Use FreeRegions inplace of `std::vector<FreeRegion>`

gcc/rust/ChangeLog:

	* checks/errors/borrowck/rust-bir-builder-internal.h: Use
	FreeRegions instead of making a temporary vector of FreeRegion.
	* checks/errors/borrowck/rust-bir-builder.h: Likewise.
	* checks/errors/borrowck/rust-bir-fact-collector.h (class FactCollector):
	Likewise.
	(points): Likewise.
	* checks/errors/borrowck/rust-bir-free-region.h: Remove obsolete
	set_from() helpers, add push_back().
	* checks/errors/borrowck/rust-bir-place.h: Use FreeRegions
	instead of making a temporary vector of Origin.
	* typecheck/rust-tyty-variance-analysis-private.h: Change type
	of `regions`.
	* typecheck/rust-tyty-variance-analysis.cc (CrateCtx::query_type_regions):
	Use new type.
	(GenericTyPerCrateCtx::query_generic_variance): Likewise.
	(TyVisitorCtx::add_constraints_from_generic_args): Likewise.
	(FieldVisitorCtx::add_constraints_from_region): Likewise.
	(FieldVisitorCtx::add_constrints_from_param): Likewise.
	* typecheck/rust-tyty-variance-analysis.h: Likewise.

Signed-off-by: Kushal Pal <kushalpal109@gmail.com>

8 files changed, 38 insertions, 57 deletions

diff --git a/gcc/rust/checks/errors/borrowck/rust-bir-builder-internal.h b/gcc/rust/checks/errors/borrowck/rust-bir-builder-internal.h
index ac93714..d03bdeb 100644
--- a/gcc/rust/checks/errors/borrowck/rust-bir-builder-internal.h
+++ b/gcc/rust/checks/errors/borrowck/rust-bir-builder-internal.h
@@ -206,7 +206,7 @@ protected:
   FreeRegions bind_regions (std::vector<TyTy::Region> regions,
 			    FreeRegions parent_free_regions)
   {
-    std::vector<FreeRegion> free_regions;
+    FreeRegions free_regions;
     for (auto &region : regions)
       {
 	if (region.is_early_bound ())
@@ -231,9 +231,7 @@ protected:
 	    rust_unreachable ();
 	  }
       }
-    // This is necesarry because of clash of current gcc and gcc4.8.
-    FreeRegions free_regions_final{std::move (free_regions)};
-    return free_regions_final;
+    return free_regions;
   }
 
 protected: // Helpers to add BIR statements
diff --git a/gcc/rust/checks/errors/borrowck/rust-bir-builder.h b/gcc/rust/checks/errors/borrowck/rust-bir-builder.h
index 9509e00..19d8ce5 100644
--- a/gcc/rust/checks/errors/borrowck/rust-bir-builder.h
+++ b/gcc/rust/checks/errors/borrowck/rust-bir-builder.h
@@ -68,15 +68,15 @@ private:
   /** Instantiate `num_lifetime_params` free regions. */
   void handle_lifetime_params (size_t num_lifetime_params)
   {
-    std::vector<FreeRegion> function_free_regions;
+    FreeRegions regions;
     for (size_t i = 0; i < num_lifetime_params; i++)
       {
-	function_free_regions.push_back (ctx.place_db.get_next_free_region ());
+	regions.push_back (ctx.place_db.get_next_free_region ());
       }
 
     rust_debug ("\tctx.fn_free_region={%s}",
 		ctx.fn_free_regions.to_string ().c_str ());
-    ctx.fn_free_regions.set_from (std::move (function_free_regions));
+    ctx.fn_free_regions = regions;
   }
 
   void handle_lifetime_param_constraints (
diff --git a/gcc/rust/checks/errors/borrowck/rust-bir-fact-collector.h b/gcc/rust/checks/errors/borrowck/rust-bir-fact-collector.h
index 6ca5404..aae41ad 100644
--- a/gcc/rust/checks/errors/borrowck/rust-bir-fact-collector.h
+++ b/gcc/rust/checks/errors/borrowck/rust-bir-fact-collector.h
@@ -65,11 +65,11 @@ class FactCollector : public Visitor
 
   FreeRegions make_fresh_regions (size_t size)
   {
-    std::vector<FreeRegion> free_regions;
+    FreeRegions free_regions;
     for (size_t i = 0; i < size; i++)
       free_regions.push_back (region_binder.get_next_free_region ());
 
-    return FreeRegions (std::move (free_regions));
+    return free_regions;
   }
 
 public:
@@ -179,12 +179,12 @@ protected: // Main collection entry points (for different categories).
 
     rust_debug ("\tSanitize deref of %s", base.tyty->as_string ().c_str ());
 
-    std::vector<FreeRegion> regions;
-    regions.insert (regions.end (), base.regions.begin () + 1,
-		    base.regions.end ());
-    FreeRegions r;
-    r.set_from (std::move (regions));
-    push_subset_all (place.tyty, r, place.regions);
+    FreeRegions regions;
+    for (auto it = base.regions.begin () + 1; it != base.regions.end (); ++it)
+      {
+	regions.push_back (*it);
+      }
+    push_subset_all (place.tyty, regions, place.regions);
   }
   void sanizite_field (PlaceId place_id)
   {
@@ -201,9 +201,7 @@ protected: // Main collection entry points (for different categories).
 	       .query_field_regions (base.tyty->as<TyTy::ADTType> (), 0,
 				     place.variable_or_field_index,
 				     base.regions); // FIXME
-    FreeRegions f;
-    f.set_from (std::move (r));
-    push_subset_all (place.tyty, f, place.regions);
+    push_subset_all (place.tyty, r, place.regions);
   }
 
   void visit_statemensts ()
diff --git a/gcc/rust/checks/errors/borrowck/rust-bir-free-region.h b/gcc/rust/checks/errors/borrowck/rust-bir-free-region.h
index 95d4e11..22235ea 100644
--- a/gcc/rust/checks/errors/borrowck/rust-bir-free-region.h
+++ b/gcc/rust/checks/errors/borrowck/rust-bir-free-region.h
@@ -50,22 +50,6 @@ public:
   FreeRegion &operator[] (size_t i) { return regions.at (i); }
   const FreeRegion &operator[] (size_t i) const { return regions.at (i); }
   const std::vector<FreeRegion> &get_regions () const { return regions; }
-  void set_from (std::vector<Rust::Polonius::Origin> &&regions)
-  {
-    this->regions.clear ();
-    for (auto &region : regions)
-      {
-	this->regions.push_back ({region});
-      }
-  }
-  void set_from (std::vector<FreeRegion> &&regions)
-  {
-    this->regions.clear ();
-    for (auto &region : regions)
-      {
-	this->regions.push_back (region);
-      }
-  }
 
   WARN_UNUSED_RESULT FreeRegions prepend (FreeRegion region) const
   {
@@ -74,8 +58,10 @@ public:
     return FreeRegions (std::move (new_regions));
   }
 
-  FreeRegions (std::vector<FreeRegion> &&regions) : regions (regions) {}
+  void push_back (FreeRegion region) { regions.push_back (region); }
+
   FreeRegions () {}
+  FreeRegions (std::vector<FreeRegion> &&regions) : regions (regions) {}
 
   WARN_UNUSED_RESULT std::string to_string () const
   {
@@ -111,7 +97,7 @@ public:
   FreeRegions bind_regions (std::vector<TyTy::Region> regions,
 			    FreeRegions parent_free_regions)
   {
-    std::vector<FreeRegion> free_regions;
+    FreeRegions free_regions;
     for (auto &region : regions)
       {
 	if (region.is_early_bound ())
@@ -128,9 +114,7 @@ public:
 	    rust_unreachable ();
 	  }
       }
-    // This is necesarry because of clash of current gcc and gcc4.8.
-    FreeRegions free_regions_final{std::move (free_regions)};
-    return free_regions_final;
+    return free_regions;
   }
 };
 
diff --git a/gcc/rust/checks/errors/borrowck/rust-bir-place.h b/gcc/rust/checks/errors/borrowck/rust-bir-place.h
index 589aaf0..d857528 100644
--- a/gcc/rust/checks/errors/borrowck/rust-bir-place.h
+++ b/gcc/rust/checks/errors/borrowck/rust-bir-place.h
@@ -259,11 +259,14 @@ public:
     auto variances = Resolver::TypeCheckContext::get ()
 		       ->get_variance_analysis_ctx ()
 		       .query_type_variances (new_place_ref.tyty);
-    std::vector<Polonius::Origin> regions;
+    FreeRegions regions;
     for (size_t i = 0; i < variances.size (); ++i)
-      regions.push_back (next_free_region.value++);
+      {
+	regions.push_back (next_free_region);
+	++next_free_region.value;
+      }
 
-    new_place_ref.regions.set_from (std::move (regions));
+    new_place_ref.regions = regions;
 
     return new_place;
   }
diff --git a/gcc/rust/typecheck/rust-tyty-variance-analysis-private.h b/gcc/rust/typecheck/rust-tyty-variance-analysis-private.h
index 41a0d6f..450e53e 100644
--- a/gcc/rust/typecheck/rust-tyty-variance-analysis-private.h
+++ b/gcc/rust/typecheck/rust-tyty-variance-analysis-private.h
@@ -201,10 +201,9 @@ public: // Module internal API
 
   std::vector<Variance> query_generic_variance (const ADTType &type);
 
-  std::vector<size_t> query_field_regions (const ADTType *parent,
-					   size_t variant_index,
-					   size_t field_index,
-					   const FreeRegions &parent_regions);
+  FreeRegions query_field_regions (const ADTType *parent, size_t variant_index,
+				   size_t field_index,
+				   const FreeRegions &parent_regions);
 
   std::vector<Region> query_type_regions (BaseType *base);
 
@@ -309,7 +308,7 @@ class FieldVisitorCtx : public VarianceVisitorCtx<Variance>
 public:
   using Visitor = VisitorBase<Variance>;
 
-  std::vector<size_t> collect_regions (BaseType &ty);
+  FreeRegions collect_regions (BaseType &ty);
 
   FieldVisitorCtx (GenericTyPerCrateCtx &ctx, const SubstitutionRef &subst,
 		   const FreeRegions &parent_regions)
@@ -332,7 +331,7 @@ public:
 private:
   GenericTyPerCrateCtx &ctx;
   const SubstitutionRef &subst;
-  std::vector<size_t> regions;
+  FreeRegions regions;
   FreeRegions parent_regions;
   std::vector<size_t> type_param_ranges;
 };
diff --git a/gcc/rust/typecheck/rust-tyty-variance-analysis.cc b/gcc/rust/typecheck/rust-tyty-variance-analysis.cc
index 15c16db..1aba576 100644
--- a/gcc/rust/typecheck/rust-tyty-variance-analysis.cc
+++ b/gcc/rust/typecheck/rust-tyty-variance-analysis.cc
@@ -52,7 +52,7 @@ CrateCtx::query_type_regions (BaseType *type)
   return private_ctx->query_type_regions (type);
 }
 
-std::vector<size_t>
+FreeRegions
 CrateCtx::query_field_regions (const ADTType *parent, size_t variant_index,
 			       size_t field_index,
 			       const FreeRegions &parent_regions)
@@ -332,7 +332,7 @@ GenericTyPerCrateCtx::query_generic_variance (const ADTType &type)
   return result;
 }
 
-std::vector<size_t>
+FreeRegions
 GenericTyPerCrateCtx::query_field_regions (const ADTType *parent,
 					   size_t variant_index,
 					   size_t field_index,
@@ -537,7 +537,7 @@ TyVisitorCtx::add_constraints_from_generic_args (HirId ref,
     }
 }
 
-std::vector<size_t>
+FreeRegions
 FieldVisitorCtx::collect_regions (BaseType &ty)
 {
   // Segment the regions into ranges for each type parameter. Type parameter
@@ -570,7 +570,7 @@ FieldVisitorCtx::add_constraints_from_region (const Region &region,
 {
   if (region.is_early_bound ())
     {
-      regions.push_back (parent_regions[region.get_index ()].value);
+      regions.push_back (parent_regions[region.get_index ()]);
     }
   else if (region.is_late_bound ())
     {
@@ -585,7 +585,7 @@ FieldVisitorCtx::add_constrints_from_param (ParamType &param, Variance variance)
   for (size_t i = type_param_ranges[param_i];
        i < type_param_ranges[param_i + 1]; i++)
     {
-      regions.push_back (parent_regions[i].value);
+      regions.push_back (parent_regions[i]);
     }
 }
 
diff --git a/gcc/rust/typecheck/rust-tyty-variance-analysis.h b/gcc/rust/typecheck/rust-tyty-variance-analysis.h
index 27e8d8b..9059a2f 100644
--- a/gcc/rust/typecheck/rust-tyty-variance-analysis.h
+++ b/gcc/rust/typecheck/rust-tyty-variance-analysis.h
@@ -33,10 +33,9 @@ public:
 
   /** Get regions mentioned in a type. */
   std::vector<Region> query_type_regions (BaseType *type);
-  std::vector<size_t> query_field_regions (const ADTType *parent,
-					   size_t variant_index,
-					   size_t field_index,
-					   const FreeRegions &parent_regions);
+  FreeRegions query_field_regions (const ADTType *parent, size_t variant_index,
+				   size_t field_index,
+				   const FreeRegions &parent_regions);
 
 private:
   std::unique_ptr<GenericTyPerCrateCtx> private_ctx;