build: make needsHashRewrite a method

src/libstore/build.cc

@@ -803,9 +803,6 @@ private:
     /* Whether we're currently doing a chroot build. */
     bool useChroot = false;
 
-    /* Whether we need to perform hash rewriting if there are valid output paths. */
-    bool needsHashRewrite;
-
     Path chrootRootDir;
 
     /* RAII object to delete the chroot directory. */
@@ -885,6 +882,9 @@ public:
         Worker & worker, BuildMode buildMode = bmNormal);
     ~DerivationGoal();
 
+    /* Whether we need to perform hash rewriting if there are valid output paths. */
+    bool needsHashRewrite();
+
     void timedOut() override;
 
     string key() override
@@ -1037,6 +1037,17 @@ DerivationGoal::~DerivationGoal()
 }
 
 
+inline bool DerivationGoal::needsHashRewrite()
+{
+#if __linux__
+    return !useChroot;
+#else
+    /* Darwin requires hash rewriting even when sandboxing is enabled. */
+    return true;
+#endif
+}
+
+
 void DerivationGoal::killChild()
 {
     if (pid != -1) {
@@ -1845,13 +1856,6 @@ void DerivationGoal::startBuilder()
         #endif
     }
 
-#if __linux__
-    needsHashRewrite = !useChroot;
-#else
-    /* Darwin requires hash rewriting even when sandboxing is enabled. */
-    needsHashRewrite = true;
-#endif
-
     /* If `build-users-group' is not empty, then we have to build as
        one of the members of that group. */
     if (settings.buildUsersGroup != "" && getuid() == 0) {
@@ -2083,7 +2087,7 @@ void DerivationGoal::startBuilder()
 #endif
     }
 
-    if (needsHashRewrite) {
+    if (needsHashRewrite()) {
 
         if (pathExists(homeDir))
             throw Error(format("directory '%1%' exists; please remove it") % homeDir);
@@ -3067,7 +3071,7 @@ void DerivationGoal::registerOutputs()
             if (buildMode != bmCheck) actualPath = worker.store.toRealPath(path);
         }
 
-        if (needsHashRewrite) {
+        if (needsHashRewrite()) {
             Path redirected = redirectedOutputs[path];
             if (buildMode == bmRepair
                 && redirectedBadOutputs.find(path) != redirectedBadOutputs.end()