Test compiler flags and README.

README.rst

@@ -42,10 +42,18 @@ The C source code is designed with the following in mind:
 
 Known limitations:
 
-- Recursive messages are not yet supported (probably never will be).
+- Recursive messages are not supported.
+
+- Submessage presence detection isn't implemented.
 
 - ``char`` must be 8 bits.
 
+Support for recursive messages and submessage presence detection has
+been implemented on branch
+``submessage-presence-and-recursive-messages``. However, it makes the
+generated code slightly harder to use, so it has not been merged to
+the master branch yet.
+
 Memory management
 -----------------
 

tests/Makefile

@@ -26,8 +26,9 @@ CFLAGS ?= \
 	-Wformat=2 \
 	-Wshadow \
 	-Werror \
-	-O3 \
+	-O1 \
 	-g \
+	-no-pie \
 	-std=gnu11 \
 	-Wconversion \
 	-Wall \
@@ -39,10 +40,11 @@ all:
 	    -D PBTOOLS_CONFIG_FLOAT=0 \
 	    -I ../pbtools/c_source \
 	    -c \
+	    -no-pie \
 	    ../pbtools/c_source/pbtools.c \
 	    -o no-float.o
-	gcc -O2 -g nala.c -c -o nala.o
-	gcc -O2 -g -I../pbtools/c_source main.c -c -o main.o
+	gcc -O2 -no-pie -g nala.c -c -o nala.o
+	gcc -O2 -no-pie -g -I../pbtools/c_source main.c -c -o main.o
 	gcc \
 	    $(CFLAGS) \
 	    -I../pbtools/c_source \