Comment on
[Beginner] Call all functions from main() or jump to functions from within functions?
Reply in thread
I'd recommend not to alias compilers like that. Rather, if you're interested, you could just use a simple Makefile like shown below and get it over with. Save it into a file called Makefile (yes, uppercase M followed by akefile all lowercase) in the same directory as your program.c file.
Note, I have used -std=c89 but you can delete that line or maybe even use a more modern standard such as -std=c23 if you like. If you delete, both gcc and clang will default to the latest ISO standard supported by that version of compiler.
Also since you're compiling only a single file, I have used program.c as input producing program executable on UNIX. To run this Makefile you need to invoke make from the same directory as Makefile on command-line as:
make W=1
to enable all the warnings and compile. If you set W=0 it will not warn or even print any diagnostic unless compiler really cannot generate the executable. You can also pass D=0 for optimised/release build, D=1 for debug build so you can backtrack in gdb. You can also pass A=1 if you want address sanitisers enabled. It will report if your program is touching or even looking at pointers/memory regions the wrong way, leaking memory or just generally doing operations that cannot guarantee correct behaviour. Passing V=1 will display the exact command executed to compile, otherwise it will silently compile.
Here's the full Makefile I use:
# Control build verbosity.
V ?= 0
ifeq ($(V),1)
Q :=
else
Q := @
endif
# Control DEBUG (1) or RELEASE (0) build.
D ?= 1
# Add some warning flags?
W ?= 0
# Add some address/undefined sanitiser flags?
A ?= 1
ifeq ($(shell $(CC) -v 2>&1 | grep -c "gcc version"),1)
COMPILER := gnu
else ifeq ($(shell $(CC) -v 2>&1 | grep -c "clang version"),1)
COMPILER := llvm
endif
# Delete environment garbage so we can generate absolutely controlled
LDFLAGS :=
CFLAGS :=
ifeq ($(D),1)
CFLAGS_DEFS += -D_DEBUG
else
CFLAGS_DEFS += -DNDEBUG
endif
CFLAGS_DEFS += -D_XOPEN_SOURCE=600
ifeq ($(D),0)
CFLAGS_DEFS += -D_FORTIFY_SOURCE=2
endif
CFLAGS_DEFS += -D_LARGEFILE64_SOURCE=1
CFLAGS_DEFS += -D_LARGEFILE_SOURCE=1
ifeq ($(W),1)
CFLAGS_STDS += -std=c89
CFLAGS_STDS += -Wpedantic
CFLAGS_STDS += -pedantic-errors
CFLAGS_STDS += -Werror
CFLAGS_STDS += -Wall
CFLAGS_STDS += -Wextra
ifeq ($(COMPILER),gnu)
CFLAGS_STDS += -Wbad-function-cast
CFLAGS_STDS += -Wcast-align
CFLAGS_STDS += -Wcast-qual
CFLAGS_STDS += -Wduplicated-branches
CFLAGS_STDS += -Wduplicated-cond
CFLAGS_STDS += -Wfloat-equal
CFLAGS_STDS += -Wformat-nonliteral
CFLAGS_STDS += -Wformat-security
CFLAGS_STDS += -Wformat-signedness
CFLAGS_STDS += -Wformat-truncation=2
CFLAGS_STDS += -Wformat=2
CFLAGS_STDS += -Winline
CFLAGS_STDS += -Wlogical-op
CFLAGS_STDS += -Wmissing-declarations
CFLAGS_STDS += -Wmissing-format-attribute
CFLAGS_STDS += -Wmissing-include-dirs
CFLAGS_STDS += -Wmissing-noreturn
CFLAGS_STDS += -Wmissing-prototypes
CFLAGS_STDS += -Wnested-externs
CFLAGS_STDS += -Wno-unused-result
CFLAGS_STDS += -Wnull-dereference
CFLAGS_STDS += -Wold-style-definition
CFLAGS_STDS += -Wpointer-arith
CFLAGS_STDS += -Wpointer-sign
CFLAGS_STDS += -Wredundant-decls
CFLAGS_STDS += -Wrestrict
CFLAGS_STDS += -Wreturn-type
CFLAGS_STDS += -Wshadow
CFLAGS_STDS += -Wsign-compare
CFLAGS_STDS += -Wsign-conversion
CFLAGS_STDS += -Wstrict-aliasing
CFLAGS_STDS += -Wstrict-prototypes
CFLAGS_STDS += -Wswitch-enum
CFLAGS_STDS += -Wtrampolines
CFLAGS_STDS += -Wundef
CFLAGS_STDS += -Wuninitialized
CFLAGS_STDS += -Wunreachable-code
CFLAGS_STDS += -Wunused
CFLAGS_STDS += -Wunused-but-set-parameter
CFLAGS_STDS += -Wunused-but-set-variable
CFLAGS_STDS += -Wunused-label
CFLAGS_STDS += -Wunused-local-typedefs
CFLAGS_STDS += -Wunused-parameter
CFLAGS_STDS += -Wunused-variable
CFLAGS_STDS += -Wwrite-strings
else
CFLAGS_STDS += -Wmost
CFLAGS_STDS += -Warray-bounds-pointer-arithmetic
CFLAGS_STDS += -Wassign-enum
CFLAGS_STDS += -Wcomma
CFLAGS_STDS += -Wconditional-uninitialized
CFLAGS_STDS += -Wformat-type-confusion
CFLAGS_STDS += -Widiomatic-parentheses
CFLAGS_STDS += -Wloop-analysis
CFLAGS_STDS += -Wshift-sign-overflow
CFLAGS_STDS += -Wshorten-64-to-32
CFLAGS_STDS += -Wstrict-aliasing=2
CFLAGS_STDS += -Wstrict-overflow=5
CFLAGS_STDS += -Wtautological-constant-in-range-compare
CFLAGS_STDS += -Wthread-safety
CFLAGS_STDS += -Wunreachable-code-aggressive
CFLAGS_STDS += -Wunused
CFLAGS_STDS += -Wunused-argument
CFLAGS_STDS += -Wunused-but-set-parameter
CFLAGS_STDS += -Wunused-but-set-variable
CFLAGS_STDS += -Wunused-comparison
CFLAGS_STDS += -Wunused-const-variable
CFLAGS_STDS += -Wunused-exception-parameter
CFLAGS_STDS += -Wunused-function
CFLAGS_STDS += -Wunused-label
CFLAGS_STDS += -Wunused-local-typedefs
CFLAGS_STDS += -Wunused-macros
CFLAGS_STDS += -Wunused-parameter
CFLAGS_STDS += -Wunused-value
CFLAGS_STDS += -Wunused-variable
CFLAGS_STDS += -Wunused-volatile-lvalue
endif
else
# Disable all manners of warnings, even default ones.
CFLAGS_STDS += -w
endif
CFLAGS_OPTS += -fPIC
# These are needed anyway.
ifeq ($(D),1)
CFLAGS_OPTS += -O0 -g3 -ggdb3
CFLAGS_OPTS += -fno-omit-frame-pointer
else
CFLAGS_OPTS += -O3
CFLAGS_OPTS += -ffunction-sections
CFLAGS_OPTS += -fdata-sections
CFLAGS_OPTS += -fmerge-all-constants
endif
ifeq ($(A),1)
CFLAGS_OPTS += -fsanitize=address,leak,undefined
endif
# Add more include directories to your liking
CFLAGS_INCS += -I.
# Assemble them all into a singfle
CFLAGS += $(CFLAGS_DEFS)
CFLAGS += $(CFLAGS_INCS)
CFLAGS += $(CFLAGS_STDS)
CFLAGS += $(CFLAGS_OPTS)
LDFLAGS += -Wl,--as-needed
LDFLAGS += -Wl,--gc-sections
LDFLAGS += -Wl,--no-undefined
LDFLAGS += -Wl,-z,defs
LDFLAGS += -Wl,-z,nocombreloc
LDFLAGS += -Wl,-z,now
LDFLAGS += -Wl,-z,relro
# The $(Q)$(CC) has a real TAB before it, not space. If you copy paste from Lemmy, you might end up with spaces.
program: program.c
$(Q)$(CC) $(CFLAGS) -o $@ $< $(LDFLAGS)
.DEFAULT_GOAL := all
.PHONY: all
all: program
.PHONY: clean
# The space before $(Q)$(RM) is real TAB as well.
clean:
$(Q)$(RM) program