makefile-generator

name	makefile-generator
description	Create, generate, or scaffold Makefiles with .PHONY targets and build automation.

Makefile Generator

Overview

Generate production-ready Makefiles with best practices for C/C++, Python, Go, Java, and generic projects. Features GNU Coding Standards compliance, standard targets, security hardening, and automatic validation via devops-skills:makefile-validator skill.

When to Use

• Creating new Makefiles from scratch
• Setting up build systems for projects (C/C++, Python, Go, Java)
• Implementing build automation and CI/CD integration
• Converting manual build processes to Makefiles
• The user asks to "create", "generate", or "write" a Makefile

Do NOT use for: Validating existing Makefiles (use devops-skills:makefile-validator), debugging (use make -d), or running builds.

Trigger Phrases

Use this skill when prompts look like:

• "Generate a Makefile for a Go service"
• "Create a production Makefile with install/test/help targets"
• "Write a Makefile for a C project with dependency tracking"
• "Add standard GNU targets to this existing Makefile"

Generation Workflow

Stage 1: Gather Requirements

Collect information for the following categories. Use AskUserQuestion when information is missing or ambiguous:

Category	Information Needed
Project	Language (C/C++/Python/Go/Java), structure (single/multi-directory)
Build	Source files, output artifacts, dependencies, build order
Install	PREFIX location, directories (bin/lib/share), files to install
Targets	all, install, clean, test, dist, help (which are needed?)
Config	Compiler, flags, pkg-config dependencies, cross-compilation

When to Use AskUserQuestion (MUST ask if any apply):

Condition	Example Question
Language not specified	"What programming language is this project? (C/C++/Go/Python/Java)"
Project structure unclear	"Is this a single-directory or multi-directory project?"
Docker requested but registry unknown	"Which container registry should be used? (docker.io/ghcr.io/custom)"
Multiple binaries possible	"Should this build a single binary or multiple executables?"
Install targets needed but paths unclear	"Where should binaries be installed? (default: /usr/local/bin)"
Cross-compilation mentioned	"What is the target platform/architecture?"

When to Skip AskUserQuestion (proceed with defaults):

• User explicitly provides all required information
• Standard project type with obvious defaults (e.g., "Go project with Docker" → use standard Go+Docker patterns)
• User says "use defaults" or "standard setup"

Default Assumptions (when not asking):

• Single-directory project structure
• PREFIX=/usr/local
• Standard targets: all, build, test, clean, install, help
• No cross-compilation

Stage 2: Documentation Lookup

When REQUIRED (MUST perform lookup):

• User requests integration with unfamiliar tools, frameworks, or build systems
• Complex build patterns not covered in Stage 3 examples (e.g., Bazel, Meson, custom toolchains)
• Docker/container integration (Dockerfile builds, multi-stage, registry push)
• CI/CD platform-specific integration (GitHub Actions, GitLab CI, Jenkins)
• Cross-compilation for unusual targets or embedded systems
• Package manager integration (Conan, vcpkg, Homebrew formulas)
• Multi-binary or multi-library projects
• Version embedding via ldflags or build-time variables

When OPTIONAL (may skip external lookup):

• Standard language patterns already covered in Stage 3 (C/C++, Go, Python, Java)
• Simple single-binary projects with no external dependencies
• User provides complete requirements with no ambiguity
• Internal docs already cover the required pattern comprehensively

Lookup Process (follow in order):

1. ALWAYS consult internal docs first using explicit file-open commands (primary source of truth):

   Full doc path map (prefer full paths for deterministic access):

   Doc	Full Path
   Structure guide	devops-skills-plugin/skills/makefile-generator/docs/makefile-structure.md
   Variables guide	devops-skills-plugin/skills/makefile-generator/docs/variables-guide.md
   Targets guide	devops-skills-plugin/skills/makefile-generator/docs/targets-guide.md
   Patterns guide	devops-skills-plugin/skills/makefile-generator/docs/patterns-guide.md
   Optimization guide	devops-skills-plugin/skills/makefile-generator/docs/optimization-guide.md
   Security guide	devops-skills-plugin/skills/makefile-generator/docs/security-guide.md

   Requirement	Read This Doc
   Docker/container targets	.../docs/patterns-guide.md (Pattern 8: Docker Integration)
   Multi-binary projects	.../docs/patterns-guide.md (Pattern 7: Multi-Binary Project)
   Go projects with version embedding	.../docs/patterns-guide.md (Pattern 5: Go Project)
   Parallel builds, caching, ccache	.../docs/optimization-guide.md
   Credentials, secrets, API keys	.../docs/security-guide.md
   Complex dependencies, pattern rules	.../docs/patterns-guide.md
   Order-only prerequisites	.../docs/optimization-guide.md or .../docs/targets-guide.md
   Variables, assignment operators	.../docs/variables-guide.md

   Deterministic open/read commands:

   # From repository root:
   sed -n '1,220p' devops-skills-plugin/skills/makefile-generator/docs/patterns-guide.md
   rg -n "Pattern 5|Pattern 8" devops-skills-plugin/skills/makefile-generator/docs/patterns-guide.md
   
   # From skill directory:
   sed -n '1,220p' docs/security-guide.md
   

   If shell commands are unavailable, use the environment's file-open/read capability on the same paths.

   Required Workflow Example (Docker + Go with version embedding):

   # Step 1: Read Go pattern
   rg -n "Pattern 5" devops-skills-plugin/skills/makefile-generator/docs/patterns-guide.md
   
   # Step 2: Read Docker pattern
   rg -n "Pattern 8" devops-skills-plugin/skills/makefile-generator/docs/patterns-guide.md
   
   # Step 3: Read security guidance
   sed -n '1,220p' devops-skills-plugin/skills/makefile-generator/docs/security-guide.md
   

   Then generate Makefile and list consulted docs in a header comment.

2. Try context7 for external tool documentation (when internal docs don't cover a specific tool):

   # Only needed for tools/frameworks NOT covered in internal docs
   mcp__context7__resolve-library-id: "<tool-name>"
   mcp__context7__query-docs: query="<integration-topic>"
   
   # Example queries:
   # - For Docker: query="dockerfile best practices"
   # - For Go: query="go build ldflags"
   # - For specific tools: query="<tool> makefile integration"
   

   Fallback: If context7 is unavailable or returns nothing useful, record that and continue to Step 3.

3. Fallback to WebSearch (only if pattern not found in internal docs OR context7):

   "<specific-feature>" makefile best practices 2025
   Example: "docker makefile best practices 2025"
   Example: "go ldflags version makefile 2025"
   

   Trigger WebSearch when: Internal docs don't cover the specific integration AND context7 returns no relevant results.

Note: Document which internal docs you consulted in your response (add comment in generated Makefile header).

Stage 3: Generate Makefile

Optional helper-script fast path (for standard layouts):

# Generate template: TYPE NAME OUTPUT
bash scripts/generate_makefile_template.sh go myservice Makefile

# Add only selected standard targets
bash scripts/add_standard_targets.sh Makefile install clean help

Use manual authoring when requirements are complex (Docker release flow, multi-binary matrices, custom toolchains).

Header (choose one style)

Traditional (POSIX-compatible):

.DELETE_ON_ERROR:
.SUFFIXES:

Modern (GNU Make 4.0+, recommended):

SHELL := bash
.ONESHELL:
.SHELLFLAGS := -eu -o pipefail -c
.DELETE_ON_ERROR:
.SUFFIXES:
MAKEFLAGS += --warn-undefined-variables
MAKEFLAGS += --no-builtin-rules

Standard Variables

# User-overridable (use ?=)
CC ?= gcc
CFLAGS ?= -Wall -Wextra -O2
PREFIX ?= /usr/local
DESTDIR ?=

# GNU installation directories
BINDIR ?= $(PREFIX)/bin
LIBDIR ?= $(PREFIX)/lib
INCLUDEDIR ?= $(PREFIX)/include

# Project-specific (use :=)
PROJECT := myproject
VERSION := 1.0.0
SRCDIR := src
BUILDDIR := build
SOURCES := $(wildcard $(SRCDIR)/*.c)
OBJECTS := $(SOURCES:$(SRCDIR)/%.c=$(BUILDDIR)/%.o)

Language-Specific Build Rules

C/C++:

$(TARGET): $(OBJECTS)
	$(CC) $(LDFLAGS) $^ $(LDLIBS) -o $@

$(BUILDDIR)/%.o: $(SRCDIR)/%.c
	@mkdir -p $(@D)
	$(CC) $(CPPFLAGS) $(CFLAGS) -MMD -MP -c $< -o $@

-include $(OBJECTS:.o=.d)

Go:

$(TARGET): $(shell find . -name '*.go') go.mod
	go build -o $@ ./cmd/$(PROJECT)

Python:

.PHONY: build
build:
	python -m build

.PHONY: develop
develop:
	pip install -e .[dev]

Java:

$(BUILDDIR)/%.class: $(SRCDIR)/%.java
	@mkdir -p $(@D)
	javac -d $(BUILDDIR) -sourcepath $(SRCDIR) $<

Standard Targets

.PHONY: all clean install uninstall test help

## Build all targets
all: $(TARGET)

## Install to PREFIX
install: all
	install -d $(DESTDIR)$(BINDIR)
	install -m 755 $(TARGET) $(DESTDIR)$(BINDIR)/

## Remove built files
clean:
	$(RM) -r $(BUILDDIR) $(TARGET)

## Run tests
test:
	# Add test commands

## Show help
help:
	@echo "$(PROJECT) v$(VERSION)"
	@echo "Targets: all, install, clean, test, help"
	@echo "Override: make CC=clang PREFIX=/opt"

Stage 4: Validate and Format

Validation is required for every generated Makefile.

Validation Tool Preflight (default + fallback)

1. Preferred path: run devops-skills:makefile-validator.
2. If validator skill is unavailable: run local fallback checks:

   # Required fallback check (if make exists)
   make -f <Makefile> -n --dry-run
   
   # Structural fallback checks
   rg -n '^ {1,}\S' <Makefile>         # suspicious space-indented recipe lines
   rg -n '^\.PHONY:' <Makefile>
   

3. If make is unavailable: run structural checks only, report "partial validation due to missing make binary", and request user confirmation before claiming production readiness.

Required Validation Loop

1. Generate Makefile following stages above
2. Run validator skill (or fallback checks if unavailable)
3. Fix all errors (MUST have 0 errors before completion)
4. Apply formatting fixes (see "Formatting Step" below)
5. Fix warnings when feasible (SHOULD fix; explain if skipped)
6. Address info items for large/production projects
7. Re-run validation until checks pass
8. Output structured validation report (REQUIRED - see format below)

Formatting Step (REQUIRED)

When mbake reports formatting issues, you MUST either:

1. Auto-apply formatting (preferred for minor issues):

   mbake format <Makefile>
   

2. Explain why not applied (if formatting would break functionality):

   Formatting not applied because:
   - [specific reason, e.g., "heredoc syntax would be corrupted"]
   - Manual review recommended for: [specific lines]
   

If mbake is not installed or not executable, skip formatter execution and record: Formatting skipped: mbake unavailable in current environment.

Formatting Decision Guide:

mbake Report	Action
"Would reformat" with no specific issues	Auto-apply with mbake format
Specific whitespace/indentation issues	Auto-apply with mbake format
Issues in complex heredocs or multi-line strings	Skip formatting, explain in output
Issues in # bake-format off sections	Skip (intentionally disabled)
mbake command unavailable	Skip formatting, record tool-unavailable reason

Validation Pass Criteria:

Level	Requirement	Action
Errors (0 required)	Syntax errors, missing tabs, invalid targets	MUST fix before completion
Warnings (fix if feasible)	Formatting issues, missing optimizations	SHOULD fix; explain if skipped
Info (address for production)	Enhancement suggestions, style preferences	SHOULD address for production Makefiles

Known mbake False Positives (can be safely ignored):

The mbake validator may report warnings for valid GNU Make special targets. These are false positives and can be ignored:

mbake Warning	Actual Status	Explanation
"Unknown special target '.DELETE_ON_ERROR'"	✅ Valid	Critical GNU Make target that deletes failed build artifacts
"Unknown special target '.SUFFIXES'"	✅ Valid	Standard GNU Make target for disabling/setting suffix rules
"Unknown special target '.ONESHELL'"	✅ Valid	GNU Make 3.82+ feature for single-shell recipe execution
"Unknown special target '.POSIX'"	✅ Valid	POSIX compliance declaration

Validation Report Output (REQUIRED)

After validation completes, you MUST output a structured report in the following format. This is not optional.

Required Report Format:

## Validation Report

**Result:** [PASSED / PASSED with warnings / FAILED]
**Errors:** [count]
**Warnings:** [count]
**Info:** [count]

### Errors Fixed
- [List each error and how it was fixed, or "None" if 0 errors]

### Warnings Addressed
- [List each warning that was fixed]

### Warnings Skipped (with reasons)
- [List each warning that was NOT fixed and explain why]
- Example: "mbake reports '.DELETE_ON_ERROR' as unknown - this is a valid GNU Make
  special target (false positive)"

### Formatting Applied
- [Yes/No] - [If No, explain why formatting was skipped]

### Info Items Addressed
- [List info items that were addressed for production Makefiles]
- [Or "N/A - simple project" if not applicable]

### Remaining Issues (if any)
- [List any issues requiring user attention]
- [Or "None - Makefile is production-ready"]

Example Complete Report:

## Validation Report

**Result:** PASSED with warnings
**Errors:** 0
**Warnings:** 2
**Info:** 1

### Errors Fixed
- None

### Warnings Addressed
- Fixed: Added error handling to install target (|| exit 1)

### Warnings Skipped (with reasons)
- mbake reports ".DELETE_ON_ERROR" as unknown - this is a valid and critical
  GNU Make special target that ensures failed builds don't leave corrupt files.
  See: https://www.gnu.org/software/make/manual/html_node/Special-Targets.html

### Formatting Applied
- Yes - Applied `mbake format` to fix whitespace issues

### Info Items Addressed
- Added .NOTPARALLEL for Docker targets (parallel safety)
- Added error handling for docker-push target

### Remaining Issues
- None - Makefile is production-ready

Common Info Items to Address:

Info Item	When to Fix	How to Fix
"mkdir without order-only prerequisites"	Large projects (>10 targets)	Use target: prereqs | $(BUILDDIR) pattern
"recipe commands lack error handling"	Critical operations (install, deploy)	Add set -e in .SHELLFLAGS or use && chaining
"consider using ccache"	Long compile times	Add CC := ccache $(CC) pattern
"parallel-sensitive commands detected"	Docker/npm/pip targets	Add .NOTPARALLEL: for affected targets or proper dependencies

Production-Quality Requirements (MUST address for Docker/deploy targets):

When generating Makefiles with Docker or deployment targets, you MUST apply these production patterns:

1. Error Handling for docker-push:

   ## Push Docker image to registry (with error handling)
   docker-push: docker-build
   	@echo "Pushing $(IMAGE)..."
   	docker push $(IMAGE) || { echo "Failed to push $(IMAGE)"; exit 1; }
   	docker push $(IMAGE_LATEST) || { echo "Failed to push $(IMAGE_LATEST)"; exit 1; }
   

2. Parallel Safety for Docker targets:

   # Prevent parallel execution of Docker targets (race conditions)
   .NOTPARALLEL: docker-build docker-push docker-run
   

   Or use proper dependencies to serialize:

   docker-push: docker-build  # Ensures build completes before push
   docker-run: docker-build   # Ensures build completes before run
   

3. Install target error handling:

   install: $(TARGET)
   	install -d $(DESTDIR)$(PREFIX)/bin || exit 1
   	install -m 755 $(TARGET) $(DESTDIR)$(PREFIX)/bin/ || exit 1
   

Note: When validation shows info items about error handling or parallel safety, you MUST address them for any Makefile containing Docker, deploy, or install targets. Explain in your response which patterns were applied.

Validation Checklist:

• Syntax correct (make -n passes)
• All non-file targets have .PHONY
• Tab indentation (not spaces)
• No hardcoded credentials
• User-overridable variables use ?=
• .DELETE_ON_ERROR present
• MAKEFLAGS optimizations included (Modern header)
• Order-only prerequisites for build directories (large projects)
• Error handling in critical recipes (install, deploy, docker-push)

Best Practices

Variables

• ?= for user-overridable (CC, CFLAGS, PREFIX)
• := for project-specific (SOURCES, OBJECTS)
• Use pkg-config: CFLAGS += $(shell pkg-config --cflags lib)

Targets

• Always declare .PHONY for non-file targets
• Default target should be all
• Use .DELETE_ON_ERROR for safety
• Document with ## comments for help target

Directory Creation

Two approaches for creating build directories:

Simple (inline mkdir):

$(BUILDDIR)/%.o: $(SRCDIR)/%.c
	@mkdir -p $(@D)
	$(CC) $(CFLAGS) -c $< -o $@

Optimized (order-only prerequisites): Prevents unnecessary rebuilds when directory timestamps change.

$(BUILDDIR):
	@mkdir -p $@

$(BUILDDIR)/%.o: $(SRCDIR)/%.c | $(BUILDDIR)
	$(CC) $(CFLAGS) -c $< -o $@

Use order-only prerequisites (|) for large projects with many targets.

Recipes

• Use tabs, never spaces
• Quote variables in shell: $(RM) "$(TARGET)"
• Use @ prefix for quiet commands
• Test with make -n first

Helper Scripts (Optional)

These scripts are optional convenience tools for quick template generation.

When to Use Scripts vs Manual Generation

Scenario	Recommendation
Simple, standard project (single binary, no special features)	✅ Use generate_makefile_template.sh for speed
Complex project (Docker, multi-binary, custom patterns)	❌ Use manual generation for full control
Adding targets to existing Makefile	✅ Use add_standard_targets.sh
User has specific formatting/style requirements	❌ Use manual generation
Rapid prototyping / proof-of-concept	✅ Use scripts, customize later
Production-ready Makefile	⚠️ Start with script, then customize manually

generate_makefile_template.sh

Generates a complete Makefile template for a specific project type. Script path: scripts/generate_makefile_template.sh

bash scripts/generate_makefile_template.sh [TYPE] [NAME] [OUTPUT_FILE]

Types: c, c-lib, cpp, go, python, java, generic

Example:

bash scripts/generate_makefile_template.sh go myservice
# Creates Makefile with Go patterns, version embedding, standard targets

bash scripts/generate_makefile_template.sh go myservice build/Makefile
# Writes template to build/Makefile (TYPE NAME OUTPUT)

add_standard_targets.sh

Adds missing standard GNU targets to an existing Makefile. Script path: scripts/add_standard_targets.sh

bash scripts/add_standard_targets.sh [MAKEFILE] [TARGETS...]
bash scripts/add_standard_targets.sh [TARGETS...]  # uses ./Makefile

Targets: all, install, uninstall, clean, distclean, test, check, help, dist

Example:

bash scripts/add_standard_targets.sh Makefile install uninstall help
# Adds install, uninstall, help targets if they don't exist

bash scripts/add_standard_targets.sh clean test
# Explicit-target mode: modifies ./Makefile

bash scripts/add_standard_targets.sh -n Makefile dist
# Dry-run mode: shows planned changes without editing files

Note: Manual generation following the Stage 3 patterns produces equivalent results but allows for more customization.

Helper Script Regression Smoke Tests

Run after modifying helper scripts or templates:

bash test/test_helper_scripts.sh

Done Criteria

Consider the task complete only when all checks below are satisfied:

• Trigger matched and missing requirements were clarified (or documented defaults were applied).
• Relevant internal docs were opened via explicit file paths before generation.
• Generated Makefile has complete .PHONY coverage for non-file targets.
• Go templates include optional go.sum handling and configurable GO_MAIN entrypoint.
• Validation ran with makefile-validator (preferred) or documented fallback checks.
• Formatting was applied with mbake, or skipped with an explicit tool-unavailable/compatibility reason.
• Final response includes the required structured validation report.

Documentation

Detailed guides in docs/:

• makefile-structure.md - Organization, layout, includes
• variables-guide.md - Assignment operators, automatic variables
• targets-guide.md - Standard targets, .PHONY, prerequisites
• patterns-guide.md - Pattern rules, dependencies
• optimization-guide.md - Parallel builds, caching
• security-guide.md - Safe expansion, credential handling

Resources

• GNU Make Manual
• GNU Coding Standards
• Makefile Conventions