[PATCH v2 0/3] Implement pid_to_exec_file for Windows in gdbserver

[PATCH v2 0/3] Implement pid_to_exec_file for Windows in gdbserver

[Tom Tromey]

Here's v2 of the series to implement pid_to_exec_file for Windows in
gdbserver.

This version adds a patch to remove windows_process_info::id, which
isn't really needed.

Tom

[PATCH v2 1/3] Constify target_pid_to_exec_file

[Tom Tromey]

This changes target_pid_to_exec_file and target_ops::pid_to_exec_file
to return a "const char *".  I couldn't build many of these targets,
but did examine the code by hand -- also, as this only affects the
return type, it's normally pretty safe.  This brings gdb and gdbserver
a bit closer, and allows for the removal of a const_cast as well.
---
 gdb/darwin-nat.c       |  2 +-
 gdb/darwin-nat.h       |  2 +-
 gdb/exec.c             |  2 +-
 gdb/fbsd-nat.c         |  2 +-
 gdb/fbsd-nat.h         |  2 +-
 gdb/inf-child.c        |  2 +-
 gdb/inf-child.h        |  2 +-
 gdb/linux-nat.c        |  2 +-
 gdb/linux-nat.h        |  2 +-
 gdb/nat/linux-procfs.c |  2 +-
 gdb/nat/linux-procfs.h |  2 +-
 gdb/netbsd-nat.c       |  4 ++--
 gdb/netbsd-nat.h       |  2 +-
 gdb/nto-procfs.c       |  4 ++--
 gdb/procfs.c           |  4 ++--
 gdb/remote.c           |  4 ++--
 gdb/target-delegates.c | 14 +++++++-------
 gdb/target.c           |  2 +-
 gdb/target.h           |  4 ++--
 gdb/windows-nat.c      |  4 ++--
 20 files changed, 32 insertions(+), 32 deletions(-)

diff --git a/gdb/darwin-nat.c b/gdb/darwin-nat.c
index 17723656930..eca97c9bde9 100644
--- a/gdb/darwin-nat.c
+++ b/gdb/darwin-nat.c
@@ -2373,7 +2373,7 @@ set_enable_mach_exceptions (const char *args, int from_tty,
     }
 }
 
-char *
+const char *
 darwin_nat_target::pid_to_exec_file (int pid)
 {
   static char path[PATH_MAX];
diff --git a/gdb/darwin-nat.h b/gdb/darwin-nat.h
index 733ac7cc058..e3dcd963706 100644
--- a/gdb/darwin-nat.h
+++ b/gdb/darwin-nat.h
@@ -100,7 +100,7 @@ class darwin_nat_target : public inf_child_target
 
   std::string pid_to_str (ptid_t) override;
 
-  char *pid_to_exec_file (int pid) override;
+  const char *pid_to_exec_file (int pid) override;
 
   enum target_xfer_status xfer_partial (enum target_object object,
 					const char *annex,
diff --git a/gdb/exec.c b/gdb/exec.c
index 38540c0840b..40c89d53ba9 100644
--- a/gdb/exec.c
+++ b/gdb/exec.c
@@ -314,7 +314,7 @@ validate_exec_file (int from_tty)
 void
 exec_file_locate_attach (int pid, int defer_bp_reset, int from_tty)
 {
-  char *exec_file_target;
+  const char *exec_file_target;
   symfile_add_flags add_flags = 0;
 
   /* Do nothing if we already have an executable filename.  */
diff --git a/gdb/fbsd-nat.c b/gdb/fbsd-nat.c
index 8e5107c26f8..22349d49aee 100644
--- a/gdb/fbsd-nat.c
+++ b/gdb/fbsd-nat.c
@@ -52,7 +52,7 @@
 /* Return the name of a file that can be opened to get the symbols for
    the child process identified by PID.  */
 
-char *
+const char *
 fbsd_nat_target::pid_to_exec_file (int pid)
 {
   static char buf[PATH_MAX];
diff --git a/gdb/fbsd-nat.h b/gdb/fbsd-nat.h
index 82f7ee47949..ff62a5826a9 100644
--- a/gdb/fbsd-nat.h
+++ b/gdb/fbsd-nat.h
@@ -44,7 +44,7 @@
 class fbsd_nat_target : public inf_ptrace_target
 {
 public:
-  char *pid_to_exec_file (int pid) override;
+  const char *pid_to_exec_file (int pid) override;
 
   int find_memory_regions (find_memory_region_ftype func, void *data) override;
 
diff --git a/gdb/inf-child.c b/gdb/inf-child.c
index cc00867787a..56ebd2a5549 100644
--- a/gdb/inf-child.c
+++ b/gdb/inf-child.c
@@ -220,7 +220,7 @@ inf_child_target::can_attach ()
   return true;
 }
 
-char *
+const char *
 inf_child_target::pid_to_exec_file (int pid)
 {
   /* This target doesn't support translation of a process ID to the
diff --git a/gdb/inf-child.h b/gdb/inf-child.h
index a017032a32f..ae5ace46f30 100644
--- a/gdb/inf-child.h
+++ b/gdb/inf-child.h
@@ -71,7 +71,7 @@ class inf_child_target
 
   void post_attach (int) override;
 
-  char *pid_to_exec_file (int pid) override;
+  const char *pid_to_exec_file (int pid) override;
 
   int fileio_open (struct inferior *inf, const char *filename,
 		   int flags, int mode, int warn_if_slow,
diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c
index 740cc0ddfc0..3b5400896bc 100644
--- a/gdb/linux-nat.c
+++ b/gdb/linux-nat.c
@@ -3764,7 +3764,7 @@ linux_nat_target::thread_name (struct thread_info *thr)
 /* Accepts an integer PID; Returns a string representing a file that
    can be opened to get the symbols for the child process.  */
 
-char *
+const char *
 linux_nat_target::pid_to_exec_file (int pid)
 {
   return linux_proc_pid_to_exec_file (pid);
diff --git a/gdb/linux-nat.h b/gdb/linux-nat.h
index 12a90eccb28..11043c4b9f6 100644
--- a/gdb/linux-nat.h
+++ b/gdb/linux-nat.h
@@ -123,7 +123,7 @@ class linux_nat_target : public inf_ptrace_target
   int set_syscall_catchpoint (int pid, bool needed, int any_count,
 			      gdb::array_view<const int> syscall_counts) override;
 
-  char *pid_to_exec_file (int pid) override;
+  const char *pid_to_exec_file (int pid) override;
 
   void post_attach (int) override;
 
diff --git a/gdb/nat/linux-procfs.c b/gdb/nat/linux-procfs.c
index 2618c99d9f4..99e645786c2 100644
--- a/gdb/nat/linux-procfs.c
+++ b/gdb/nat/linux-procfs.c
@@ -341,7 +341,7 @@ linux_proc_task_list_dir_exists (pid_t pid)
 
 /* See linux-procfs.h.  */
 
-char *
+const char *
 linux_proc_pid_to_exec_file (int pid)
 {
   static char buf[PATH_MAX];
diff --git a/gdb/nat/linux-procfs.h b/gdb/nat/linux-procfs.h
index fa1280a8967..fcc8280adf1 100644
--- a/gdb/nat/linux-procfs.h
+++ b/gdb/nat/linux-procfs.h
@@ -78,7 +78,7 @@ extern int linux_proc_task_list_dir_exists (pid_t pid);
    to create the process PID.  The returned value persists until this
    function is next called.  */
 
-extern char *linux_proc_pid_to_exec_file (int pid);
+extern const char *linux_proc_pid_to_exec_file (int pid);
 
 /* Display possible problems on this system.  Display them only once
    per GDB execution.  */
diff --git a/gdb/netbsd-nat.c b/gdb/netbsd-nat.c
index f2eeb3ff61e..2ccd0e014c2 100644
--- a/gdb/netbsd-nat.c
+++ b/gdb/netbsd-nat.c
@@ -34,10 +34,10 @@
 /* Return the name of a file that can be opened to get the symbols for
    the child process identified by PID.  */
 
-char *
+const char *
 nbsd_nat_target::pid_to_exec_file (int pid)
 {
-  return const_cast<char *> (netbsd_nat::pid_to_exec_file (pid));
+  return netbsd_nat::pid_to_exec_file (pid);
 }
 
 /* Return the current directory for the process identified by PID.  */
diff --git a/gdb/netbsd-nat.h b/gdb/netbsd-nat.h
index ef190c4e471..ff468452b2c 100644
--- a/gdb/netbsd-nat.h
+++ b/gdb/netbsd-nat.h
@@ -28,7 +28,7 @@ struct thread_info;
 
 struct nbsd_nat_target : public inf_ptrace_target
 {
-  char *pid_to_exec_file (int pid) override;
+  const char *pid_to_exec_file (int pid) override;
 
   bool thread_alive (ptid_t ptid) override;
   const char *thread_name (struct thread_info *thr) override;
diff --git a/gdb/nto-procfs.c b/gdb/nto-procfs.c
index 61374c9fad4..ef9e0f05261 100644
--- a/gdb/nto-procfs.c
+++ b/gdb/nto-procfs.c
@@ -121,7 +121,7 @@ struct nto_procfs_target : public inf_child_target
 
   const char *extra_thread_info (struct thread_info *) override;
 
-  char *pid_to_exec_file (int pid) override;
+  const char *pid_to_exec_file (int pid) override;
 };
 
 /* For "target native".  */
@@ -664,7 +664,7 @@ nto_procfs_target::files_info ()
 
 /* Target to_pid_to_exec_file implementation.  */
 
-char *
+const char *
 nto_procfs_target::pid_to_exec_file (const int pid)
 {
   int proc_fd;
diff --git a/gdb/procfs.c b/gdb/procfs.c
index f6ca1345a21..d290505d8c3 100644
--- a/gdb/procfs.c
+++ b/gdb/procfs.c
@@ -127,7 +127,7 @@ class procfs_target final : public inf_child_target
 
   std::string pid_to_str (ptid_t) override;
 
-  char *pid_to_exec_file (int pid) override;
+  const char *pid_to_exec_file (int pid) override;
 
   thread_control_capabilities get_thread_control_capabilities () override
   { return tc_schedlock; }
@@ -2927,7 +2927,7 @@ procfs_target::pid_to_str (ptid_t ptid)
 /* Accepts an integer PID; Returns a string representing a file that
    can be opened to get the symbols for the child process.  */
 
-char *
+const char *
 procfs_target::pid_to_exec_file (int pid)
 {
   static char buf[PATH_MAX];
diff --git a/gdb/remote.c b/gdb/remote.c
index ff98024cd78..f6c53eb585e 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -508,7 +508,7 @@ class remote_target : public process_stratum_target
 
   void rcmd (const char *command, struct ui_file *output) override;
 
-  char *pid_to_exec_file (int pid) override;
+  const char *pid_to_exec_file (int pid) override;
 
   void log_command (const char *cmd) override
   {
@@ -14336,7 +14336,7 @@ remote_target::load (const char *name, int from_tty)
    can be opened on the remote side to get the symbols for the child
    process.  Returns NULL if the operation is not supported.  */
 
-char *
+const char *
 remote_target::pid_to_exec_file (int pid)
 {
   static gdb::optional<gdb::char_vector> filename;
diff --git a/gdb/target-delegates.c b/gdb/target-delegates.c
index 4e653e8f429..8a9986454dd 100644
--- a/gdb/target-delegates.c
+++ b/gdb/target-delegates.c
@@ -94,7 +94,7 @@ struct dummy_target : public target_ops
   void interrupt () override;
   void pass_ctrlc () override;
   void rcmd (const char *arg0, struct ui_file *arg1) override;
-  char *pid_to_exec_file (int arg0) override;
+  const char *pid_to_exec_file (int arg0) override;
   void log_command (const char *arg0) override;
   const target_section_table *get_section_table () override;
   thread_control_capabilities get_thread_control_capabilities () override;
@@ -268,7 +268,7 @@ struct debug_target : public target_ops
   void interrupt () override;
   void pass_ctrlc () override;
   void rcmd (const char *arg0, struct ui_file *arg1) override;
-  char *pid_to_exec_file (int arg0) override;
+  const char *pid_to_exec_file (int arg0) override;
   void log_command (const char *arg0) override;
   const target_section_table *get_section_table () override;
   thread_control_capabilities get_thread_control_capabilities () override;
@@ -1983,28 +1983,28 @@ debug_target::rcmd (const char *arg0, struct ui_file *arg1)
   gdb_puts (")\n", gdb_stdlog);
 }
 
-char *
+const char *
 target_ops::pid_to_exec_file (int arg0)
 {
   return this->beneath ()->pid_to_exec_file (arg0);
 }
 
-char *
+const char *
 dummy_target::pid_to_exec_file (int arg0)
 {
   return NULL;
 }
 
-char *
+const char *
 debug_target::pid_to_exec_file (int arg0)
 {
-  char * result;
+  const char * result;
   gdb_printf (gdb_stdlog, "-> %s->pid_to_exec_file (...)\n", this->beneath ()->shortname ());
   result = this->beneath ()->pid_to_exec_file (arg0);
   gdb_printf (gdb_stdlog, "<- %s->pid_to_exec_file (", this->beneath ()->shortname ());
   target_debug_print_int (arg0);
   gdb_puts (") = ", gdb_stdlog);
-  target_debug_print_char_p (result);
+  target_debug_print_const_char_p (result);
   gdb_puts ("\n", gdb_stdlog);
   return result;
 }
diff --git a/gdb/target.c b/gdb/target.c
index 1063f8086bc..18e53aa5d27 100644
--- a/gdb/target.c
+++ b/gdb/target.c
@@ -423,7 +423,7 @@ target_extra_thread_info (thread_info *tp)
 
 /* See target.h.  */
 
-char *
+const char *
 target_pid_to_exec_file (int pid)
 {
   return current_inferior ()->top_target ()->pid_to_exec_file (pid);
diff --git a/gdb/target.h b/gdb/target.h
index f77dbf05113..18559feef89 100644
--- a/gdb/target.h
+++ b/gdb/target.h
@@ -688,7 +688,7 @@ struct target_ops
       TARGET_DEFAULT_FUNC (default_target_pass_ctrlc);
     virtual void rcmd (const char *command, struct ui_file *output)
       TARGET_DEFAULT_FUNC (default_rcmd);
-    virtual char *pid_to_exec_file (int pid)
+    virtual const char *pid_to_exec_file (int pid)
       TARGET_DEFAULT_RETURN (NULL);
     virtual void log_command (const char *)
       TARGET_DEFAULT_IGNORE ();
@@ -1951,7 +1951,7 @@ extern gdb::byte_vector target_thread_info_to_thread_handle
    the client if the string will not be immediately used, or if
    it must persist.  */
 
-extern char *target_pid_to_exec_file (int pid);
+extern const char *target_pid_to_exec_file (int pid);
 
 /* See the to_thread_architecture description in struct target_ops.  */
 
diff --git a/gdb/windows-nat.c b/gdb/windows-nat.c
index 1068558cd21..cd43409a02f 100644
--- a/gdb/windows-nat.c
+++ b/gdb/windows-nat.c
@@ -276,7 +276,7 @@ struct windows_nat_target final : public x86_nat_target<inf_child_target>
 
   void interrupt () override;
 
-  char *pid_to_exec_file (int pid) override;
+  const char *pid_to_exec_file (int pid) override;
 
   ptid_t get_ada_task_ptid (long lwp, ULONGEST thread) override;
 
@@ -2005,7 +2005,7 @@ windows_get_exec_module_filename (char *exe_name_ret, size_t exe_name_max_len)
 
 /* The pid_to_exec_file target_ops method for this platform.  */
 
-char *
+const char *
 windows_nat_target::pid_to_exec_file (int pid)
 {
   static char path[__PMAX];
-- 
2.34.1

[PATCH v2 2/3] Remove windows_process_info::id

[Tom Tromey]

I noticed that windows_process_info::id is only used by gdbserver, and
not really necessary.  This patch removes it.
---
 gdb/nat/windows-nat.h  |  1 -
 gdbserver/win32-low.cc | 11 +++++------
 2 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/gdb/nat/windows-nat.h b/gdb/nat/windows-nat.h
index 27b653674c3..9f7f8b63192 100644
--- a/gdb/nat/windows-nat.h
+++ b/gdb/nat/windows-nat.h
@@ -144,7 +144,6 @@ struct windows_process_info
 {
   /* The process handle */
   HANDLE handle = 0;
-  DWORD id = 0;
   DWORD main_thread_id = 0;
   enum gdb_signal last_sig = GDB_SIGNAL_0;
 
diff --git a/gdbserver/win32-low.cc b/gdbserver/win32-low.cc
index 192ea465e69..5b91ab768e5 100644
--- a/gdbserver/win32-low.cc
+++ b/gdbserver/win32-low.cc
@@ -337,7 +337,6 @@ do_initial_child_stuff (HANDLE proch, DWORD pid, int attached)
 
   windows_process.last_sig = GDB_SIGNAL_0;
   windows_process.handle = proch;
-  windows_process.id = pid;
   windows_process.main_thread_id = 0;
 
   soft_interrupt_requested = 0;
@@ -678,12 +677,12 @@ win32_process_target::create_inferior (const char *program,
 
   /* Wait till we are at 1st instruction in program, return new pid
      (assuming success).  */
-  cs.last_ptid = wait (ptid_t (windows_process.id), &cs.last_status, 0);
+  cs.last_ptid = wait (ptid_t (pi.dwProcessId), &cs.last_status, 0);
 
   /* Necessary for handle_v_kill.  */
-  signal_pid = windows_process.id;
+  signal_pid = pi.dwProcessId;
 
-  return windows_process.id;
+  return pi.dwProcessId;
 }
 
 /* Attach to a running process.
@@ -816,7 +815,7 @@ win32_process_target::detach (process_info *process)
   resume.sig = 0;
   this->resume (&resume, 1);
 
-  if (!DebugActiveProcessStop (windows_process.id))
+  if (!DebugActiveProcessStop (process->pid))
     return -1;
 
   DebugSetProcessKillOnExit (FALSE);
@@ -1375,7 +1374,7 @@ win32_process_target::write_memory (CORE_ADDR memaddr,
 void
 win32_process_target::request_interrupt ()
 {
-  if (GenerateConsoleCtrlEvent (CTRL_BREAK_EVENT, windows_process.id))
+  if (GenerateConsoleCtrlEvent (CTRL_BREAK_EVENT, signal_pid))
     return;
 
   /* GenerateConsoleCtrlEvent can fail if process id being debugged is
-- 
2.34.1

[PATCH v2 3/3] Implement pid_to_exec_file for Windows in gdbserver

[Tom Tromey]

I noticed that gdbserver did not implement pid_to_exec_file for
Windows, while gdb did implement it.  This patch moves the code to
nat/windows-nat.c, so that it can be shared.  This makes the gdbserver
implementation trivial.
---
 gdb/nat/windows-nat.c  | 93 ++++++++++++++++++++++++++++++++++++++++++
 gdb/nat/windows-nat.h  | 14 +++++++
 gdb/windows-nat.c      | 88 +--------------------------------------
 gdbserver/win32-low.cc |  6 +++
 gdbserver/win32-low.h  |  5 +++
 5 files changed, 119 insertions(+), 87 deletions(-)

diff --git a/gdb/nat/windows-nat.c b/gdb/nat/windows-nat.c
index c8db19439f3..71a18a0efa9 100644
--- a/gdb/nat/windows-nat.c
+++ b/gdb/nat/windows-nat.c
@@ -144,6 +144,99 @@ windows_thread_info::thread_name ()
   return name.get ();
 }
 
+/* Try to determine the executable filename.
+
+   EXE_NAME_RET is a pointer to a buffer whose size is EXE_NAME_MAX_LEN.
+
+   Upon success, the filename is stored inside EXE_NAME_RET, and
+   this function returns nonzero.
+
+   Otherwise, this function returns zero and the contents of
+   EXE_NAME_RET is undefined.  */
+
+int
+windows_process_info::get_exec_module_filename (char *exe_name_ret,
+						size_t exe_name_max_len)
+{
+  DWORD len;
+  HMODULE dh_buf;
+  DWORD cbNeeded;
+
+  cbNeeded = 0;
+#ifdef __x86_64__
+  if (wow64_process)
+    {
+      if (!EnumProcessModulesEx (handle,
+				 &dh_buf, sizeof (HMODULE), &cbNeeded,
+				 LIST_MODULES_32BIT)
+	  || !cbNeeded)
+	return 0;
+    }
+  else
+#endif
+    {
+      if (!EnumProcessModules (handle,
+			       &dh_buf, sizeof (HMODULE), &cbNeeded)
+	  || !cbNeeded)
+	return 0;
+    }
+
+  /* We know the executable is always first in the list of modules,
+     which we just fetched.  So no need to fetch more.  */
+
+#ifdef __CYGWIN__
+  {
+    /* Cygwin prefers that the path be in /x/y/z format, so extract
+       the filename into a temporary buffer first, and then convert it
+       to POSIX format into the destination buffer.  */
+    cygwin_buf_t *pathbuf = (cygwin_buf_t *) alloca (exe_name_max_len * sizeof (cygwin_buf_t));
+
+    len = GetModuleFileNameEx (current_process_handle,
+			       dh_buf, pathbuf, exe_name_max_len);
+    if (len == 0)
+      error (_("Error getting executable filename: %u."),
+	     (unsigned) GetLastError ());
+    if (cygwin_conv_path (CCP_WIN_W_TO_POSIX, pathbuf, exe_name_ret,
+			  exe_name_max_len) < 0)
+      error (_("Error converting executable filename to POSIX: %d."), errno);
+  }
+#else
+  len = GetModuleFileNameEx (handle,
+			     dh_buf, exe_name_ret, exe_name_max_len);
+  if (len == 0)
+    error (_("Error getting executable filename: %u."),
+	   (unsigned) GetLastError ());
+#endif
+
+    return 1;	/* success */
+}
+
+const char *
+windows_process_info::pid_to_exec_file (int pid)
+{
+  static char path[MAX_PATH];
+#ifdef __CYGWIN__
+  /* Try to find exe name as symlink target of /proc/<pid>/exe.  */
+  int nchars;
+  char procexe[sizeof ("/proc/4294967295/exe")];
+
+  xsnprintf (procexe, sizeof (procexe), "/proc/%u/exe", pid);
+  nchars = readlink (procexe, path, sizeof(path));
+  if (nchars > 0 && nchars < sizeof (path))
+    {
+      path[nchars] = '\0';	/* Got it */
+      return path;
+    }
+#endif
+
+  /* If we get here then either Cygwin is hosed, this isn't a Cygwin version
+     of gdb, or we're trying to debug a non-Cygwin windows executable.  */
+  if (!get_exec_module_filename (path, sizeof (path)))
+    path[0] = '\0';
+
+  return path;
+}
+
 /* Return the name of the DLL referenced by H at ADDRESS.  UNICODE
    determines what sort of string is read from the inferior.  Returns
    the name of the DLL, or NULL on error.  If a name is returned, it
diff --git a/gdb/nat/windows-nat.h b/gdb/nat/windows-nat.h
index 9f7f8b63192..450ba69c844 100644
--- a/gdb/nat/windows-nat.h
+++ b/gdb/nat/windows-nat.h
@@ -248,6 +248,8 @@ struct windows_process_info
 
   gdb::optional<pending_stop> fetch_pending_stop (bool debug_events);
 
+  const char *pid_to_exec_file (int);
+
 private:
 
   /* Handle MS_VC_EXCEPTION when processing a stop.  MS_VC_EXCEPTION is
@@ -266,6 +268,18 @@ struct windows_process_info
      presumed loaded.  */
 
   void add_dll (LPVOID load_addr);
+
+  /* Try to determine the executable filename.
+
+     EXE_NAME_RET is a pointer to a buffer whose size is EXE_NAME_MAX_LEN.
+
+     Upon success, the filename is stored inside EXE_NAME_RET, and
+     this function returns nonzero.
+
+     Otherwise, this function returns zero and the contents of
+     EXE_NAME_RET is undefined.  */
+
+  int get_exec_module_filename (char *exe_name_ret, size_t exe_name_max_len);
 };
 
 /* A simple wrapper for ContinueDebugEvent that continues the last
diff --git a/gdb/windows-nat.c b/gdb/windows-nat.c
index cd43409a02f..11f54302b11 100644
--- a/gdb/windows-nat.c
+++ b/gdb/windows-nat.c
@@ -1937,98 +1937,12 @@ windows_nat_target::detach (inferior *inf, int from_tty)
   maybe_unpush_target ();
 }
 
-/* Try to determine the executable filename.
-
-   EXE_NAME_RET is a pointer to a buffer whose size is EXE_NAME_MAX_LEN.
-
-   Upon success, the filename is stored inside EXE_NAME_RET, and
-   this function returns nonzero.
-
-   Otherwise, this function returns zero and the contents of
-   EXE_NAME_RET is undefined.  */
-
-static int
-windows_get_exec_module_filename (char *exe_name_ret, size_t exe_name_max_len)
-{
-  DWORD len;
-  HMODULE dh_buf;
-  DWORD cbNeeded;
-
-  cbNeeded = 0;
-#ifdef __x86_64__
-  if (windows_process.wow64_process)
-    {
-      if (!EnumProcessModulesEx (windows_process.handle,
-				 &dh_buf, sizeof (HMODULE), &cbNeeded,
-				 LIST_MODULES_32BIT)
-	  || !cbNeeded)
-	return 0;
-    }
-  else
-#endif
-    {
-      if (!EnumProcessModules (windows_process.handle,
-			       &dh_buf, sizeof (HMODULE), &cbNeeded)
-	  || !cbNeeded)
-	return 0;
-    }
-
-  /* We know the executable is always first in the list of modules,
-     which we just fetched.  So no need to fetch more.  */
-
-#ifdef __CYGWIN__
-  {
-    /* Cygwin prefers that the path be in /x/y/z format, so extract
-       the filename into a temporary buffer first, and then convert it
-       to POSIX format into the destination buffer.  */
-    cygwin_buf_t *pathbuf = (cygwin_buf_t *) alloca (exe_name_max_len * sizeof (cygwin_buf_t));
-
-    len = GetModuleFileNameEx (current_process_handle,
-			       dh_buf, pathbuf, exe_name_max_len);
-    if (len == 0)
-      error (_("Error getting executable filename: %u."),
-	     (unsigned) GetLastError ());
-    if (cygwin_conv_path (CCP_WIN_W_TO_POSIX, pathbuf, exe_name_ret,
-			  exe_name_max_len) < 0)
-      error (_("Error converting executable filename to POSIX: %d."), errno);
-  }
-#else
-  len = GetModuleFileNameEx (windows_process.handle,
-			     dh_buf, exe_name_ret, exe_name_max_len);
-  if (len == 0)
-    error (_("Error getting executable filename: %u."),
-	   (unsigned) GetLastError ());
-#endif
-
-    return 1;	/* success */
-}
-
 /* The pid_to_exec_file target_ops method for this platform.  */
 
 const char *
 windows_nat_target::pid_to_exec_file (int pid)
 {
-  static char path[__PMAX];
-#ifdef __CYGWIN__
-  /* Try to find exe name as symlink target of /proc/<pid>/exe.  */
-  int nchars;
-  char procexe[sizeof ("/proc/4294967295/exe")];
-
-  xsnprintf (procexe, sizeof (procexe), "/proc/%u/exe", pid);
-  nchars = readlink (procexe, path, sizeof(path));
-  if (nchars > 0 && nchars < sizeof (path))
-    {
-      path[nchars] = '\0';	/* Got it */
-      return path;
-    }
-#endif
-
-  /* If we get here then either Cygwin is hosed, this isn't a Cygwin version
-     of gdb, or we're trying to debug a non-Cygwin windows executable.  */
-  if (!windows_get_exec_module_filename (path, sizeof (path)))
-    path[0] = '\0';
-
-  return path;
+  return windows_process.pid_to_exec_file (pid);
 }
 
 /* Print status information about what we're accessing.  */
diff --git a/gdbserver/win32-low.cc b/gdbserver/win32-low.cc
index 5b91ab768e5..f941e8d2903 100644
--- a/gdbserver/win32-low.cc
+++ b/gdbserver/win32-low.cc
@@ -1515,6 +1515,12 @@ win32_process_target::thread_name (ptid_t thread)
   return th->thread_name ();
 }
 
+const char *
+win32_process_target::pid_to_exec_file (int pid)
+{
+  return windows_process.pid_to_exec_file (pid);
+}
+
 /* 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 c5f40dd8d0a..d16f1f9609c 100644
--- a/gdbserver/win32-low.h
+++ b/gdbserver/win32-low.h
@@ -160,6 +160,11 @@ class win32_process_target : public process_stratum_target
   bool supports_stopped_by_sw_breakpoint () override;
 
   const char *thread_name (ptid_t thread) override;
+
+  bool supports_pid_to_exec_file () override
+  { return true; }
+
+  const char *pid_to_exec_file (int pid) override;
 };
 
 /* The sole Windows process.  */
-- 
2.34.1

Re: [PATCH v2 0/3] Implement pid_to_exec_file for Windows in gdbserver

[Tom Tromey]

>>>>> "Tom" == Tom Tromey via Gdb-patches <gdb-patches@sourceware.org> writes:

Tom> Here's v2 of the series to implement pid_to_exec_file for Windows in
Tom> gdbserver.

Tom> This version adds a patch to remove windows_process_info::id, which
Tom> isn't really needed.

I'm checking these in.

Tom