Hi,
When looking into PR109108, the reason why things go awry is because
of the logic around functions with thunks - they have their definitions
generated even when they are external. This subsequently then relied on
the detection of whether a function receiving codegen really is extern
or not, and this check ultimately prunes too much.
This is a first step to both removing the call to `build_decl_tree' from
`make_thunk' and the pruning of symbols within the `build_decl_tree'
visitor method for functions. Move the generation of DECL_ARGUMENT and
DECL_RESULT out of `build_decl_tree' and into their own functions.
Bootstrapped and regression tested on x86_64-linux/-m32/-mx32, committed
to mainline and backported to the releases/gcc-11 and gcc-12 branches.
Regards,
Iain.
---
gcc/d/ChangeLog:
* decl.cc (get_fndecl_result): New function.
(get_fndecl_arguments): New function.
(DeclVisitor::visit (FuncDeclaration *)): Adjust to call
get_fndecl_arguments.
(make_thunk): Adjust to call get_fndecl_arguments and
get_fndecl_result.
(start_function): Adjust to call get_fndecl_result.
---
gcc/d/decl.cc | 206 +++++++++++++++++++++++++++++---------------------
1 file changed, 118 insertions(+), 88 deletions(-)
@@ -117,6 +117,113 @@ gcc_attribute_p (Dsymbol *decl)
return false;
}
+/* Return the DECL_RESULT for the function declaration DECL, create it if it
+ doesn't already exist. */
+
+static tree
+get_fndecl_result (FuncDeclaration *decl)
+{
+ tree fndecl = get_symbol_decl (decl);
+ tree resdecl = DECL_RESULT (fndecl);
+
+ if (resdecl != NULL_TREE)
+ return resdecl;
+
+ resdecl = build_decl (make_location_t (decl->loc), RESULT_DECL,
+ NULL_TREE, TREE_TYPE (TREE_TYPE (fndecl)));
+
+ DECL_ARTIFICIAL (resdecl) = 1;
+ DECL_IGNORED_P (resdecl) = 1;
+ DECL_CONTEXT (resdecl) = fndecl;
+ DECL_RESULT (fndecl) = resdecl;
+ return resdecl;
+}
+
+/* Return the list of PARAM_DECLs for the function declaration DECL, create it
+ if it doesn't already exist. */
+
+static tree
+get_fndecl_arguments (FuncDeclaration *decl)
+{
+ tree fndecl = get_symbol_decl (decl);
+ tree param_list = DECL_ARGUMENTS (fndecl);
+
+ if (param_list != NULL_TREE)
+ return param_list;
+
+ if (decl->fbody)
+ {
+ /* Handle special arguments first. */
+
+ /* `this' parameter:
+ For nested functions, D still generates a vthis, but it
+ should not be referenced in any expression. */
+ if (decl->vthis)
+ {
+ tree parm_decl = get_symbol_decl (decl->vthis);
+ DECL_ARTIFICIAL (parm_decl) = 1;
+ TREE_READONLY (parm_decl) = 1;
+
+ if (decl->vthis->type == Type::tvoidptr)
+ {
+ /* Replace generic pointer with back-end closure type
+ (this wins for gdb). */
+ tree frame_type = FRAMEINFO_TYPE (get_frameinfo (decl));
+ gcc_assert (frame_type != NULL_TREE);
+ TREE_TYPE (parm_decl) = build_pointer_type (frame_type);
+ }
+
+ param_list = chainon (param_list, parm_decl);
+ }
+
+ /* `_arguments' parameter. */
+ if (decl->v_arguments)
+ {
+ tree parm_decl = get_symbol_decl (decl->v_arguments);
+ param_list = chainon (param_list, parm_decl);
+ }
+
+ /* Now add on formal function parameters. */
+ size_t n_parameters = decl->parameters ? decl->parameters->length : 0;
+
+ for (size_t i = 0; i < n_parameters; i++)
+ {
+ VarDeclaration *param = (*decl->parameters)[i];
+ tree parm_decl = get_symbol_decl (param);
+
+ /* Type `noreturn` is a terminator, as no other arguments can possibly
+ be evaluated after it. */
+ if (TREE_TYPE (parm_decl) == noreturn_type_node)
+ break;
+
+ /* Chain them in the correct order. */
+ param_list = chainon (param_list, parm_decl);
+ }
+ }
+ else
+ {
+ /* Build parameters from the function type. */
+ tree fntype = TREE_TYPE (fndecl);
+
+ for (tree t = TYPE_ARG_TYPES (fntype); t; t = TREE_CHAIN (t))
+ {
+ if (t == void_list_node)
+ break;
+
+ tree param = build_decl (DECL_SOURCE_LOCATION (fndecl),
+ PARM_DECL, NULL_TREE, TREE_VALUE (t));
+ DECL_ARG_TYPE (param) = TREE_TYPE (param);
+ DECL_ARTIFICIAL (param) = 1;
+ DECL_IGNORED_P (param) = 1;
+ DECL_CONTEXT (param) = fndecl;
+ param_list = chainon (param_list, param);
+ }
+ }
+
+ DECL_ARGUMENTS (fndecl) = param_list;
+ return param_list;
+}
+
/* Implements the visitor interface to lower all Declaration AST classes
emitted from the D Front-end to GCC trees.
All visit methods accept one parameter D, which holds the frontend AST
@@ -861,66 +968,17 @@ public:
message ("function %s", d->toPrettyChars ());
tree old_context = start_function (d);
+ tree param_list = get_fndecl_arguments (d);
- tree parm_decl = NULL_TREE;
- tree param_list = NULL_TREE;
-
- /* Special arguments... */
-
- /* `this' parameter:
- For nested functions, D still generates a vthis, but it
- should not be referenced in any expression. */
- if (d->vthis)
- {
- parm_decl = get_symbol_decl (d->vthis);
- DECL_ARTIFICIAL (parm_decl) = 1;
- TREE_READONLY (parm_decl) = 1;
-
- if (d->vthis->type == Type::tvoidptr)
- {
- /* Replace generic pointer with back-end closure type
- (this wins for gdb). */
- tree frame_type = FRAMEINFO_TYPE (get_frameinfo (d));
- gcc_assert (frame_type != NULL_TREE);
- TREE_TYPE (parm_decl) = build_pointer_type (frame_type);
- }
-
- param_list = chainon (param_list, parm_decl);
- d_function_chain->static_chain = parm_decl;
- }
-
- /* _arguments parameter. */
- if (d->v_arguments)
- {
- parm_decl = get_symbol_decl (d->v_arguments);
- param_list = chainon (param_list, parm_decl);
- }
-
- /* formal function parameters. */
- const size_t n_parameters = d->parameters ? d->parameters->length : 0;
-
- for (size_t i = 0; i < n_parameters; i++)
- {
- VarDeclaration *param = (*d->parameters)[i];
-
- parm_decl = get_symbol_decl (param);
-
- /* Type `noreturn` is a terminator, as no other arguments can possibly
- be evaluated after it. */
- if (TREE_TYPE (parm_decl) == noreturn_type_node)
- break;
-
- /* Chain them in the correct order. */
- param_list = chainon (param_list, parm_decl);
- }
-
- DECL_ARGUMENTS (fndecl) = param_list;
DECL_IN_UNITTEST_CONDITION_P (fndecl) = this->in_version_unittest_;
rest_of_decl_compilation (fndecl, 1, 0);
/* If this is a member function that nested (possibly indirectly) in another
function, construct an expession for this member function's static chain
by going through parent link of nested classes. */
+ if (d->vthis)
+ d_function_chain->static_chain = get_symbol_decl (d->vthis);
+
if (d->isThis ())
{
AggregateDeclaration *ad = d->isThis ();
@@ -935,7 +993,7 @@ public:
ad = pd->isAggregateDeclaration ();
if (ad == NULL)
{
- cfun->language->static_chain = this_tree;
+ d_function_chain->static_chain = this_tree;
break;
}
}
@@ -996,7 +1054,7 @@ public:
var = build_address (var);
tree init = build_call_expr (builtin_decl_explicit (BUILT_IN_VA_START),
- 2, var, parm_decl);
+ 2, var, tree_last (param_list));
declare_local_var (d->v_argptr);
add_stmt (init);
@@ -1879,34 +1937,12 @@ make_thunk (FuncDeclaration *decl, int offset)
{
/* Build parameters for functions that are not being compiled,
so that they can be correctly cloned in finish_thunk. */
- tree fntype = TREE_TYPE (function);
- tree params = NULL_TREE;
-
- for (tree t = TYPE_ARG_TYPES (fntype); t; t = TREE_CHAIN (t))
- {
- if (t == void_list_node)
- break;
-
- tree param = build_decl (DECL_SOURCE_LOCATION (function),
- PARM_DECL, NULL_TREE, TREE_VALUE (t));
- DECL_ARG_TYPE (param) = TREE_TYPE (param);
- DECL_ARTIFICIAL (param) = 1;
- DECL_IGNORED_P (param) = 1;
- DECL_CONTEXT (param) = function;
- params = chainon (params, param);
- }
-
- DECL_ARGUMENTS (function) = params;
+ tree function = get_symbol_decl (decl);
+ DECL_ARGUMENTS (function) = get_fndecl_arguments (decl);
/* Also build the result decl, which is needed when force creating
the thunk in gimple inside cgraph_node::expand_thunk. */
- tree resdecl = build_decl (DECL_SOURCE_LOCATION (function),
- RESULT_DECL, NULL_TREE,
- TREE_TYPE (fntype));
- DECL_ARTIFICIAL (resdecl) = 1;
- DECL_IGNORED_P (resdecl) = 1;
- DECL_CONTEXT (resdecl) = function;
- DECL_RESULT (function) = resdecl;
+ DECL_RESULT (function) = get_fndecl_result (decl);
}
}
@@ -2018,14 +2054,8 @@ start_function (FuncDeclaration *fd)
/* Let GCC know the current scope is this function. */
current_function_decl = fndecl;
- tree restype = TREE_TYPE (TREE_TYPE (fndecl));
- tree resdecl = build_decl (make_location_t (fd->loc), RESULT_DECL,
- NULL_TREE, restype);
-
- DECL_RESULT (fndecl) = resdecl;
- DECL_CONTEXT (resdecl) = fndecl;
- DECL_ARTIFICIAL (resdecl) = 1;
- DECL_IGNORED_P (resdecl) = 1;
+ /* Build the result decl before calling allocate_struct_function. */
+ DECL_RESULT (fndecl) = get_fndecl_result (fd);
/* Initialize the RTL code for the function. */
allocate_struct_function (fndecl, false);