Merge #917

917: remove tree addressable context during type checking r=philberty a=philberty

We can reuse more C front-end code c_mark_addressable can be used instead
of trying to track TREE_ADDRESSABLE as part of type-checking. This also
pulls the GCC::Backend::address_expression to be part of the HIRCompileBase
class during code-generation.

Co-authored-by: Philip Herron <philip.herron@embecosm.com>

1 files changed, 5 insertions, 244 deletions

diff --git a/gcc/rust/rust-gcc.cc b/gcc/rust/rust-gcc.cc
index 62c9d80..86a4106 100644
--- a/gcc/rust/rust-gcc.cc
+++ b/gcc/rust/rust-gcc.cc
@@ -231,8 +231,6 @@ public:
 
   tree function_code_expression (tree, Location);
 
-  tree address_expression (tree, Location);
-
   tree struct_field_expression (tree, size_t, Location);
 
   tree compound_expression (tree, tree, Location);
@@ -312,35 +310,16 @@ public:
 
   void global_variable_set_init (Bvariable *, tree);
 
-  Bvariable *local_variable (tree, const std::string &, tree, Bvariable *, bool,
+  Bvariable *local_variable (tree, const std::string &, tree, Bvariable *,
 			     Location);
 
-  Bvariable *parameter_variable (tree, const std::string &, tree, bool,
-				 Location);
+  Bvariable *parameter_variable (tree, const std::string &, tree, Location);
 
   Bvariable *static_chain_variable (tree, const std::string &, tree, Location);
 
   Bvariable *temporary_variable (tree, tree, tree, tree, bool, Location,
 				 tree *);
 
-  Bvariable *implicit_variable (const std::string &, const std::string &, tree,
-				bool, bool, bool, int64_t);
-
-  void implicit_variable_set_init (Bvariable *, const std::string &, tree, bool,
-				   bool, bool, tree);
-
-  Bvariable *implicit_variable_reference (const std::string &,
-					  const std::string &, tree);
-
-  Bvariable *immutable_struct (const std::string &, const std::string &, bool,
-			       bool, tree, Location);
-
-  void immutable_struct_set_init (Bvariable *, const std::string &, bool, bool,
-				  tree, Location, tree);
-
-  Bvariable *immutable_struct_reference (const std::string &,
-					 const std::string &, tree, Location);
-
   // Labels.
 
   tree label (tree, const std::string &name, Location);
@@ -1338,17 +1317,6 @@ Gcc_backend::function_code_expression (tree func, Location location)
   return ret;
 }
 
-// Get the address of an expression.
-
-tree
-Gcc_backend::address_expression (tree expr, Location location)
-{
-  if (expr == error_mark_node)
-    return this->error_expression ();
-
-  return build_fold_addr_expr_loc (location.gcc_location (), expr);
-}
-
 // Return an expression for the field at INDEX in BSTRUCT.
 
 tree
@@ -2495,7 +2463,7 @@ Gcc_backend::global_variable_set_init (Bvariable *var, tree expr_tree)
 Bvariable *
 Gcc_backend::local_variable (tree function, const std::string &name,
 			     tree type_tree, Bvariable *decl_var,
-			     bool is_address_taken, Location location)
+			     Location location)
 {
   if (type_tree == error_mark_node)
     return this->error_variable ();
@@ -2503,8 +2471,7 @@ Gcc_backend::local_variable (tree function, const std::string &name,
 			  get_identifier_from_string (name), type_tree);
   DECL_CONTEXT (decl) = function;
   TREE_USED (decl) = 1;
-  if (is_address_taken)
-    TREE_ADDRESSABLE (decl) = 1;
+
   if (decl_var != NULL)
     {
       DECL_HAS_VALUE_EXPR_P (decl) = 1;
@@ -2518,8 +2485,7 @@ Gcc_backend::local_variable (tree function, const std::string &name,
 
 Bvariable *
 Gcc_backend::parameter_variable (tree function, const std::string &name,
-				 tree type_tree, bool is_address_taken,
-				 Location location)
+				 tree type_tree, Location location)
 {
   if (type_tree == error_mark_node)
     return this->error_variable ();
@@ -2528,8 +2494,6 @@ Gcc_backend::parameter_variable (tree function, const std::string &name,
   DECL_CONTEXT (decl) = function;
   DECL_ARG_TYPE (decl) = type_tree;
   TREE_USED (decl) = 1;
-  if (is_address_taken)
-    TREE_ADDRESSABLE (decl) = 1;
   rust_preserve_from_gc (decl);
   return new Bvariable (decl);
 }
@@ -2633,209 +2597,6 @@ Gcc_backend::temporary_variable (tree fndecl, tree bind_tree, tree type_tree,
   return new Bvariable (var);
 }
 
-// Create an implicit variable that is compiler-defined.  This is used when
-// generating GC root variables and storing the values of a slice initializer.
-
-Bvariable *
-Gcc_backend::implicit_variable (const std::string &name,
-				const std::string &asm_name, tree type_tree,
-				bool is_hidden, bool is_constant,
-				bool is_common, int64_t alignment)
-{
-  if (type_tree == error_mark_node)
-    return this->error_variable ();
-
-  tree decl = build_decl (BUILTINS_LOCATION, VAR_DECL,
-			  get_identifier_from_string (name), type_tree);
-  DECL_EXTERNAL (decl) = 0;
-  TREE_PUBLIC (decl) = !is_hidden;
-  TREE_STATIC (decl) = 1;
-  TREE_USED (decl) = 1;
-  DECL_ARTIFICIAL (decl) = 1;
-  if (is_common)
-    {
-      DECL_COMMON (decl) = 1;
-
-      // When the initializer for one implicit_variable refers to another,
-      // it needs to know the visibility of the referenced struct so that
-      // compute_reloc_for_constant will return the right value.  On many
-      // systems calling make_decl_one_only will mark the decl as weak,
-      // which will change the return value of compute_reloc_for_constant.
-      // We can't reliably call make_decl_one_only yet, because we don't
-      // yet know the initializer.  This issue doesn't arise in C because
-      // Rust initializers, unlike C initializers, can be indirectly
-      // recursive.  To ensure that compute_reloc_for_constant computes
-      // the right value if some other initializer refers to this one, we
-      // mark this symbol as weak here.  We undo that below in
-      // immutable_struct_set_init before calling mark_decl_one_only.
-      DECL_WEAK (decl) = 1;
-    }
-  if (is_constant)
-    {
-      TREE_READONLY (decl) = 1;
-      TREE_CONSTANT (decl) = 1;
-    }
-  if (alignment != 0)
-    {
-      SET_DECL_ALIGN (decl, alignment * BITS_PER_UNIT);
-      DECL_USER_ALIGN (decl) = 1;
-    }
-  if (!asm_name.empty ())
-    SET_DECL_ASSEMBLER_NAME (decl, get_identifier_from_string (asm_name));
-
-  rust_preserve_from_gc (decl);
-  return new Bvariable (decl);
-}
-
-// Set the initalizer for a variable created by implicit_variable.
-// This is where we finish compiling the variable.
-
-void
-Gcc_backend::implicit_variable_set_init (Bvariable *var, const std::string &,
-					 tree, bool, bool, bool is_common,
-					 tree init_tree)
-{
-  tree decl = var->get_decl ();
-  if (decl == error_mark_node || init_tree == error_mark_node)
-    return;
-
-  DECL_INITIAL (decl) = init_tree;
-
-  // Now that DECL_INITIAL is set, we can't call make_decl_one_only.
-  // See the comment where DECL_WEAK is set in implicit_variable.
-  if (is_common)
-    {
-      DECL_WEAK (decl) = 0;
-      make_decl_one_only (decl, DECL_ASSEMBLER_NAME (decl));
-    }
-
-  resolve_unique_section (decl, 2, 1);
-
-  rest_of_decl_compilation (decl, 1, 0);
-}
-
-// Return a reference to an implicit variable defined in another package.
-
-Bvariable *
-Gcc_backend::implicit_variable_reference (const std::string &name,
-					  const std::string &asm_name,
-					  tree type_tree)
-{
-  if (type_tree == error_mark_node)
-    return this->error_variable ();
-
-  tree decl = build_decl (BUILTINS_LOCATION, VAR_DECL,
-			  get_identifier_from_string (name), type_tree);
-  DECL_EXTERNAL (decl) = 1;
-  TREE_PUBLIC (decl) = 1;
-  TREE_STATIC (decl) = 0;
-  DECL_ARTIFICIAL (decl) = 1;
-  if (!asm_name.empty ())
-    SET_DECL_ASSEMBLER_NAME (decl, get_identifier_from_string (asm_name));
-  rust_preserve_from_gc (decl);
-  return new Bvariable (decl);
-}
-
-// Create a named immutable initialized data structure.
-
-Bvariable *
-Gcc_backend::immutable_struct (const std::string &name,
-			       const std::string &asm_name, bool is_hidden,
-			       bool is_common, tree type_tree,
-			       Location location)
-{
-  if (type_tree == error_mark_node)
-    return this->error_variable ();
-  gcc_assert (TREE_CODE (type_tree) == RECORD_TYPE);
-  tree decl = build_decl (location.gcc_location (), VAR_DECL,
-			  get_identifier_from_string (name),
-			  build_qualified_type (type_tree, TYPE_QUAL_CONST));
-  TREE_STATIC (decl) = 1;
-  TREE_USED (decl) = 1;
-  TREE_READONLY (decl) = 1;
-  TREE_CONSTANT (decl) = 1;
-  DECL_ARTIFICIAL (decl) = 1;
-  if (!is_hidden)
-    TREE_PUBLIC (decl) = 1;
-  if (!asm_name.empty ())
-    SET_DECL_ASSEMBLER_NAME (decl, get_identifier_from_string (asm_name));
-
-  // When the initializer for one immutable_struct refers to another,
-  // it needs to know the visibility of the referenced struct so that
-  // compute_reloc_for_constant will return the right value.  On many
-  // systems calling make_decl_one_only will mark the decl as weak,
-  // which will change the return value of compute_reloc_for_constant.
-  // We can't reliably call make_decl_one_only yet, because we don't
-  // yet know the initializer.  This issue doesn't arise in C because
-  // Rust initializers, unlike C initializers, can be indirectly
-  // recursive.  To ensure that compute_reloc_for_constant computes
-  // the right value if some other initializer refers to this one, we
-  // mark this symbol as weak here.  We undo that below in
-  // immutable_struct_set_init before calling mark_decl_one_only.
-  if (is_common)
-    DECL_WEAK (decl) = 1;
-
-  // We don't call rest_of_decl_compilation until we have the
-  // initializer.
-
-  rust_preserve_from_gc (decl);
-  return new Bvariable (decl);
-}
-
-// Set the initializer for a variable created by immutable_struct.
-// This is where we finish compiling the variable.
-
-void
-Gcc_backend::immutable_struct_set_init (Bvariable *var, const std::string &,
-					bool, bool is_common, tree, Location,
-					tree init_tree)
-{
-  tree decl = var->get_decl ();
-  if (decl == error_mark_node || init_tree == error_mark_node)
-    return;
-
-  DECL_INITIAL (decl) = init_tree;
-
-  // Now that DECL_INITIAL is set, we can't call make_decl_one_only.
-  // See the comment where DECL_WEAK is set in immutable_struct.
-  if (is_common)
-    {
-      DECL_WEAK (decl) = 0;
-      make_decl_one_only (decl, DECL_ASSEMBLER_NAME (decl));
-    }
-
-  // These variables are often unneeded in the final program, so put
-  // them in their own section so that linker GC can discard them.
-  resolve_unique_section (decl, compute_reloc_for_constant (init_tree), 1);
-
-  rest_of_decl_compilation (decl, 1, 0);
-}
-
-// Return a reference to an immutable initialized data structure
-// defined in another package.
-
-Bvariable *
-Gcc_backend::immutable_struct_reference (const std::string &name,
-					 const std::string &asm_name,
-					 tree type_tree, Location location)
-{
-  if (type_tree == error_mark_node)
-    return this->error_variable ();
-  gcc_assert (TREE_CODE (type_tree) == RECORD_TYPE);
-  tree decl = build_decl (location.gcc_location (), VAR_DECL,
-			  get_identifier_from_string (name),
-			  build_qualified_type (type_tree, TYPE_QUAL_CONST));
-  TREE_READONLY (decl) = 1;
-  TREE_CONSTANT (decl) = 1;
-  DECL_ARTIFICIAL (decl) = 1;
-  TREE_PUBLIC (decl) = 1;
-  DECL_EXTERNAL (decl) = 1;
-  if (!asm_name.empty ())
-    SET_DECL_ASSEMBLER_NAME (decl, get_identifier_from_string (asm_name));
-  rust_preserve_from_gc (decl);
-  return new Bvariable (decl);
-}
-
 // Make a label.
 
 tree