Add a fuzz target for SSML input

https://github.com/espeak-ng/espeak-ng/issues/407

.gitignore

 libespeak-ng-test.la
 libespeak-ng-test.so*
 
+tests/libfuzzrunner.a
+tests/libfuzzrunner.la
+tests/libfuzzrunner.so*
+
 # build output
 
 *.html

Makefile.am

 clean-local:
 	cd src && rm -f *.o *~ && cd ..
 	cd src/libespeak-ng/ && rm -f *.o *.lo && cd ../..
+	cd tests && rm -f *.o *.lo && cd ..
 if HAVE_GRADLE
 	cd android && $(GRADLE) clean
 endif
 	tests/readclause.check \
 	tests/translate.check \
 	tests/ssml.check \
+	tests/ssml-fuzzer.check \
 	tests/api.check \
 	tests/language-phonemes.check \
 	tests/language-pronunciation.check
 
+
+##### fuzzer:
+
+# When OSS-Fuzz [https://github.com/google/oss-fuzz] runs our fuzzer, it sets
+# LIB_FUZZING_ENGINE to libFuzzer [http://llvm.org/docs/LibFuzzer.html].
+# When running outside OSS-Fuzz, we link against our own stub fuzzrunner.
+LIB_FUZZING_ENGINE ?= tests/libfuzzrunner.la
+
+lib_LTLIBRARIES += tests/libfuzzrunner.la
+tests_libfuzzrunner_la_CFLAGS  = -Isrc/libespeak-ng ${AM_CFLAGS}
+tests_libfuzzrunner_la_SOURCES = tests/fuzzrunner.c
+
+noinst_bin_PROGRAMS += tests/ssml-fuzzer.test
+tests_ssml_fuzzer_test_LDADD   = src/libespeak-ng.la ${LIB_FUZZING_ENGINE}
+tests_ssml_fuzzer_test_SOURCES = tests/ssml-fuzzer.c
+tests_ssml_fuzzer_test_DEPENDENCIES = src/libespeak-ng.la tests/libfuzzrunner.la
+
+tests/ssml-fuzzer.check: tests/ssml-fuzzer.test
+	@echo "  TEST      $<"
+	@ESPEAK_DATA_PATH=$(PWD) $< tests/ssml/*.ssml tests/ssml-fuzzer/*.ssml && echo "  PASSED    $<"
+
+
 ##### phoneme data:
 
 espeak-ng-data/phondata: phsource/phonemes.stamp

tests/fuzzrunner.c

+/*
+ * Copyright (C) 2018 Sascha Brawer
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write see:
+ *             <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+#include "speech.h"
+
+#include <errno.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <espeak-ng/espeak_ng.h>
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size);
+
+int main(int argc, char **argv) {
+	int i;
+
+	for (i = 1; i < argc; i++) {
+		size_t filesize = GetFileLength(argv[i]);
+		FILE *stream = fopen(argv[i], "r");
+		unsigned char *text = NULL;
+		if (stream == NULL) {
+			perror(argv[i]);
+			exit(EXIT_FAILURE);
+		}
+
+		text = (unsigned char *) malloc(filesize + 1);
+		if (text == NULL) {
+			espeak_ng_PrintStatusCodeMessage(ENOMEM, stderr, NULL);
+			exit(EXIT_FAILURE);
+		}
+
+		fread(text, 1, filesize, stream);
+		text[filesize] = 0;
+		fclose(stream);
+		LLVMFuzzerTestOneInput(text, filesize);
+	}
+
+	return EXIT_SUCCESS;
+}

tests/ssml-fuzzer.c

+/*
+ * Copyright (C) 2018 Sascha Brawer
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write see:
+ *             <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <stdint.h>
+#include <stdlib.h>
+
+#include <espeak-ng/espeak_ng.h>
+
+static int initialized = 0;
+
+static int SynthCallback(short *wav, int numsamples, espeak_EVENT *events) {
+	/* prevent warning for unused arguments */
+	(void) wav;
+	(void) numsamples;
+	(void) events;
+
+	return 0;
+}
+
+
+/* See http://llvm.org/docs/LibFuzzer.html */
+extern int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size);
+extern int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+	if (!initialized) {
+		espeak_Initialize(AUDIO_OUTPUT_SYNCHRONOUS, 0, NULL, 0);
+		espeak_SetSynthCallback(SynthCallback);
+		initialized = 1;
+	}
+
+	int synth_flags = espeakCHARS_UTF8 | espeakPHONEMES | espeakSSML;
+	espeak_Synth((char*) data, size + 1, 0, POS_CHARACTER, 0,
+	             synth_flags, NULL, NULL);
+
+	return 0;
+}

tests/ssml-fuzzer/100e74d96310ff38a0747812810a713d21dab708.ssml

+<?xml version="1.0"?>
+<speak version="1.1"
+       xmlns="http://www.w3.org/2001 10/synthesis"
+       xml:lang="de">
+  <p>Test</p>
+</speak>

tests/ssml-fuzzer/ca53d4601ced9346305e5b66b1e3d2012395ab25.ssml

+
B"!"";"�.<<<<G<<<	���B"!"""�..r";j"�..r";j"""""""�..r

tests/ssml-fuzzer/cf29484e6a29123590ba3400bb1d4d834e2f3d03.ssml

+<?xml
+