Finish rewrite to C

Signed-off-by: Mattias Andrée <maandree@kth.se>

5 files changed, 331 insertions, 244 deletions

diff --git a/README b/README
index ec06c25..9d39bdf 100644
--- a/README
+++ b/README
@@ -23,12 +23,12 @@ DESCRIPTION
 	symbol for preprocessing directives) or @>, or is
 	between a line starting with @< and a line starting
 	with @>, is parsed as a line, written in Bash, that
-	is executed during preprocessing.
-	A @< line must have an associated @> line somewhere
-	after it, all lines between them are parsed as
-	preprocessing directives. A @> does however not need
-	an associated @< line somewhere before it, making
-	@> suitable for single line directives.
+	is executed during preprocessing. A @< line must have
+	an associated @> line somewhere after it, all lines
+	between them are parsed as preprocessing directives.
+	A @> does however not need an associated @< line
+	somewhere before it, making @> suitable for single
+	line directives.
 
 	Preprocessing directives can also be inline. For this,
 	use @(COMMAND) where COMMAND is the Bash code to run.
@@ -41,7 +41,7 @@ DESCRIPTION
 	for lowercase.
 
 	Everything that is not a preprocessing directive is
-	echo verbatim.
+	echo verbatim, except all @@ are replaced by @.
 
 OPTIONS
 	-D name=value
diff --git a/config.mk b/config.mk
index 2e90419..20f922d 100644
--- a/config.mk
+++ b/config.mk
@@ -2,5 +2,5 @@ PREFIX    = /usr
 MANPREFIX = $(PREFIX)/share/man
 
 CPPFLAGS  = -D_DEFAULT_SOURCE -D_BSD_SOURCE -D_XOPEN_SOURCE=700
-CFLAGS    = -std=c99 -Wall -O2
-LDFLAGS   = -s
+CFLAGS    = -std=c99 -Wall -Og -g
+LDFLAGS   =
diff --git a/gpp.1 b/gpp.1
index 1b7bb69..8841a2e 100644
--- a/gpp.1
+++ b/gpp.1
@@ -85,7 +85,10 @@ or
 for lowercase.
 .PP
 Everything that is not a preprocessing directive is
-echo verbatim.
+echo verbatim, except all
+.B @@
+are replaced by
+.BR @ .
 
 .SH OPTIONS
 The
diff --git a/gpp.c b/gpp.c
index 569ae76..bc466af 100644
--- a/gpp.c
+++ b/gpp.c
@@ -1,8 +1,12 @@
 /* See LICENSE file for copyright and license details. */
+#include <sys/wait.h>
 #include <ctype.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <limits.h>
+#include <poll.h>
+#include <stdarg.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -87,6 +91,29 @@ xcreate(const char *path)
 }
 
 
+static void
+append(char **restrict out_datap, size_t *restrict out_lenp, size_t *restrict out_sizep, const char *fmt, ...)
+{
+	va_list ap, ap2;
+	size_t len;
+	va_start(ap, fmt);
+	va_copy(ap2, ap);
+	len = (size_t)vsnprintf(NULL, 0, fmt, ap2);
+	va_end(ap2);
+	if (*out_lenp + len + 1 > *out_sizep) {
+		*out_sizep = *out_lenp + len + 1;
+		*out_datap = realloc(*out_datap, *out_sizep);
+		if (!*out_datap) {
+			fprintf(stderr, "%s: realloc: %s\n", argv0, strerror(errno));
+			exit(1);
+		}
+	}
+	vsprintf(&(*out_datap)[*out_lenp], fmt, ap);
+	*out_lenp += len;
+	va_end(ap);
+}
+
+
 int
 main(int argc, char *argv[])
 {
@@ -94,6 +121,7 @@ main(int argc, char *argv[])
 	const char *input_file = NULL;
 	const char *output_file = NULL;
 	const char *symbol = NULL;
+	size_t symlen = 1;
 	int iterations = -1;
 	int unshebang = 0;
 	long int tmp;
@@ -101,8 +129,16 @@ main(int argc, char *argv[])
 	char *in_data = NULL, *out_data = NULL;
 	size_t in_size = 0, in_len = 0, in_off = 0;
 	size_t out_size = 0, out_len = 0, out_off = 0;
-	int in_fd, out_fd, do_close;
+	int in_fd, out_fd, do_close, fds_in[2], fds_out[2];
+	struct pollfd pfds[2];
+	size_t npfds;
+	char buffer[4096], c, *quotes = NULL, quote;
+	size_t brackets, nquotes, quotes_size = 0;
+	int symb, esc, dollar;
+	size_t len, j, lineno, no = 0, cnt;
+	int i, n, status, state, entered;
 	ssize_t r;
+	pid_t pid;
 
 	ARGBEGIN {
 	case 'D':
@@ -154,6 +190,9 @@ main(int argc, char *argv[])
 		if (symbol)
 			usage();
 		symbol = EARGF(usage());
+		symlen = strlen(symbol);
+		if (!symlen)
+			usage();
 		break;
 	case 'u':
 		if (unshebang == 2)
@@ -164,8 +203,11 @@ main(int argc, char *argv[])
 		usage();
 	} ARGEND;
 
-	if (argc)
+	if (argc) {
+		if (!**argv)
+			usage();
 		shell = (void *)argv;
+	}
 
 	if (setenv("_GPP", argv0, 1))
 		fprintf(stderr, "%s: setenv _GPP %s 1: %s\n", argv0, argv0, strerror(errno));
@@ -217,17 +259,289 @@ main(int argc, char *argv[])
 after_unshebang:
 
 	while (iterations--) {
-		/* TODO parse: in -> out */
+		entered = 0;
+		state = 0;
+		lineno = 0;
+		brackets = nquotes = 0;
+		symb = esc = dollar = 0;
+		while (in_off < in_len) {
+			if (state == 2) {
+			preprocess:
+				c = in_data[in_off++];
+				if (c == '\n') {
+					state = 0;
+					brackets = nquotes = 0;
+					symb = esc = dollar = 0;
+					append(&out_data, &out_len, &out_size, "'\n");
+				} else if (brackets) {
+					if (esc) {
+						esc = 0;
+					} else if (nquotes) {
+						if (dollar) {
+							dollar = 0;
+							if (c == '(') {
+								quote = ')';
+								goto add_to_quotes;
+							} else if (c == '{') {
+								quote = '}';
+								goto add_to_quotes;
+							}
+						} else if (c == quotes[nquotes - 1]) {
+							nquotes -= 1;
+						} else if ((quotes[nquotes - 1] == ')' || quotes[nquotes - 1] == '}') &&
+							   (c == '"' || c == '\'' || c == '`')) {
+							quote = c;
+							goto add_to_quotes;
+						} else if (c == '\\' && quotes[nquotes - 1] != '\'') {
+							esc = 1;
+						} else if (c == '$') {
+							dollar = 1;
+						}
+					} else if (c == '"' || c == '\'' || c == '`') {
+						quote = c;
+					add_to_quotes:
+						if (nquotes == quotes_size) {
+							quotes = realloc(quotes, quotes_size += 1);
+							if (!quotes) {
+								fprintf(stderr, "%s: realloc: %s\n", argv0, strerror(errno));
+								return 1;
+							}
+						}
+						quotes[nquotes++] = quote;
+					} else if (c == ')' || c == '}') {
+						if (!--brackets) {
+							append(&out_data, &out_len, &out_size, "%c\"'", c);
+							continue;
+						}
+					} else if (c == '(' || c == '}') {
+						brackets += 1;
+					} else if (c == '\\') {
+						esc = 1;
+					}
+					append(&out_data, &out_len, &out_size, "%c", c);
+				} else if (c == *symbol && in_len - (in_off - 1) >= symlen &&
+					   !memcmp(&in_data[in_off - 1], symbol, symlen)) {
+					if (symb)
+						append(&out_data, &out_len, &out_size, "%s", symbol);
+					symb ^= 1;
+					in_off += symlen - 1;
+				} else if (symb) {
+					symb = 0;
+					if (c == '(' || c == '{') {
+						brackets += 1;
+						append(&out_data, &out_len, &out_size, "'\"$%c", c);
+					} else if (c == '\'') {
+						append(&out_data, &out_len, &out_size, "%s'\\''", symbol);
+					} else {
+						append(&out_data, &out_len, &out_size, "%s%c", symbol, c);
+					}
+				} else if (c == '\'') {
+					append(&out_data, &out_len, &out_size, "'\\''");
+				} else {
+					if (out_len == out_size) {
+						out_data = realloc(out_data, out_size += 4096);
+						if (!out_data) {
+							fprintf(stderr, "%s: realloc: %s\n", argv0, strerror(errno));
+							return 1;
+						}
+					} else {
+						if ((out_data[out_len++] = c) == '\n')
+							state = 0;
+					}
+				}
+			} else if (state == 1) {
+			append_char:
+				if (out_len == out_size) {
+					out_data = realloc(out_data, out_size += 4096);
+					if (!out_data) {
+						fprintf(stderr, "%s: realloc: %s\n", argv0, strerror(errno));
+						return 1;
+					}
+				} else {
+					if ((out_data[out_len++] = in_data[in_off++]) == '\n')
+						state = 0;
+				}
+			} else {
+				lineno += 1;
+				if (in_len - in_off > symlen && !memcmp(&in_data[in_off], symbol, symlen) &&
+				    (in_data[in_off + symlen] == '<' || in_data[in_off + symlen] == '>')) {
+					state = 1;
+					entered = in_data[in_off + symlen] == '<';
+					in_off += symlen + 1;
+				} else if (entered) {
+					goto append_char;
+				} else {
+					append(&out_data, &out_len, &out_size, "printf '\\000%%zu\\000%%s\\n' %zu '", lineno);
+					state = 2;
+					goto preprocess;
+				}
+			}
+		}
+		if (state == 2)
+			append(&out_data, &out_len, &out_size, "'");
 
 		in_len = 0;
 		in_off = 0;
 
-		/* TODO shell: out -> in */
+		if (pipe(fds_in) || pipe(fds_out)) {
+			fprintf(stderr, "%s: pipe: %s\n", argv0, strerror(errno));
+			return 1;
+		}
+		pid = fork();
+		switch (pid) {
+		case -1:
+			fprintf(stderr, "%s: fork: %s\n", argv0, strerror(errno));
+			return 1;
+		case 0:
+			close(fds_in[1]);
+			close(fds_out[0]);
+			if (dup2(fds_in[0], STDIN_FILENO) != STDIN_FILENO) {
+				fprintf(stderr, "%s: dup2 <pipe> STDIN_FILENO: %s\n", argv0, strerror(errno));
+				return 1;
+			}
+			if (dup2(fds_out[1], STDOUT_FILENO) != STDOUT_FILENO) {
+				fprintf(stderr, "%s: dup2 <pipe> STDOUT_FILENO: %s\n", argv0, strerror(errno));
+				return 1;
+			}
+			close(fds_in[0]);
+			close(fds_out[1]);
+			execvp(*shell, (void *)shell);
+			fprintf(stderr, "%s: execvp %s: %s\n", argv0, *shell, strerror(errno));
+			return 1;
+		default:
+			close(fds_in[0]);
+			close(fds_out[1]);
+			break;
+		}
+		pfds[0].fd = fds_in[1];
+		pfds[0].events = POLLOUT;
+		pfds[1].fd = fds_out[0];
+		pfds[1].events = POLLIN;
+		npfds = 2;
+		lineno = 1;
+		state = 0;
+		while (npfds) {
+			n = poll(pfds, npfds, -1);
+			if (n < 0) {
+				fprintf(stderr, "%s: poll: %s\n", argv0, strerror(errno));
+				return 1;
+			}
+			for (i = 0; i < n; i++) {
+				if (!pfds[i].revents)
+					continue;
+				if (pfds[i].fd == fds_in[1]) {
+					if (out_off == out_len) {
+						if (close(fds_in[1])) {
+							fprintf(stderr, "%s: write <pipe>: %s\n", argv0, strerror(errno));
+							return 1;
+						}
+						pfds[i] = pfds[--npfds];
+						continue;
+					}
+					r = write(fds_in[1], &out_data[out_off], out_len - out_off);
+					if (r <= 0) {
+						fprintf(stderr, "%s: write <pipe>: %s\n", argv0, strerror(errno));
+						return 1;
+					}
+					out_off += (size_t)r;
+				} else {
+					r = read(fds_out[0], buffer, sizeof(buffer));
+					if (r <= 0) {
+						if (r < 0 || close(fds_out[0])) {
+							fprintf(stderr, "%s: read <pipe>: %s\n", argv0, strerror(errno));
+							return 1;
+						}
+						pfds[i] = pfds[--npfds];
+						continue;
+					}
+					len = (size_t)r;
+					for (j = 0; j < len; j++) {
+						switch (state) {
+						case 0:
+							no = 0;
+							if (!buffer[j]) {
+								state = 1;
+							} else {
+								state = 3;
+								goto state3;
+							}
+							break;
+						case 1:
+							if (isdigit(buffer[j])) {
+								if (buffer[j] == '0') {
+									append(&in_data, &in_len, &in_size, "%c", 0);
+									state = 3;
+									goto state3;
+								}
+								state = 2;
+							}
+							/* fall through */
+						case 2:
+							if (isdigit(buffer[j])) {
+								if (buffer[j] > (SIZE_MAX - (buffer[j] & 15)) / 10) {
+									append(&in_data, &in_len, &in_size, "%c%zu", 0, no);
+									state = 3;
+									goto state3;
+								}
+								no = no * 10 + (buffer[j] & 15);
+							} else if (!buffer[j]) {
+								if (no > lineno) {
+									cnt = no - lineno;
+									lineno = no;
+									if (in_len + cnt > in_size) {
+										in_size = in_len + cnt;
+										in_data = realloc(in_data, in_size);
+										if (!in_data) {
+											fprintf(stderr, "%s: realloc: %s\n",
+											        argv0, strerror(errno));
+											return 1;
+										}
+									}
+									while (cnt--)
+										in_data[in_len++] = '\n';
+								}
+								state = 3;
+							} else {
+								append(&in_data, &in_len, &in_size, "%c%zu", 0, no);
+								state = 3;
+								goto state3;
+							}
+							break;
+						default:
+						state3:
+							if (in_len == in_size) {
+								in_size += 4096;
+								in_data = realloc(in_data, in_size);
+								if (!in_data) {
+									fprintf(stderr, "%s: realloc: %s\n", argv0, strerror(errno));
+									return 1;
+								}
+							}
+							in_data[in_len++] = buffer[j];
+							if (buffer[j] == '\n') {
+								lineno += 1;
+								state = 0;
+							}
+							break;
+						}
+					}
+				}
+			}
+		}
+		if (waitpid(pid, &status, 0) != pid) {
+			fprintf(stderr, "%s: waitpid %s <&status> 0: %s\n", argv0, *shell, strerror(errno));
+			return 1;
+		}
+		if (status)
+			return WIFEXITED(status) ? WEXITSTATUS(status) : 1;
 
 		out_len = 0;
 		out_off = 0;
+		in_off = 0;
 	}
 
+	free(quotes);
+
 	free(out_data);
 	out_fd = xcreate(output_file);
 	while (in_off < in_len) {
diff --git a/gpp.py b/gpp.py
deleted file mode 100755
index 68a317f..0000000
--- a/gpp.py
+++ /dev/null
@@ -1,230 +0,0 @@
-#!@{SHEBANG}
-# -*- coding: utf-8 -*-
-
-import os
-import sys
-import shlex
-from subprocess import Popen, PIPE
-
-if sys.version_info.major < 3:
-    def bytes(string):
-        r = bytearray(len(string))
-        b = buffer(r)
-        r[:] = string
-        return r
-
-if sys.version_info.major < 3:
-    def bytelist(string):
-        return [ord(c) for c in string]
-else:
-    bytelist = list
-
-symbol = '@'
-encoding = sys.getdefaultencoding()
-iterations = 1
-input_file = '/dev/stdin'
-output_file = '/dev/stdout'
-unshebang = 0
-
-args = sys.argv
-
-# If the file is executed, the first command line argument will be the first argument in the shebang,
-# the second will be the rest of the arguments in the command line as is and the third and final will
-# be the executed file.
-if len(args) == 3:
-    if os.path.exists(args[2]) and os.path.isfile(args[2]) and ((os.stat(args[2]).st_mode & 0o111) != 0):
-        args[1 : 2] = shlex.split(args[1])
-
-for i in range(1, len(args)):
-    arg = args[i]
-    i += 1
-    if   arg in ('-s', '--symbol'):      symbol      = sys.argv[i]
-    elif arg in ('-e', '--encoding'):    encoding    = sys.argv[i]
-    elif arg in ('-n', '--iterations'):  iterations  = int(sys.argv[i])
-    elif arg in ('-u', '--unshebang'):   unshebang   += 1; continue
-    elif arg in ('-i', '--input'):       input_file  = sys.argv[i]
-    elif arg in ('-o', '--output'):      output_file = sys.argv[i]
-    elif arg in ('-f', '--file'):
-        input_file  = sys.argv[i]
-        output_file = sys.argv[i]
-    elif arg in ('-D', '--export'):
-        export = sys.argv[i]
-        if '=' not in export:
-            export += '=1'
-        export = (export.split('=')[0], '='.join(export.split('=')[1:]))
-        os.putenv(export[0], export[1])
-    else:
-        continue
-    i += 1
-
-if input_file == '-':   input_file = '/dev/stdin'
-if output_file == '-':  output_file = '/dev/stdout'
-
-symbol = bytelist(symbol.encode(encoding))
-symlen = len(symbol)
-
-if iterations < 1:
-    if input_file != output_file:
-        data = None
-        with open(input_file, 'rb') as file:
-            data = file.read()
-        with open(output_file, 'wb') as file:
-            file.write(data)
-            file.flush()
-    sys.exit(0)
-
-def linesplit(bs):
-    rc = []
-    elem = []
-    for b in bs:
-        if b == 10:
-            rc.append(elem)
-            elem = []
-        else:
-            elem.append(b)
-    rc.append(elem)
-    return rc
-
-def linejoin(bss):
-    rc = []
-    if len(bss) > 0:
-        rc += bss[0]
-    for bs in bss[1:]:
-        rc.append(10)
-        rc += bs
-    return rc
-
-data = None
-with open(input_file, 'rb') as file:
-    data = file.read()
-data = linesplit(bytelist(data))
-
-if unshebang == 1:
-    if (len(data[0]) >= 2) and (data[0][0] == ord('#')) and (data[0][1] == ord('!')):
-        data[0] = []
-
-if unshebang >= 2:
-    if (len(data[0]) >= 2) and (data[0][0] == ord('#')) and (data[0][1] == ord('!')):
-        data[0] = data[1]
-        data[1] = []
-
-def pp(line):
-    rc = []
-    symb = False
-    brackets = 0
-    esc = False
-    dollar = False
-    quote = []
-    n = len(line)
-    i = 0
-    rc.append(ord('\''))
-    while i < n:
-        c = line[i]
-        i += 1
-        if brackets > 0:
-            if esc:
-                esc = False
-            elif len(quote) > 0:
-                if dollar:
-                    dollar = False
-                    if c == ord('('):
-                        quote.append(ord(')'))
-                    elif c == ord('{'):
-                        quote.append(ord('}'))
-                elif c == quote[-1]:
-                    quote[:] = quote[:-1]
-                elif (quote[-1] in (ord(')'), ord('}'))) and (c in (ord('"'), ord('\''), ord('`'))):
-                    quote.append(c)
-                elif (c == ord('\\')) and (quote[-1] != ord('\'')):
-                    esc = True
-                elif c == ord('$'):
-                    dollar = True
-            elif c in (ord('"'), ord('\''), ord('`')):
-                quote.append(c)
-            elif c in (ord(')'), ord('}')):
-                brackets -= 1
-                if brackets == 0:
-                    rc.append(c)
-                    rc.append(ord('"'))
-                    rc.append(ord('\''))
-                    continue
-            elif c in (ord('('), ord('{')):
-                brackets += 1
-            elif c == ord('\\'):
-                esc = True
-            rc.append(c)
-        elif line[i - 1 : i + symlen - 1] == symbol:
-            if symb:
-                rc += symbol
-            symb = not symb
-            i += symlen - 1
-        elif symb:
-            symb = False
-            if c in (ord('('), ord('{')):
-                brackets += 1
-                rc.append(ord('\''))
-                rc.append(ord('"'))
-                rc.append(ord('$'))
-            else:
-                rc += symbol
-            if c == ord('\''):
-                rc.append(c)
-                rc.append(ord('\\'))
-                rc.append(c)
-            rc.append(c)
-        elif c == ord('\''):
-            rc.append(c)
-            rc.append(ord('\\'))
-            rc.append(c)
-            rc.append(c)
-        else:
-            rc.append(c)
-    rc.append(ord('\''))
-    return rc
-
-for _ in range(iterations):
-    entered = False
-    bashed = []
-    
-    for lineno in range(len(data)):
-        line = data[lineno]
-        if (len(line) > symlen) and (line[:symlen] == symbol) and (line[symlen] in (ord('<'), ord('>'))):
-            bashed.append(line[symlen + 1:])
-            entered = line[symlen] == ord('<')
-        elif entered:
-            bashed.append(line)
-        else:
-            buf = bytelist(('echo $\'\\e%i\\e\'' % lineno).encode())
-            bashed.append(buf + pp(line))
-    
-    bashed = bytes(linejoin(bashed))
-    bash = Popen(["bash"], stdin = PIPE, stdout = PIPE, stderr = sys.stderr)
-    bashed = bash.communicate(bashed)[0]
-    
-    if bash.returncode != 0:
-        sys.exit(bash.returncode)
-    
-    bashed = linesplit(bytelist(bashed))
-    data = []
-    lineno = -1
-    
-    for line in bashed:
-        no = -1
-        if (len(line) > 0) and (line[0] == 0o33):
-            no = 0
-            for i in range(1, len(line)):
-                if line[i] == 0o33:
-                    line = line[i + 1:]
-                    break
-                no = no * 10 + (line[i] - ord('0'))
-        if no > lineno:
-            while no != lineno + 1:
-                data.append([])
-                lineno += 1
-        data.append(line)
-        lineno += 1
-
-data = bytes(linejoin(data))
-with open(output_file, 'wb') as file:
-    file.write(data)
-    file.flush()