Assert on lval_register

This patch adds asserts where the value's lval must be lval_register.
This triggers an error in frame_register_unwind because VALUE_REGNUM
is used but value's lval is not lval_register.

This also reveals a design issue in frame_register_unwind, that is
arguments addrp and realnump are mutually exclusive, we either use
addrp (for lval_memory), or use realnump (for lval_register).  This
can be done in a separate patch.

gdb:

2016-12-06  Yao Qi  <yao.qi@linaro.org>

	* frame.c (frame_register_unwind): Set *realnump if *lvalp is
	lval_register.
	* value.c (deprecated_value_next_frame_id_hack): Assert
	value->lval is lval_register.
	(deprecated_value_regnum_hack): Likewise.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 4a64fca..ea1cff3 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,11 @@
+2016-12-06  Yao Qi  <yao.qi@linaro.org>
+
+       * frame.c (frame_register_unwind): Set *realnump if *lvalp is
+       lval_register.
+       * value.c (deprecated_value_next_frame_id_hack): Assert
+       value->lval is lval_register.
+       (deprecated_value_regnum_hack): Likewise.
+
 2016-12-02  Simon Marchi  <simon.marchi@polymtl.ca>
 
        * ui-out.h: Include "common/enum-flags.h".

diff --git a/gdb/frame.c b/gdb/frame.c
index 5414cb3..00001bc 100644 (file)
--- a/gdb/frame.c
+++ b/gdb/frame.c
@@ -1107,7 +1107,10 @@ frame_register_unwind (struct frame_info *frame, int regnum,
   *unavailablep = !value_entirely_available (value);
   *lvalp = VALUE_LVAL (value);
   *addrp = value_address (value);
-  *realnump = VALUE_REGNUM (value);
+  if (*lvalp == lval_register)
+    *realnump = VALUE_REGNUM (value);
+  else
+    *realnump = -1;
 
   if (bufferp)
     {

diff --git a/gdb/value.c b/gdb/value.c
index cc291cf..022900f 100644 (file)
--- a/gdb/value.c
+++ b/gdb/value.c
@@ -1576,12 +1576,14 @@ deprecated_value_internalvar_hack (struct value *value)
 struct frame_id *
 deprecated_value_next_frame_id_hack (struct value *value)
 {
+  gdb_assert (value->lval == lval_register);
   return &value->location.reg.next_frame_id;
 }
 
 int *
 deprecated_value_regnum_hack (struct value *value)
 {
+  gdb_assert (value->lval == lval_register);
   return &value->location.reg.regnum;
 }