Add fuzzing infrastructure

This commit adds the --enable-fuzzing (and --enable-asan, to make
fuzzing more useful) options and a sample fuzzer for the terminal
parser. At this time only libfuzzer is supported. Future changes to
add AFL to get more fuzzing capability should be possible with the
addition of the afl_driver.cc from Chromium.

src/fuzz/Makefile.am

@@ -0,0 +1,7 @@
+AM_CXXFLAGS = $(WARNING_CXXFLAGS) $(PICKY_CXXFLAGS) $(HARDEN_CFLAGS) $(MISC_CXXFLAGS) $(CODE_COVERAGE_CXXFLAGS) $(FUZZING_CFLAGS)
+
+noinst_PROGRAMS = terminal_parser_fuzzer
+
+terminal_parser_fuzzer_CPPFLAGS = -I$(srcdir)/../terminal -I$(srcdir)/../util
+terminal_parser_fuzzer_LDADD = ../terminal/libmoshterminal.a ../util/libmoshutil.a
+terminal_parser_fuzzer_SOURCES = terminal_parser_fuzzer.cc

src/fuzz/terminal_parser_corpus/7164cb6ab7e834fa6145bcf283e94b981313980d

@@ -0,0 +1,2 @@
+�
+

src/fuzz/terminal_parser_corpus/71853c6197a6a7f222db0f1978c7cb232b87c5ee

@@ -0,0 +1,2 @@
+
+

src/fuzz/terminal_parser_corpus/a09fd95888cb80e1dcea4cc9dbd7d76928909927

@@ -0,0 +1,2 @@
+
+��������

src/fuzz/terminal_parser_corpus/adc83b19e793491b1c6ea0fd8b46cd9f32e592fc

@@ -0,0 +1 @@
+

src/fuzz/terminal_parser_corpus/b67f23988e8274fcf6150a18dacb5ab3db49520d

@@ -0,0 +1,2 @@
+
+����

src/fuzz/terminal_parser_fuzzer.cc

@@ -0,0 +1,15 @@
+#include <cstddef>
+#include <cstdint>
+
+#include "parser.h"
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  Parser::UTF8Parser parser;
+  Parser::Actions result;
+
+  for (size_t i = 0; i < size; i++) {
+    parser.input(data[i], result);
+  }
+  
+  return 0;
+}