From 09150e53b3d4442c6e7afd3696691c16baaea8f0 Mon Sep 17 00:00:00 2001
From: midipix <writeonce@midipix.org>
Date: Sun, 8 Sep 2019 14:24:03 +0000
Subject: mgdb: amd64_winnt_fetch_registers(): initial implementation and
 integration.

---
 overlay/mgdb/gdb/amd64-winnt-tdep.c | 36 ++++++++++++++++++++++++++++++++++++
 overlay/mgdb/gdb/i386-winnt-tdep.c  | 12 ++++++++++++
 overlay/mgdb/gdb/winnt-nat.c        | 33 ++++++++++++++++++++++++++++++---
 3 files changed, 78 insertions(+), 3 deletions(-)

diff --git a/overlay/mgdb/gdb/amd64-winnt-tdep.c b/overlay/mgdb/gdb/amd64-winnt-tdep.c
index cf53d3d..f663677 100644
--- a/overlay/mgdb/gdb/amd64-winnt-tdep.c
+++ b/overlay/mgdb/gdb/amd64-winnt-tdep.c
@@ -6,10 +6,14 @@
 
 #include "defs.h"
 #include "osabi.h"
+#include "regcache.h"
 #include "frame-unwind.h"
 #include "windows-tdep.h"
 #include "amd64-windows-tdep.c"
 
+#include <signal.h>
+#include <sys/debug.h>
+
 #define amd64_winnt_push_dummy_call		amd64_windows_push_dummy_call
 #define amd64_winnt_return_value		amd64_windows_return_value
 #define amd64_winnt_skip_trampoline_code	amd64_windows_skip_trampoline_code
@@ -18,6 +22,38 @@
 #define amd64_winnt_skip_main_prologue		amd64_skip_main_prologue
 #define amd64_winnt_frame_unwind                amd64_windows_frame_unwind
 
+struct regcache;
+
+static void amd64_winnt_supply_reg(
+	struct regcache * rcache,
+	int regnum, uintptr_t regval)
+{
+	regcache_raw_supply(rcache,regnum,&regval);
+}
+
+static void amd64_winnt_supply_pc_regs(
+	struct regcache * rcache,
+	mcontext_t * regctx)
+{
+	amd64_winnt_supply_reg(rcache,AMD64_RIP_REGNUM,regctx->uc_rip);
+}
+
+int amd64_winnt_fetch_registers(
+	int pfd, struct regcache * rcache,
+	int regnum, pid_t tid)
+{
+	int ret;
+	mcontext_t regctx;
+
+	if ((ret = __dbg_regs_fetch(pfd,tid,&regctx)) < 0)
+		return ret;
+
+	if (regnum == AMD64_RIP_REGNUM)
+		amd64_winnt_supply_pc_regs(rcache,&regctx);
+
+	return 0;
+}
+
 static void amd64_winnt_init_abi (struct gdbarch_info info, struct gdbarch * gdbarch)
 {
 	/* abi */
diff --git a/overlay/mgdb/gdb/i386-winnt-tdep.c b/overlay/mgdb/gdb/i386-winnt-tdep.c
index d212959..919fa30 100644
--- a/overlay/mgdb/gdb/i386-winnt-tdep.c
+++ b/overlay/mgdb/gdb/i386-winnt-tdep.c
@@ -9,6 +9,18 @@
 #include "frame-unwind.h"
 #include "windows-tdep.h"
 
+struct regcache;
+
+void i386_winnt_fetch_registers(
+	int pfd, struct regcache * rcache,
+	int regnum, pid_t tid)
+{
+	(void)pfd;
+	(void)rcache;
+	(void)regnum;
+	(void)tid;
+}
+
 static void i386_winnt_init_abi (struct gdbarch_info info, struct gdbarch * gdbarch)
 {
 	/* abi */
diff --git a/overlay/mgdb/gdb/winnt-nat.c b/overlay/mgdb/gdb/winnt-nat.c
index d32464c..449b740 100644
--- a/overlay/mgdb/gdb/winnt-nat.c
+++ b/overlay/mgdb/gdb/winnt-nat.c
@@ -30,6 +30,8 @@
 #define winnt_perror(msg,pid) \
 	error("%s(): %s (pid %d).",__FUNCTION__,msg,pid)
 
+struct regcache;
+
 struct winnt_process {
 	int	pfd;
 	pid_t	pid;
@@ -42,6 +44,14 @@ static size_t          pcnt;
 static winnt_process * plist;
 static char *          outbuf;
 
+extern void amd64_winnt_fetch_registers(
+	int pfd, struct regcache * rcache,
+	int regnum, pid_t tid);
+
+extern void i386_winnt_fetch_registers(
+	int pfd, struct regcache * rcache,
+	int regnum, pid_t tid);
+
 static winnt_process * winnt_plist_expand (void)
 {
 	struct winnt_process * pnew;
@@ -122,9 +132,26 @@ static void winnt_fetch_registers (
 	struct regcache *   rcache,
 	int                 regnum)
 {
-	(void)t;
-	(void)rcache;
-	(void)regnum;
+	pid_t pid;
+	pid_t tid;
+	struct winnt_process * pidinfo;
+
+	pid = inferior_ptid.pid;
+	tid = inferior_ptid.tid;
+
+	if (!(pidinfo = winnt_process_record(pid)))
+		winnt_perror("internal error: record not found",pid);
+
+	if (sizeof(uintptr_t) == 8)
+		amd64_winnt_fetch_registers(
+			pidinfo->pfd,
+			rcache,regnum,
+			tid);
+	else
+		i386_winnt_fetch_registers(
+			pidinfo->pfd,
+			rcache,regnum,
+			tid);
 }
 
 static void winnt_store_registers (
-- 
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