[PATCH v3 26/29] Add read_pc / write_pc support to win32-low

Tom Tromey
2020-03-13T19:09:05Z

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.

gdbserver/ChangeLog
2020-03-13 Tom Tromey <tromey@adacore.com>

* win32-low.h (win32_process_target::read_pc)
(win32_process_target::write_pc): Declare.
* win32-low.c (win32_process_target::read_pc)
(win32_process_target::write_pc): New methods.
* 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.
---
gdbserver/ChangeLog | 13 +++++++++++
gdbserver/win32-arm-low.cc | 23 +++++++++++++++++++
gdbserver/win32-i386-low.cc | 46 +++++++++++++++++++++++++++++++++++++
gdbserver/win32-low.cc | 12 ++++++++++
gdbserver/win32-low.h | 9 ++++++++
5 files changed, 103 insertions(+)

diff --git a/gdbserver/win32-arm-low.cc b/gdbserver/win32-arm-low.cc
index 78b7fd09ec3..77200112df1 100644
--- a/gdbserver/win32-arm-low.cc
+++ b/gdbserver/win32-arm-low.cc
@@ -115,6 +115,27 @@ arm_arch_setup (void)
static const unsigned long arm_wince_breakpoint = 0xe6000010;
#define arm_wince_breakpoint_len 4

+/* Implement win32_target_ops "get_pc" method. */
+
+static CORE_ADDR
+arm_win32_get_pc (struct regcache *regcache)
+{
+ uint32_t pc;
+
+ collect_register_by_name (regcache, "pc", &pc);
+ return (CORE_ADDR) pc;
+}
+
+/* Implement win32_target_ops "set_pc" method. */
+
+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]),
@@ -127,6 +148,8 @@ struct win32_target_ops the_low_target = {
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/gdbserver/win32-i386-low.cc b/gdbserver/win32-i386-low.cc
index 1c14bc70362..eac15b5694a 100644
--- a/gdbserver/win32-i386-low.cc
+++ b/gdbserver/win32-i386-low.cc
@@ -450,6 +450,50 @@ i386_arch_setup (void)
win32_tdesc = tdesc;
}

+/* Implement win32_target_ops "get_pc" method. */
+
+static CORE_ADDR
+i386_win32_get_pc (struct regcache *regcache)
+{
+ bool 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;
+ }
+}
+
+/* Implement win32_target_ops "set_pc" method. */
+
+static void
+i386_win32_set_pc (struct regcache *regcache, CORE_ADDR pc)
+{
+ bool 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]),
@@ -462,6 +506,8 @@ struct win32_target_ops the_low_target = {
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/gdbserver/win32-low.cc b/gdbserver/win32-low.cc
index d151505e9f8..131eacb13c4 100644
--- a/gdbserver/win32-low.cc
+++ b/gdbserver/win32-low.cc
@@ -1659,6 +1659,18 @@ win32_process_target::sw_breakpoint_from_kind (int kind, int *size)
return the_low_target.breakpoint;
}

+CORE_ADDR
+win32_process_target::read_pc (struct regcache *regcache)
+{
+ return (*the_low_target.get_pc) (regcache);
+}
+
+void
+win32_process_target::write_pc (struct regcache *regcache, CORE_ADDR pc)
+{
+ return (*the_low_target.set_pc) (regcache, pc);
+}
+
/* The win32 target ops object. */

static win32_process_target the_win32_target;
diff --git a/gdbserver/win32-low.h b/gdbserver/win32-low.h
index 917f7275622..56ff8a9baf2 100644
--- a/gdbserver/win32-low.h
+++ b/gdbserver/win32-low.h
@@ -63,6 +63,11 @@ struct win32_target_ops
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,
@@ -142,6 +147,10 @@ class win32_process_target : public process_stratum_target
int get_tib_address (ptid_t ptid, CORE_ADDR *addr) override;

const gdb_byte *sw_breakpoint_from_kind (int kind, int *size) override;
+
+ CORE_ADDR read_pc (regcache *regcache) override;
+
+ void write_pc (regcache *regcache, CORE_ADDR pc) override;
};

/* Retrieve the context for this thread, if not already retrieved. */
--
2.21.1