louisswarren/.gitignore

## .gitignore
main
templates.h
template_*.h
*.o

## main.c
#include <stdio.h>
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

#include <assert.h>

typedef int64_t i64;

typedef struct {
	const char *p;
	ptrdiff_t n;
} slice;

#define S(X) ((slice){X, sizeof(X) - 1})

typedef struct {
	char *start;
	ptrdiff_t len;
	ptrdiff_t cap;
} Arena;

void
push(Arena *buf, const void *p, ptrdiff_t n)
{
	assert(buf->len + n < buf->cap);
	memcpy(buf->start + buf->len, p, n);
	buf->len += n;
}

void
push_int(Arena *buf, i64 n)
{
	char b[32];
	char *p = b + sizeof(b) - 1;

	int sign = n < 0 ? -1 : 1;

	do {
		*(p--) = (char)('0' + (n % 10) * sign);
		n /= 10;
	} while (n);

	if (sign < 0) {
		*p = '-';
	} else {
		++p;
	}

	push(buf, p, b + sizeof(b) - p);
}

#define template(F, A, ...) \
	template_##F##_raw(A, &(struct template_##F##_args){__VA_ARGS__})


#include "templates.h"

int
main(void)
{
	Arena a = {NULL, 0, 1 << 20};
	a.start = malloc(a.cap);
	if (!a.start)
		return 1;

	template(webpage_html, &a,
		.title = S("Hello, world!"),
		.num = INT64_MIN,
		.body = S("This is a test"));
	fwrite(a.start, 1, a.len, stdout);

	return 0;
}

## Makefile
CFLAGS = -Wall -Warray-bounds=2 -Wcast-align=strict -Wcast-qual -Wconversion -Wno-sign-conversion -Wdangling-else -Wdate-time -Wdouble-promotion -Wextra -Wfloat-conversion -Wformat-overflow=2 -Wformat-signedness -Wformat-truncation=2 -Wformat=2 -Winit-self -Wjump-misses-init -Wlogical-op -Wmissing-include-dirs -Wnested-externs -Wnull-dereference -Wpacked -Wpedantic -Wredundant-decls -Wshadow -Wshift-negative-value -Wshift-overflow=2 -Wstrict-aliasing -Wstrict-overflow=2 -Wstrict-prototypes -Wstringop-overflow=4 -Wstringop-truncation -Wswitch-default -Wswitch-enum -Wuninitialized -Wunsafe-loop-optimizations -Wunused -Wuse-after-free=3 -Wwrite-strings -fanalyzer -fmax-errors=2 -pedantic-errors

template_html = $(shell find . -name 'template_*.html')
template_o = $(patsubst ./template_%.html,./template_%.o,$(template_html))
template_h = $(patsubst ./template_%.html,./template_%.h,$(template_html))

.PHONY: default
default: main
	./$<

.PHONY: test
test: out.txt
	diff expected.txt $<

out.txt: main
	./$< > $@

main: main.o $(template_o)
main.o: main.c templates.h $(template_h)

templates.h: $(template_h)
	for x in $^; do echo "#include \"$$x\""; done > $@

template_%.o: template_%.html
	ld -z noexecstack -r -b binary -o $@ $<

template_%.h: tempp.py template_%.html
	python3 $^ > $@

.PHONY: clean
clean:
	rm -f main templates.h template_*.h *.o

## template_webpage.html
<html>
	<head>
		<title><{title}></title>
	</head>
	<body>
		<h1>Number <{num:d}></h1>
		<p>
			<{body}>
		</p>
		<p>
			Escape a template by putting a minus sign inside like <{-this}>.
		</p>
	</body>
</html>

## tempp.py
import itertools
import re
import sys

from collections import namedtuple

class Parameter(namedtuple('Parameter', (
            'raw',
            'ident',
            'ctype',
            'start',
            'end',
            'disabled'
        ))):
    pass

def print_extern_include(file_ident):
    print("extern const char");
    print(f"\t_binary_{file_ident}_start[],")
    print(f"\t_binary_{file_ident}_end[];")
    print()

def print_arg_struct(file_ident, params):
    print(f"struct {file_ident}_args", "{")
    param_types = set((p.ctype, p.ident) for p in params if not p.disabled)
    for ctype, ident in sorted(param_types):
        print(f"\t{ctype} {ident};")
    print("};")
    print()

def print_template_function(file_ident, params, content_len):
    src = f"_binary_{file_ident}_start"

    last = 0
    print("void")
    print(f"{file_ident}_raw(Arena *buf, const struct {file_ident}_args *args)")
    print("{")
    for p in params:
        if last < p.start:
            print(f"\tpush(buf, {src} + {last}, {p.start - last});")
        if p.disabled:
            lit = '"' + p.raw[:2] + p.raw[3:] + '"'
            print(f"\tpush(buf, {lit}, sizeof({lit}) - 1);")
        elif p.ctype == 'slice':
            print(f"\tpush(buf, args->{p.ident}.p, args->{p.ident}.n);")
        elif p.ctype == 'int64_t':
            print(f"\tpush_int(buf, args->{p.ident});")
        last = p.end
    print(f"\tpush(buf, {src} + {last}, {content_len - last});")
    print("}")

def make_header(filename):
    file_ident = ''.join(c if c.isalnum() else '_' for c in filename)

    with open(filename) as f:
        contents = f.read()

    print_extern_include(file_ident)

    r = re.compile(flags=(re.ASCII | re.VERBOSE), pattern=r'''
        <[{]
        (?P<disable>[-]+)?
        (?P<ident>\w+)
        (:(?P<ftype>\w+))?
        [}]>
    ''')

    typedict = {
            None: 'slice',
            'd': 'int64_t',
            's': 'slice',
    }

    params = [
        Parameter(
            raw=m.group(0),
            ctype=typedict[m.groupdict()['ftype']],
            ident=m.groupdict()['ident'],
            start=m.start(),
            end=m.end(),
            disabled=m.groupdict()['disable'] is not None,
        )
        for m in r.finditer(contents)]

    print_arg_struct(file_ident, params)

    print_template_function(file_ident, params, len(contents))

if __name__ == '__main__':
    filename = sys.argv[1]
    make_header(filename)
	#include <stdio.h>
	#include <stddef.h>
	#include <stdint.h>
	#include <stdlib.h>
	#include <string.h>

	#include <assert.h>

	typedef int64_t i64;

	typedef struct {
	const char *p;
	ptrdiff_t n;
	} slice;

	#define S(X) ((slice){X, sizeof(X) - 1})

	typedef struct {
	char *start;
	ptrdiff_t len;
	ptrdiff_t cap;
	} Arena;

	void
	push(Arena buf, const void p, ptrdiff_t n)
	{
	assert(buf->len + n < buf->cap);
	memcpy(buf->start + buf->len, p, n);
	buf->len += n;
	}

	void
	push_int(Arena *buf, i64 n)
	{
	char b[32];
	char *p = b + sizeof(b) - 1;

	int sign = n < 0 ? -1 : 1;

	do {
	(p--) = (char)('0' + (n % 10) sign);
	n /= 10;
	} while (n);

	if (sign < 0) {
	*p = '-';
	} else {
	++p;
	}

	push(buf, p, b + sizeof(b) - p);
	}

	#define template(F, A, ...) \
	template_##F##_raw(A, &(struct template_##F##_args){__VA_ARGS__})


	#include "templates.h"

	int
	main(void)
	{
	Arena a = {NULL, 0, 1 << 20};
	a.start = malloc(a.cap);
	if (!a.start)
	return 1;

	template(webpage_html, &a,
	.title = S("Hello, world!"),
	.num = INT64_MIN,
	.body = S("This is a test"));
	fwrite(a.start, 1, a.len, stdout);

	return 0;
	}
	CFLAGS = -Wall -Warray-bounds=2 -Wcast-align=strict -Wcast-qual -Wconversion -Wno-sign-conversion -Wdangling-else -Wdate-time -Wdouble-promotion -Wextra -Wfloat-conversion -Wformat-overflow=2 -Wformat-signedness -Wformat-truncation=2 -Wformat=2 -Winit-self -Wjump-misses-init -Wlogical-op -Wmissing-include-dirs -Wnested-externs -Wnull-dereference -Wpacked -Wpedantic -Wredundant-decls -Wshadow -Wshift-negative-value -Wshift-overflow=2 -Wstrict-aliasing -Wstrict-overflow=2 -Wstrict-prototypes -Wstringop-overflow=4 -Wstringop-truncation -Wswitch-default -Wswitch-enum -Wuninitialized -Wunsafe-loop-optimizations -Wunused -Wuse-after-free=3 -Wwrite-strings -fanalyzer -fmax-errors=2 -pedantic-errors

	template_html = $(shell find . -name 'template_*.html')
	template_o = $(patsubst ./template_%.html,./template_%.o,$(template_html))
	template_h = $(patsubst ./template_%.html,./template_%.h,$(template_html))

	.PHONY: default
	default: main
	./$<

	.PHONY: test
	test: out.txt
	diff expected.txt $<

	out.txt: main
	./$< > $@

	main: main.o $(template_o)
	main.o: main.c templates.h $(template_h)

	templates.h: $(template_h)
	for x in $^; do echo "#include \"$$x\""; done > $@

	template_%.o: template_%.html
	ld -z noexecstack -r -b binary -o $@ $<

	template_%.h: tempp.py template_%.html
	python3 $^ > $@

	.PHONY: clean
	clean:
	rm -f main templates.h template_.h .o
	<html>
	<head>
	<title><{title}></title>
	</head>
	<body>
	<h1>Number <{num:d}></h1>
	<p>
	<{body}>
	</p>
	<p>
	Escape a template by putting a minus sign inside like <{-this}>.
	</p>
	</body>
	</html>
	import itertools
	import re
	import sys

	from collections import namedtuple

	class Parameter(namedtuple('Parameter', (
	'raw',
	'ident',
	'ctype',
	'start',
	'end',
	'disabled'
	))):
	pass

	def print_extern_include(file_ident):
	print("extern const char");
	print(f"\t_binary_{file_ident}_start[],")
	print(f"\t_binary_{file_ident}_end[];")
	print()

	def print_arg_struct(file_ident, params):
	print(f"struct {file_ident}_args", "{")
	param_types = set((p.ctype, p.ident) for p in params if not p.disabled)
	for ctype, ident in sorted(param_types):
	print(f"\t{ctype} {ident};")
	print("};")
	print()

	def print_template_function(file_ident, params, content_len):
	src = f"_binary_{file_ident}_start"

	last = 0
	print("void")
	print(f"{file_ident}_raw(Arena buf, const struct {file_ident}_args args)")
	print("{")
	for p in params:
	if last < p.start:
	print(f"\tpush(buf, {src} + {last}, {p.start - last});")
	if p.disabled:
	lit = '"' + p.raw[:2] + p.raw[3:] + '"'
	print(f"\tpush(buf, {lit}, sizeof({lit}) - 1);")
	elif p.ctype == 'slice':
	print(f"\tpush(buf, args->{p.ident}.p, args->{p.ident}.n);")
	elif p.ctype == 'int64_t':
	print(f"\tpush_int(buf, args->{p.ident});")
	last = p.end
	print(f"\tpush(buf, {src} + {last}, {content_len - last});")
	print("}")

	def make_header(filename):
	file_ident = ''.join(c if c.isalnum() else '_' for c in filename)

	with open(filename) as f:
	contents = f.read()

	print_extern_include(file_ident)

	r = re.compile(flags=(re.ASCII \| re.VERBOSE), pattern=r'''
	<[{]
	(?P<disable>[-]+)?
	(?P<ident>\w+)
	(:(?P<ftype>\w+))?
	[}]>
	''')

	typedict = {
	None: 'slice',
	'd': 'int64_t',
	's': 'slice',
	}

	params = [
	Parameter(
	raw=m.group(0),
	ctype=typedict[m.groupdict()['ftype']],
	ident=m.groupdict()['ident'],
	start=m.start(),
	end=m.end(),
	disabled=m.groupdict()['disable'] is not None,
	)
	for m in r.finditer(contents)]

	print_arg_struct(file_ident, params)

	print_template_function(file_ident, params, len(contents))

	if __name__ == '__main__':
	filename = sys.argv[1]
	make_header(filename)