Rust: Macro call resolution

Author: hvitved

rust/ql/integration-tests/hello-workspace/functions.expected

@@ -1,2 +1,2 @@
 | exe/src/main.rs:5:1:7:1 | fn main |
-| lib/src/a_module/mod.rs:1:1:3:1 | fn hello |
+| lib/src/a_module/mod.rs:1:1:4:1 | fn hello |

rust/ql/integration-tests/hello-workspace/lib/src/a_module/mod.rs

@@ -1,3 +1,4 @@
 pub fn hello() {
-    println!("Hello, world!");
+    my_macro!(); // $ item=my_macro
+    println!("Hello, world!"); // $ item=println
 } // HELLO

rust/ql/integration-tests/hello-workspace/lib/src/lib.rs

@@ -1 +1,10 @@
+#[macro_use]
+mod macros {
+    macro_rules! my_macro {
+        () => {
+            println!("my_macro!");
+        };
+    }
+}
+
 pub mod a_module;

rust/ql/integration-tests/hello-workspace/summary.cargo.expected

@@ -9,8 +9,8 @@
 | Inconsistencies - Path resolution | 0 |
 | Inconsistencies - SSA | 0 |
 | Inconsistencies - data flow | 0 |
-| Lines of code extracted | 9 |
-| Lines of user code extracted | 9 |
-| Macro calls - resolved | 2 |
-| Macro calls - total | 2 |
+| Lines of code extracted | 15 |
+| Lines of user code extracted | 15 |
+| Macro calls - resolved | 5 |
+| Macro calls - total | 5 |
 | Macro calls - unresolved | 0 |

rust/ql/integration-tests/hello-workspace/summary.rust-project.expected

@@ -9,8 +9,8 @@
 | Inconsistencies - Path resolution | 0 |
 | Inconsistencies - SSA | 0 |
 | Inconsistencies - data flow | 0 |
-| Lines of code extracted | 9 |
-| Lines of user code extracted | 9 |
-| Macro calls - resolved | 2 |
-| Macro calls - total | 2 |
+| Lines of code extracted | 15 |
+| Lines of user code extracted | 15 |
+| Macro calls - resolved | 5 |
+| Macro calls - total | 5 |
 | Macro calls - unresolved | 0 |

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

@@ -12,6 +12,7 @@ private import codeql.rust.elements.internal.generated.MacroCall
  */
 module Impl {
   private import rust
+  private import codeql.rust.internal.PathResolution
 
   pragma[nomagic]
   predicate isInMacroExpansion(AstNode root, AstNode n) {
@@ -44,5 +45,12 @@ module Impl {
       isInMacroExpansion(this, result) and
       this.getTokenTree().getLocation().contains(result.getLocation())
     }
+
+    /**
+     * Gets the macro definition that this macro call resolves to.
+     *
+     * The result is either a `MacroDef` or a `MacroRules`.
+     */
+    Item resolveMacro() { result = resolvePath(this.getPath()) }
   }
 }