Landing: 81a0bec12189

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Project / Subsystem

gcc / fortran

Date

2026-06-05

Author

Jerry DeLisle

Commit

81a0bec12189136350dbb43969743fab8b87a212

Source

github

Perf win

No

Breaking

No

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All attributes

project: gcc
subsystem: fortran
patch_id: —
commit_hash: 81a0bec12189136350dbb43969743fab8b87a212
source_type: github
headline: ALLOCATE of parameterized derived-type array initializes only first element
tldr: A Fortran compiler bug incorrectly initialized only the first element of parameterized derived-type arrays during allocation, leading to crashes due to uniniti…
author: Jerry DeLisle
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • fortran
• compiler-bug
• memory-initialization
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/81a0bec12189136350dbb43969743fab8b87a212
date: 2026-06-05T00:00:00.000Z

When allocating arrays of parameterized derived types in Fortran, only the first element’s allocatable components were being initialized. This was due to an incorrect rank being passed to the initialization routines; expr->rank was 0 for array allocation expressions, even though the symbol itself represented an array. Consequently, access to subsequent elements would result in use of uninitialized pointers and program crashes. The compiler now correctly determines the array rank from the GFC array descriptor, ensuring all elements are properly initialized.