make

Name: make
Author: mohitmishra786

341installs19forks

How to install make?

mohitmishra786/low-level-dev-skills/make

$npx -y skills add mohitmishra786/low-level-dev-skills --skill make

Installs into the current project.

Summary

GNU Make skill for C/C++ build systems. Use when writing or debugging Makefiles, understanding pattern rules and automatic dependency generation, managing CFLAGS/LDFLAGS, converting ad-hoc compile commands into maintainable Makefiles, or diagnosing incremental build issues. Activ

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SKILL.md

1	# GNU Make
2
3	## Purpose
4
5	Guide agents through idiomatic Makefile patterns for C/C++ projects: phony targets, pattern rules, automatic dependency generation, and common build idioms.
6
7	## Triggers
8
9	- "How do I write a Makefile for my C project?"
10	- "My Makefile rebuilds everything every time"
11	- "How do I add dependency tracking to Make?"
12	- "What does `$@`, `$<`, `$^` mean?"
13	- "I'm getting 'make: Nothing to be done for all'"
14	- "How do I convert my shell compile script to a Makefile?"
15
16	## Workflow
17
18	### 1. Minimal correct Makefile for C
19
20	```makefile
21	CC := gcc
22	CFLAGS := -std=c11 -Wall -Wextra -g -O2
23	LDFLAGS :=
24	LDLIBS :=
25
26	SRCS := $(wildcard src/*.c)
27	OBJS := $(SRCS:src/%.c=build/%.o)
28	TARGET := build/prog
29
30	.PHONY: all clean
31
32	all: $(TARGET)
33
34	$(TARGET): $(OBJS)
35	$(CC) $(LDFLAGS) -o $@ $^ $(LDLIBS)
36
37	build/%.o: src/%.c \| build
38	$(CC) $(CFLAGS) -c -o $@ $<
39
40	build:
41	mkdir -p build
42
43	clean:
44	rm -rf build
45	```
46
47	Automatic variables:
48
49	- `$@` — target name
50	- `$<` — first prerequisite
51	- `$^` — all prerequisites (deduplicated)
52	- `$*` — stem (the `%` part in a pattern rule)
53	- `$(@D)` — directory part of `$@`
54
55	### 2. Automatic dependency generation
56
57	Without this, changing a header doesn't trigger a rebuild of `.c` files that include it.
58
59	```makefile
60	CC := gcc
61	CFLAGS := -std=c11 -Wall -Wextra -g -O2
62	DEPFLAGS = -MMD -MP # -MMD: generate .d file; -MP: phony targets for headers
63
64	SRCS := $(wildcard src/*.c)
65	OBJS := $(SRCS:src/%.c=build/%.o)
66	DEPS := $(OBJS:.o=.d)
67	TARGET := build/prog
68
69	.PHONY: all clean
70
71	all: $(TARGET)
72
73	$(TARGET): $(OBJS)
74	$(CC) $(LDFLAGS) -o $@ $^ $(LDLIBS)
75
76	build/%.o: src/%.c \| build
77	$(CC) $(CFLAGS) $(DEPFLAGS) -MF $(@:.o=.d) -c -o $@ $<
78
79	-include $(DEPS) # '-' ignores errors on first build (no .d files yet)
80
81	build:
82	mkdir -p build
83
84	clean:
85	rm -rf build
86	```
87
88	### 3. Pattern rules cheatsheet
89
90	```makefile
91	# Compile C
92	%.o: %.c
93	$(CC) $(CFLAGS) -c -o $@ $<
94
95	# Compile C++
96	%.o: %.cpp
97	$(CXX) $(CXXFLAGS) -c -o $@ $<
98
99	# Generate assembly
100	%.s: %.c
101	$(CC) $(CFLAGS) -S -o $@ $<
102
103	# Run a tool on each file
104	build/%.processed: src/%.raw \| build
105	mytool $< > $@
106	```
107
108	### 4. Common Make patterns
109
110	#### Debug and release builds
111
112	```makefile
113	BUILD ?= release
114
115	ifeq ($(BUILD),debug)
116	CFLAGS += -g -Og -DDEBUG
117	else
118	CFLAGS += -O2 -DNDEBUG
119	endif
120	```
121
122	Usage: `make BUILD=debug`
123
124	#### Parallel builds
125
126	```bash
127	make -j$(nproc) # use all CPUs
128	make -j4 # exactly 4 jobs
129	```
130
131	Add `-Otarget` (or `-O`) for ordered output: `make -j$(nproc) -O`
132
133	#### Verbose output
134
135	```makefile
136	# In Makefile: suppress with @
137	build/%.o: src/%.c \| build
138	@echo " CC $<"
139	@$(CC) $(CFLAGS) -c -o $@ $<
140	```
141
142	Override silence: `make V=1` if you guard with `$(V)`:
143
144	```makefile
145	Q := $(if $(V),,@)
146	build/%.o: src/%.c
147	$(Q)$(CC) $(CFLAGS) -c -o $@ $<
148	```
149
150	#### Installing
151
152	```makefile
153	PREFIX ?= /usr/local
154
155	install: $(TARGET)
156	install -d $(DESTDIR)$(PREFIX)/bin
157	install -m 0755 $(TARGET) $(DESTDIR)$(PREFIX)/bin/
158	```
159
160	### 5. Multi-directory projects
161
162	For medium projects, avoid recursive make (fragile, slow). Use a flat Makefile that includes sub-makefiles:
163
164	```makefile
165	# project/Makefile
166	include lib/module.mk
167	include src/app.mk
168	```
169
170	```makefile
171	# lib/module.mk
172	LIB_SRCS := $(wildcard lib/*.c)
173	LIB_OBJS := $(LIB_SRCS:lib/%.c=build/lib_%.o)
174	OBJS += $(LIB_OBJS)
175
176	build/lib_%.o: lib/%.c
177	$(CC) $(CFLAGS) -c -o $@ $<
178	```
179
180	### 6. Common errors
181
182	\| Error \| Cause \| Fix \|
183	\|-------\|-------\|-----\|
184	\| `No rule to make target 'foo.o'` \| Missing source or rule \| Check source path and pattern rule \|
185	\| `Nothing to be done for 'all'` \| Targets up to date \| Touch a source file or run `make clean` \|
186	\| `Circular dependency dropped` \| Target depends on itself \| Check dependency chain \|
187	\| `missing separator` \| Tab vs spaces \| Recipes must use a tab, not spaces \|
188	\| `*** multiple target patterns` \| Pattern rule syntax error \| Check `%` placement \|
189	\| Rebuilds everything every time \| Timestamps wrong, or PHONY missing \| Check `date`; ensure `all` is `.PHONY` \|
190	\| Header change not detected \| No dep tracking \| Add `-MMD -MP` and `-include $(DEPS)` \|
191
192	For a full variable and function reference, see [references/cheatsheet.md](references/cheatsheet.md).
193
194	## Related skills
195
196	- Use `skills/build-systems/cmake` for CMake-based projects
197	- Use `skills/build-systems/ninja` for Ninja as a make backend
198	- Use `skills/compilers/gcc` for CFLAGS details

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Type

make

341installs19forks

View on GitHub

How to install make?

mohitmishra786/low-level-dev-skills/make

$npx -y skills add mohitmishra786/low-level-dev-skills --skill make

Installs into the current project.

Summary

Files · 1

View on GitHub

SKILL.md

1	# GNU Make
2
3	## Purpose
4
5	Guide agents through idiomatic Makefile patterns for C/C++ projects: phony targets, pattern rules, automatic dependency generation, and common build idioms.
6
7	## Triggers
8
9	- "How do I write a Makefile for my C project?"
10	- "My Makefile rebuilds everything every time"
11	- "How do I add dependency tracking to Make?"
12	- "What does `$@`, `$<`, `$^` mean?"
13	- "I'm getting 'make: Nothing to be done for all'"
14	- "How do I convert my shell compile script to a Makefile?"
15
16	## Workflow
17
18	### 1. Minimal correct Makefile for C
19
20	```makefile
21	CC := gcc
22	CFLAGS := -std=c11 -Wall -Wextra -g -O2
23	LDFLAGS :=
24	LDLIBS :=
25
26	SRCS := $(wildcard src/*.c)
27	OBJS := $(SRCS:src/%.c=build/%.o)
28	TARGET := build/prog
29
30	.PHONY: all clean
31
32	all: $(TARGET)
33
34	$(TARGET): $(OBJS)
35	$(CC) $(LDFLAGS) -o $@ $^ $(LDLIBS)
36
37	build/%.o: src/%.c \| build
38	$(CC) $(CFLAGS) -c -o $@ $<
39
40	build:
41	mkdir -p build
42
43	clean:
44	rm -rf build
45	```
46
47	Automatic variables:
48
49	- `$@` — target name
50	- `$<` — first prerequisite
51	- `$^` — all prerequisites (deduplicated)
52	- `$*` — stem (the `%` part in a pattern rule)
53	- `$(@D)` — directory part of `$@`
54
55	### 2. Automatic dependency generation
56
57	Without this, changing a header doesn't trigger a rebuild of `.c` files that include it.
58
59	```makefile
60	CC := gcc
61	CFLAGS := -std=c11 -Wall -Wextra -g -O2
62	DEPFLAGS = -MMD -MP # -MMD: generate .d file; -MP: phony targets for headers
63
64	SRCS := $(wildcard src/*.c)
65	OBJS := $(SRCS:src/%.c=build/%.o)
66	DEPS := $(OBJS:.o=.d)
67	TARGET := build/prog
68
69	.PHONY: all clean
70
71	all: $(TARGET)
72
73	$(TARGET): $(OBJS)
74	$(CC) $(LDFLAGS) -o $@ $^ $(LDLIBS)
75
76	build/%.o: src/%.c \| build
77	$(CC) $(CFLAGS) $(DEPFLAGS) -MF $(@:.o=.d) -c -o $@ $<
78
79	-include $(DEPS) # '-' ignores errors on first build (no .d files yet)
80
81	build:
82	mkdir -p build
83
84	clean:
85	rm -rf build
86	```
87
88	### 3. Pattern rules cheatsheet
89
90	```makefile
91	# Compile C
92	%.o: %.c
93	$(CC) $(CFLAGS) -c -o $@ $<
94
95	# Compile C++
96	%.o: %.cpp
97	$(CXX) $(CXXFLAGS) -c -o $@ $<
98
99	# Generate assembly
100	%.s: %.c
101	$(CC) $(CFLAGS) -S -o $@ $<
102
103	# Run a tool on each file
104	build/%.processed: src/%.raw \| build
105	mytool $< > $@
106	```
107
108	### 4. Common Make patterns
109
110	#### Debug and release builds
111
112	```makefile
113	BUILD ?= release
114
115	ifeq ($(BUILD),debug)
116	CFLAGS += -g -Og -DDEBUG
117	else
118	CFLAGS += -O2 -DNDEBUG
119	endif
120	```
121
122	Usage: `make BUILD=debug`
123
124	#### Parallel builds
125
126	```bash
127	make -j$(nproc) # use all CPUs
128	make -j4 # exactly 4 jobs
129	```
130
131	Add `-Otarget` (or `-O`) for ordered output: `make -j$(nproc) -O`
132
133	#### Verbose output
134
135	```makefile
136	# In Makefile: suppress with @
137	build/%.o: src/%.c \| build
138	@echo " CC $<"
139	@$(CC) $(CFLAGS) -c -o $@ $<
140	```
141
142	Override silence: `make V=1` if you guard with `$(V)`:
143
144	```makefile
145	Q := $(if $(V),,@)
146	build/%.o: src/%.c
147	$(Q)$(CC) $(CFLAGS) -c -o $@ $<
148	```
149
150	#### Installing
151
152	```makefile
153	PREFIX ?= /usr/local
154
155	install: $(TARGET)
156	install -d $(DESTDIR)$(PREFIX)/bin
157	install -m 0755 $(TARGET) $(DESTDIR)$(PREFIX)/bin/
158	```
159
160	### 5. Multi-directory projects
161
162	For medium projects, avoid recursive make (fragile, slow). Use a flat Makefile that includes sub-makefiles:
163
164	```makefile
165	# project/Makefile
166	include lib/module.mk
167	include src/app.mk
168	```
169
170	```makefile
171	# lib/module.mk
172	LIB_SRCS := $(wildcard lib/*.c)
173	LIB_OBJS := $(LIB_SRCS:lib/%.c=build/lib_%.o)
174	OBJS += $(LIB_OBJS)
175
176	build/lib_%.o: lib/%.c
177	$(CC) $(CFLAGS) -c -o $@ $<
178	```
179
180	### 6. Common errors
181
182	\| Error \| Cause \| Fix \|
183	\|-------\|-------\|-----\|
184	\| `No rule to make target 'foo.o'` \| Missing source or rule \| Check source path and pattern rule \|
185	\| `Nothing to be done for 'all'` \| Targets up to date \| Touch a source file or run `make clean` \|
186	\| `Circular dependency dropped` \| Target depends on itself \| Check dependency chain \|
187	\| `missing separator` \| Tab vs spaces \| Recipes must use a tab, not spaces \|
188	\| `*** multiple target patterns` \| Pattern rule syntax error \| Check `%` placement \|
189	\| Rebuilds everything every time \| Timestamps wrong, or PHONY missing \| Check `date`; ensure `all` is `.PHONY` \|
190	\| Header change not detected \| No dep tracking \| Add `-MMD -MP` and `-include $(DEPS)` \|
191
192	For a full variable and function reference, see [references/cheatsheet.md](references/cheatsheet.md).
193
194	## Related skills
195
196	- Use `skills/build-systems/cmake` for CMake-based projects
197	- Use `skills/build-systems/ninja` for Ninja as a make backend
198	- Use `skills/compilers/gcc` for CFLAGS details

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Type