tmpl

commit 110975105e860a4530f9d5b1595d063b8356ccd6
Author: Louis Burda <quent.burda@gmail.com>
Date:   Fri, 26 May 2023 20:44:50 +0200

Add initial version

Diffstat:
A
.gitignore
 | 
2
++
A
Makefile
 | 
17
+++++++++++++++++
A
test
 | 
10
++++++++++
A
tmpl.c
 | 
238
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

4 files changed, 267 insertions(+), 0 deletions(-)
diff --git a/.gitignore b/.gitignore
@@ -0,0 +1,2 @@
+tmpl
+.gdb_history
diff --git a/Makefile b/Makefile
@@ -0,0 +1,17 @@
+PREFIX ?= /usr/local
+BINDIR ?= /bin
+
+all: tmpl
+
+clean:
+	rm -f tmpl
+
+tmp: tmpl.c
+
+install:
+	install -m755 tmpl -t "$(DESTDIR)$(PREFIX)$(BINDIR)"
+
+uninstall:
+	rm -f "$(DESTDIR)$(PREFIX)$(BINDIR)/tmpl"
+
+.PHONY: all clean install uninstall
diff --git a/test b/test
@@ -0,0 +1,10 @@
+#default PREFIX /usr/local
+#default BINDIR /bin
+
+#ifdef DEBUG
+yes debug
+#else
+no debug
+#endif
+
+install -m755 "#{TARGET}" -t "#{DESTDIR}#{PREFIX}#{BINDIR}"
diff --git a/tmpl.c b/tmpl.c
@@ -0,0 +1,238 @@
+#include <err.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+enum {
+	IFEQ,
+	IFDEF,
+	ELSE
+};
+
+struct block {
+	int active;
+	int type;
+};
+
+struct var {
+	const char *name;
+	const char *value;
+	struct var *next;
+};
+
+struct var *vars, **vars_end;
+
+struct var *
+getvar(const char *name)
+{
+	struct var *var;
+
+	for (var = vars; var; var = var->next) {
+		if (!strcmp(var->name, name))
+			return var;
+	}
+
+	return NULL;
+}
+
+void
+assign(char *line)
+{
+	char *name, *value, *sep;
+	struct var *var;
+
+	sep = strchr(line, '=');
+	if (!sep) err(1, "invalid assign: '%s'", line);
+	*sep = '\0';
+
+	var = malloc(sizeof(struct var));
+	if (!var) err(1, "malloc");
+	var->name = line;
+	var->value = sep + 1;
+	var->next = NULL;
+
+	*vars_end = var;
+	vars_end = &var->next;
+}
+
+void
+template(char *line)
+{
+	static struct block stack[32] = { 0 };
+	static int stack_top = 0;
+	static size_t lineno = 0;
+	struct var *var;
+	char *open, *close;
+	char *sep;
+
+	lineno++;
+
+	if (!strncmp(line, "#ifdef ", 7)) {
+		if (stack_top == 32) errx(1, "too much nesting");
+		stack[stack_top].active = 0;
+		stack[stack_top].type = IFDEF;
+		if (!stack_top || stack[stack_top-1].active) {
+			if (getvar(line + 7))
+				stack[stack_top].active = 1;
+		}
+		stack_top++;
+	} else if (!strncmp(line, "#ifeq ", 6)) {
+		if (stack_top == 32) errx(1, "too much nesting");
+		stack[stack_top].active = 0;
+		stack[stack_top].type = IFEQ;
+		if (!stack_top || stack[stack_top-1].active) {
+			var = getvar(line + 6);
+			sep = strchr(line + 6, ' ');
+			if (!sep) err(1, "invalid #ifeq: %lu:%s", lineno, line);
+			if (!strcmp(var->value, sep + 1)) {
+				stack[stack_top].active = 1;
+			}
+		}
+		stack_top++;
+	} else if (!strcmp(line, "#else")) {
+		if (!stack_top || stack[stack_top-1].type != IFDEF
+				&& stack[stack_top-1].type != IFEQ)
+			err(1, "invalid #else: %lu:%s", lineno, line);
+		stack[stack_top-1].active ^= 1;
+		stack[stack_top-1].type = ELSE;
+	} else if (!strcmp(line, "#endif")) {
+		if (!stack_top) err(1, "invalid #endif: %lu:%s", lineno, line);
+		stack_top--;
+	} else if (!strncmp(line, "#define ", 8)) {
+		if (stack_top && !stack[stack_top-1].active)
+			return;
+
+		sep = strchr(line + 8, ' ');
+		if (!sep) err(1, "invalid #default: %lu:%s", lineno, line);
+		*sep = '=';
+		assign(line + 8);
+	} else if (!strncmp(line, "#default ", 9)) {
+		if (stack_top && !stack[stack_top-1].active)
+			return;
+
+		sep = strchr(line + 9, ' ');
+		if (!sep) err(1, "invalid #default: %lu:%s", lineno, line);
+		*sep = '\0';
+		var = getvar(line + 9);
+		if (!var) {
+			*sep = '=';
+			assign(line + 9);
+		}
+	} else {
+		if (stack_top && !stack[stack_top-1].active)
+			return;
+
+		while (1) {
+			open = strstr(line, "#{");
+			if (!open) break;
+
+			if (open != line && open[-1] == '\\') {
+				open[-1] = '\0';
+				fputs(line, stdout);
+				fputs("#{", stdout);
+				line = open + 2;
+				continue;
+			}
+
+			close = strchr(open, '}');
+			if (!close) break;
+
+			*open = '\0';
+			fputs(line, stdout);
+
+			*close = '\0';
+			var = getvar(open + 2);
+			if (var) fputs(var->value, stdout);
+
+			line = close + 1;
+		}
+
+		puts(line);
+	}
+}
+
+void
+perline(char *contents, int nonempty, void (*process)(char *))
+{
+	char *line, *sep, *end;
+
+	line = contents;
+	do {
+		sep = strchr(line, '\n');
+		end = sep ? sep : line + strlen(line);
+		*end = '\0';
+		if (!nonempty || end > line + 1)
+			process(line);
+		line = end + 1;
+	} while (sep);
+}
+
+char *
+readall(const char *path)
+{
+	char buf[BUFSIZ];
+	char *contents;
+	ssize_t ret;
+	size_t len, cap;
+	int fd;
+
+	fd = open(path, O_RDONLY);
+	if (fd < 0) err(1, "open '%s'", path);
+
+	cap = BUFSIZ + 1;
+	contents = malloc(cap);
+	if (!contents) err(1, "malloc");
+
+	len = 0;
+	while ((ret = read(fd, buf, BUFSIZ)) > 0) {
+		if (len + ret >= cap) {
+			cap *= 2;
+			contents = realloc(contents, cap);
+			if (!contents) err(1, "realloc");
+		}
+		memcpy(contents + len, buf, ret);
+		len += ret;
+	}
+	contents[len] = '\0';
+
+	return contents;
+}
+
+int
+main(int argc, const char **argv)
+{
+	const char **arg;
+	const char *path;
+	char *str, *contents;
+	int fd;
+
+	vars = NULL;
+	vars_end = &vars;
+
+	if (!argc) return 1;
+	for (arg = argv + 1; *arg; arg++) {
+		if (!strcmp(*arg, "-h") || !strcmp(*arg, "--help")) {
+			fprintf(stderr, "Usage: tmpl [-C CONFIG].. [-D NAME=VALUE].. FILE..\n");
+			return 1;
+		} else if (!strcmp(*arg, "-D") || !strcmp(*arg, "--define")) {
+			str = strdup(*++arg);
+			if (!str) err(1, "strdup");
+			assign(str);
+		} else if (!strcmp(*arg, "-C") || !strcmp(*arg, "--config")) {
+			contents = readall(*++arg);
+			perline(contents, 1, assign);
+			free(contents);
+		} else {
+			break;
+		}
+	}
+
+	for (; *arg; arg++) {
+		path = !strcmp(*arg, "-") ? "/dev/stdin" : *arg;
+		contents = readall(path);
+		perline(contents, 0, template);
+		free(contents);
+	}
+}