[PATCH v3 15/29] Share get_image_name between gdb and gdbserver

Tom Tromey
2020-03-13T19:09:02Z

This moves get_image_name to nat/windows-nat.c so that it can be
shared between gdb and gdbserver.

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

* windows-nat.c (get_image_name): Move to nat/windows-nat.c.
(handle_load_dll): Update.
* nat/windows-nat.c (get_image_name): Move from windows-nat.c.

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

* win32-low.c (get_image_name): Remove.
(handle_load_dll): Update.
---
gdb/ChangeLog | 6 +++++
gdb/nat/windows-nat.c | 57 ++++++++++++++++++++++++++++++++++++++++++
gdb/nat/windows-nat.h | 7 ++++++
gdb/windows-nat.c | 52 +-------------------------------------
gdbserver/ChangeLog | 5 ++++
gdbserver/win32-low.cc | 51 +------------------------------------
6 files changed, 77 insertions(+), 101 deletions(-)

diff --git a/gdb/nat/windows-nat.c b/gdb/nat/windows-nat.c
index 6c0218cd9d8..8217a985320 100644
--- a/gdb/nat/windows-nat.c
+++ b/gdb/nat/windows-nat.c
@@ -69,4 +69,61 @@ windows_thread_info::resume ()
suspended = 0;
}

+const char *
+get_image_name (HANDLE h, void *address, int unicode)
+{
+#ifdef __CYGWIN__
+ static char buf[MAX_PATH];
+#else
+ static char buf[(2 * MAX_PATH) + 1];
+#endif
+ DWORD size = unicode ? sizeof (WCHAR) : sizeof (char);
+ char *address_ptr;
+ int len = 0;
+ char b[2];
+ SIZE_T done;
+
+ /* Attempt to read the name of the dll that was detected.
+ This is documented to work only when actively debugging
+ a program. It will not work for attached processes. */
+ if (address == NULL)
+ return NULL;
+
+#ifdef _WIN32_WCE
+ /* Windows CE reports the address of the image name,
+ instead of an address of a pointer into the image name. */
+ address_ptr = address;
+#else
+ /* See if we could read the address of a string, and that the
+ address isn't null. */
+ if (!ReadProcessMemory (h, address, &address_ptr,
+ sizeof (address_ptr), &done)
+ || done != sizeof (address_ptr)
+ || !address_ptr)
+ return NULL;
+#endif
+
+ /* Find the length of the string. */
+ while (ReadProcessMemory (h, address_ptr + len++ * size, &b, size, &done)
+ && (b[0] != 0 || b[size - 1] != 0) && done == size)
+ continue;
+
+ if (!unicode)
+ ReadProcessMemory (h, address_ptr, buf, len, &done);
+ else
+ {
+ WCHAR *unicode_address = (WCHAR *) alloca (len * sizeof (WCHAR));
+ ReadProcessMemory (h, address_ptr, unicode_address, len * sizeof (WCHAR),
+ &done);
+#ifdef __CYGWIN__
+ wcstombs (buf, unicode_address, MAX_PATH);
+#else
+ WideCharToMultiByte (CP_ACP, 0, unicode_address, len, buf, sizeof buf,
+ 0, 0);
+#endif
+ }
+
+ return buf;
+}
+
}
diff --git a/gdb/nat/windows-nat.h b/gdb/nat/windows-nat.h
index e63ef753c92..4176ed7f660 100644
--- a/gdb/nat/windows-nat.h
+++ b/gdb/nat/windows-nat.h
@@ -111,6 +111,13 @@ enum thread_disposition_type
extern windows_thread_info *thread_rec (ptid_t ptid,
thread_disposition_type disposition);

+/* 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
+ is stored in a static buffer which is valid until the next call to
+ get_image_name. */
+extern const char *get_image_name (HANDLE h, void *address, int unicode);
+
}

#endif
diff --git a/gdb/windows-nat.c b/gdb/windows-nat.c
index 1192b9abac4..c0b1b8521db 100644
--- a/gdb/windows-nat.c
+++ b/gdb/windows-nat.c
@@ -921,56 +921,6 @@ windows_make_so (const char *name, LPVOID load_addr)
return so;
}

-static char *
-get_image_name (HANDLE h, void *address, int unicode)
-{
-#ifdef __CYGWIN__
- static char buf[__PMAX];
-#else
- static char buf[(2 * __PMAX) + 1];
-#endif
- DWORD size = unicode ? sizeof (WCHAR) : sizeof (char);
- char *address_ptr;
- int len = 0;
- char b[2];
- SIZE_T done;
-
- /* Attempt to read the name of the dll that was detected.
- This is documented to work only when actively debugging
- a program. It will not work for attached processes. */
- if (address == NULL)
- return NULL;
-
- /* See if we could read the address of a string, and that the
- address isn't null. */
- if (!ReadProcessMemory (h, address, &address_ptr,
- sizeof (address_ptr), &done)
- || done != sizeof (address_ptr) || !address_ptr)
- return NULL;
-
- /* Find the length of the string. */
- while (ReadProcessMemory (h, address_ptr + len++ * size, &b, size, &done)
- && (b[0] != 0 || b[size - 1] != 0) && done == size)
- continue;
-
- if (!unicode)
- ReadProcessMemory (h, address_ptr, buf, len, &done);
- else
- {
- WCHAR *unicode_address = (WCHAR *) alloca (len * sizeof (WCHAR));
- ReadProcessMemory (h, address_ptr, unicode_address, len * sizeof (WCHAR),
- &done);
-#ifdef __CYGWIN__
- wcstombs (buf, unicode_address, __PMAX);
-#else
- WideCharToMultiByte (CP_ACP, 0, unicode_address, len, buf, sizeof buf,
- 0, 0);
-#endif
- }
-
- return buf;
-}
-
/* Handle a DLL load event, and return 1.

This function assumes that this event did not occur during inferior
@@ -982,7 +932,7 @@ static void
handle_load_dll ()
{
LOAD_DLL_DEBUG_INFO *event = &current_event.u.LoadDll;
- char *dll_name;
+ const char *dll_name;

/* Try getting the DLL name via the lpImageName field of the event.
Note that Microsoft documents this fields as strictly optional,
diff --git a/gdbserver/win32-low.cc b/gdbserver/win32-low.cc
index 1e86b3b5926..810896e87ca 100644
--- a/gdbserver/win32-low.cc
+++ b/gdbserver/win32-low.cc
@@ -1031,55 +1031,6 @@ win32_add_one_solib (const char *name, CORE_ADDR load_addr)
loaded_dll (buf2, load_addr);
}

-static char *
-get_image_name (HANDLE h, void *address, int unicode)
-{
- static char buf[(2 * MAX_PATH) + 1];
- DWORD size = unicode ? sizeof (WCHAR) : sizeof (char);
- char *address_ptr;
- int len = 0;
- char b[2];
- SIZE_T done;
-
- /* Attempt to read the name of the dll that was detected.
- This is documented to work only when actively debugging
- a program. It will not work for attached processes. */
- if (address == NULL)
- return NULL;
-
-#ifdef _WIN32_WCE
- /* Windows CE reports the address of the image name,
- instead of an address of a pointer into the image name. */
- address_ptr = address;
-#else
- /* See if we could read the address of a string, and that the
- address isn't null. */
- if (!ReadProcessMemory (h, address, &address_ptr,
- sizeof (address_ptr), &done)
- || done != sizeof (address_ptr)
- || !address_ptr)
- return NULL;
-#endif
-
- /* Find the length of the string */
- while (ReadProcessMemory (h, address_ptr + len++ * size, &b, size, &done)
- && (b[0] != 0 || b[size - 1] != 0) && done == size)
- continue;
-
- if (!unicode)
- ReadProcessMemory (h, address_ptr, buf, len, &done);
- else
- {
- WCHAR *unicode_address = XALLOCAVEC (WCHAR, len);
- ReadProcessMemory (h, address_ptr, unicode_address, len * sizeof (WCHAR),
- &done);
-
- WideCharToMultiByte (CP_ACP, 0, unicode_address, len, buf, len, 0, 0);
- }
-
- return buf;
-}
-
typedef BOOL (WINAPI *winapi_EnumProcessModules) (HANDLE, HMODULE *,
DWORD, LPDWORD);
typedef BOOL (WINAPI *winapi_GetModuleInformation) (HANDLE, HMODULE,
@@ -1188,7 +1139,7 @@ static void
handle_load_dll (void)
{
LOAD_DLL_DEBUG_INFO *event = &current_event.u.LoadDll;
- char *dll_name;
+ const char *dll_name;

dll_name = get_image_name (current_process_handle,
event->lpImageName, event->fUnicode);
--
2.21.1