[PATCH 3/3] Warn if core file register section is larger than expected

[Andreas Arnez <arnez@linux.vnet.ibm.com>]

When reading a core file register section which is larger than
expected, emit a warning.  Assume that a register section usually has
exactly the size specified by the regset section iterator.  In some
special cases this assumption is wrong, or at least does not match the
regset supply function's logic.  Thus also add a way to suppress the
warning in those cases, using a new flag REGSET_VARIABLE_SIZE.

gdb/ChangeLog:

	* regset.h (struct regset): Add flags field.
	(REGSET_VARIABLE_SIZE): New value for a regset's flags field.
	* corelow.c (get_core_register_section): Add warning if the size
	exceeds the requested size and the regset does not have the
	REGSET_VARIABLE_SIZE flag set.
	* alphanbsd-tdep.c (alphanbsd_gregset): Add REGSET_VARIABLE_SIZE
	flag.
	* armbsd-tdep.c (armbsd_gregset): Likewise.
	* hppa-hpux-tdep.c (hppa_hpux_regset): Likewise.
	* hppaobsd-tdep.c (hppaobsd_gregset): Likewise.
	* m68kbsd-tdep.c (m68kbsd_gregset): Likewise.
	* mipsnbsd-tdep.c (mipsnbsd_gregset): Likewise.
---
 gdb/alphanbsd-tdep.c | 4 +++-
 gdb/armbsd-tdep.c    | 4 +++-
 gdb/corelow.c        | 5 +++++
 gdb/hppa-hpux-tdep.c | 4 +++-
 gdb/hppaobsd-tdep.c  | 4 +++-
 gdb/m68kbsd-tdep.c   | 4 +++-
 gdb/mipsnbsd-tdep.c  | 4 +++-
 gdb/regset.h         | 7 +++++++
 8 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/gdb/alphanbsd-tdep.c b/gdb/alphanbsd-tdep.c
index 6b13fad..69be265 100644
--- a/gdb/alphanbsd-tdep.c
+++ b/gdb/alphanbsd-tdep.c
@@ -145,7 +145,9 @@ alphanbsd_supply_gregset (const struct regset *regset,
 static const struct regset alphanbsd_gregset =
 {
   NULL,
-  alphanbsd_supply_gregset
+  alphanbsd_supply_gregset,
+  NULL,
+  REGSET_VARIABLE_SIZE
 };
 
 static const struct regset alphanbsd_fpregset =
diff --git a/gdb/armbsd-tdep.c b/gdb/armbsd-tdep.c
index 7923cad..c043b51 100644
--- a/gdb/armbsd-tdep.c
+++ b/gdb/armbsd-tdep.c
@@ -98,7 +98,9 @@ armbsd_supply_gregset (const struct regset *regset,
 static const struct regset armbsd_gregset =
 {
   NULL,
-  armbsd_supply_gregset
+  armbsd_supply_gregset,
+  NULL,
+  REGSET_VARIABLE_SIZE
 };
 
 static const struct regset armbsd_fpregset =
diff --git a/gdb/corelow.c b/gdb/corelow.c
index a9eadd5..12cbcba 100644
--- a/gdb/corelow.c
+++ b/gdb/corelow.c
@@ -523,6 +523,11 @@ get_core_register_section (struct regcache *regcache,
       warning (_("Section `%s' in core file too small."), section_name);
       return;
     }
+  if (size != min_size && !(regset->flags & REGSET_VARIABLE_SIZE))
+    {
+      warning (_("Unexpected size of section `%s' in core file."),
+	       section_name);
+    }
 
   contents = alloca (size);
   if (! bfd_get_section_contents (core_bfd, section, contents,
diff --git a/gdb/hppa-hpux-tdep.c b/gdb/hppa-hpux-tdep.c
index 0c8575d..3c0f390 100644
--- a/gdb/hppa-hpux-tdep.c
+++ b/gdb/hppa-hpux-tdep.c
@@ -1367,7 +1367,9 @@ hppa_hpux_supply_save_state (const struct regset *regset,
 static const struct regset hppa_hpux_regset =
 {
   NULL,
-  hppa_hpux_supply_save_state
+  hppa_hpux_supply_save_state,
+  NULL,
+  REGSET_VARIABLE_SIZE
 };
 
 static void
diff --git a/gdb/hppaobsd-tdep.c b/gdb/hppaobsd-tdep.c
index 9ec7fdf..c9bc1bf 100644
--- a/gdb/hppaobsd-tdep.c
+++ b/gdb/hppaobsd-tdep.c
@@ -131,7 +131,9 @@ hppaobsd_supply_fpregset (const struct regset *regset,
 static const struct regset hppaobsd_gregset =
 {
   NULL,
-  hppaobsd_supply_gregset
+  hppaobsd_supply_gregset,
+  NULL,
+  REGSET_VARIABLE_SIZE
 };
 
 static const struct regset hppaobsd_fpregset =
diff --git a/gdb/m68kbsd-tdep.c b/gdb/m68kbsd-tdep.c
index b1ae4c1..ae0cecf 100644
--- a/gdb/m68kbsd-tdep.c
+++ b/gdb/m68kbsd-tdep.c
@@ -105,7 +105,9 @@ m68kbsd_supply_gregset (const struct regset *regset,
 static const struct regset m68kbsd_gregset =
 {
   NULL,
-  m68kbsd_supply_gregset
+  m68kbsd_supply_gregset,
+  NULL,
+  REGSET_VARIABLE_SIZE
 };
 
 static const struct regset m68kbsd_fpregset =
diff --git a/gdb/mipsnbsd-tdep.c b/gdb/mipsnbsd-tdep.c
index ee68f3d..d15c88c 100644
--- a/gdb/mipsnbsd-tdep.c
+++ b/gdb/mipsnbsd-tdep.c
@@ -103,7 +103,9 @@ mipsnbsd_supply_gregset (const struct regset *regset,
 static const struct regset mipsnbsd_gregset =
 {
   NULL,
-  mipsnbsd_supply_gregset
+  mipsnbsd_supply_gregset,
+  NULL,
+  REGSET_VARIABLE_SIZE
 };
 
 static const struct regset mipsnbsd_fpregset =
diff --git a/gdb/regset.h b/gdb/regset.h
index 3585322..d6edaa5 100644
--- a/gdb/regset.h
+++ b/gdb/regset.h
@@ -43,6 +43,13 @@ struct regset
 
   /* Function collecting values in a register set from a register cache.  */
   collect_regset_ftype *collect_regset;
+
+  unsigned flags;
 };
 
+/* Values for a regset's 'flags' field.  */
+
+#define REGSET_VARIABLE_SIZE 1	/* Accept a larger regset section size
+				   in a core file without warning.  */
+
 #endif /* regset.h */
-- 
1.8.4.2