[binutils-gdb] gdb: fix logic of find_comp_unit and set_comp_unit

[Simon Marchi]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=0bc2e38dd71e24676e180b6b37e0a2cd1186994d

commit 0bc2e38dd71e24676e180b6b37e0a2cd1186994d
Author: Simon Marchi <simon.marchi@polymtl.ca>
Date:   Thu Dec 3 15:47:56 2020 -0500

    gdb: fix logic of find_comp_unit and set_comp_unit
    
    The logic in find_comp_unit and set_comp_unit is reversed.  When the BFD
    requires relocation, we want to put the comp_unit structure in the
    map where the comp_unit objects are not shared, that is the one indexed
    by objfile.  If the BFD does not require relocation, then, we can share
    a single comp_unit structure for all users of that BFD, so we want to
    put it in the BFD-indexed map.  The comments on top of
    dwarf2_frame_bfd_data and dwarf2_frame_objfile_data make that clear.
    
    Fix it by swapping the two in find_comp_unit and set_comp_unit.
    
    I don't have a test for this, because I don't see how to write one in a
    reasonable amount of time.
    
    gdb/ChangeLog:
    
            PR gdb/26876
            * dwarf2/frame.c (find_comp_unit, set_comp_unit): Reverse use of
            dwarf2_frame_bfd_data and dwarf2_frame_objfile_data.
    
    Change-Id: I80c1ee7ad8425fa4947de65b170973d05f5a52ec

Diff:
---
 gdb/ChangeLog      |  6 ++++++
 gdb/dwarf2/frame.c | 10 ++++++----
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 7c0739368ec..75d7422559d 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2020-12-03  Simon Marchi  <simon.marchi@polymtl.ca>
+
+	PR gdb/26876
+	* dwarf2/frame.c (find_comp_unit, set_comp_unit): Reverse use of
+	dwarf2_frame_bfd_data and dwarf2_frame_objfile_data.
+
 2020-12-02  Andrew Burgess  <andrew.burgess@embecosm.com>
 
 	* arch/riscv.c: Include 'rv32e-xregs.c'.
diff --git a/gdb/dwarf2/frame.c b/gdb/dwarf2/frame.c
index a577a671f24..7df3ccfe46a 100644
--- a/gdb/dwarf2/frame.c
+++ b/gdb/dwarf2/frame.c
@@ -1640,8 +1640,9 @@ find_comp_unit (struct objfile *objfile)
 {
   bfd *abfd = objfile->obfd;
   if (gdb_bfd_requires_relocations (abfd))
-    return dwarf2_frame_bfd_data.get (abfd);
-  return dwarf2_frame_objfile_data.get (objfile);
+    return dwarf2_frame_objfile_data.get (objfile);
+
+  return dwarf2_frame_bfd_data.get (abfd);
 }
 
 /* Store the comp_unit on OBJFILE, or the corresponding BFD, as
@@ -1652,8 +1653,9 @@ set_comp_unit (struct objfile *objfile, struct comp_unit *unit)
 {
   bfd *abfd = objfile->obfd;
   if (gdb_bfd_requires_relocations (abfd))
-    return dwarf2_frame_bfd_data.set (abfd, unit);
-  return dwarf2_frame_objfile_data.set (objfile, unit);
+    return dwarf2_frame_objfile_data.set (objfile, unit);
+
+  return dwarf2_frame_bfd_data.set (abfd, unit);
 }
 
 /* Find the FDE for *PC.  Return a pointer to the FDE, and store the