format-code

name	format-code
description	Format C/C++ code in BartonCore. Use when the user wants to format source files, understand formatting conventions, or fix formatting issues. Covers clang-format usage, the diff-only rule, manual blank-line conventions that clang-format cannot enforce, and the pre-commit hook.
license	Apache-2.0
compatibility	Requires clang-format (pre-installed in the BartonCore Docker development container).
metadata	{"author":"rdkcentral","version":"1.0"}

Format Code

Running clang-format

Always run from the repository root so it picks up the .clang-format configuration:

clang-format -i <file>

Example:

clang-format -i core/src/deviceService.c

To check formatting without modifying (useful for verification):

clang-format --dry-run --Werror <file>

The Diff-Only Rule

Only format files you have modified. Do not reformat entire files or directories that are not part of your current change. The pre-commit hook enforces formatting on staged files automatically — there is no need to bulk-format.

Manual Blank-Line Conventions

These rules are NOT enforced by clang-format and must be applied manually:

Blank line BEFORE control flow statements

Always place a blank line before if, for, while, switch, and return statements, unless the preceding line is:

• An opening brace {
• Another control flow statement's opening line

int result = compute();

if (result < 0)
{
    handleError();
}

return result;

NOT:

int result = compute();
if (result < 0)  // missing blank line before if
{
    handleError();
}
return result;  // missing blank line before return

Blank line AFTER closing braces

Always place a blank line after a closing brace }, unless it is followed by:

• else
• catch
• Another closing brace }

if (condition)
{
    doSomething();
}
else
{
    doOther();
}

nextStatement();

Pre-Commit Hook

A pre-commit hook at hooks/pre-commit automatically runs clang-format on staged files at commit time. Install hooks with:

./hooks/install.sh

The hook calls hooks/format-hooks/clang-format/git-pre-commit-format which formats only the staged diff (C/C++). JavaScript SBMD drivers are formatted separately by Prettier via lint-staged (see .lintstagedrc.json and .prettierrc.yaml).

Key clang-format Settings

The .clang-format configuration uses:

• Allman brace style (braces on their own line)
• 4-space indentation
• 120-column line width
• SeparateDefinitionBlocks: Always (blank lines between top-level definitions)

C API Exception

Code under api/c/ follows glib/GObject conventions using snake_case for function names, parameters, and variables instead of the camelCase/PascalCase used elsewhere.

Error Recovery

If clang-format is not found:

1. Check if /.dockerenv exists
2. If it does NOT exist, stop and tell the user: "clang-format is not available. Please run inside the BartonCore development container."
3. If it does exist, the tool may need to be installed — check with apt list --installed 2>/dev/null | grep clang-format