Agent skill

Gcc

by mohitmishra786 in mohitmishra786/low-level-dev-skills

GCC compiler skill for C/C++ projects. An agent skill from mohitmishra786/low-level-dev-skills.

MITAuto-check passed

Install Gcc

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill gcc -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills gcc --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/compilers/gcc .claude/skills/gcc && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "gcc" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/compilers/gcc into .claude/skills/gcc/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gcc", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/compilers/gcc

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill gcc -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills gcc --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/compilers/gcc .agents/skills/gcc && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "gcc" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/compilers/gcc into .agents/skills/gcc/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gcc", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill gcc -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills gcc --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/compilers/gcc .cursor/skills/gcc && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "gcc" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/compilers/gcc into .cursor/skills/gcc/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gcc", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/mohitmishra786/low-level-dev-skills.git --path skills/compilers/gcc

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill gcc -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills gcc --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/compilers/gcc .gemini/skills/gcc && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "gcc" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/compilers/gcc into .gemini/skills/gcc/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gcc", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills gcc

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill gcc -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/compilers/gcc .github/skills/gcc && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "gcc" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/compilers/gcc into .github/skills/gcc/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gcc", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill gcc -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills gcc --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/compilers/gcc .opencode/skills/gcc && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "gcc" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/compilers/gcc into .opencode/skills/gcc/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "gcc", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: gcc
GitHub stars: 252
Token cost: ~1.4k tokens
SKILL.md length: 505 words
Files: 3 (incl. references)
Skills in repo: 138
Repo updated: Jun 27, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

GCC compiler skill for C/C++ projects. An agent skill from mohitmishra786/low-level-dev-skills.

Works in 9 steps: Choose a build mode → Warning discipline → Debug information → …
Selecting optimization levels
SKILL.md covers Purpose, Triggers, Workflow and Related skills
Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Gcc is an agent skill from mohitmishra786/low-level-dev-skills. GCC compiler skill for C/C++ projects. Use when selecting optimization levels, warning flags, debug builds, LTO, sanitizer instrumentation, or diagnosing compilation errors with GCC. Covers flag selection for debug vs release, ABI concerns, preprocessor macros, profile-guided optimization, and integration with build systems. Activates on queries about gcc flags, compilation errors, performance tuning, warning suppression, or cross-standard compilation.

Its SKILL.md is about 1.4k tokens, which your agent loads only when the skill is triggered. The skill folder holds 3 other files, including reference files (for example `references/examples.md` and `references/flags.md`).

It works with C++. The repository describes itself as: A curated suite of AI agent skills for systems and low-level programming with C/C++, Rust, and Zig toolchains, covering compilers, debuggers, profilers, build systems…. The licence is MIT.

When your agent uses it

Selecting optimization levels
Sanitizer instrumentation
Diagnosing compilation errors with GCC

Example prompts

“/gcc”

Workflow steps

9 steps, taken from the step headings in SKILL.md.

Choose a build mode
Warning discipline
Debug information
Optimisation decision tree
Link-time optimisation (LTO)
Profile-guided optimisation (PGO)
Preprocessor and standards
Common error triage
Useful one-liners

What it can do on your machine

Read from SKILL.md and the folder at commit bdc5847. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md (its code samples are bash and c).
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Gcc loads about 1.4k tokens when it runs, and up to ~3.7k if it reads all its reference files. Until then it costs about 115 tokens; SKILL.md has 505 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~115
When it runs · the whole SKILL.md, loaded when a task matches: ~1.4k
With references · SKILL.md plus every file in references/, read only if the agent opens them: ~3.7k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from mohitmishra786/low-level-dev-skills at commit bdc5847, republished under its MIT licence (© mohitmishra786). 505 words, ~1,431 tokens.

Download SKILL.mdSave it as .claude/skills/gcc/SKILL.md (or your agent's skills folder). This skill also uses 2 other files; get the full folder from GitHub.

name: gcc
description: GCC compiler skill for C/C++ projects. Use when selecting optimization levels, warning flags, debug builds, LTO, sanitizer instrumentation, or diagnosing compilation errors with GCC. Covers flag selection for debug vs release, ABI concerns, preprocessor macros, profile-guided optimization, and integration with build systems. Activates on queries about gcc flags, compilation errors, performance tuning, warning suppression, or cross-standard compilation.

GCC

Purpose

Guide agents through GCC invocation: flag selection, build modes, warning triage, PGO, LTO, and common error patterns. Assume the project uses GNU Make, CMake, or a shell script.

Triggers

"What flags should I use for a release build?"
"GCC is giving me a warning/error I don't understand"
"How do I enable LTO / PGO with GCC?"
"How do I compile with -fsanitize?"
"My binary is too large / too slow"
Undefined reference errors, ABI mismatch, missing symbols

Workflow

1. Choose a build mode

Goal	Recommended flags
Debug	`-g -O0 -Wall -Wextra`
Debug + debuggable optimisation	`-g -Og -Wall -Wextra`
Release	`-O2 -DNDEBUG -Wall`
Release (max perf, native only)	`-O3 -march=native -DNDEBUG`
Release (min size)	`-Os -DNDEBUG`
Sanitizer (dev)	`-g -O1 -fsanitize=address,undefined`

Always pass -std=c11 / -std=c++17 (or the required standard) explicitly. Never rely on the implicit default.

2. Warning discipline

Start with -Wall -Wextra. For stricter standards compliance add -Wpedantic. To treat all warnings as errors in CI: -Werror.

Suppress a specific warning only in a narrow scope:

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-parameter"
// ...
#pragma GCC diagnostic pop

Do not pass -w (silences everything) except as a last resort for third-party headers.

3. Debug information

-g — DWARF debug info, default level 2
-g3 — includes macro definitions (useful with GDB macro expand)
-ggdb — DWARF extensions optimal for GDB
-gsplit-dwarf — splits .dwo files; reduces link time, needed for debuginfod

Pair -g with -Og (not -O0) when you need readable optimised code in GDB.

4. Optimisation decision tree

text

Need max throughput on a fixed machine?
  yes -> -O3 -march=native -flto
  no  -> profiling available?
           yes -> -O2 -fprofile-use
           no  -> -O2
Size-constrained (embedded, shared lib)?
  yes -> -Os  (or -Oz with clang)

-O3 vs -O2: -O3 adds aggressive loop transformations (-funswitch-loops, -fpeel-loops, -floop-interchange) and more aggressive inlining. Use -O3 only after benchmarking; it occasionally regresses due to i-cache pressure.

-Ofast: enables -ffast-math which breaks IEEE 754 semantics (NaN handling, associativity). Avoid unless the numerical domain explicitly permits it.

5. Link-time optimisation (LTO)

bash

# Compile
gcc -O2 -flto -c foo.c -o foo.o
gcc -O2 -flto -c bar.c -o bar.o
# Link (must pass -flto again)
gcc -O2 -flto foo.o bar.o -o prog

Use gcc-ar / gcc-ranlib instead of ar / ranlib when archiving LTO objects into static libs.

For parallel LTO: -flto=auto (uses make-style jobserver) or -flto=N.

See references/flags.md for full flag reference. See skills/binaries/linkers-lto for linker-level LTO configuration.

Show full SKILL.md (187 more words)Show less

6. Profile-guided optimisation (PGO)

bash

# Step 1: instrument
gcc -O2 -fprofile-generate prog.c -o prog_inst
# Step 2: run with representative workload
./prog_inst < workload.input
# Step 3: optimise with profile
gcc -O2 -fprofile-use -fprofile-correction prog.c -o prog

-fprofile-correction handles profile data inconsistencies from multi-threaded runs.

7. Preprocessor and standards

Inspect macro expansion: gcc -E file.c | less
Dump predefined macros: gcc -dM -E - < /dev/null
Force strict standard: -std=c11 -pedantic-errors
Disable GNU extensions: -std=c11 (not -std=gnu11)

8. Common error triage

Symptom	Likely cause	Fix
`undefined reference to 'foo'`	Missing `-lfoo` or wrong link order	Add `-lfoo`; move `-l` flags after object files
`multiple definition of 'x'`	Variable defined (not just declared) in a header	Add `extern` in header, define in one `.c`
`implicit declaration of function`	Missing `#include`	Add the header
`warning: incompatible pointer types`	Wrong cast or missing prototype	Fix the type; check headers
ABI errors with C++	Mixed `-std=` or different `libstdc++`	Unify `-std=` across all TUs
`relocation truncated`	Overflow on a 32-bit relative relocation	Use `-mcmodel=large` or restructure code

For sanitizer reports, use skills/runtimes/sanitizers.

9. Useful one-liners

bash

# Show all flags enabled at -O2
gcc -Q --help=optimizers -O2 | grep enabled

# Preprocess only (check includes/macros)
gcc -E -dD src.c -o src.i

# Assembly output (Intel syntax)
gcc -S -masm=intel -O2 foo.c -o foo.s

# Show include search path
gcc -v -E - < /dev/null 2>&1 | grep -A20 '#include <...>'

# Check if a flag is supported
gcc -Q --help=target | grep march

For a complete flag cheatsheet, see references/flags.md. For common error patterns and examples, see references/examples.md.

Use skills/runtimes/sanitizers to add -fsanitize=* builds
Use skills/compilers/clang when switching to clang/LLVM
Use skills/binaries/linkers-lto for advanced LTO linker flags
Use skills/debuggers/gdb for debugging GCC-built binaries

Files

SKILL.md and 2 other files (references) in skills/compilers/gcc of mohitmishra786/low-level-dev-skills.

SKILL.md
references/examples.md
references/flags.md

Open the folder on GitHubat commit bdc5847

Compare with similar skills

Gcc next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Gcc compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Gcc this skillmohitmishra786/low-level-dev-skills	252	—	~1.4k	Automated safety check: Pass	MIT	3 mo ago
Paddle BuildPaddlePaddle/Paddle	24k	—	~1k	Automated safety check: Pass	Apache-2.0	today
Fory Releaseapache/fory	4.6k	—	~2.9k	Automated safety check: Pass	Apache-2.0	today
ONNX Runtime Shape Inference Safety Auditmicrosoft/onnxruntime	22k	—	~3.3k	Automated safety check: Pass	MIT	today
Code Audit3stoneBrother/code-audit	892	1 repos	~2.7k	Automated safety check: Pass	None	7 mo ago
Qt C++ Code Reviewx-tools-author/x-tools	1.1k	2 repos	~4.3k	Automated safety check: Pass	BSD-3-Clause	today

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Questions about Gcc

What does Gcc do?

GCC compiler skill for C/C++ projects. An agent skill from mohitmishra786/low-level-dev-skills. Gcc is an agent skill from mohitmishra786/low-level-dev-skills. GCC compiler skill for C/C++ projects.

When should I use Gcc?

Gcc fits situations like: selecting optimization levels; sanitizer instrumentation; diagnosing compilation errors with GCC.

How do I install Gcc in Claude Code?

Run `npx skills add mohitmishra786/low-level-dev-skills --skill gcc -a claude-code`. Or copy the skill folder (skills/compilers/gcc in mohitmishra786/low-level-dev-skills) into .claude/skills/gcc in your project. Claude Code loads it when a task matches its description.

How do I install Gcc in Codex?

Run `npx skills add mohitmishra786/low-level-dev-skills --skill gcc -a codex`. Or copy the skill folder (skills/compilers/gcc in mohitmishra786/low-level-dev-skills) into .agents/skills/gcc in your project. Codex loads it when a task matches its description.

Can I use Gcc in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add mohitmishra786/low-level-dev-skills --skill gcc -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/gcc, .gemini/skills/gcc, .github/skills/gcc and .opencode/skills/gcc in your project.

What does Gcc need to run?

SKILL.md names no scripts, command-line tools or credentials: Gcc is instructions for the agent only.

Does Gcc access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Gcc safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Gcc use?

Gcc is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Gcc use?

About 1.4k tokens (SKILL.md is roughly 5.7k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 2.3k tokens, read only when the agent opens those files.

What are the alternatives to Gcc?

Skills that share tags, products or a category with Gcc: Paddle Build (PaddlePaddle/Paddle, 24k stars), Fory Release (apache/fory, 4.6k stars), ONNX Runtime Shape Inference Safety Audit (microsoft/onnxruntime, 22k stars) and Code Audit (3stoneBrother/code-audit, 892 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Gcc?

mohitmishra786 (a GitHub user) maintains it in mohitmishra786/low-level-dev-skills, which has 252 GitHub stars. The repository holds 138 skills in this directory. The repository was last updated on June 27, 2026.

Source: mohitmishra786/low-level-dev-skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Gcc

Facts

At a glance

What it does

When your agent uses it

Example prompts

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

GCC

Purpose

Triggers

Workflow

1. Choose a build mode

2. Warning discipline

3. Debug information

4. Optimisation decision tree

5. Link-time optimisation (LTO)

6. Profile-guided optimisation (PGO)

7. Preprocessor and standards

8. Common error triage

9. Useful one-liners

Related skills

Files

Compare with similar skills

Similar skills

More from mohitmishra786/low-level-dev-skills

Related

Questions about Gcc