern: | yes | hasParentInitializer: | no | hasPropertyWrapperBackingVarBinding: | no | hasPropertyWrapperBackingVar: | no | hasPropertyWrapperProjectionVarBinding: | no | hasPropertyWrapperProjectionVar: | no | getIntroducerInt: | 0 |
 | var_decls.swift:65:34:65:34 | $match | getModule: | file://:0:0:0:0 | var_decls | getNumberOfMembers: | 0 | getInterfaceType: | Int | getNumberOfAccessors: | 0 | getName: | $match | getType: | Int | hasAttachedPropertyWrapperType: | no | hasParentPattern: | no | hasParentInitializer: | no | hasPropertyWrapperBackingVarBinding: | no | hasPropertyWrapperBackingVar: | no | hasPropertyWrapperProjectionVarBinding: | no | hasPropertyWrapperProjectionVar: | no | getIntroducerInt: | 0 |
 | var_decls.swift:67:15:67:15 | $match | getModule: | file://:0:0:0:0 | var_decls | getNumberOfMembers: | 0 | getInterfaceType: | Int | getNumberOfAccessors: | 0 | getName: | $match | getType: | Int | hasAttachedPropertyWrapperType: | no | hasParentPattern: | no | hasParentInitializer: | no | hasPropertyWrapperBackingVarBinding: | no | hasPropertyWrapperBackingVar: | no | hasPropertyWrapperProjectionVarBinding: | no | hasPropertyWrapperProjectionVar: | no | getIntroducerInt: | 0 |
 | var_decls.swift:67:22:67:22 | unused_case_variable | getModule: | file://:0:0:0:0 | var_decls | getNumberOfMembers: | 0 | getInterfaceType: | Int | getNumberOfAccessors: | 0 | getName: | unused_case_variable | getType: | Int | hasAttachedPropertyWrapperType: | no | hasParentPattern: | yes | hasParentInitializer: | no | hasPropertyWrapperBackingVarBinding: | no | hasPropertyWrapperBackingVar: | no | hasPropertyWrapperProjectionVarBinding: | no | hasPropertyWrapperProjectionVar: | no | getIntroducerInt: | 0 |

swift/ql/test/extractor-tests/generated/decl/ConcreteVarDecl/ConcreteVarDecl_getParentPattern.expected

@@ -23,5 +23,4 @@
 | var_decls.swift:57:36:57:36 | _w4 | var_decls.swift:57:36:57:36 | ... as ... |
 | var_decls.swift:57:36:57:36 | w4 | var_decls.swift:57:36:57:36 | w4 |
 | var_decls.swift:65:19:65:19 | case_variable | var_decls.swift:65:8:65:35 | .value(...) |
-| var_decls.swift:65:19:65:19 | case_variable | var_decls.swift:65:8:65:35 | .value(...) |
 | var_decls.swift:67:22:67:22 | unused_case_variable | var_decls.swift:67:8:67:42 | .value(...) |