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Fix unintialized pointer warning in Objects/obmalloc.c#15293

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hansrajdas wants to merge 1 commit intopython:masterfrom
hansrajdas:warning-fix
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Fix unintialized pointer warning in Objects/obmalloc.c#15293
hansrajdas wants to merge 1 commit intopython:masterfrom
hansrajdas:warning-fix

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@hansrajdas hansrajdas commented Aug 14, 2019

Steps to reproduce, check compilation logs:

make clean;make

warning-2019-08-15 01-15-06

vstinner
vstinner requested changes Aug 14, 2019
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This change is useless and would have a big negative impact on performances.

If you want initialized memory, use PyObject_Calloc(), not PyObject_Malloc(). PyObject_Malloc() returns uninitialized memory by design.

I understand that the compiler warnings says that ptr value may be initialized. GCC is wrong: it is always initialized. What is your GCC version? What is your OS? Please open a bug report.

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bedevere-bot commented Aug 14, 2019

A Python core developer has requested some changes be made to your pull request before we can consider merging it. If you could please address their requests along with any other requests in other reviews from core developers that would be appreciated.

Once you have made the requested changes, please leave a comment on this pull request containing the phrase I have made the requested changes; please review again. I will then notify any core developers who have left a review that you're ready for them to take another look at this pull request.

@vstinner vstinner closed this Aug 14, 2019
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vstinner commented Aug 14, 2019

If you want the compiler bug to be fixed, please open a bug report. But this change is wrong, so I closed the PR.

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hansrajdas commented Aug 15, 2019

Thanks @vstinner for your valuable inputs. I am using Ubuntu 18.04.2 LTS and GCC version 7.4.0-1ubuntu1~18.04.1. I will open a bug for this compiler warning.

As PyObject_Malloc is designed to return uninitialized memory, we can assign ptr to NULL(void* ptr = NULL) while declaration to fix this warning, will this be a better approach?

@hansrajdas hansrajdas mentioned this pull request Aug 17, 2019
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