Add new target_read_raw_memory function, and consolidate comments.

Tested on x86_64 Fedora 17.

gdb/
2013-12-02  Pedro Alves  <palves@redhat.com>

	* dcache.c (dcache_read_line): Use target_read_raw_memory.
	* target.c (target_read_raw_memory): New function.
	(target_read_stack, target_write_memory, target_write_raw_memory):
	Update comment.
	(target_read_code): Add comment.
	* target.h (target_read_raw_memory): Declare.

gdb/ChangeLog

@@ -1,3 +1,12 @@
+2013-12-02  Pedro Alves  <palves@redhat.com>
+
+	* dcache.c (dcache_read_line): Use target_read_raw_memory.
+	* target.c (target_read_raw_memory): New function.
+	(target_read_stack, target_write_memory, target_write_raw_memory):
+	Update comment.
+	(target_read_code): Add comment.
+	* target.h (target_read_raw_memory): Declare.
+
 2013-12-02  Pedro Alves  <palves@redhat.com>
 
 	* ctf.c (ctf_start): Use S_IRGRP, S_IXGRP, S_IXOTH

gdb/dcache.c

@@ -337,14 +337,13 @@ dcache_read_line (DCACHE *dcache, struct dcache_block *db)
 	  continue;
 	}
 
-      res = target_read (current_target.beneath, TARGET_OBJECT_RAW_MEMORY,
-			 NULL, myaddr, memaddr, reg_len);
-      if (res < reg_len)
+      res = target_read_raw_memory (memaddr, myaddr, reg_len);
+      if (res != 0)
 	return 0;
 
-      memaddr += res;
-      myaddr += res;
-      len -= res;
+      memaddr += reg_len;
+      myaddr += reg_len;
+      len -= reg_len;
     }
 
   return 1;

gdb/target.c

@@ -1791,16 +1791,30 @@ target_read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
     return TARGET_XFER_E_IO;
 }
 
+/* Like target_read_memory, but specify explicitly that this is a read
+   from the target's raw memory.  That is, this read bypasses the
+   dcache, breakpoint shadowing, etc.  */
+
+int
+target_read_raw_memory (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
+{
+  /* See comment in target_read_memory about why the request starts at
+     current_target.beneath.  */
+  if (target_read (current_target.beneath, TARGET_OBJECT_RAW_MEMORY, NULL,
+		   myaddr, memaddr, len) == len)
+    return 0;
+  else
+    return TARGET_XFER_E_IO;
+}
+
 /* Like target_read_memory, but specify explicitly that this is a read from
    the target's stack.  This may trigger different cache behavior.  */
 
 int
 target_read_stack (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
 {
-  /* Dispatch to the topmost target, not the flattened current_target.
-     Memory accesses check target->to_has_(all_)memory, and the
-     flattened target doesn't inherit those.  */
-
+  /* See comment in target_read_memory about why the request starts at
+     current_target.beneath.  */
   if (target_read (current_target.beneath, TARGET_OBJECT_STACK_MEMORY, NULL,
 		   myaddr, memaddr, len) == len)
     return 0;
@@ -1814,6 +1828,8 @@ target_read_stack (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
 int
 target_read_code (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
 {
+  /* See comment in target_read_memory about why the request starts at
+     current_target.beneath.  */
   if (target_read (current_target.beneath, TARGET_OBJECT_CODE_MEMORY, NULL,
 		   myaddr, memaddr, len) == len)
     return 0;
@@ -1830,9 +1846,8 @@ target_read_code (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
 int
 target_write_memory (CORE_ADDR memaddr, const gdb_byte *myaddr, ssize_t len)
 {
-  /* Dispatch to the topmost target, not the flattened current_target.
-     Memory accesses check target->to_has_(all_)memory, and the
-     flattened target doesn't inherit those.  */
+  /* See comment in target_read_memory about why the request starts at
+     current_target.beneath.  */
   if (target_write (current_target.beneath, TARGET_OBJECT_MEMORY, NULL,
 		    myaddr, memaddr, len) == len)
     return 0;
@@ -1849,9 +1864,8 @@ target_write_memory (CORE_ADDR memaddr, const gdb_byte *myaddr, ssize_t len)
 int
 target_write_raw_memory (CORE_ADDR memaddr, const gdb_byte *myaddr, ssize_t len)
 {
-  /* Dispatch to the topmost target, not the flattened current_target.
-     Memory accesses check target->to_has_(all_)memory, and the
-     flattened target doesn't inherit those.  */
+  /* See comment in target_read_memory about why the request starts at
+     current_target.beneath.  */
   if (target_write (current_target.beneath, TARGET_OBJECT_RAW_MEMORY, NULL,
 		    myaddr, memaddr, len) == len)
     return 0;

gdb/target.h

@@ -1051,6 +1051,9 @@ extern int target_read_string (CORE_ADDR, char **, int, int *);
 extern int target_read_memory (CORE_ADDR memaddr, gdb_byte *myaddr,
 			       ssize_t len);
 
+extern int target_read_raw_memory (CORE_ADDR memaddr, gdb_byte *myaddr,
+				   ssize_t len);
+
 extern int target_read_stack (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len);
 
 extern int target_read_code (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len);