* Re: [PATCH, GDB] Fix Windows gdb build failure with python support
2017-04-06 15:05 ` [PATCH, GDB] Fix Windows gdb build failure with python support Pedro Alves
@ 2017-04-06 16:20 ` Thomas Preudhomme
2017-04-06 16:24 ` Pedro Alves
0 siblings, 1 reply; 3+ messages in thread
From: Thomas Preudhomme @ 2017-04-06 16:20 UTC (permalink / raw)
To: Pedro Alves, gdb-patches
[-- Attachment #1: Type: text/plain, Size: 1728 bytes --]
Thanks Pedro.
Committed the attached patch.
Best regards,
Thomas
On 06/04/17 16:05, Pedro Alves wrote:
> On 04/06/2017 03:28 PM, Thomas Preudhomme wrote:
>>
>>
>> GDB fails to build for Windows host with python support enabled due to
>
> Uppercase "Python", and would be a good idea to mention that this is
> Python 2.
>
>> python_file's second argument
>
> It's actually PyFile_FromString's second parameter, not python_file's.
> "python_file" is a reference that is being initialized from the result
> of PyFile_FromString.
>
>> being of type char * and being passed a
>> string litteral.
>
> Typo "literal".
>
>> This patch takes the conservative assumptions that the
>> function might indeed modify the character string and use a local char
>> array to pass the mode instead.
>
> The Python API is notoriously buggy wrt to const-correctness when
> it comes to string parameters.
>
> Note that in gdb/python/python-internal.h, we have fixups for all of:
>
> PyObject_GetAttrString
> PyObject_HasAttrString
> PyObject_CallMethod
> PyErr_NewException
> PySys_GetObject
> PySys_SetPath
> PyGetSetDef
> PyArg_ParseTupleAndKeywords
>
> Over the years it's been getting better.
>
> A few of those were added just yesterday, but I didn't build Windows
> with Python so I missed this one.
>
> Now, this API in particular seems to have been removed completely
> in Python 3, so there's no "it was fixed in 3.x" that we could put
> in a comment. Anyway, since this is just one single place, let's just
> not bother with anything fancy.
>
> Please just add a cast instead (and update the commit log accordingly):
>
> PyFile_FromString (full_path.get (), (char *) "r")
>
> OK with that change.
>
> Thanks,
> Pedro Alves
>
[-- Attachment #2: 0001-Fix-Windows-gdb-build-failure-with-Python-2-support.patch --]
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From 0dedf3777db42712f460123ac0c63c49de5456f5 Mon Sep 17 00:00:00 2001
From: Thomas Preud'homme <thomas.preudhomme@arm.com>
Date: Thu, 6 Apr 2017 17:17:23 +0100
Subject: [PATCH] Fix Windows gdb build failure with Python 2 support
GDB fails to build for Windows host with Python 2 support enabled due
to PyFile_FromString's second argument being of type char * and being
passed a (const) string literal. This parameter is input only so this
commit fixes the issue by casting to char *.
2017-04-06 Thomas Preud'homme <thomas.preudhomme@arm.com>
gdb/
* python/python.c (python_run_simple_file): Cast mode literal to
non-const char pointer as expected by PyFile_FromString.
---
gdb/ChangeLog | 5 +++++
gdb/python/python.c | 2 +-
2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 880af5b..e906b87 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2017-04-06 Thomas Preud'homme <thomas.preudhomme@arm.com>
+
+ * python/python.c (python_run_simple_file): Cast mode literal to
+ non-const char pointer as expected by PyFile_FromString.
+
2017-04-05 Simon Marchi <simon.marchi@ericsson.com>
* common/ptid.c (ptid_lwp_p, ptid_tid_p): Remove comparison with
diff --git a/gdb/python/python.c b/gdb/python/python.c
index cc58267..e0e24ac 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -352,7 +352,7 @@ python_run_simple_file (FILE *file, const char *filename)
/* Because we have a string for a filename, and are using Python to
open the file, we need to expand any tilde in the path first. */
gdb::unique_xmalloc_ptr<char> full_path (tilde_expand (filename));
- gdbpy_ref<> python_file (PyFile_FromString (full_path.get (), "r"));
+ gdbpy_ref<> python_file (PyFile_FromString (full_path.get (), (char *) "r"));
if (python_file == NULL)
{
gdbpy_print_stack ();
--
1.9.1
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