Add Makefile target to fuzz with AFL

Also add a compact test case. As far as I understand, a good test case
should exercise many code paths while being as small as possible.
There's probably still room for improvement.

The variable $AFL_PATH must point to the directory containing the AFL
binaries. It can be set as an environment variable or passed to make on
the command line.

2 files changed, 47 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index e6a2314..7cf1cc8 100644
--- a/Makefile
+++ b/Makefile
@@ -59,6 +59,17 @@ prof:
 	cmake .. -DCMAKE_BUILD_TYPE=Profile; \
 	make
 
+afl:
+	@[ -n "$(AFL_PATH)" ] || { echo '$$AFL_PATH not set'; false; }
+	mkdir -p $(BUILDDIR)
+	cd $(BUILDDIR) && cmake .. -DCMAKE_C_COMPILER=$(AFL_PATH)/afl-gcc
+	make
+	$(AFL_PATH)/afl-fuzz \
+	    -i test/afl_test_cases \
+	    -o test/afl_results \
+	    -m none \
+	    $(CMARK)
+
 mingw:
 	mkdir -p $(MINGW_BUILDDIR); \
 	cd $(MINGW_BUILDDIR); \
diff --git a/test/afl_test_cases/test.md b/test/afl_test_cases/test.md
new file mode 100644
index 0000000..27eee00
--- /dev/null
+++ b/test/afl_test_cases/test.md
@@ -0,0 +1,36 @@
+# H1
+
+H2
+--
+
+t ☺  
+*b* **em** `c`
+≥\&\
+\_e\_
+
+4) I1
+
+5) I2
+   > [l](/u "t")
+   >
+   > - [f]
+   > - ![a](/u "t")
+   >
+   >> <ftp://hh>
+   >> <u@hh>
+
+~~~ l☺
+cb
+~~~
+
+    c1
+    c2
+
+***
+
+<div>
+<b>x</b>
+</div>
+
+[f]: /u "t"
+