Re: [PATCH 1/3] Detect GDB is in cygwin

Yao Qi
2013-08-01T07:52:14Z

On 07/30/2013 11:33 PM, Eli Zaretskii wrote:
> There's no need to probe that at configure time: this code can always
> be compiled on any MS-Windows system. The compiler doesn't care and
> doesn't check at compile time whether there is in fact
> NtQueryInformationFile function inside the DLL.

OK. If so, in configure.ac, we only need to check headers, and don't need
AC_TRY_COMPILE at all. Here is the updated one, with several changes,

- Remove AC_TRY_COMPILE,
- Include fewer headers in mingw-htep.c, and don't have to check them
in configure.ac.
- Rename is_in_cygwin to using_cygwin_pty,

--
Yao (é½å°§)

gdb:

2013-08-01 Yao Qi <yao@codesourcery.com>
Corinna Vinschen <vinschen@redhat.com>

* configure.ac: Invoke AC_CHECK_HEADERS to check winternl.h,
and ddk/ntddk.h.
* config.in: Re-generated.
* configure: Re-generated.
* defs.h [__MINGW32__] (using_cygwin_pty): Declare.
* mingw-hdep.c: Inlcude wchar.h.
[HAVE_WINTERNL_H]: Include winternl.h. Define
USE_NTQUERYINFORMATIONFILE.
[!HAVE_WINTERNL_H] [HAVE_DDK_NTDDK_H]: Include ddk/ntddk.h.
Define USE_NTQUERYINFORMATIONFILE..
[USE_NTQUERYINFORMATIONFILE] (get_filename_from_handle): New.
(using_cygwin_pty): New.
---
gdb/config.in | 6 ++++
gdb/configure | 30 ++++++++++++++++++
gdb/configure.ac | 7 ++++
gdb/defs.h | 4 ++
gdb/mingw-hdep.c | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 135 insertions(+), 0 deletions(-)

diff --git a/gdb/config.in b/gdb/config.in
index 92c2789..010146c 100644
--- a/gdb/config.in
+++ b/gdb/config.in
@@ -84,6 +84,9 @@
/* Define to 1 if you have the <curses.h> header file. */
#undef HAVE_CURSES_H

+/* Define to 1 if you have the <ddk/ntddk.h> header file. */
+#undef HAVE_DDK_NTDDK_H
+
/* Define to 1 if you have the declaration of `ADDR_NO_RANDOMIZE', and to 0 if
you don't. */
#undef HAVE_DECL_ADDR_NO_RANDOMIZE
@@ -572,6 +575,9 @@
/* Define to 1 if you have the `wborder' function. */
#undef HAVE_WBORDER

+/* Define to 1 if you have the <winternl.h> header file. */
+#undef HAVE_WINTERNL_H
+
/* Define to 1 if `fork' works. */
#undef HAVE_WORKING_FORK

diff --git a/gdb/configure b/gdb/configure
index 4833297..ecfa203 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -9030,6 +9030,36 @@ fi
done

+# Check header winternl.h, if not found, check ddk/ntddk.h.
+case "${host}" in
+ *-*-mingw*) for ac_header in winternl.h
+do :
+ ac_fn_c_check_header_mongrel "$LINENO" "winternl.h" "ac_cv_header_winternl_h" "$ac_includes_default"
+if test "x$ac_cv_header_winternl_h" = x""yes; then :
+ cat >>confdefs.h <<_ACEOF
+#define HAVE_WINTERNL_H 1
+_ACEOF
+
+else
+ for ac_header in ddk/ntddk.h
+do :
+ ac_fn_c_check_header_mongrel "$LINENO" "ddk/ntddk.h" "ac_cv_header_ddk_ntddk_h" "$ac_includes_default"
+if test "x$ac_cv_header_ddk_ntddk_h" = x""yes; then :
+ cat >>confdefs.h <<_ACEOF
+#define HAVE_DDK_NTDDK_H 1
+_ACEOF
+
+fi
+
+done
+
+fi
+
+done
+
+ ;;
+esac
+
# ------------------------- #
# Checks for declarations. #
# ------------------------- #
diff --git a/gdb/configure.ac b/gdb/configure.ac
index 48f37c8..c3df68e 100644
--- a/gdb/configure.ac
+++ b/gdb/configure.ac
@@ -1121,6 +1121,13 @@ AC_CHECK_HEADERS(term.h, [], [],
#endif
])

+# Check header winternl.h, if not found, check ddk/ntddk.h.
+case "${host}" in
+ *-*-mingw*) AC_CHECK_HEADERS(winternl.h, [],
+ [AC_CHECK_HEADERS(ddk/ntddk.h, [], [],[])], [])
+ ;;
+esac
+
# ------------------------- #
# Checks for declarations. #
# ------------------------- #
diff --git a/gdb/defs.h b/gdb/defs.h
index 014d7d4..71c1c30 100644
--- a/gdb/defs.h
+++ b/gdb/defs.h
@@ -790,6 +790,10 @@ enum block_enum
FIRST_LOCAL_BLOCK = 2
};

+#ifdef __MINGW32__
+int using_cygwin_pty (void);
+#endif
+
#include "utils.h"

#endif /* #ifndef DEFS_H */
diff --git a/gdb/mingw-hdep.c b/gdb/mingw-hdep.c
index efc9848..0ca15ee 100644
--- a/gdb/mingw-hdep.c
+++ b/gdb/mingw-hdep.c
@@ -28,6 +28,19 @@
#include "readline/readline.h"

#include <windows.h>
+#include <wchar.h>
+
+#ifdef HAVE_WINTERNL_H
+#include <winternl.h>
+#define USE_NTQUERYINFORMATIONFILE 1
+#else
+
+#ifdef HAVE_DDK_NTDDK_H
+#include <ddk/ntddk.h>
+#define USE_NTQUERYINFORMATIONFILE 1
+#endif /*HAVE_DDK_NTDDK_H */
+
+#endif /* HAVE_WINTERNL_H */

/* This event is signalled whenever an asynchronous SIGINT handler
needs to perform an action in the main thread. */
@@ -265,6 +278,81 @@ gdb_call_async_signal_handler (struct async_signal_handler *handler,
SetEvent (sigint_event);
}

+#ifdef USE_NTQUERYINFORMATIONFILE
+
+/* Return the file name of handle FH. */
+
+static PWCHAR
+get_filename_from_handle (HANDLE fh)
+{
+ IO_STATUS_BLOCK io;
+ NTSTATUS status;
+ long buf[66]; /* NAME_MAX + 1 + sizeof ULONG */
+ PFILE_NAME_INFORMATION pfni = (PFILE_NAME_INFORMATION) buf;
+ static NTSTATUS (NTAPI *pNtQueryInformationFile) (HANDLE,
+ PIO_STATUS_BLOCK,
+ PVOID, ULONG,
+ FILE_INFORMATION_CLASS);
+
+ /* Calling the native NT function NtQueryInformationFile is required to
+ support pre-Vista systems. If that's of no concern, Vista introduced
+ the GetFileInformationByHandleEx call with the FileNameInfo info class,
+ which can be used instead. */
+ if (!pNtQueryInformationFile)
+ {
+ pNtQueryInformationFile = (NTSTATUS (NTAPI *)(HANDLE, PIO_STATUS_BLOCK,
+ PVOID, ULONG, FILE_INFORMATION_CLASS))
+ GetProcAddress (GetModuleHandle ("ntdll.dll"),
+ "NtQueryInformationFile");
+ if (pNtQueryInformationFile == NULL)
+ return NULL;
+ }
+ if (!NT_SUCCESS (pNtQueryInformationFile (fh, &io, pfni, sizeof buf,
+ FileNameInformation)))
+ return NULL;
+
+ /* The filename is not guaranteed to be NUL-terminated. */
+ pfni->FileName[pfni->FileNameLength / sizeof (WCHAR)] = L'\0';
+
+ return pfni->FileName;
+}
+
+#endif /* USE_NTQUERYINFORMATIONFILE */
+
+/* Return true if GDB is running in Cygwin pseudo-tty. */
+
+int
+using_cygwin_pty (void)
+{
+ PWCHAR cp;
+ /* Now fetch the underlying HANDLE of stdin. */
+ HANDLE fh = (HANDLE) _get_osfhandle (fileno (stdin));
+
+ if (!fh || fh == INVALID_HANDLE_VALUE)
+ return 0;
+
+#ifdef USE_NTQUERYINFORMATIONFILE
+ cp = get_filename_from_handle (fh);
+#else
+ cp = NULL;
+#endif
+
+ /* Now check the name pattern. With pseudo-tty allocated in ssh,
+ the filename of handle of stdin looks like this:
+
+ \cygwin-c5e39b7a9d22bafb-{p,t}ty1-from-master
+
+ Without pseudo-tty allocated in ssh, the filename of handle of
+ stdin looks like this:
+
+ \cygwin-c5e39b7a9d22bafb-pipe-0x14C8-0x3
+
+ If the file name is prefixed with "\cygwin-", GDB is running in
+ cygwin. */
+
+ return (cp != NULL && wcsncmp (cp, L"\\cygwin-", 8) == 0);
+}
+
/* -Wmissing-prototypes */
extern initialize_file_ftype _initialize_mingw_hdep;

--
1.7.7.6