[binutils-gdb] gdb: recognize new DWARF attributes: defaulted, deleted, calling conv.

[binutils-gdb] gdb: recognize new DWARF attributes: defaulted, deleted, calling conv.

[Tankut Baris Aktemur]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=e35000a7f8be021459102751db7e0b7e2868b57e

commit e35000a7f8be021459102751db7e0b7e2868b57e
Author: Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
Date:   Fri Dec 20 17:43:06 2019 +0100

    gdb: recognize new DWARF attributes: defaulted, deleted, calling conv.
    
    Extend GDB's internal representation of types to include the
    DW_AT_calling_convention, DW_AT_defaulted, and DW_AT_deleted attributes
    that were introduced in DWARF5.
    
    These attributes will be helpful in a future patch about infcall'ing
    functions with call-by-value parameters.  GDB will use the attributes
    to decide whether the type of a call-by-value parameter is implicitly
    pass-by-reference.
    
    gdb/ChangeLog:
    2019-12-20  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>
    
    	* dwarf2read.c (dwarf2_add_member_fn): Read the DW_AT_defaulted
    	and DW_AT_deleted attributes of a function.
    	(read_structure_type): Read the DW_AT_calling_convention attribute
    	of a type.
    	(is_valid_DW_AT_defaulted): New function.
    	(is_valid_DW_AT_calling_convention_for_type): New function.
    	* gdbtypes.h: Include dwarf2.h.
    	(struct fn_field)<defaulted>: New field to store the
    	DW_AT_defaulted attribute.
    	(struct fn_field)<is_deleted>: New field to store the
    	DW_AT_deleted attribute.
    	(struct cplus_struct_type)<calling_convention>: New field to store
    	the DW_AT_calling_convention attribute.
    	(TYPE_FN_FIELD_DEFAULTED): New macro.
    	(TYPE_FN_FIELD_DELETED): New macro.
    	(TYPE_CPLUS_CALLING_CONVENTION): New macro.
    	* gdbtypes.c (dump_fn_fieldlists): Update for the changes made
    	to the .h file.
    	(print_cplus_stuff): Likewise.
    
    Change-Id: I54192f363115b78ec7435a8563b73fcace420765

Diff:
---
 gdb/ChangeLog    | 22 ++++++++++++++++++++
 gdb/dwarf2read.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 gdb/gdbtypes.c   |  7 +++++++
 gdb/gdbtypes.h   | 22 +++++++++++++++++++-
 4 files changed, 111 insertions(+), 1 deletion(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 0f35def..5175ebc 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,25 @@
+2019-12-20  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>
+
+	* dwarf2read.c (dwarf2_add_member_fn): Read the DW_AT_defaulted
+	and DW_AT_deleted attributes of a function.
+	(read_structure_type): Read the DW_AT_calling_convention attribute
+	of a type.
+	(is_valid_DW_AT_defaulted): New function.
+	(is_valid_DW_AT_calling_convention_for_type): New function.
+	* gdbtypes.h: Include dwarf2.h.
+	(struct fn_field)<defaulted>: New field to store the
+	DW_AT_defaulted attribute.
+	(struct fn_field)<is_deleted>: New field to store the
+	DW_AT_deleted attribute.
+	(struct cplus_struct_type)<calling_convention>: New field to store
+	the DW_AT_calling_convention attribute.
+	(TYPE_FN_FIELD_DEFAULTED): New macro.
+	(TYPE_FN_FIELD_DELETED): New macro.
+	(TYPE_CPLUS_CALLING_CONVENTION): New macro.
+	* gdbtypes.c (dump_fn_fieldlists): Update for the changes made
+	to the .h file.
+	(print_cplus_stuff): Likewise.
+
 2019-12-20  Tom Tromey  <tom@tromey.com>
 
 	* tui/tui.c (tui_show_source): Remove.
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index ecfae68..6492889 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -15472,6 +15472,25 @@ dwarf2_is_constructor (struct die_info *die, struct dwarf2_cu *cu)
 	  && (type_name[len] == '\0' || type_name[len] == '<'));
 }
 
+/* Check if the given VALUE is a recognized enum
+   dwarf_defaulted_attribute constant according to DWARF5 spec,
+   Table 7.24.  */
+
+static bool
+is_valid_DW_AT_defaulted (ULONGEST value)
+{
+  switch (value)
+    {
+    case DW_DEFAULTED_no:
+    case DW_DEFAULTED_in_class:
+    case DW_DEFAULTED_out_of_class:
+      return true;
+    }
+
+  complaint (_("unrecognized DW_AT_defaulted value (%lu)"), value);
+  return false;
+}
+
 /* Add a member function to the proper fieldlist.  */
 
 static void
@@ -15584,6 +15603,16 @@ dwarf2_add_member_fn (struct field_info *fip, struct die_info *die,
   if (attr && DW_UNSND (attr) != 0)
     fnp->is_artificial = 1;
 
+  /* Check for defaulted methods.  */
+  attr = dwarf2_attr (die, DW_AT_defaulted, cu);
+  if (attr != nullptr && is_valid_DW_AT_defaulted (DW_UNSND (attr)))
+    fnp->defaulted = (enum dwarf_defaulted_attribute) DW_UNSND (attr);
+
+  /* Check for deleted methods.  */
+  attr = dwarf2_attr (die, DW_AT_deleted, cu);
+  if (attr != nullptr && DW_UNSND (attr) != 0)
+    fnp->is_deleted = 1;
+
   fnp->is_constructor = dwarf2_is_constructor (die, cu);
 
   /* Get index in virtual function table if it is a virtual member
@@ -15823,6 +15852,26 @@ maybe_set_alignment (struct dwarf2_cu *cu, struct die_info *die,
 	       objfile_name (cu->per_cu->dwarf2_per_objfile->objfile));
 }
 
+/* Check if the given VALUE is a valid enum dwarf_calling_convention
+   constant for a type, according to DWARF5 spec, Table 5.5.  */
+
+static bool
+is_valid_DW_AT_calling_convention_for_type (ULONGEST value)
+{
+  switch (value)
+    {
+    case DW_CC_normal:
+    case DW_CC_pass_by_reference:
+    case DW_CC_pass_by_value:
+      return true;
+
+    default:
+      complaint (_("unrecognized DW_AT_calling_convention value "
+		   "(%lu) for a type"), value);
+      return false;
+    }
+}
+
 /* Called when we find the DIE that starts a structure or union scope
    (definition) to create a type for the structure or union.  Fill in
    the type's name and general properties; the members will not be
@@ -15904,6 +15953,18 @@ read_structure_type (struct die_info *die, struct dwarf2_cu *cu)
   if (cu->language == language_cplus && die->tag == DW_TAG_class_type)
     TYPE_DECLARED_CLASS (type) = 1;
 
+  /* Store the calling convention in the type if it's available in
+     the die.  Otherwise the calling convention remains set to
+     the default value DW_CC_normal.  */
+  attr = dwarf2_attr (die, DW_AT_calling_convention, cu);
+  if (attr != nullptr
+      && is_valid_DW_AT_calling_convention_for_type (DW_UNSND (attr)))
+    {
+      ALLOCATE_CPLUS_STRUCT_TYPE (type);
+      TYPE_CPLUS_CALLING_CONVENTION (type)
+	= (enum dwarf_calling_convention) (DW_UNSND (attr));
+    }
+
   attr = dwarf2_attr (die, DW_AT_byte_size, cu);
   if (attr != nullptr)
     {
diff --git a/gdb/gdbtypes.c b/gdb/gdbtypes.c
index 0896f71..7e80b45 100644
--- a/gdb/gdbtypes.c
+++ b/gdb/gdbtypes.c
@@ -4494,6 +4494,10 @@ dump_fn_fieldlists (struct type *type, int spaces)
 			    TYPE_FN_FIELD_PROTECTED (f, overload_idx));
 	  printfi_filtered (spaces + 8, "is_stub %d\n",
 			    TYPE_FN_FIELD_STUB (f, overload_idx));
+	  printfi_filtered (spaces + 8, "defaulted %d\n",
+			    TYPE_FN_FIELD_DEFAULTED (f, overload_idx));
+	  printfi_filtered (spaces + 8, "is_deleted %d\n",
+			    TYPE_FN_FIELD_DELETED (f, overload_idx));
 	  printfi_filtered (spaces + 8, "voffset %u\n",
 			    TYPE_FN_FIELD_VOFFSET (f, overload_idx));
 	}
@@ -4557,6 +4561,9 @@ print_cplus_stuff (struct type *type, int spaces)
     {
       dump_fn_fieldlists (type, spaces);
     }
+
+  printfi_filtered (spaces, "calling_convention %d\n",
+		    TYPE_CPLUS_CALLING_CONVENTION (type));
 }
 
 /* Print the contents of the TYPE's type_specific union, assuming that
diff --git a/gdb/gdbtypes.h b/gdb/gdbtypes.h
index a1d95e0..12fa437 100644
--- a/gdb/gdbtypes.h
+++ b/gdb/gdbtypes.h
@@ -50,6 +50,7 @@
 #include "gdbsupport/enum-flags.h"
 #include "gdbsupport/underlying.h"
 #include "gdbsupport/print-utils.h"
+#include "dwarf2.h"
 
 /* Forward declarations for prototypes.  */
 struct field;
@@ -957,9 +958,18 @@ struct fn_field
 
   unsigned int is_constructor : 1;
 
+  /* * True if this function is deleted, false otherwise.  */
+
+  unsigned int is_deleted : 1;
+
+  /* * DW_AT_defaulted attribute for this function.  The value is one
+     of the DW_DEFAULTED constants.  */
+
+  ENUM_BITFIELD (dwarf_defaulted_attribute) defaulted : 2;
+
   /* * Unused.  */
 
-  unsigned int dummy:9;
+  unsigned int dummy:6;
 
   /* * Index into that baseclass's virtual function table, minus 2;
      else if static: VOFFSET_STATIC; else: 0.  */
@@ -1033,6 +1043,12 @@ struct cplus_struct_type
 
     int is_dynamic : 2;
 
+    /* * The calling convention for this type, fetched from the
+       DW_AT_calling_convention attribute.  The value is one of the
+       DW_CC constants.  */
+
+    ENUM_BITFIELD (dwarf_calling_convention) calling_convention : 8;
+
     /* * The base class which defined the virtual function table pointer.  */
 
     struct type *vptr_basetype;
@@ -1437,6 +1453,8 @@ extern void set_type_vptr_basetype (struct type *, struct type *);
     ? (struct cplus_struct_type*)&cplus_struct_default \
     : TYPE_RAW_CPLUS_SPECIFIC(thistype))
 #define TYPE_RAW_CPLUS_SPECIFIC(thistype) TYPE_MAIN_TYPE(thistype)->type_specific.cplus_stuff
+#define TYPE_CPLUS_CALLING_CONVENTION(thistype) \
+  TYPE_MAIN_TYPE(thistype)->type_specific.cplus_stuff->calling_convention
 #define TYPE_FLOATFORMAT(thistype) TYPE_MAIN_TYPE(thistype)->type_specific.floatformat
 #define TYPE_GNAT_SPECIFIC(thistype) TYPE_MAIN_TYPE(thistype)->type_specific.gnat_stuff
 #define TYPE_DESCRIPTIVE_TYPE(thistype) TYPE_GNAT_SPECIFIC(thistype)->descriptive_type
@@ -1553,6 +1571,8 @@ extern void set_type_vptr_basetype (struct type *, struct type *);
 #define TYPE_FN_FIELD_VOFFSET(thisfn, n) ((thisfn)[n].voffset-2)
 #define TYPE_FN_FIELD_VIRTUAL_P(thisfn, n) ((thisfn)[n].voffset > 1)
 #define TYPE_FN_FIELD_STATIC_P(thisfn, n) ((thisfn)[n].voffset == VOFFSET_STATIC)
+#define TYPE_FN_FIELD_DEFAULTED(thisfn, n) ((thisfn)[n].defaulted)
+#define TYPE_FN_FIELD_DELETED(thisfn, n) ((thisfn)[n].is_deleted)
 
 /* Accessors for typedefs defined by a class.  */
 #define TYPE_TYPEDEF_FIELD_ARRAY(thistype) \