llvm/llvm-project

modernize-use-digit-separator

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#35,414 opened on Jan 23, 2018

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bugzillacheck-requestclang-tidygood first issue

Description
Bugzilla Link 36066
Version unspecified
OS All

Extended Description

Create a check that looks for long integral constants and inserts the digits separator (') appropriately.

Suggested groupings:

  • decimal integral constants, groups of 3 digits, e.g. int x = 1'000;
  • binary integral constants, groups of 4 digits, e.g. int x = 0b0010'0011;
  • octal integral constants, groups of 3 digits, e.g. int x = 0377'777;
  • hexadecimal integral constants, groups of 4 digits, e.g. unsigned long x = 0xffff'0000;
  • floating-point constnats, group into 3 digits on either side of the decimal point, e.g. float x = 3'456.001'25f;

This check requires C++14.

Provision could be made for supplying a mapping of numeric literal type to number of digits to be grouped.

Contributor guide

Tech stack
cpp
Domain
tooling
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
blocked
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
C++14clang tidy check developmentAST matchers
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60
Research direction
Review existing clang tidy checks in the 'modernize' module under llvm project/clang tools extra/clang tidy/ for patterns. The new check should use AST matchers to identify numeric literals (integer and floating point) and apply digit separators according to the specified groupings. Implementation details can follow the structure of other checks in the same directory, such as modernize use auto. The check must be C++14 aware and allow configurable grouping sizes.
modernize-use-digit-separator · llvm/llvm-project#35414 | Good First Issue