From 8d743ac19a1b0c15deccfb14525eaeef56b4135b Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Tue, 2 Jan 2018 14:28:10 +0200
Subject: Fix few undefined behavior (ubsan) bugs

---
 build2/function.cxx            |  6 +--
 build2/function.hxx            | 97 +++++++++++++++++++++---------------------
 build2/functions-path.cxx      |  2 +-
 build2/install/functions.cxx   |  8 +++-
 build2/parser.cxx              |  6 +--
 build2/test/script/script.cxx  |  6 +--
 build2/test/script/script.hxx  |  8 ++--
 build2/version/rule.cxx        |  2 +-
 unit-tests/function/driver.cxx | 12 +++---
 9 files changed, 77 insertions(+), 70 deletions(-)

diff --git a/build2/function.cxx b/build2/function.cxx
index 4421c86..e71f158 100644
--- a/build2/function.cxx
+++ b/build2/function.cxx
@@ -97,7 +97,7 @@ namespace build2
   }
 
   pair<value, bool> function_map::
-  call (const scope& base,
+  call (const scope* base,
         const string& name,
         vector_view<value> args,
         const location& loc,
@@ -255,7 +255,7 @@ namespace build2
   }
 
   value function_family::
-  default_thunk (const scope& base,
+  default_thunk (const scope* base,
                  vector_view<value> args,
                  const function_overload& f)
   try
@@ -264,7 +264,7 @@ namespace build2
     //
     struct cast_data // Prefix of function_cast::data.
     {
-      value (*const thunk) (const scope&, vector_view<value>, const void*);
+      value (*const thunk) (const scope*, vector_view<value>, const void*);
     };
 
     auto d (reinterpret_cast<const cast_data*> (&f.data));
diff --git a/build2/function.hxx b/build2/function.hxx
index 7507bec..45fe4e8 100644
--- a/build2/function.hxx
+++ b/build2/function.hxx
@@ -46,7 +46,8 @@ namespace build2
   // are conceptually "moved" and can be reused by the implementation.
   //
   // A function can also optionally receive the current scope by having the
-  // first argument of the const scope& type.
+  // first argument of the const scope* type. It may be NULL is the function
+  // is called out of any scope (e.g., command line).
   //
   // Normally functions come in families that share a common qualification
   // (e.g., string. or path.). The function_family class is a "registrar"
@@ -67,7 +68,7 @@ namespace build2
   //
   struct function_overload;
 
-  using function_impl = value (const scope&,
+  using function_impl = value (const scope*,
                                vector_view<value>,
                                const function_overload&);
 
@@ -150,7 +151,7 @@ namespace build2
     erase (iterator i) {map_.erase (i);}
 
     value
-    call (const scope& base,
+    call (const scope* base,
           const string& name,
           vector_view<value> args,
           const location& l) const
@@ -164,7 +165,7 @@ namespace build2
     // functions.
     //
     pair<value, bool>
-    try_call (const scope& base,
+    try_call (const scope* base,
               const string& name,
               vector_view<value> args,
               const location& l) const
@@ -193,7 +194,7 @@ namespace build2
 
   private:
     pair<value, bool>
-    call (const scope&,
+    call (const scope*,
           const string&,
           vector_view<value>,
           const location&,
@@ -215,7 +216,7 @@ namespace build2
     // exceptions), you would normally call the default implementation.
     //
     static value
-    default_thunk (const scope&, vector_view<value>, const function_overload&);
+    default_thunk (const scope*, vector_view<value>, const function_overload&);
 
     // A function family uses a common qualification (though you can pass
     // empty string to supress it). For an unqualified name (doesn't not
@@ -419,12 +420,12 @@ namespace build2
     //
     struct data
     {
-      value (*const thunk) (const scope&, vector_view<value>, const void*);
+      value (*const thunk) (const scope*, vector_view<value>, const void*);
       R (*const impl) (A...);
     };
 
     static value
-    thunk (const scope&, vector_view<value> args, const void* d)
+    thunk (const scope*, vector_view<value> args, const void* d)
     {
       return thunk (move (args),
                     static_cast<const data*> (d)->impl,
@@ -448,16 +449,16 @@ namespace build2
   // argument.
   //
   template <typename R, typename... A>
-  struct function_cast<R, const scope&, A...>
+  struct function_cast<R, const scope*, A...>
   {
     struct data
     {
-      value (*const thunk) (const scope&, vector_view<value>, const void*);
-      R (*const impl) (const scope&, A...);
+      value (*const thunk) (const scope*, vector_view<value>, const void*);
+      R (*const impl) (const scope*, A...);
     };
 
     static value
-    thunk (const scope& base, vector_view<value> args, const void* d)
+    thunk (const scope* base, vector_view<value> args, const void* d)
     {
       return thunk (base, move (args),
                     static_cast<const data*> (d)->impl,
@@ -466,8 +467,8 @@ namespace build2
 
     template <size_t... i>
     static value
-    thunk (const scope& base, vector_view<value> args,
-           R (*impl) (const scope&, A...),
+    thunk (const scope* base, vector_view<value> args,
+           R (*impl) (const scope*, A...),
            std::index_sequence<i...>)
     {
       return value (
@@ -484,12 +485,12 @@ namespace build2
   {
     struct data
     {
-      value (*const thunk) (const scope&, vector_view<value>, const void*);
+      value (*const thunk) (const scope*, vector_view<value>, const void*);
       void (*const impl) (A...);
     };
 
     static value
-    thunk (const scope&, vector_view<value> args, const void* d)
+    thunk (const scope*, vector_view<value> args, const void* d)
     {
       thunk (move (args),
              static_cast<const data*> (d)->impl,
@@ -508,16 +509,16 @@ namespace build2
   };
 
   template <typename... A>
-  struct function_cast<void, const scope&, A...>
+  struct function_cast<void, const scope*, A...>
   {
     struct data
     {
-      value (*const thunk) (const scope&, vector_view<value>, const void*);
-      void (*const impl) (const scope&, A...);
+      value (*const thunk) (const scope*, vector_view<value>, const void*);
+      void (*const impl) (const scope*, A...);
     };
 
     static value
-    thunk (const scope& base, vector_view<value> args, const void* d)
+    thunk (const scope* base, vector_view<value> args, const void* d)
     {
       thunk (base, move (args),
              static_cast<const data*> (d)->impl,
@@ -527,8 +528,8 @@ namespace build2
 
     template <size_t... i>
     static void
-    thunk (const scope& base, vector_view<value> args,
-           void (*impl) (const scope&, A...),
+    thunk (const scope* base, vector_view<value> args,
+           void (*impl) (const scope*, A...),
            std::index_sequence<i...>)
     {
       impl (base,
@@ -544,12 +545,12 @@ namespace build2
   {
     struct data
     {
-      value (*const thunk) (const scope&, vector_view<value>, const void*);
+      value (*const thunk) (const scope*, vector_view<value>, const void*);
       R (L::*const impl) (A...) const;
     };
 
     static value
-    thunk (const scope&, vector_view<value> args, const void* d)
+    thunk (const scope*, vector_view<value> args, const void* d)
     {
       return thunk (move (args),
                     static_cast<const data*> (d)->impl,
@@ -572,16 +573,16 @@ namespace build2
   };
 
   template <typename L, typename R, typename... A>
-  struct function_cast_lamb<L, R, const scope&, A...>
+  struct function_cast_lamb<L, R, const scope*, A...>
   {
     struct data
     {
-      value (*const thunk) (const scope&, vector_view<value>, const void*);
-      R (L::*const impl) (const scope&, A...) const;
+      value (*const thunk) (const scope*, vector_view<value>, const void*);
+      R (L::*const impl) (const scope*, A...) const;
     };
 
     static value
-    thunk (const scope& base, vector_view<value> args, const void* d)
+    thunk (const scope* base, vector_view<value> args, const void* d)
     {
       return thunk (base, move (args),
                     static_cast<const data*> (d)->impl,
@@ -590,8 +591,8 @@ namespace build2
 
     template <size_t... i>
     static value
-    thunk (const scope& base, vector_view<value> args,
-           R (L::*impl) (const scope&, A...) const,
+    thunk (const scope* base, vector_view<value> args,
+           R (L::*impl) (const scope*, A...) const,
            std::index_sequence<i...>)
     {
       const L* l (nullptr); // Undefined behavior.
@@ -608,12 +609,12 @@ namespace build2
   {
     struct data
     {
-      value (*const thunk) (const scope&, vector_view<value>, const void*);
+      value (*const thunk) (const scope*, vector_view<value>, const void*);
       void (L::*const impl) (A...) const;
     };
 
     static value
-    thunk (const scope&, vector_view<value> args, const void* d)
+    thunk (const scope*, vector_view<value> args, const void* d)
     {
       thunk (move (args),
              static_cast<const data*> (d)->impl,
@@ -635,16 +636,16 @@ namespace build2
   };
 
   template <typename L, typename... A>
-  struct function_cast_lamb<L, void, const scope&, A...>
+  struct function_cast_lamb<L, void, const scope*, A...>
   {
     struct data
     {
-      value (*const thunk) (const scope&, vector_view<value>, const void*);
-      void (L::*const impl) (const scope&, A...) const;
+      value (*const thunk) (const scope*, vector_view<value>, const void*);
+      void (L::*const impl) (const scope*, A...) const;
     };
 
     static value
-    thunk (const scope& base, vector_view<value> args, const void* d)
+    thunk (const scope* base, vector_view<value> args, const void* d)
     {
       thunk (base, move (args),
              static_cast<const data*> (d)->impl,
@@ -654,8 +655,8 @@ namespace build2
 
     template <size_t... i>
     static void
-    thunk (const scope& base, vector_view<value> args,
-           void (L::*impl) (const scope&, A...) const,
+    thunk (const scope* base, vector_view<value> args,
+           void (L::*impl) (const scope*, A...) const,
            std::index_sequence<i...>)
     {
       const L* l (nullptr);
@@ -673,12 +674,12 @@ namespace build2
   {
     struct data
     {
-      value (*const thunk) (const scope&, vector_view<value>, const void*);
+      value (*const thunk) (const scope*, vector_view<value>, const void*);
       R (T::*const impl) () const;
     };
 
     static value
-    thunk (const scope&, vector_view<value> args, const void* d)
+    thunk (const scope*, vector_view<value> args, const void* d)
     {
       auto mf (static_cast<const data*> (d)->impl);
       return value ((function_arg<T>::cast (&args[0]).*mf) ());
@@ -690,12 +691,12 @@ namespace build2
   {
     struct data
     {
-      value (*const thunk) (const scope&, vector_view<value>, const void*);
+      value (*const thunk) (const scope*, vector_view<value>, const void*);
       void (T::*const impl) () const;
     };
 
     static value
-    thunk (const scope&, vector_view<value> args, const void* d)
+    thunk (const scope*, vector_view<value> args, const void* d)
     {
       auto mf (static_cast<const data*> (d)->impl);
       (function_arg<T>::cast (args[0]).*mf) ();
@@ -710,12 +711,12 @@ namespace build2
   {
     struct data
     {
-      value (*const thunk) (const scope&, vector_view<value>, const void*);
+      value (*const thunk) (const scope*, vector_view<value>, const void*);
       R T::*const impl;
     };
 
     static value
-    thunk (const scope&, vector_view<value> args, const void* d)
+    thunk (const scope*, vector_view<value> args, const void* d)
     {
       auto dm (static_cast<const data*> (d)->impl);
       return value (move (function_arg<T>::cast (&args[0]).*dm));
@@ -747,10 +748,10 @@ namespace build2
 
     template <typename R, typename... A>
     void
-    operator= (R (*impl) (const scope&, A...)) &&
+    operator= (R (*impl) (const scope*, A...)) &&
     {
       using args = function_args<A...>;
-      using cast = function_cast<R, const scope&, A...>;
+      using cast = function_cast<R, const scope*, A...>;
 
       insert (move (name),
               function_overload (
@@ -797,10 +798,10 @@ namespace build2
 
     template <typename L, typename R, typename... A>
     void
-    coerce_lambda (R (L::*op) (const scope&, A...) const) &&
+    coerce_lambda (R (L::*op) (const scope*, A...) const) &&
     {
       using args = function_args<A...>;
-      using cast = function_cast_lamb<L, R, const scope&, A...>;
+      using cast = function_cast_lamb<L, R, const scope*, A...>;
 
       insert (move (name),
               function_overload (
diff --git a/build2/functions-path.cxx b/build2/functions-path.cxx
index 77c1464..1abaf40 100644
--- a/build2/functions-path.cxx
+++ b/build2/functions-path.cxx
@@ -10,7 +10,7 @@ using namespace std;
 namespace build2
 {
   static value
-  path_thunk (const scope& base,
+  path_thunk (const scope* base,
               vector_view<value> args,
               const function_overload& f)
   try
diff --git a/build2/install/functions.cxx b/build2/install/functions.cxx
index b9298b2..dbe43c8 100644
--- a/build2/install/functions.cxx
+++ b/build2/install/functions.cxx
@@ -21,7 +21,13 @@ namespace build2
       // Resolve potentially relative install.* value to an absolute directory
       // based on (other) install.* values visible from the calling scope.
       //
-      f["resolve"] = &resolve_dir;
+      f[".resolve"] = [] (const scope* s, dir_path d)
+      {
+        if (s == nullptr)
+          fail << "install.resolve() called out of scope" << endf;
+
+        return resolve_dir (*s, move (d));
+      };
     }
   }
 }
diff --git a/build2/parser.cxx b/build2/parser.cxx
index 48902b8..b21d51c 100644
--- a/build2/parser.cxx
+++ b/build2/parser.cxx
@@ -3248,7 +3248,7 @@ namespace build2
               }));
 
           p = functions.try_call (
-            *scope_, "builtin.concat", vector_view<value> (a), loc);
+            scope_, "builtin.concat", vector_view<value> (a), loc);
         }
 
         if (!p.second)
@@ -3848,7 +3848,7 @@ namespace build2
 
             // Note that we "move" args to call().
             //
-            result_data = functions.call (*scope_, name, args, loc);
+            result_data = functions.call (scope_, name, args, loc);
             what = "function call";
           }
           else
@@ -3956,7 +3956,7 @@ namespace build2
                   }));
 
               p = functions.try_call (
-                *scope_, "string", vector_view<value> (&result_data, 1), loc);
+                scope_, "string", vector_view<value> (&result_data, 1), loc);
             }
 
             if (!p.second)
diff --git a/build2/test/script/script.cxx b/build2/test/script/script.cxx
index 5a9ad3c..99ace23 100644
--- a/build2/test/script/script.cxx
+++ b/build2/test/script/script.cxx
@@ -435,9 +435,9 @@ namespace build2
       // scope
       //
       scope::
-      scope (const string& id, scope* p)
+      scope (const string& id, scope* p, script* r)
           : parent (p),
-            root (p != nullptr ? p->root : static_cast<script*> (this)),
+            root (r),
             vars (false /* global */),
             id_path (cast<path> (assign (root->id_var) = path ())),
             wd_path (cast<dir_path> (assign (root->wd_var) = dir_path ()))
@@ -528,7 +528,7 @@ namespace build2
       //
       script::
       script (const target& tt, const testscript& st, const dir_path& rwd)
-          : group (st.name == "testscript" ? string () : st.name),
+          : group (st.name == "testscript" ? string () : st.name, this),
             test_target (tt),
             script_target (st)
       {
diff --git a/build2/test/script/script.hxx b/build2/test/script/script.hxx
index e76d0ba..c511f01 100644
--- a/build2/test/script/script.hxx
+++ b/build2/test/script/script.hxx
@@ -427,7 +427,7 @@ namespace build2
         ~scope () = default;
 
       protected:
-        scope (const string& id, scope* parent);
+        scope (const string& id, scope* parent, script* root);
 
         // Pre-parse data.
         //
@@ -452,10 +452,10 @@ namespace build2
         vector<unique_ptr<scope>> scopes;
 
       public:
-        group (const string& id, group& p): scope (id, &p) {}
+        group (const string& id, group& p): scope (id, &p, p.root) {}
 
       protected:
-        group (const string& id): scope (id, nullptr) {} // For root.
+        group (const string& id, script* r): scope (id, nullptr, r) {}
 
         // Pre-parse data.
         //
@@ -486,7 +486,7 @@ namespace build2
       class test: public scope
       {
       public:
-        test (const string& id, group& p): scope (id, &p) {}
+        test (const string& id, group& p): scope (id, &p, p.root) {}
 
         // Pre-parse data.
         //
diff --git a/build2/version/rule.cxx b/build2/version/rule.cxx
index 962a75e..9e127ca 100644
--- a/build2/version/rule.cxx
+++ b/build2/version/rule.cxx
@@ -335,7 +335,7 @@ namespace build2
               v.type == nullptr
               ? move (v)
               : functions.call (
-                t.base_scope (), "string", vector_view<value> (&v, 1), l));
+                &t.base_scope (), "string", vector_view<value> (&v, 1), l));
           }
           catch (const invalid_argument& e)
           {
diff --git a/unit-tests/function/driver.cxx b/unit-tests/function/driver.cxx
index 80c4120..627f76a 100644
--- a/unit-tests/function/driver.cxx
+++ b/unit-tests/function/driver.cxx
@@ -23,13 +23,13 @@ namespace build2
   };
 
   static dir_path
-  scoped (const scope&, dir_path d)
+  scoped (const scope*, dir_path d)
   {
     return d;
   }
 
   static void
-  scoped_void (const scope&, dir_path)
+  scoped_void (const scope*, dir_path)
   {
   }
 
@@ -54,8 +54,8 @@ namespace build2
     f["ambig"] = [](names a, optional<string>)   {return a;};
     f["ambig"] = [](names a, optional<uint64_t>) {return a;};
 
-    f["scoped"]      = [](const scope&, names a) {return a;};
-    f["scoped_void"] = [](const scope&, names) {};
+    f["scoped"]      = [](const scope*, names a) {return a;};
+    f["scoped_void"] = [](const scope*, names) {};
     f["scoped"]      = &scoped;
     f["scoped_void"] = &scoped_void;
 
@@ -76,7 +76,7 @@ namespace build2
         1,
         function_overload::arg_variadic,
         function_overload::types (arg_bool, 1),
-        [] (const scope&, vector_view<value> args, const function_overload&)
+        [] (const scope*, vector_view<value> args, const function_overload&)
         {
           return value (static_cast<uint64_t> (args.size ()));
         }));
@@ -90,7 +90,7 @@ namespace build2
         0,
         function_overload::arg_variadic,
         function_overload::types (),
-        [] (const scope&, vector_view<value> args, const function_overload&)
+        [] (const scope*, vector_view<value> args, const function_overload&)
         {
           for (value& a: args)
           {
-- 
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