[review] Add read_pc / write_pc support to win32-low

Message ID gerrit.1572371871000.I4dcb72f262b778c2db554f6ff9b675a35f14318b@gnutoolchain-gerrit.osci.io
State New, archived
Headers

Commit Message

Simon Marchi (Code Review) Oct. 29, 2019, 5:57 p.m. UTC
  Change URL: https://gnutoolchain-gerrit.osci.io/r/c/binutils-gdb/+/430
......................................................................

Add read_pc / write_pc support to win32-low

This changes win32-low.c to implement the read_pc and write_pc
methods.  A subsequent patch will need these.

Note that I have no way to test, or even compile, the win32-arm-low.c
change.

Change-Id: I83552edd4ec61204a7e56f1adbd5a9c941bb52e5

gdb/gdbserver/ChangeLog
2019-10-29  Tom Tromey  <tromey@adacore.com>

	* win32-low.c (win32_read_pc, win32_write_pc): New functions.
	(win32_target_ops): Update.
	* win32-i386-low.c (i386_win32_get_pc, i386_win32_set_pc): New
	functions.
	(the_low_target): Update.
	* win32-arm-low.c (arm_win32_get_pc, arm_win32_set_pc): New
	functions.
	(the_low_target): Update.

Change-Id: I4dcb72f262b778c2db554f6ff9b675a35f14318b
---
M gdb/gdbserver/ChangeLog
M gdb/gdbserver/win32-arm-low.c
M gdb/gdbserver/win32-i386-low.c
M gdb/gdbserver/win32-low.c
M gdb/gdbserver/win32-low.h
5 files changed, 95 insertions(+), 2 deletions(-)
  

Comments

Simon Marchi (Code Review) Nov. 21, 2019, 6:43 p.m. UTC | #1
Pedro Alves has posted comments on this change.

Change URL: https://gnutoolchain-gerrit.osci.io/r/c/binutils-gdb/+/430
......................................................................


Patch Set 1: Code-Review+2

(4 comments)

LGTM.  Minor nits below.

| --- gdb/gdbserver/win32-i386-low.c
| +++ gdb/gdbserver/win32-i386-low.c
| @@ -443,8 +443,42 @@ #else
|    const char **expedite_regs = i386_expedite_regs;
|  #endif
|  
|    init_target_desc (tdesc, expedite_regs);
|  
|    win32_tdesc = tdesc;
|  }
|  
| +static CORE_ADDR
| +i386_win32_get_pc (struct regcache *regcache)

PS1, Line 452:

Missing typical intro comment.

| +{
| +  int use_64bit = register_size (regcache->tdesc, 0) == 8;

PS1, Line 454:

bool

| +
| +  if (use_64bit)
| +    {
| +      uint64_t pc;
| +
| +      collect_register_by_name (regcache, "rip", &pc);
| +      return (CORE_ADDR) pc;
| +    }
| +  else
| +    {
| +      uint32_t pc;
| +
| +      collect_register_by_name (regcache, "eip", &pc);
| +      return (CORE_ADDR) pc;
| +    }
| +}
| +
| +static void
| +i386_win32_set_pc (struct regcache *regcache, CORE_ADDR pc)

PS1, Line 473:

Ditto.

| +{
| +  int use_64bit = register_size (regcache->tdesc, 0) == 8;

PS1, Line 475:

bool

| +
| +  if (use_64bit)
| +    {
| +      uint64_t newpc = pc;
| +
| +      supply_register_by_name (regcache, "rip", &newpc);
| +    }
| +  else
| +    {
  

Patch

diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index c36dcb0..fb2fbef 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,5 +1,16 @@ 
 2019-10-29  Tom Tromey  <tromey@adacore.com>
 
+	* win32-low.c (win32_read_pc, win32_write_pc): New functions.
+	(win32_target_ops): Update.
+	* win32-i386-low.c (i386_win32_get_pc, i386_win32_set_pc): New
+	functions.
+	(the_low_target): Update.
+	* win32-arm-low.c (arm_win32_get_pc, arm_win32_set_pc): New
+	functions.
+	(the_low_target): Update.
+
+2019-10-29  Tom Tromey  <tromey@adacore.com>
+
 	* win32-low.c (win32_kill, get_child_debug_event): Use
 	wait_for_debug_event.
 
diff --git a/gdb/gdbserver/win32-arm-low.c b/gdb/gdbserver/win32-arm-low.c
index c465aed..f2052c6 100644
--- a/gdb/gdbserver/win32-arm-low.c
+++ b/gdb/gdbserver/win32-arm-low.c
@@ -113,6 +113,23 @@ 
 static const unsigned long arm_wince_breakpoint = 0xe6000010;
 #define arm_wince_breakpoint_len 4
 
+static CORE_ADDR
+arm_win32_get_pc (struct regcache *regcache)
+{
+  uint32_t pc;
+
+  collect_register_by_name (regcache, "pc", &pc);
+  return (CORE_ADDR) pc;
+}
+
+static void
+arm_win32_set_pc (struct regcache *regcache, CORE_ADDR pc)
+{
+  uint32_t newpc = pc;
+
+  supply_register_by_name (regcache, "pc", &newpc);
+}
+
 struct win32_target_ops the_low_target = {
   arm_arch_setup,
   sizeof (mappings) / sizeof (mappings[0]),
@@ -125,6 +142,8 @@ 
   NULL, /* single_step */
   (const unsigned char *) &arm_wince_breakpoint,
   arm_wince_breakpoint_len,
+  arm_win32_get_pc,
+  arm_win32_set_pc,
   /* Watchpoint related functions.  See target.h for comments.  */
   NULL, /* supports_z_point_type */
   NULL, /* insert_point */
diff --git a/gdb/gdbserver/win32-i386-low.c b/gdb/gdbserver/win32-i386-low.c
index b834b16..421f969 100644
--- a/gdb/gdbserver/win32-i386-low.c
+++ b/gdb/gdbserver/win32-i386-low.c
@@ -448,6 +448,46 @@ 
   win32_tdesc = tdesc;
 }
 
+static CORE_ADDR
+i386_win32_get_pc (struct regcache *regcache)
+{
+  int use_64bit = register_size (regcache->tdesc, 0) == 8;
+
+  if (use_64bit)
+    {
+      uint64_t pc;
+
+      collect_register_by_name (regcache, "rip", &pc);
+      return (CORE_ADDR) pc;
+    }
+  else
+    {
+      uint32_t pc;
+
+      collect_register_by_name (regcache, "eip", &pc);
+      return (CORE_ADDR) pc;
+    }
+}
+
+static void
+i386_win32_set_pc (struct regcache *regcache, CORE_ADDR pc)
+{
+  int use_64bit = register_size (regcache->tdesc, 0) == 8;
+
+  if (use_64bit)
+    {
+      uint64_t newpc = pc;
+
+      supply_register_by_name (regcache, "rip", &newpc);
+    }
+  else
+    {
+      uint32_t newpc = pc;
+
+      supply_register_by_name (regcache, "eip", &newpc);
+    }
+}
+
 struct win32_target_ops the_low_target = {
   i386_arch_setup,
   sizeof (mappings) / sizeof (mappings[0]),
@@ -460,6 +500,8 @@ 
   i386_single_step,
   &i386_win32_breakpoint,
   i386_win32_breakpoint_len,
+  i386_win32_get_pc,
+  i386_win32_set_pc,
   i386_supports_z_point_type,
   i386_insert_point,
   i386_remove_point,
diff --git a/gdb/gdbserver/win32-low.c b/gdb/gdbserver/win32-low.c
index 10b14df..14bd79f 100644
--- a/gdb/gdbserver/win32-low.c
+++ b/gdb/gdbserver/win32-low.c
@@ -1585,6 +1585,22 @@ 
   return the_low_target.breakpoint;
 }
 
+/* Implementation of the target_ops method "read_pc".  */
+
+static CORE_ADDR
+win32_read_pc (struct regcache *regcache)
+{
+  return (*the_low_target.get_pc) (regcache);
+}
+
+/* Implementation of the target_ops method "write_pc".  */
+
+static void
+win32_write_pc (struct regcache *regcache, CORE_ADDR pc)
+{
+  return (*the_low_target.set_pc) (regcache, pc);
+}
+
 static struct target_ops win32_target_ops = {
   win32_create_inferior,
   NULL,  /* post_create_inferior */
@@ -1637,8 +1653,8 @@ 
   NULL, /* read_loadmap */
   NULL, /* process_qsupported */
   NULL, /* supports_tracepoints */
-  NULL, /* read_pc */
-  NULL, /* write_pc */
+  win32_read_pc,
+  win32_write_pc,
   NULL, /* thread_stopped */
   win32_get_tib_address,
   NULL, /* pause_all */
diff --git a/gdb/gdbserver/win32-low.h b/gdb/gdbserver/win32-low.h
index 5a94686..73ceb4b 100644
--- a/gdb/gdbserver/win32-low.h
+++ b/gdb/gdbserver/win32-low.h
@@ -63,6 +63,11 @@ 
   const unsigned char *breakpoint;
   int breakpoint_len;
 
+  /* Get the PC register from REGCACHE.  */
+  CORE_ADDR (*get_pc) (struct regcache *regcache);
+  /* Set the PC register in REGCACHE.  */
+  void (*set_pc) (struct regcache *regcache, CORE_ADDR newpc);
+
   /* Breakpoint/Watchpoint related functions.  See target.h for comments.  */
   int (*supports_z_point_type) (char z_type);
   int (*insert_point) (enum raw_bkpt_type type, CORE_ADDR addr,