Remove a use of the comp_unit backlink

The DWARF frame comp_unit object still has a backlink to the objfile.
In order to be truly objfile-independent, this must be removed.

This patch removes one such use, by passing the gdbarch to
decode_frame_entry directly.

gdb/ChangeLog
2020-02-12  Tom Tromey  <tom@tromey.com>

	* dwarf2/frame.c (decode_frame_entry_1): Add gdbarch parameter.
	(decode_frame_entry): Likewise.
	(dwarf2_build_frame_info): Update.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 5b705632af3d45f993f98725d1e5345a435d2310..9bc686b293f10c68f193fbff4cc84dc562d31bc9 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2020-02-12  Tom Tromey  <tom@tromey.com>
+
+       * dwarf2/frame.c (decode_frame_entry_1): Add gdbarch parameter.
+       (decode_frame_entry): Likewise.
+       (dwarf2_build_frame_info): Update.
+
 2020-02-12  Tom Tromey  <tom@tromey.com>
 
        * dwarf2/frame.c (struct comp_unit) <obstack>: New member.

diff --git a/gdb/dwarf2/frame.c b/gdb/dwarf2/frame.c
index 53f90799819a11afa61a51cf9b132e1b099d5b90..7397a7fbeb28cc11df4105de3e69cd7bfd543b3c 100644 (file)
--- a/gdb/dwarf2/frame.c
+++ b/gdb/dwarf2/frame.c
@@ -1701,7 +1701,8 @@ enum eh_frame_type
   EH_CIE_OR_FDE_TYPE_ID = EH_CIE_TYPE_ID | EH_FDE_TYPE_ID
 };
 
-static const gdb_byte *decode_frame_entry (struct comp_unit *unit,
+static const gdb_byte *decode_frame_entry (struct gdbarch *gdbarch,
+                                          struct comp_unit *unit,
                                           const gdb_byte *start,
                                           int eh_frame_p,
                                           dwarf2_cie_table &cie_table,
@@ -1712,13 +1713,13 @@ static const gdb_byte *decode_frame_entry (struct comp_unit *unit,
    Return NULL if invalid input, otherwise the next byte to be processed.  */
 
 static const gdb_byte *
-decode_frame_entry_1 (struct comp_unit *unit, const gdb_byte *start,
+decode_frame_entry_1 (struct gdbarch *gdbarch,
+                     struct comp_unit *unit, const gdb_byte *start,
                      int eh_frame_p,
                       dwarf2_cie_table &cie_table,
                       dwarf2_fde_table *fde_table,
                       enum eh_frame_type entry_type)
 {
-  struct gdbarch *gdbarch = get_objfile_arch (unit->objfile);
   const gdb_byte *buf, *end;
   ULONGEST length;
   unsigned int bytes_read;
@@ -1963,7 +1964,8 @@ decode_frame_entry_1 (struct comp_unit *unit, const gdb_byte *start,
       fde->cie = find_cie (cie_table, cie_pointer);
       if (fde->cie == NULL)
        {
-         decode_frame_entry (unit, unit->dwarf_frame_buffer + cie_pointer,
+         decode_frame_entry (gdbarch, unit,
+                             unit->dwarf_frame_buffer + cie_pointer,
                              eh_frame_p, cie_table, fde_table,
                              EH_CIE_TYPE_ID);
          fde->cie = find_cie (cie_table, cie_pointer);
@@ -2014,7 +2016,8 @@ decode_frame_entry_1 (struct comp_unit *unit, const gdb_byte *start,
    expect an FDE or a CIE.  */
 
 static const gdb_byte *
-decode_frame_entry (struct comp_unit *unit, const gdb_byte *start,
+decode_frame_entry (struct gdbarch *gdbarch,
+                   struct comp_unit *unit, const gdb_byte *start,
                    int eh_frame_p,
                    dwarf2_cie_table &cie_table,
                     dwarf2_fde_table *fde_table,
@@ -2026,7 +2029,7 @@ decode_frame_entry (struct comp_unit *unit, const gdb_byte *start,
 
   while (1)
     {
-      ret = decode_frame_entry_1 (unit, start, eh_frame_p,
+      ret = decode_frame_entry_1 (gdbarch, unit, start, eh_frame_p,
                                  cie_table, fde_table, entry_type);
       if (ret != NULL)
        break;
@@ -2132,6 +2135,8 @@ dwarf2_build_frame_info (struct objfile *objfile)
   dwarf2_cie_table cie_table;
   dwarf2_fde_table fde_table;
 
+  struct gdbarch *gdbarch = get_objfile_arch (objfile);
+
   /* Build a minimal decoding of the DWARF2 compilation unit.  */
   std::unique_ptr<comp_unit> unit (new comp_unit (objfile));
 
@@ -2165,7 +2170,8 @@ dwarf2_build_frame_info (struct objfile *objfile)
            {
              frame_ptr = unit->dwarf_frame_buffer;
              while (frame_ptr < unit->dwarf_frame_buffer + unit->dwarf_frame_size)
-               frame_ptr = decode_frame_entry (unit.get (), frame_ptr, 1,
+               frame_ptr = decode_frame_entry (gdbarch, unit.get (),
+                                               frame_ptr, 1,
                                                cie_table, &fde_table,
                                                EH_CIE_OR_FDE_TYPE_ID);
            }
@@ -2195,7 +2201,7 @@ dwarf2_build_frame_info (struct objfile *objfile)
        {
          frame_ptr = unit->dwarf_frame_buffer;
          while (frame_ptr < unit->dwarf_frame_buffer + unit->dwarf_frame_size)
-           frame_ptr = decode_frame_entry (unit.get (), frame_ptr, 0,
+           frame_ptr = decode_frame_entry (gdbarch, unit.get (), frame_ptr, 0,
                                            cie_table, &fde_table,
                                            EH_CIE_OR_FDE_TYPE_ID);
        }