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/* Generated by re2c */
// Copyright 2011 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "depfile_parser.h"
#include "util.h"
#include <algorithm>
using namespace std;
DepfileParser::DepfileParser(DepfileParserOptions options)
: options_(options)
{
}
// A note on backslashes in Makefiles, from reading the docs:
// Backslash-newline is the line continuation character.
// Backslash-# escapes a # (otherwise meaningful as a comment start).
// Backslash-% escapes a % (otherwise meaningful as a special).
// Finally, quoting the GNU manual, "Backslashes that are not in danger
// of quoting ‘%’ characters go unmolested."
// How do you end a line with a backslash? The netbsd Make docs suggest
// reading the result of a shell command echoing a backslash!
//
// Rather than implement all of above, we follow what GCC/Clang produces:
// Backslashes escape a space or hash sign.
// When a space is preceded by 2N+1 backslashes, it is represents N backslashes
// followed by space.
// When a space is preceded by 2N backslashes, it represents 2N backslashes at
// the end of a filename.
// A hash sign is escaped by a single backslash. All other backslashes remain
// unchanged.
//
// If anyone actually has depfiles that rely on the more complicated
// behavior we can adjust this.
bool DepfileParser::Parse(string* content, string* err) {
// in: current parser input point.
// end: end of input.
// parsing_targets: whether we are parsing targets or dependencies.
char* in = &(*content)[0];
char* end = in + content->size();
bool have_target = false;
bool parsing_targets = true;
bool poisoned_input = false;
bool is_empty = true;
while (in < end) {
bool have_newline = false;
// out: current output point (typically same as in, but can fall behind
// as we de-escape backslashes).
char* out = in;
// filename: start of the current parsed filename.
char* filename = out;
for (;;) {
// start: beginning of the current parsed span.
const char* start = in;
char* yymarker = NULL;
{
unsigned char yych;
static const unsigned char yybm[] = {
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 128, 0, 0, 0, 128, 0, 0,
128, 128, 0, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 0, 0, 128, 0, 0,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 0, 128, 0, 128,
0, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 0, 128, 128, 0,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 128, 128, 128, 128, 128, 128,
};
yych = *in;
if (yybm[0+yych] & 128) {
goto yy9;
}
if (yych <= '\r') {
if (yych <= '\t') {
if (yych >= 0x01) goto yy4;
} else {
if (yych <= '\n') goto yy6;
if (yych <= '\f') goto yy4;
goto yy8;
}
} else {
if (yych <= '$') {
if (yych <= '#') goto yy4;
goto yy12;
} else {
if (yych <= '?') goto yy4;
if (yych <= '\\') goto yy13;
goto yy4;
}
}
++in;
{
break;
}
yy4:
++in;
yy5:
{
// For any other character (e.g. whitespace), swallow it here,
// allowing the outer logic to loop around again.
break;
}
yy6:
++in;
{
// A newline ends the current file name and the current rule.
have_newline = true;
break;
}
yy8:
yych = *++in;
if (yych == '\n') goto yy6;
goto yy5;
yy9:
yych = *++in;
if (yybm[0+yych] & 128) {
goto yy9;
}
yy11:
{
// Got a span of plain text.
int len = (int)(in - start);
// Need to shift it over if we're overwriting backslashes.
if (out < start)
memmove(out, start, len);
out += len;
continue;
}
yy12:
yych = *++in;
if (yych == '$') goto yy14;
goto yy5;
yy13:
yych = *(yymarker = ++in);
if (yych <= ' ') {
if (yych <= '\n') {
if (yych <= 0x00) goto yy5;
if (yych <= '\t') goto yy16;
goto yy17;
} else {
if (yych == '\r') goto yy19;
if (yych <= 0x1F) goto yy16;
goto yy21;
}
} else {
if (yych <= '9') {
if (yych == '#') goto yy23;
goto yy16;
} else {
if (yych <= ':') goto yy25;
if (yych == '\\') goto yy27;
goto yy16;
}
}
yy14:
++in;
{
// De-escape dollar character.
*out++ = '$';
continue;
}
yy16:
++in;
goto yy11;
yy17:
++in;
{
// A line continuation ends the current file name.
break;
}
yy19:
yych = *++in;
if (yych == '\n') goto yy17;
in = yymarker;
goto yy5;
yy21:
++in;
{
// 2N+1 backslashes plus space -> N backslashes plus space.
int len = (int)(in - start);
int n = len / 2 - 1;
if (out < start)
memset(out, '\\', n);
out += n;
*out++ = ' ';
continue;
}
yy23:
++in;
{
// De-escape hash sign, but preserve other leading backslashes.
int len = (int)(in - start);
if (len > 2 && out < start)
memset(out, '\\', len - 2);
out += len - 2;
*out++ = '#';
continue;
}
yy25:
yych = *++in;
if (yych <= '\f') {
if (yych <= 0x00) goto yy28;
if (yych <= 0x08) goto yy26;
if (yych <= '\n') goto yy28;
} else {
if (yych <= '\r') goto yy28;
if (yych == ' ') goto yy28;
}
yy26:
{
// De-escape colon sign, but preserve other leading backslashes.
// Regular expression uses lookahead to make sure that no whitespace
// nor EOF follows. In that case it'd be the : at the end of a target
int len = (int)(in - start);
if (len > 2 && out < start)
memset(out, '\\', len - 2);
out += len - 2;
*out++ = ':';
continue;
}
yy27:
yych = *++in;
if (yych <= ' ') {
if (yych <= '\n') {
if (yych <= 0x00) goto yy11;
if (yych <= '\t') goto yy16;
goto yy11;
} else {
if (yych == '\r') goto yy11;
if (yych <= 0x1F) goto yy16;
goto yy30;
}
} else {
if (yych <= '9') {
if (yych == '#') goto yy23;
goto yy16;
} else {
if (yych <= ':') goto yy25;
if (yych == '\\') goto yy32;
goto yy16;
}
}
yy28:
++in;
{
// Backslash followed by : and whitespace.
// It is therefore normal text and not an escaped colon
int len = (int)(in - start - 1);
// Need to shift it over if we're overwriting backslashes.
if (out < start)
memmove(out, start, len);
out += len;
if (*(in - 1) == '\n')
have_newline = true;
break;
}
yy30:
++in;
{
// 2N backslashes plus space -> 2N backslashes, end of filename.
int len = (int)(in - start);
if (out < start)
memset(out, '\\', len - 1);
out += len - 1;
break;
}
yy32:
yych = *++in;
if (yych <= ' ') {
if (yych <= '\n') {
if (yych <= 0x00) goto yy11;
if (yych <= '\t') goto yy16;
goto yy11;
} else {
if (yych == '\r') goto yy11;
if (yych <= 0x1F) goto yy16;
goto yy21;
}
} else {
if (yych <= '9') {
if (yych == '#') goto yy23;
goto yy16;
} else {
if (yych <= ':') goto yy25;
if (yych == '\\') goto yy27;
goto yy16;
}
}
}
}
int len = (int)(out - filename);
const bool is_dependency = !parsing_targets;
if (len > 0 && filename[len - 1] == ':') {
len--; // Strip off trailing colon, if any.
parsing_targets = false;
have_target = true;
}
if (len > 0) {
is_empty = false;
StringPiece piece = StringPiece(filename, len);
// If we've seen this as an input before, skip it.
std::vector<StringPiece>::iterator pos = std::find(ins_.begin(), ins_.end(), piece);
if (pos == ins_.end()) {
if (is_dependency) {
if (poisoned_input) {
*err = "inputs may not also have inputs";
return false;
}
// New input.
ins_.push_back(piece);
} else {
// Check for a new output.
if (std::find(outs_.begin(), outs_.end(), piece) == outs_.end())
outs_.push_back(piece);
}
} else if (!is_dependency) {
// We've passed an input on the left side; reject new inputs.
poisoned_input = true;
}
}
if (have_newline) {
// A newline ends a rule so the next filename will be a new target.
parsing_targets = true;
poisoned_input = false;
}
}
if (!have_target && !is_empty) {
*err = "expected ':' in depfile";
return false;
}
return true;
}
|