Add noexcept to move constructors and move assignment operators

18 files changed, 73 insertions, 51 deletions

diff --git a/libbuild2/algorithm.hxx b/libbuild2/algorithm.hxx
index 9a6a56b..aa0ec44 100644
--- a/libbuild2/algorithm.hxx
+++ b/libbuild2/algorithm.hxx
@@ -203,8 +203,8 @@ namespace build2
     // Movable-only type with move-assignment only to NULL lock.
     //
     target_lock () = default;
-    target_lock (target_lock&&);
-    target_lock& operator= (target_lock&&);
+    target_lock (target_lock&&) noexcept;
+    target_lock& operator= (target_lock&&) noexcept;
 
     target_lock (const target_lock&) = delete;
     target_lock& operator= (const target_lock&) = delete;
diff --git a/libbuild2/algorithm.ixx b/libbuild2/algorithm.ixx
index 3c6c2fa..b87a535 100644
--- a/libbuild2/algorithm.ixx
+++ b/libbuild2/algorithm.ixx
@@ -284,7 +284,7 @@ namespace build2
   }
 
   inline target_lock::
-  target_lock (target_lock&& x)
+  target_lock (target_lock&& x) noexcept
       : action (x.action), target (x.target), offset (x.offset)
   {
     if (target != nullptr)
@@ -304,7 +304,7 @@ namespace build2
   }
 
   inline target_lock& target_lock::
-  operator= (target_lock&& x)
+  operator= (target_lock&& x) noexcept
   {
     if (this != &x)
     {
diff --git a/libbuild2/cc/pkgconfig.hxx b/libbuild2/cc/pkgconfig.hxx
index 7959da1..a1bcdee 100644
--- a/libbuild2/cc/pkgconfig.hxx
+++ b/libbuild2/cc/pkgconfig.hxx
@@ -56,8 +56,8 @@ namespace build2
 
       // Movable-only type.
       //
-      pkgconfig (pkgconfig&&);
-      pkgconfig& operator= (pkgconfig&&);
+      pkgconfig (pkgconfig&&) noexcept;
+      pkgconfig& operator= (pkgconfig&&) noexcept;
 
       pkgconfig (const pkgconfig&) = delete;
       pkgconfig& operator= (const pkgconfig&) = delete;
@@ -95,7 +95,7 @@ namespace build2
     }
 
     inline pkgconfig::
-    pkgconfig (pkgconfig&& p)
+    pkgconfig (pkgconfig&& p) noexcept
         : path (move (p.path)),
           client_ (p.client_),
           pkg_ (p.pkg_)
@@ -105,7 +105,7 @@ namespace build2
     }
 
     inline pkgconfig& pkgconfig::
-    operator= (pkgconfig&& p)
+    operator= (pkgconfig&& p) noexcept
     {
       if (this != &p)
       {
diff --git a/libbuild2/context.hxx b/libbuild2/context.hxx
index 27c3cc0..bb8f31f 100644
--- a/libbuild2/context.hxx
+++ b/libbuild2/context.hxx
@@ -834,8 +834,8 @@ namespace build2
 
     // Note: move-assignable to empty only.
     //
-    wait_guard (wait_guard&&);
-    wait_guard& operator= (wait_guard&&);
+    wait_guard (wait_guard&&) noexcept;
+    wait_guard& operator= (wait_guard&&) noexcept;
 
     wait_guard (const wait_guard&) = delete;
     wait_guard& operator= (const wait_guard&) = delete;
diff --git a/libbuild2/context.ixx b/libbuild2/context.ixx
index 4f86c28..95c5416 100644
--- a/libbuild2/context.ixx
+++ b/libbuild2/context.ixx
@@ -31,7 +31,7 @@ namespace build2
   }
 
   inline wait_guard::
-  wait_guard (wait_guard&& x)
+  wait_guard (wait_guard&& x) noexcept
       : ctx (x.ctx),
         start_count (x.start_count),
         task_count (x.task_count),
@@ -41,7 +41,7 @@ namespace build2
   }
 
   inline wait_guard& wait_guard::
-  operator= (wait_guard&& x)
+  operator= (wait_guard&& x) noexcept
   {
     if (&x != this)
     {
diff --git a/libbuild2/file-cache.hxx b/libbuild2/file-cache.hxx
index e31517e..98c2b67 100644
--- a/libbuild2/file-cache.hxx
+++ b/libbuild2/file-cache.hxx
@@ -119,9 +119,9 @@ namespace build2
 
       // Move-to-NULL-only type.
       //
-      write (write&&);
+      write (write&&) noexcept;
       write (const write&) = delete;
-      write& operator= (write&&);
+      write& operator= (write&&) noexcept;
       write& operator= (const write&) = delete;
 
       ~write ();
@@ -145,9 +145,9 @@ namespace build2
 
       // Move-to-NULL-only type.
       //
-      read (read&&);
+      read (read&&) noexcept;
       read (const read&) = delete;
-      read& operator= (read&&);
+      read& operator= (read&&) noexcept;
       read& operator= (const read&) = delete;
 
       ~read ();
diff --git a/libbuild2/file-cache.ixx b/libbuild2/file-cache.ixx
index 026f3fd..99be5ad 100644
--- a/libbuild2/file-cache.ixx
+++ b/libbuild2/file-cache.ixx
@@ -109,14 +109,14 @@ namespace build2
   }
 
   inline file_cache::write::
-  write (write&& e)
+  write (write&& e) noexcept
       : entry_ (e.entry_)
   {
     e.entry_ = nullptr;
   }
 
   inline file_cache::write& file_cache::write::
-  operator= (write&& e)
+  operator= (write&& e) noexcept
   {
     if (this != &e)
     {
@@ -136,14 +136,14 @@ namespace build2
   }
 
   inline file_cache::read::
-  read (read&& e)
+  read (read&& e) noexcept
       : entry_ (e.entry_)
   {
     e.entry_ = nullptr;
   }
 
   inline file_cache::read& file_cache::read::
-  operator= (read&& e)
+  operator= (read&& e) noexcept
   {
     if (this != &e)
     {
diff --git a/libbuild2/parser.cxx b/libbuild2/parser.cxx
index 2507a02..5128979 100644
--- a/libbuild2/parser.cxx
+++ b/libbuild2/parser.cxx
@@ -88,8 +88,8 @@ namespace build2
 
     // Note: move-assignable to empty only.
     //
-    enter_scope (enter_scope&& x) {*this = move (x);}
-    enter_scope& operator= (enter_scope&& x)
+    enter_scope (enter_scope&& x) noexcept {*this = move (x);}
+    enter_scope& operator= (enter_scope&& x) noexcept
     {
       if (this != &x)
       {
@@ -208,8 +208,8 @@ namespace build2
 
     // Note: move-assignable to empty only.
     //
-    enter_target (enter_target&& x) {*this = move (x);}
-    enter_target& operator= (enter_target&& x) {
+    enter_target (enter_target&& x) noexcept {*this = move (x);}
+    enter_target& operator= (enter_target&& x) noexcept {
       p_ = x.p_; t_ = x.t_; x.p_ = nullptr; return *this;}
 
     enter_target (const enter_target&) = delete;
@@ -240,8 +240,8 @@ namespace build2
 
     // Note: move-assignable to empty only.
     //
-    enter_prerequisite (enter_prerequisite&& x) {*this = move (x);}
-    enter_prerequisite& operator= (enter_prerequisite&& x) {
+    enter_prerequisite (enter_prerequisite&& x) noexcept {*this = move (x);}
+    enter_prerequisite& operator= (enter_prerequisite&& x) noexcept {
       p_ = x.p_; r_ = x.r_; x.p_ = nullptr; return *this;}
 
     enter_prerequisite (const enter_prerequisite&) = delete;
diff --git a/libbuild2/prerequisite.hxx b/libbuild2/prerequisite.hxx
index 33efed0..2f63056 100644
--- a/libbuild2/prerequisite.hxx
+++ b/libbuild2/prerequisite.hxx
@@ -63,6 +63,8 @@ namespace build2
     // Note that the lookup is often ad hoc (see bin.whole as an example).
     // But see also parser::lookup_variable() if adding something here.
     //
+    // @@ PERF: redo as vector so can make move constructor noexcept.
+    //
   public:
     variable_map vars;
 
@@ -138,7 +140,10 @@ namespace build2
     is_a (const target_type_type& tt) const {return type.is_a (tt);}
 
   public:
-    prerequisite (prerequisite&& x)
+    // Note that we have the noexcept specification even though vars
+    // (std::map) could potentially throw.
+    //
+    prerequisite (prerequisite&& x) noexcept
         : proj (move (x.proj)),
           type (x.type),
           dir (move (x.dir)),
@@ -147,7 +152,8 @@ namespace build2
           ext (move (x.ext)),
           scope (x.scope),
           target (x.target.load (memory_order_relaxed)),
-          vars (move (x.vars), *this, false /* shared */) {}
+          vars (move (x.vars), *this, false /* shared */)
+          {}
 
     prerequisite (const prerequisite& x, memory_order o = memory_order_consume)
         : proj (x.proj),
diff --git a/libbuild2/scheduler.hxx b/libbuild2/scheduler.hxx
index dc18859..c34d41b 100644
--- a/libbuild2/scheduler.hxx
+++ b/libbuild2/scheduler.hxx
@@ -247,8 +247,12 @@ namespace build2
 
       alloc_guard (): n (0), s_ (nullptr) {}
       alloc_guard (scheduler& s, size_t m): n (s.allocate (m)), s_ (&s) {}
-      alloc_guard (alloc_guard&& x): n (x.n), s_ (x.s_) {x.s_ = nullptr;}
-      alloc_guard& operator= (alloc_guard&& x)
+
+      alloc_guard (alloc_guard&& x) noexcept
+        : n (x.n), s_ (x.s_) {x.s_ = nullptr;}
+
+      alloc_guard&
+      operator= (alloc_guard&& x) noexcept
       {
         if (&x != this)
         {
@@ -357,8 +361,12 @@ namespace build2
     {
       tune_guard (): s_ (nullptr), o_ (0) {}
       tune_guard (scheduler& s, size_t ma): s_ (&s), o_ (s_->tune (ma)) {}
-      tune_guard (tune_guard&& x): s_ (x.s_), o_ (x.o_) {x.s_ = nullptr;}
-      tune_guard& operator= (tune_guard&& x)
+
+      tune_guard (tune_guard&& x) noexcept
+        : s_ (x.s_), o_ (x.o_) {x.s_ = nullptr;}
+
+      tune_guard&
+      operator= (tune_guard&& x) noexcept
       {
         if (&x != this)
         {
@@ -426,8 +434,8 @@ namespace build2
     {
       explicit
       monitor_guard (scheduler* s = nullptr): s_ (s) {}
-      monitor_guard (monitor_guard&& x): s_ (x.s_) {x.s_ = nullptr;}
-      monitor_guard& operator= (monitor_guard&& x)
+      monitor_guard (monitor_guard&& x) noexcept: s_ (x.s_) {x.s_ = nullptr;}
+      monitor_guard& operator= (monitor_guard&& x) noexcept
       {
         if (&x != this)
         {
diff --git a/libbuild2/script/parser.cxx b/libbuild2/script/parser.cxx
index 0be22a6..ae6da76 100644
--- a/libbuild2/script/parser.cxx
+++ b/libbuild2/script/parser.cxx
@@ -2763,7 +2763,7 @@ namespace build2
     }
 
     parser::parsed_doc::
-    parsed_doc (parsed_doc&& d)
+    parsed_doc (parsed_doc&& d) noexcept
         : re (d.re), end_line (d.end_line), end_column (d.end_column)
     {
       if (re)
diff --git a/libbuild2/script/parser.hxx b/libbuild2/script/parser.hxx
index 91f50bf..cadf909 100644
--- a/libbuild2/script/parser.hxx
+++ b/libbuild2/script/parser.hxx
@@ -140,7 +140,7 @@ namespace build2
 
         parsed_doc (string, uint64_t line, uint64_t column);
         parsed_doc (regex_lines&&, uint64_t line, uint64_t column);
-        parsed_doc (parsed_doc&&); // Note: move constuctible-only type.
+        parsed_doc (parsed_doc&&) noexcept; // Note: move constuctible-only type.
         ~parsed_doc ();
       };
 
diff --git a/libbuild2/script/regex.hxx b/libbuild2/script/regex.hxx
index f6cf566..3c49b31 100644
--- a/libbuild2/script/regex.hxx
+++ b/libbuild2/script/regex.hxx
@@ -271,8 +271,8 @@ namespace build2
       template <typename T>
       struct line_char_cmp
         : public std::enable_if<std::is_integral<T>::value ||
-      (std::is_enum<T>::value &&
-       !std::is_same<T, char_flags>::value)> {};
+                                (std::is_enum<T>::value &&
+                                 !std::is_same<T, char_flags>::value)> {};
 
       template <typename T, typename = typename line_char_cmp<T>::type>
       bool
@@ -470,10 +470,10 @@ namespace std
     is (mask m, char_type c) const
     {
       return m ==
-        (c.type () == line_type::special && c.special () >= 0 &&
-         build2::digit (static_cast<char> (c.special ()))
-         ? digit
-         : 0);
+             (c.type () == line_type::special && c.special () >= 0 &&
+              build2::digit (static_cast<char> (c.special ()))
+              ? digit
+              : 0);
     }
 
     const char_type*
diff --git a/libbuild2/target-type.hxx b/libbuild2/target-type.hxx
index eae2caf..16f07fa 100644
--- a/libbuild2/target-type.hxx
+++ b/libbuild2/target-type.hxx
@@ -248,7 +248,7 @@ namespace build2
       target_type_ref (unique_ptr<target_type>&& p)
           : p_ (p.release ()), d_ (true) {}
 
-      target_type_ref (target_type_ref&& r)
+      target_type_ref (target_type_ref&& r) noexcept
           : p_ (r.p_), d_ (r.d_) {r.p_ = nullptr;}
 
       ~target_type_ref () {if (p_ != nullptr && d_) delete p_;}
diff --git a/libbuild2/types.hxx b/libbuild2/types.hxx
index bf412a3..20b10de 100644
--- a/libbuild2/types.hxx
+++ b/libbuild2/types.hxx
@@ -511,9 +511,9 @@ namespace build2
 
     location_value (const location&);
 
-    location_value (location_value&&);
+    location_value (location_value&&) noexcept;
     location_value (const location_value&);
-    location_value& operator= (location_value&&);
+    location_value& operator= (location_value&&) noexcept;
     location_value& operator= (const location_value&);
   };
 
diff --git a/libbuild2/types.ixx b/libbuild2/types.ixx
index 750c8c7..bf44cff 100644
--- a/libbuild2/types.ixx
+++ b/libbuild2/types.ixx
@@ -43,7 +43,7 @@ namespace build2
   }
 
   inline location_value::
-  location_value (location_value&& l)
+  location_value (location_value&& l) noexcept
       : location (l.line, l.column),
         file (std::move (l.file))
   {
@@ -58,7 +58,7 @@ namespace build2
   }
 
   inline location_value& location_value::
-  operator= (location_value&& l)
+  operator= (location_value&& l) noexcept
   {
     if (this != &l)
     {
diff --git a/libbuild2/variable.cxx b/libbuild2/variable.cxx
index fefea98..260d664 100644
--- a/libbuild2/variable.cxx
+++ b/libbuild2/variable.cxx
@@ -47,7 +47,7 @@ namespace build2
   }
 
   value::
-  value (value&& v)
+  value (value&& v) noexcept
       : type (v.type), null (v.null), extra (v.extra)
   {
     if (!null)
@@ -99,6 +99,8 @@ namespace build2
           if (null)
             new (&data_) names (move (v).as<names> ());
           else
+            // Note: can throw (see small_vector for details).
+            //
             as<names> () = move (v).as<names> ();
         }
         else if (auto f = null ? type->copy_ctor : type->copy_assign)
diff --git a/libbuild2/variable.hxx b/libbuild2/variable.hxx
index 2942f1c..8a0adf8 100644
--- a/libbuild2/variable.hxx
+++ b/libbuild2/variable.hxx
@@ -358,9 +358,13 @@ namespace build2
     value&
     operator= (nullptr_t) {if (!null) reset (); return *this;}
 
-    value (value&&);
+    // Note that we have the noexcept specification even though copy_ctor()
+    // could potentially throw (for example, for std::map).
+    //
+    value (value&&) noexcept;
+
     explicit value (const value&);
-    value& operator= (value&&);
+    value& operator= (value&&);      // Note: can throw for untyped RHS.
     value& operator= (const value&);
     value& operator= (reference_wrapper<value>);
     value& operator= (reference_wrapper<const value>);
@@ -1859,7 +1863,7 @@ namespace build2
     variable_map (const variable_map&, const prerequisite&, bool shared = false);
 
     variable_map&
-    operator= (variable_map&& v) {m_ = move (v.m_); return *this;}
+    operator= (variable_map&& v) noexcept {m_ = move (v.m_); return *this;}
 
     variable_map&
     operator= (const variable_map& v) {m_ = v.m_; return *this;}
@@ -1870,6 +1874,8 @@ namespace build2
     variable_map (context& c, bool shared)
       : shared_ (shared), owner_ (owner::context), ctx (&c) {}
 
+    // Note: std::map's move constructor can throw.
+    //
     variable_map (variable_map&& v)
       : shared_ (v.shared_), owner_ (v.owner_), ctx (v.ctx), m_ (move (v.m_))
     {