Rust: turn off the test cfg by default

Author: Paolo Tranquilli

rust/extractor/src/config.rs

@@ -137,20 +137,31 @@ fn to_cfg_override(spec: &str) -> CfgAtom {
 fn to_cfg_overrides(specs: &Vec<String>) -> CfgOverrides {
     let mut enabled_cfgs = Vec::new();
     let mut disabled_cfgs = Vec::new();
+    let mut has_test_explicitly_enabled = false;
     for spec in specs {
         if spec.starts_with("-") {
             disabled_cfgs.push(to_cfg_override(&spec[1..]));
         } else {
             enabled_cfgs.push(to_cfg_override(spec));
+            if spec == "test" {
+                has_test_explicitly_enabled = true;
+            }
         }
     }
+    if !has_test_explicitly_enabled {
+        disabled_cfgs.push(to_cfg_override("test"));
+    }
     if let Some(global) = CfgDiff::new(enabled_cfgs, disabled_cfgs) {
         CfgOverrides {
             global,
             ..Default::default()
         }
     } else {
         warn!("non-disjoint cfg overrides, ignoring: {}", specs.join(", "));
-        CfgOverrides::default()
+        CfgOverrides {
+            global: CfgDiff::new(Vec::new(), vec![to_cfg_override("test")])
+                .expect("disabling one cfg should always succeed"),
+            ..Default::default()
+        }
     }
 }

rust/ql/integration-tests/options/cfg_functions.override.expected

@@ -1,3 +1,4 @@
 | src/cfg.rs:1:1:2:16 | cfg_flag |
 | src/cfg.rs:4:1:5:15 | cfg_key |
-| src/cfg.rs:13:1:14:15 | no_test |
+| src/cfg.rs:13:1:14:12 | test |
+| src/cfg.rs:16:1:17:24 | pointer_width_32 |

rust/ql/integration-tests/options/src/cfg.rs

@@ -10,5 +10,8 @@ fn cfg_no_flag() {}
 #[cfg(not(cfg_key = "value"))]
 fn cfg_no_key() {}
 
-#[cfg(not(test))]
-fn no_test() {}
+#[cfg(test)]
+fn test() {}
+
+#[cfg(target_pointer_width = "32")]
+fn pointer_width_32() {}

rust/ql/integration-tests/options/test_options.py

@@ -23,7 +23,7 @@ def test_target_linux(codeql, rust):
 @pytest.mark.ql_test("arch_functions.ql", expected=f".{platform.system()}.expected")
 def test_cfg_override(codeql, rust):
     # currently codeql CLI has a limitation not allow to pass `=` in values via `--extractor-option`
-    os.environ["CODEQL_EXTRACTOR_RUST_OPTION_CARGO_CFG_OVERRIDES"] = "cfg_flag,cfg_key=value,-test"
+    os.environ["CODEQL_EXTRACTOR_RUST_OPTION_CARGO_CFG_OVERRIDES"] = "cfg_flag,cfg_key=value,-target_pointer_width=64,target_pointer_width=32,test"
     codeql.database.create()
 
 @pytest.mark.ql_test("arch_functions.ql", expected=f".{platform.system()}.expected")