rust

Author: hvitved

rust/ql/lib/codeql/rust/elements/internal/AstNodeImpl.qll

@@ -29,6 +29,57 @@ module Impl {
     result = getImmediateParent(e)
   }
 
+  cached
+  private module MacroExpansion {
+    pragma[nomagic]
+    private predicate isInMacroExpansion(AstNode root, AstNode n) {
+      n = root.(MacroCall).getMacroCallExpansion()
+      or
+      n = root.(Adt).getDeriveMacroExpansion(_)
+      or
+      n = root.(Item).getAttributeMacroExpansion()
+      or
+      isInMacroExpansion(root, n.getParentNode())
+    }
+
+    pragma[nomagic]
+    private predicate isInAttributeMacroExpansionSource(Item i, AstNode n) {
+      i.hasAttributeMacroExpansion() and
+      n.getParentNode() = i and
+      not n = i.getAttributeMacroExpansion() and
+      not n instanceof Attr
+      or
+      isInAttributeMacroExpansionSource(i, n.getParentNode())
+    }
+
+    pragma[nomagic]
+    private predicate isAttributeMacroExpansionSourceLocation(Item i, Location l) {
+      exists(AstNode n |
+        isInAttributeMacroExpansionSource(i, n) and
+        n.getLocation() = l
+      )
+    }
+
+    /** Gets an AST node whose location is inside the token tree belonging to `mc`. */
+    pragma[nomagic]
+    private AstNode getATokenTreeNode(MacroCall mc) {
+      isInMacroExpansion(mc, result) and
+      mc.getTokenTree().getLocation().contains(result.getLocation())
+    }
+
+    cached
+    predicate isInMacroExpansion(AstNode n) { isInMacroExpansion(_, n) }
+
+    cached
+    predicate isFromMacroExpansion(AstNode n) {
+      exists(AstNode root |
+        isInMacroExpansion(root, n) and
+        not n = getATokenTreeNode(root) and
+        not isAttributeMacroExpansionSourceLocation(root, n.getLocation())
+      )
+    }
+  }
+
   class AstNode extends Generated::AstNode {
     /**
      * Gets the nearest enclosing parent of this node, which is also an `AstNode`,
@@ -71,21 +122,15 @@ module Impl {
     }
 
     /** Holds if this node is inside a macro expansion. */
-    predicate isInMacroExpansion() { MacroCallImpl::isInMacroExpansion(_, this) }
+    predicate isInMacroExpansion() { MacroExpansion::isInMacroExpansion(this) }
 
     /**
      * Holds if this node exists only as the result of a macro expansion.
      *
      * This is the same as `isInMacroExpansion()`, but excludes AST nodes corresponding
-     * to macro arguments.
+     * to macro arguments, including attribute macro targets.
      */
-    pragma[nomagic]
-    predicate isFromMacroExpansion() {
-      exists(AstNode root |
-        MacroCallImpl::isInMacroExpansion(root, this) and
-        not this = root.(MacroCall).getATokenTreeNode()
-      )
-    }
+    predicate isFromMacroExpansion() { MacroExpansion::isFromMacroExpansion(this) }
 
     /**
      * Gets a control flow node for this AST node, if any.

rust/ql/lib/codeql/rust/elements/internal/MacroCallImpl.qll

@@ -14,15 +14,6 @@ module Impl {
   private import rust
   private import codeql.rust.internal.PathResolution
 
-  pragma[nomagic]
-  predicate isInMacroExpansion(AstNode root, AstNode n) {
-    n = root.(MacroCall).getMacroCallExpansion()
-    or
-    n = root.(Adt).getDeriveMacroExpansion(_)
-    or
-    isInMacroExpansion(root, n.getParentNode())
-  }
-
   // the following QLdoc is generated: if you need to edit it, do it in the schema file
   /**
    * A macro invocation.
@@ -35,13 +26,6 @@ module Impl {
   class MacroCall extends Generated::MacroCall {
     override string toStringImpl() { result = this.getPath().toAbbreviatedString() + "!..." }
 
-    /** Gets an AST node whose location is inside the token tree belonging to this macro call. */
-    pragma[nomagic]
-    AstNode getATokenTreeNode() {
-      isInMacroExpansion(this, result) and
-      this.getTokenTree().getLocation().contains(result.getLocation())
-    }
-
     /**
      * Gets the macro definition that this macro call resolves to.
      *

rust/ql/lib/utils/test/PathResolutionInlineExpectationsTest.qll

@@ -12,7 +12,7 @@ private module ResolveTest implements TestSig {
 
   private predicate itemAt(ItemNode i, string filepath, int line, boolean inMacro) {
     i.getLocation().hasLocationInfo(filepath, _, _, line, _) and
-    if i.(AstNode).isInMacroExpansion() then inMacro = true else inMacro = false
+    if i.(AstNode).isFromMacroExpansion() then inMacro = true else inMacro = false
   }
 
   private predicate commmentAt(string text, string filepath, int line) {

rust/ql/src/queries/unusedentities/UnreachableCode.ql

@@ -33,7 +33,7 @@ predicate hiddenNode(AstNode n) {
   n instanceof ControlFlowGraphImpl::PostOrderTree and // location is counter-intuitive
   not n instanceof MacroExpr
   or
-  n.isInMacroExpansion()
+  n.isFromMacroExpansion()
 }
 
 /**

rust/ql/src/queries/unusedentities/UnusedValue.ql

@@ -18,7 +18,7 @@ from AstNode write, Ssa::Variable v
 where
   variableWrite(_, write, v) and
   not v instanceof DiscardVariable and
-  not write.isInMacroExpansion() and
+  not write.isFromMacroExpansion() and
   not isAllowableUnused(v) and
   // SSA definitions are only created for live writes
   not write = any(Ssa::WriteDefinition def).getWriteAccess().getAstNode() and

rust/ql/src/queries/unusedentities/UnusedVariable.qll

@@ -36,7 +36,7 @@ class IncompleteCallable extends Callable {
  */
 predicate isAllowableUnused(Variable v) {
   // in a macro expansion
-  v.getPat().isInMacroExpansion()
+  v.getPat().isFromMacroExpansion()
   or
   // declared in an incomplete callable
   v.getEnclosingCfgScope() instanceof IncompleteCallable

rust/ql/test/library-tests/variables/variables.ql

@@ -35,7 +35,7 @@ module VariableAccessTest implements TestSig {
   private predicate declAt(Variable v, string filepath, int line, boolean inMacro) {
     variable(v) and
     v.getLocation().hasLocationInfo(filepath, _, _, line, _) and
-    if v.getPat().isInMacroExpansion() then inMacro = true else inMacro = false
+    if v.getPat().isFromMacroExpansion() then inMacro = true else inMacro = false
   }
 
   private predicate commmentAt(string text, string filepath, int line) {