Landing: 6e2ffc51ae89

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Project / Subsystem

gcc / gcc/c++

Date

2026-06-08

Author

Zhou Qiankang

Commit

6e2ffc51ae89f88292dc9b7256e9fba8db199499

Source

github

Perf win

Breaking

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All attributes

project: gcc
subsystem: gcc/c++
patch_id: —
commit_hash: 6e2ffc51ae89f88292dc9b7256e9fba8db199499
source_type: github
headline: C++ no longer defines __FRACT_FBIT__
tldr: GCC's C++ front end no longer predefines the __FRACT_FBIT__ macro, fixing a bug where it was incorrectly available in C++ code.
author: Zhou Qiankang
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • c++
• preprocessor
• bugfix
discussion_id_link: github:gcc-mirror/gcc#125642
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/6e2ffc51ae89f88292dc9b7256e9fba8db199499
date: 2026-06-08T00:00:00.000Z

The GCC C++ front end previously defined the FRACT_FBIT macro, which is specific to the C standard. This change removes the definition of this macro in C++ contexts, aligning GCC’s behavior with the C++ standard and preventing potential issues when using the macro in C++ code. A new test case verifies this corrected behavior.