Create dwarf2/attribute.[ch]

This moves the attribute-related code out of dwarf2read.c and into the
new files dwarf2/attribute.[ch].

gdb/ChangeLog
2020-02-08  Tom Tromey  <tom@tromey.com>

	* dwarf2read.c (struct attribute, DW_STRING)
	(DW_STRING_IS_CANONICAL, DW_UNSND, DW_BLOCK, DW_SND, DW_ADDR)
	(DW_SIGNATURE, struct dwarf_block, attr_value_as_address)
	(attr_form_is_block, attr_form_is_section_offset)
	(attr_form_is_constant, attr_form_is_ref): Move.
	* dwarf2/attribute.h: New file.
	* dwarf2/attribute.c: New file, from dwarf2read.c.
	* Makefile.in (COMMON_SFILES): Add dwarf2/attribute.c.

Change-Id: I1ea4c146256a1b9e38b66f1c605d782a14eeded7

5 files changed, 253 insertions, 168 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 5b6feb6..741d4bf 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,16 @@
 2020-02-08  Tom Tromey  <tom@tromey.com>
 
+	* dwarf2read.c (struct attribute, DW_STRING)
+	(DW_STRING_IS_CANONICAL, DW_UNSND, DW_BLOCK, DW_SND, DW_ADDR)
+	(DW_SIGNATURE, struct dwarf_block, attr_value_as_address)
+	(attr_form_is_block, attr_form_is_section_offset)
+	(attr_form_is_constant, attr_form_is_ref): Move.
+	* dwarf2/attribute.h: New file.
+	* dwarf2/attribute.c: New file, from dwarf2read.c.
+	* Makefile.in (COMMON_SFILES): Add dwarf2/attribute.c.
+
+2020-02-08  Tom Tromey  <tom@tromey.com>
+
 	* dwarf2read.c (abbrev_table_up, struct abbrev_info)
 	(struct attr_abbrev, ABBREV_HASH_SIZE, struct abbrev_table):
 	Move.
diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 12abfa4..b726ae8 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -1003,6 +1003,7 @@ COMMON_SFILES = \
 	dwarf2loc.c \
 	dwarf2read.c \
 	dwarf2/abbrev.c \
+	dwarf2/attribute.c \
 	dwarf2/leb.c \
 	dwarf2/section.c \
 	eval.c \
diff --git a/gdb/dwarf2/attribute.c b/gdb/dwarf2/attribute.c
new file mode 100644
index 0000000..75a2fa3
--- /dev/null
+++ b/gdb/dwarf2/attribute.c
@@ -0,0 +1,122 @@
+/* DWARF attributes
+
+   Copyright (C) 1994-2020 Free Software Foundation, Inc.
+
+   Adapted by Gary Funck (gary@intrepid.com), Intrepid Technology,
+   Inc.  with support from Florida State University (under contract
+   with the Ada Joint Program Office), and Silicon Graphics, Inc.
+   Initial contribution by Brent Benson, Harris Computer Systems, Inc.,
+   based on Fred Fish's (Cygnus Support) implementation of DWARF 1
+   support.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "defs.h"
+#include "dwarf2/attribute.h"
+
+/* See attribute.h.  */
+
+CORE_ADDR
+attr_value_as_address (struct attribute *attr)
+{
+  CORE_ADDR addr;
+
+  if (attr->form != DW_FORM_addr && attr->form != DW_FORM_addrx
+      && attr->form != DW_FORM_GNU_addr_index)
+    {
+      /* Aside from a few clearly defined exceptions, attributes that
+	 contain an address must always be in DW_FORM_addr form.
+	 Unfortunately, some compilers happen to be violating this
+	 requirement by encoding addresses using other forms, such
+	 as DW_FORM_data4 for example.  For those broken compilers,
+	 we try to do our best, without any guarantee of success,
+	 to interpret the address correctly.  It would also be nice
+	 to generate a complaint, but that would require us to maintain
+	 a list of legitimate cases where a non-address form is allowed,
+	 as well as update callers to pass in at least the CU's DWARF
+	 version.  This is more overhead than what we're willing to
+	 expand for a pretty rare case.  */
+      addr = DW_UNSND (attr);
+    }
+  else
+    addr = DW_ADDR (attr);
+
+  return addr;
+}
+
+/* See attribute.h.  */
+
+int
+attr_form_is_block (const struct attribute *attr)
+{
+  return (attr == NULL ? 0 :
+      attr->form == DW_FORM_block1
+      || attr->form == DW_FORM_block2
+      || attr->form == DW_FORM_block4
+      || attr->form == DW_FORM_block
+      || attr->form == DW_FORM_exprloc);
+}
+
+/* See attribute.h.  */
+
+int
+attr_form_is_section_offset (const struct attribute *attr)
+{
+  return (attr->form == DW_FORM_data4
+          || attr->form == DW_FORM_data8
+	  || attr->form == DW_FORM_sec_offset);
+}
+
+/* See attribute.h.  */
+
+int
+attr_form_is_constant (const struct attribute *attr)
+{
+  switch (attr->form)
+    {
+    case DW_FORM_sdata:
+    case DW_FORM_udata:
+    case DW_FORM_data1:
+    case DW_FORM_data2:
+    case DW_FORM_data4:
+    case DW_FORM_data8:
+    case DW_FORM_implicit_const:
+      return 1;
+    default:
+      return 0;
+    }
+}
+
+/* DW_ADDR is always stored already as sect_offset; despite for the forms
+   besides DW_FORM_ref_addr it is stored as cu_offset in the DWARF file.  */
+
+int
+attr_form_is_ref (const struct attribute *attr)
+{
+  switch (attr->form)
+    {
+    case DW_FORM_ref_addr:
+    case DW_FORM_ref1:
+    case DW_FORM_ref2:
+    case DW_FORM_ref4:
+    case DW_FORM_ref8:
+    case DW_FORM_ref_udata:
+    case DW_FORM_GNU_ref_alt:
+      return 1;
+    default:
+      return 0;
+    }
+}
diff --git a/gdb/dwarf2/attribute.h b/gdb/dwarf2/attribute.h
new file mode 100644
index 0000000..11c6cb9
--- /dev/null
+++ b/gdb/dwarf2/attribute.h
@@ -0,0 +1,118 @@
+/* DWARF attributes
+
+   Copyright (C) 1994-2020 Free Software Foundation, Inc.
+
+   Adapted by Gary Funck (gary@intrepid.com), Intrepid Technology,
+   Inc.  with support from Florida State University (under contract
+   with the Ada Joint Program Office), and Silicon Graphics, Inc.
+   Initial contribution by Brent Benson, Harris Computer Systems, Inc.,
+   based on Fred Fish's (Cygnus Support) implementation of DWARF 1
+   support.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef GDB_DWARF2_ATTRIBUTE_H
+#define GDB_DWARF2_ATTRIBUTE_H
+
+#include "dwarf2.h"
+
+/* Blocks are a bunch of untyped bytes.  */
+struct dwarf_block
+{
+  size_t size;
+
+  /* Valid only if SIZE is not zero.  */
+  const gdb_byte *data;
+};
+
+/* Attributes have a name and a value.  */
+struct attribute
+{
+  ENUM_BITFIELD(dwarf_attribute) name : 16;
+  ENUM_BITFIELD(dwarf_form) form : 15;
+
+  /* Has DW_STRING already been updated by dwarf2_canonicalize_name?  This
+     field should be in u.str (existing only for DW_STRING) but it is kept
+     here for better struct attribute alignment.  */
+  unsigned int string_is_canonical : 1;
+
+  union
+    {
+      const char *str;
+      struct dwarf_block *blk;
+      ULONGEST unsnd;
+      LONGEST snd;
+      CORE_ADDR addr;
+      ULONGEST signature;
+    }
+  u;
+};
+
+/* Get at parts of an attribute structure.  */
+
+#define DW_STRING(attr)    ((attr)->u.str)
+#define DW_STRING_IS_CANONICAL(attr) ((attr)->string_is_canonical)
+#define DW_UNSND(attr)     ((attr)->u.unsnd)
+#define DW_BLOCK(attr)     ((attr)->u.blk)
+#define DW_SND(attr)       ((attr)->u.snd)
+#define DW_ADDR(attr)	   ((attr)->u.addr)
+#define DW_SIGNATURE(attr) ((attr)->u.signature)
+
+/* Read the given attribute value as an address, taking the attribute's
+   form into account.  */
+
+extern CORE_ADDR attr_value_as_address (struct attribute *attr);
+
+/* Check if the attribute's form is a DW_FORM_block*
+   if so return true else false.  */
+
+extern int attr_form_is_block (const struct attribute *attr);
+
+/* Return non-zero if ATTR's value is a section offset --- classes
+   lineptr, loclistptr, macptr or rangelistptr --- or zero, otherwise.
+   You may use DW_UNSND (attr) to retrieve such offsets.
+
+   Section 7.5.4, "Attribute Encodings", explains that no attribute
+   may have a value that belongs to more than one of these classes; it
+   would be ambiguous if we did, because we use the same forms for all
+   of them.  */
+
+extern int attr_form_is_section_offset (const struct attribute *attr);
+
+/* Return non-zero if ATTR's value falls in the 'constant' class, or
+   zero otherwise.  When this function returns true, you can apply
+   dwarf2_get_attr_constant_value to it.
+
+   However, note that for some attributes you must check
+   attr_form_is_section_offset before using this test.  DW_FORM_data4
+   and DW_FORM_data8 are members of both the constant class, and of
+   the classes that contain offsets into other debug sections
+   (lineptr, loclistptr, macptr or rangelistptr).  The DWARF spec says
+   that, if an attribute's can be either a constant or one of the
+   section offset classes, DW_FORM_data4 and DW_FORM_data8 should be
+   taken as section offsets, not constants.
+
+   DW_FORM_data16 is not considered as dwarf2_get_attr_constant_value
+   cannot handle that.  */
+
+extern int attr_form_is_constant (const struct attribute *attr);
+
+/* DW_ADDR is always stored already as sect_offset; despite for the forms
+   besides DW_FORM_ref_addr it is stored as cu_offset in the DWARF file.  */
+
+extern int attr_form_is_ref (const struct attribute *attr);
+
+#endif /* GDB_DWARF2_ATTRIBUTE_H */
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index 59ed073..02bf1ef 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -31,6 +31,7 @@
 #include "defs.h"
 #include "dwarf2read.h"
 #include "dwarf2/abbrev.h"
+#include "dwarf2/attribute.h"
 #include "dwarf-index-cache.h"
 #include "dwarf-index-common.h"
 #include "dwarf2/leb.h"
@@ -1233,29 +1234,6 @@ struct partial_die_info : public allocate_on_obstack
     }
   };
 
-/* Attributes have a name and a value.  */
-struct attribute
-  {
-    ENUM_BITFIELD(dwarf_attribute) name : 16;
-    ENUM_BITFIELD(dwarf_form) form : 15;
-
-    /* Has DW_STRING already been updated by dwarf2_canonicalize_name?  This
-       field should be in u.str (existing only for DW_STRING) but it is kept
-       here for better struct attribute alignment.  */
-    unsigned int string_is_canonical : 1;
-
-    union
-      {
-	const char *str;
-	struct dwarf_block *blk;
-	ULONGEST unsnd;
-	LONGEST snd;
-	CORE_ADDR addr;
-	ULONGEST signature;
-      }
-    u;
-  };
-
 /* This data structure holds a complete die structure.  */
 struct die_info
   {
@@ -1292,25 +1270,6 @@ struct die_info
     struct attribute attrs[1];
   };
 
-/* Get at parts of an attribute structure.  */
-
-#define DW_STRING(attr)    ((attr)->u.str)
-#define DW_STRING_IS_CANONICAL(attr) ((attr)->string_is_canonical)
-#define DW_UNSND(attr)     ((attr)->u.unsnd)
-#define DW_BLOCK(attr)     ((attr)->u.blk)
-#define DW_SND(attr)       ((attr)->u.snd)
-#define DW_ADDR(attr)	   ((attr)->u.addr)
-#define DW_SIGNATURE(attr) ((attr)->u.signature)
-
-/* Blocks are a bunch of untyped bytes.  */
-struct dwarf_block
-  {
-    size_t size;
-
-    /* Valid only if SIZE is not zero.  */
-    const gdb_byte *data;
-  };
-
 /* FIXME: We might want to set this from BFD via bfd_arch_bits_per_byte,
    but this would require a corresponding change in unpack_field_as_long
    and friends.  */
@@ -1780,14 +1739,6 @@ static struct die_info *dwarf_alloc_die (struct dwarf2_cu *, int);
 
 static void dwarf_decode_macros (struct dwarf2_cu *, unsigned int, int);
 
-static int attr_form_is_block (const struct attribute *);
-
-static int attr_form_is_section_offset (const struct attribute *);
-
-static int attr_form_is_constant (const struct attribute *);
-
-static int attr_form_is_ref (const struct attribute *);
-
 static void fill_in_loclist_baton (struct dwarf2_cu *cu,
 				   struct dwarf2_loclist_baton *baton,
 				   const struct attribute *attr);
@@ -2050,37 +2001,6 @@ line_header_eq_voidp (const void *item_lhs, const void *item_rhs)
 
 
 
-/* Read the given attribute value as an address, taking the attribute's
-   form into account.  */
-
-static CORE_ADDR
-attr_value_as_address (struct attribute *attr)
-{
-  CORE_ADDR addr;
-
-  if (attr->form != DW_FORM_addr && attr->form != DW_FORM_addrx
-      && attr->form != DW_FORM_GNU_addr_index)
-    {
-      /* Aside from a few clearly defined exceptions, attributes that
-	 contain an address must always be in DW_FORM_addr form.
-	 Unfortunately, some compilers happen to be violating this
-	 requirement by encoding addresses using other forms, such
-	 as DW_FORM_data4 for example.  For those broken compilers,
-	 we try to do our best, without any guarantee of success,
-	 to interpret the address correctly.  It would also be nice
-	 to generate a complaint, but that would require us to maintain
-	 a list of legitimate cases where a non-address form is allowed,
-	 as well as update callers to pass in at least the CU's DWARF
-	 version.  This is more overhead than what we're willing to
-	 expand for a pretty rare case.  */
-      addr = DW_UNSND (attr);
-    }
-  else
-    addr = DW_ADDR (attr);
-
-  return addr;
-}
-
 /* See declaration.  */
 
 dwarf2_per_objfile::dwarf2_per_objfile (struct objfile *objfile_,
@@ -24814,93 +24734,6 @@ dwarf_decode_macros (struct dwarf2_cu *cu, unsigned int offset,
 			    include_hash.get ());
 }
 
-/* Check if the attribute's form is a DW_FORM_block*
-   if so return true else false.  */
-
-static int
-attr_form_is_block (const struct attribute *attr)
-{
-  return (attr == NULL ? 0 :
-      attr->form == DW_FORM_block1
-      || attr->form == DW_FORM_block2
-      || attr->form == DW_FORM_block4
-      || attr->form == DW_FORM_block
-      || attr->form == DW_FORM_exprloc);
-}
-
-/* Return non-zero if ATTR's value is a section offset --- classes
-   lineptr, loclistptr, macptr or rangelistptr --- or zero, otherwise.
-   You may use DW_UNSND (attr) to retrieve such offsets.
-
-   Section 7.5.4, "Attribute Encodings", explains that no attribute
-   may have a value that belongs to more than one of these classes; it
-   would be ambiguous if we did, because we use the same forms for all
-   of them.  */
-
-static int
-attr_form_is_section_offset (const struct attribute *attr)
-{
-  return (attr->form == DW_FORM_data4
-          || attr->form == DW_FORM_data8
-	  || attr->form == DW_FORM_sec_offset);
-}
-
-/* Return non-zero if ATTR's value falls in the 'constant' class, or
-   zero otherwise.  When this function returns true, you can apply
-   dwarf2_get_attr_constant_value to it.
-
-   However, note that for some attributes you must check
-   attr_form_is_section_offset before using this test.  DW_FORM_data4
-   and DW_FORM_data8 are members of both the constant class, and of
-   the classes that contain offsets into other debug sections
-   (lineptr, loclistptr, macptr or rangelistptr).  The DWARF spec says
-   that, if an attribute's can be either a constant or one of the
-   section offset classes, DW_FORM_data4 and DW_FORM_data8 should be
-   taken as section offsets, not constants.
-
-   DW_FORM_data16 is not considered as dwarf2_get_attr_constant_value
-   cannot handle that.  */
-
-static int
-attr_form_is_constant (const struct attribute *attr)
-{
-  switch (attr->form)
-    {
-    case DW_FORM_sdata:
-    case DW_FORM_udata:
-    case DW_FORM_data1:
-    case DW_FORM_data2:
-    case DW_FORM_data4:
-    case DW_FORM_data8:
-    case DW_FORM_implicit_const:
-      return 1;
-    default:
-      return 0;
-    }
-}
-
-
-/* DW_ADDR is always stored already as sect_offset; despite for the forms
-   besides DW_FORM_ref_addr it is stored as cu_offset in the DWARF file.  */
-
-static int
-attr_form_is_ref (const struct attribute *attr)
-{
-  switch (attr->form)
-    {
-    case DW_FORM_ref_addr:
-    case DW_FORM_ref1:
-    case DW_FORM_ref2:
-    case DW_FORM_ref4:
-    case DW_FORM_ref8:
-    case DW_FORM_ref_udata:
-    case DW_FORM_GNU_ref_alt:
-      return 1;
-    default:
-      return 0;
-    }
-}
-
 /* Return the .debug_loc section to use for CU.
    For DWO files use .debug_loc.dwo.  */