winedbg: Add a backend-specific vector for retrieving a thread's context.

Signed-off-by: Zebediah Figura <zfigura@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>

programs/winedbg/be_arm.c

@@ -1889,6 +1889,16 @@ static BOOL be_arm_store_integer(const struct dbg_lvalue* lvalue, unsigned size,
     return memory_write_value(lvalue, size, &val);
 }
 
+static BOOL be_arm_get_context(HANDLE thread, dbg_ctx_t *ctx)
+{
+#ifdef __arm__
+    ctx->ctx.ContextFlags = CONTEXT_ALL;
+    return GetThreadContext(thread, &ctx->ctx);
+#else
+    WINE_FIXME("Cannot debug an ARM process on this architecture.\n");
+#endif
+}
+
 struct backend_cpu be_arm =
 {
     IMAGE_FILE_MACHINE_ARMNT,
@@ -1915,5 +1925,6 @@ struct backend_cpu be_arm =
     be_arm_fetch_integer,
     be_arm_fetch_float,
     be_arm_store_integer,
+    be_arm_get_context,
 };
 #endif

programs/winedbg/be_arm64.c

@@ -278,6 +278,16 @@ void be_arm64_disasm_one_insn(ADDRESS64 *addr, int display)
     dbg_printf("be_arm64_disasm_one_insn: not done\n");
 }
 
+static BOOL be_arm64_get_context(HANDLE thread, dbg_ctx_t *ctx)
+{
+#ifdef __aarch64__
+    ctx->ctx.ContextFlags = CONTEXT_ALL;
+    return GetThreadContext(thread, &ctx->ctx);
+#else
+    WINE_FIXME("Cannot debug an ARM64 process on this architecture.\n");
+#endif
+}
+
 struct backend_cpu be_arm64 =
 {
     IMAGE_FILE_MACHINE_ARM64,
@@ -304,5 +314,6 @@ struct backend_cpu be_arm64 =
     be_arm64_fetch_integer,
     be_arm64_fetch_float,
     be_arm64_store_integer,
+    be_arm64_get_context,
 };
 #endif

programs/winedbg/be_cpu.h

@@ -21,6 +21,7 @@
 enum be_cpu_addr {be_cpu_addr_pc, be_cpu_addr_stack, be_cpu_addr_frame};
 enum be_xpoint_type {be_xpoint_break, be_xpoint_watch_exec, be_xpoint_watch_read,
                      be_xpoint_watch_write, be_xpoint_free=-1};
+
 struct backend_cpu
 {
     const DWORD         machine;
@@ -114,6 +115,8 @@ struct backend_cpu
     BOOL                (*fetch_float)(const struct dbg_lvalue* lvalue, unsigned size, long double*);
     /* Writes an integer to memory */
     BOOL                (*store_integer)(const struct dbg_lvalue* lvalue, unsigned size, BOOL is_signed, LONGLONG);
+
+    BOOL                (*get_context)(HANDLE thread, dbg_ctx_t *ctx);
 };
 
 /* some handy functions for non segmented CPUs */

programs/winedbg/be_i386.c

@@ -853,6 +853,12 @@ static BOOL be_i386_store_integer(const struct dbg_lvalue* lvalue, unsigned size
     return memory_write_value(lvalue, size, &val);
 }
 
+static BOOL be_i386_get_context(HANDLE thread, dbg_ctx_t *ctx)
+{
+    ctx->x86.ContextFlags = WOW64_CONTEXT_ALL;
+    return Wow64GetThreadContext(thread, &ctx->x86);
+}
+
 struct backend_cpu be_i386 =
 {
     IMAGE_FILE_MACHINE_I386,
@@ -879,5 +885,6 @@ struct backend_cpu be_i386 =
     be_i386_fetch_integer,
     be_i386_fetch_float,
     be_i386_store_integer,
+    be_i386_get_context,
 };
 #endif

programs/winedbg/be_ppc.c

@@ -180,6 +180,16 @@ static BOOL be_ppc_store_integer(const struct dbg_lvalue* lvalue, unsigned size,
     return FALSE;
 }
 
+static BOOL be_ppc_get_context(HANDLE thread, dbg_ctx_t *ctx)
+{
+#ifdef __powerpc__
+    ctx->ctx.ContextFlags = CONTEXT_ALL;
+    return GetThreadContext(thread, &ctx->ctx);
+#else
+    WINE_FIXME("Cannot debug a PowerPC process on this architecture.\n");
+#endif
+}
+
 struct backend_cpu be_ppc =
 {
     IMAGE_FILE_MACHINE_POWERPC,
@@ -206,5 +216,6 @@ struct backend_cpu be_ppc =
     be_ppc_fetch_integer,
     be_ppc_fetch_float,
     be_ppc_store_integer,
+    be_ppc_get_context,
 };
 #endif

programs/winedbg/be_x86_64.c

@@ -674,6 +674,16 @@ static BOOL be_x86_64_store_integer(const struct dbg_lvalue* lvalue, unsigned si
     return memory_write_value(lvalue, size, &val);
 }
 
+static BOOL be_x86_64_get_context(HANDLE thread, dbg_ctx_t *ctx)
+{
+#ifdef __x86_64__
+    ctx->ctx.ContextFlags = CONTEXT_ALL;
+    return GetThreadContext(thread, &ctx->ctx);
+#else
+    WINE_FIXME("Cannot debug an x86-64 process on this architecture.\n");
+#endif
+}
+
 struct backend_cpu be_x86_64 =
 {
     IMAGE_FILE_MACHINE_AMD64,
@@ -700,5 +710,6 @@ struct backend_cpu be_x86_64 =
     be_x86_64_fetch_integer,
     be_x86_64_fetch_float,
     be_x86_64_store_integer,
+    be_x86_64_get_context,
 };
 #endif

programs/winedbg/gdbproxy.c

@@ -552,7 +552,7 @@ static inline void cpu_register_hex_from(dbg_ctx_t* ctx, unsigned idx, const cha
 
 static BOOL fetch_context(struct gdb_context *gdbctx, HANDLE h, dbg_ctx_t *ctx)
 {
-    if (!GetThreadContext(h, &ctx->ctx))
+    if (!gdbctx->process->be_cpu->get_context(h, ctx))
     {
         if (gdbctx->trace & GDBPXY_TRC_WIN32_ERROR)
             fprintf(stderr, "Can't get thread's context\n");

programs/winedbg/stack.c

@@ -354,11 +354,9 @@ static void backtrace_tid(struct dbg_process* pcs, DWORD tid)
         dbg_ctx_t ctx = {0};
 
         dbg_curr_tid = dbg_curr_thread->tid;
-
-        ctx.ctx.ContextFlags = CONTEXT_FULL;
         if (SuspendThread(dbg_curr_thread->handle) != -1)
         {
-            if (!GetThreadContext(dbg_curr_thread->handle, &ctx.ctx))
+            if (!pcs->be_cpu->get_context(dbg_curr_thread->handle, &ctx))
             {
                 dbg_printf("Can't get context for thread %04x in current process\n",
                            tid);

programs/winedbg/tgt_active.c

@@ -91,19 +91,7 @@ BOOL dbg_attach_debuggee(DWORD pid, BOOL cofe)
 
 static unsigned dbg_fetch_context(void)
 {
-    dbg_context.ctx.ContextFlags = CONTEXT_CONTROL
-        | CONTEXT_INTEGER
-#ifdef CONTEXT_FLOATING_POINT
-        | CONTEXT_FLOATING_POINT
-#endif
-#ifdef CONTEXT_SEGMENTS
-        | CONTEXT_SEGMENTS
-#endif
-#ifdef CONTEXT_DEBUG_REGISTERS
-        | CONTEXT_DEBUG_REGISTERS
-#endif
-        ;
-    if (!GetThreadContext(dbg_curr_thread->handle, &dbg_context.ctx))
+    if (!dbg_curr_process->be_cpu->get_context(dbg_curr_thread->handle, &dbg_context))
     {
         WINE_WARN("Can't get thread's context\n");
         return FALSE;