diff --git a/Makefile.am b/Makefile.am
index 0bebed8..a19a29d 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,4 +1,8 @@
-SUBDIRS = . src docs
+SUBDIRS = . src
+
+if HAVE_DOXYGEN
+SUBDIRS += docs
+endif
 
 EXTRA_DIST = regen.sh
 
diff --git a/configure.ac b/configure.ac
index 6b5d1a6..6702c13 100644
--- a/configure.ac
+++ b/configure.ac
@@ -5,25 +5,37 @@ AC_PREREQ([2.69])
 AC_INIT([asmsh], [0.0-dev], [asmsh@yannweb.net])
 AM_INIT_AUTOMAKE([-Wall])
 
-AC_ARG_ENABLE([check],[  --disable-check disable unit test support],
-[case "${enableval}" in
-	yes) check=true ;;
-	no)  check=false ;;
-	*) AC_MSG_ERROR([bad value ${enableval} for --enable-check]) ;;
-esac],[check=true])
-AM_CONDITIONAL([CHECK], [test x$check = xtrue])
+AC_ARG_WITH([readline],
+	    [AS_HELP_STRING([--without-readline],
+			    [disable support for readline])],
+	    [],
+	    [with_readline=yes])
 
+AC_ARG_WITH([doxygen],
+	    [AS_HELP_STRING([--without-doxygen],
+			    [disable code documentation])],
+	    [],
+	    [with_doxygen=yes])
+
+AC_ARG_WITH([check],
+	    [AS_HELP_STRING([--without-check],
+			    [disable unit-tests])],
+	    [],
+	    [with_check=yes])
+
+AM_CONDITIONAL([CHECK], [test x$with_check = xyes])
 
 # Checks for libraries.
-if test "x$check" = "xtrue"
-then
+AS_IF([test "x$with_check" = "xyes"],
+      [
+	PKG_PROG_PKG_CONFIG([1.8])
 	PKG_CHECK_MODULES([CHECK], [check >= 0.9.4], [],
 	AC_MSG_FAILURE([Unable to locate (check unit test c framework).
 You can run ./configure --disable-check if you do not need unit tests.
 ])) 
 	AS_IF([test x$debug = xtrue], [CK_FORK=no],[])
-fi
-
+      ]
+)
 
 
 AC_CONFIG_SRCDIR([src/asmsh.c])
@@ -32,7 +44,7 @@ AC_CONFIG_HEADERS([src/config.h])
 
 
 # Checks for programs.
-AC_GNU_SOURCE
+AC_USE_SYSTEM_EXTENSIONS
 AC_C_CONST
 AC_C_INLINE
 AC_PROG_CC
@@ -41,30 +53,27 @@ AC_PROG_RANLIB
 AM_PROG_AS
 AM_PROG_AR
 
-if test "x$check" = "xtrue"
-then
+AS_IF([test "x$with_check" = "xyes"],
+      [
 	AC_CHECK_PROGS([GCOV], [gcov])
-	if test -z "$GCOV";
-	then
-		AC_MSG_WARN([gcov not found - continuing without coverage monitoring])
-	else
-		AC_CHECK_PROGS([LCOV], [lcov])
-		if test -z "$LCOV";
-		then
-			AC_MSG_WARN([lcov not found - continuing without HTML coverage summary])
-		fi
-	fi
-fi
+	AC_CHECK_PROGS([LCOV], [lcov])
+      ]
+)
 AC_CHECK_PROGS([CPPCHECK], [cppcheck])
-AC_CHECK_PROGS([DOXYGEN], [doxygen])
-if test -z "$DOXYGEN";
-then
-	AC_MSG_WARN([Doxygen not found - continuing without Doxygen support])
-fi
-AC_CHECK_PROGS([DOT], [dot])
-if test -z "$DOT"; then
-	AC_MSG_ERROR([Doxygen needs dot, please install dot first])
-fi
+
+AS_IF([test "x$with_doxygen" = "xyes"],
+      [
+	AC_CHECK_PROGS([DOXYGEN], [doxygen])
+	AS_IF([test -n "$DOXYGEN"],
+	      [
+		AC_CHECK_PROGS([DOT], [dot])
+		AS_IF([test -z "$DOT"],
+		      [AC_MSG_ERROR([Doxygen needs dot from graphviz (--without-doxygen to disable)])]
+		)
+	      ]
+	)
+      ]
+)
 AM_CONDITIONAL([HAVE_DOXYGEN], [test -n "$DOXYGEN"])
 AM_COND_IF([HAVE_DOXYGEN], [AC_CONFIG_FILES([docs/Doxyfile])])
 AM_COND_IF([HAVE_DOXYGEN], [AC_CONFIG_FILES([docs/Makefile])])
@@ -74,7 +83,13 @@ AM_CONDITIONAL([HAVE_LCOV], [test -n "$LCOV"])
 AM_CONDITIONAL([HAVE_CPPCHECK], [test -n "$CPPCHECK"])
 
 # Checks for libraries.
-AC_CHECK_LIB(readline, readline)
+LIBREADLINE=
+AS_IF([test "x$with_readline" != "xno"],
+      [AC_CHECK_LIB([readline], [readline],
+      		    [],
+		    [AC_MSG_FAILURE(
+		     	[libreadline not found (--without-readline to disable)])]
+		  )])
 
 # Checks for header files.
 AC_CHECK_HEADERS([fcntl.h limits.h stdlib.h string.h unistd.h])
@@ -91,3 +106,21 @@ AC_CHECK_FUNCS([bzero strtoull, gmtime_r, ptrace])
 
 AC_CONFIG_FILES([Makefile src/Makefile tests/Makefile tests/samples/Makefile])
 AC_OUTPUT
+
+yesno_out(){ if test -n "$1";then echo "yes";else echo "no ";fi; }
+echo "
+Features
+--------
+- libreadline support : $with_readline
+
+Tests
+-----
+- check unit tests :    $with_check
+- gcov coverage :       $(yesno_out $GCOV)
+- lcov html report :    $(yesno_out $LCOV)
+
+Documentation
+-------------
+- doxygen :             $(yesno_out $DOXYGEN)
+
+"
diff --git a/src/asm_env.c b/src/asm_env.c
index d447cae..0f9aa03 100644
--- a/src/asm_env.c
+++ b/src/asm_env.c
@@ -102,7 +102,7 @@ void asmsh_env_free(asmsh_env_t *asmenv)
 	free(asmenv);
 }
 
-int asmsh_env_write_mem(asmsh_env_t *env, void **addr, const unsigned char *buf, size_t buf_sz)
+int asmsh_env_write_mem(asmsh_env_t *env, uintptr_t *addr, const unsigned char *buf, size_t buf_sz)
 {
 	int err;
 	u_int64_t data;
@@ -175,7 +175,7 @@ int asmsh_env_write_mem(asmsh_env_t *env, void **addr, const unsigned char *buf,
 
 int asmsh_env_write_code(asmsh_env_t *env, asmsh_bytecode_t *bcode)
 {
-	return asmsh_env_write_mem(env, (void**)&env->code_write_ptr,
+	return asmsh_env_write_mem(env, (uintptr_t*)&env->code_write_ptr,
 			bcode->bytes, bcode->size);
 }
 
@@ -300,7 +300,7 @@ int asmsh_env_update_regs(asmsh_env_t *asmenv)
 	return 0;
 }
 
-int asmsh_env_read_mem(asmsh_env_t *env, void **addr, uint8_t *buf, size_t buf_sz)
+int asmsh_env_read_mem(asmsh_env_t *env, uintptr_t *addr, uint8_t *buf, size_t buf_sz)
 {
 	uint64_t data;
 	size_t readed;
diff --git a/src/asm_env.h b/src/asm_env.h
index 4cbcf56..a1aa7ac 100644
--- a/src/asm_env.h
+++ b/src/asm_env.h
@@ -93,7 +93,7 @@ void asmsh_env_free(asmsh_env_t *asmenv);
  * @param size_t number of bytes to write
  * @return 0 if no errors else -1 with errno set
  */
-int asmsh_env_write_mem(asmsh_env_t *env, void **addr, const unsigned char *buf, size_t buf_sz);
+int asmsh_env_write_mem(asmsh_env_t *env, uintptr_t *addr, const unsigned char *buf, size_t buf_sz);
 
 /** Write bytecode at the next location available in the text map
  * @param asmsh_env_t* The run environment
@@ -134,7 +134,7 @@ int asmsh_env_update_maps(asmsh_env_t *asmenv);
  * @param size_t Read buffer size
  * @return 0 if no error else -1
  */
-int asmsh_env_read_mem(asmsh_env_t *env, void **addr, uint8_t *buf, size_t buf_sz);
+int asmsh_env_read_mem(asmsh_env_t *env, uintptr_t *addr, uint8_t *buf, size_t buf_sz);
 
 /** Set a register value
  * @param asmsh_env_t*
diff --git a/src/asmsh.c b/src/asmsh.c
index 5b65e00..5cfc989 100644
--- a/src/asmsh.c
+++ b/src/asmsh.c
@@ -113,8 +113,7 @@ int main(int argc, char *argv[], char *envp[])
 #ifdef HAVE_LIBREADLINE
 	rl_special_prefixes="";
 	rl_basic_word_break_characters=" \t\n";
-	rl_attempted_completion_function =  asmsh_rl_completion;
-	//rl_completion_entry_function = asmsh_rl_completion_entry_function;
+	rl_attempted_completion_function = asmsh_rl_attempted_completion;
 
 	char * hpath = history_filename_init(NULL);
 	load_history(hpath, add_history);
diff --git a/src/completion.c b/src/completion.c
index 8e65566..77536d4 100644
--- a/src/completion.c
+++ b/src/completion.c
@@ -110,7 +110,7 @@ char **asmsh_rl_attempted_completion(const char *text, int start, int end)
 	}
 	free(tmp_cmd);
 	const char *_cmd = _cmd_from_idx(cmd_idx);
-	if(cmd_sz < strlen(_cmd))
+	if(_cmd && cmd_sz < strlen(_cmd))
 	{
 		/* reformating line buffer : lstrip + command completion */
 		const size_t needed = snprintf(NULL, 0, "%s%s",
diff --git a/src/shell.c b/src/shell.c
index bd5078e..cbd6e25 100644
--- a/src/shell.c
+++ b/src/shell.c
@@ -455,7 +455,7 @@ static int _compile_step(asmsh_t *sh, const char *cmd)
 		case ASMSH_MODE_COMPILE:
 			if(asmsh_env_write_mem(
 					sh->env,
-					(void**)&sh->env->write_ptr,
+					(uintptr_t*)&sh->env->write_ptr,
 					bcode.bytes,
 					bcode.size))
 			{
diff --git a/src/shell.h b/src/shell.h
index dd53ad7..d1fde62 100644
--- a/src/shell.h
+++ b/src/shell.h
@@ -183,6 +183,7 @@ const char* asmsh_cmdline_iter(asmsh_cmdline_t *cmdline);
  * @return 0 on error else return the needed buffer size
  * @todo move in asm_env.*
  * @todo Enhance !!! Add support for relative or absolute address replacement
+ * @todo Bugfix unused preffix argument :/
  */
 size_t asmsh_parse_labels(asmsh_t *sh, char preffix, const char *cmd,
 		char *buf, size_t buf_sz);
diff --git a/src/shell_cmd_breakpoint.c b/src/shell_cmd_breakpoint.c
index 5273d7d..5664990 100644
--- a/src/shell_cmd_breakpoint.c
+++ b/src/shell_cmd_breakpoint.c
@@ -205,10 +205,10 @@ static int brk_del(asmsh_t *sh, asmsh_cmd_args_t *args, int expr_first)
 	int ret = asmsh_brk_del(&sh->env->brks, addr);
 	if(ret < 0)
 	{
-		int err = errno;
+		int _err = errno;
 		asmsh_log_error("Unable to remove breakpoint @ %016lX : %s",
 				addr, strerror(errno));
-		errno = err;
+		errno = _err;
 		return -1;
 	}
 	else if(ret > 0)
diff --git a/src/shell_cmds.c b/src/shell_cmds.c
index 6ece197..4914384 100644
--- a/src/shell_cmds.c
+++ b/src/shell_cmds.c
@@ -398,7 +398,7 @@ int asmsh_cmd_data(asmsh_t *sh, asmsh_cmd_args_t *args)
 			args->args[0]);
 		goto error;
 	}
-	if(asmsh_env_write_mem(sh->env, (void**)&addr, (uint8_t*)data, data_sz))
+	if(asmsh_env_write_mem(sh->env, &addr, (uint8_t*)data, data_sz))
 	{
 		asmsh_log_error("Unable to write child memory");
 		goto error;
@@ -621,7 +621,7 @@ int asmsh_cmd_memdump(asmsh_t *sh, asmsh_cmd_args_t *args)
 		return -1;
 	}
 
-	if(asmsh_env_read_mem(sh->env, (void**)&addr, buf, len))
+	if(asmsh_env_read_mem(sh->env, &addr, buf, len))
 	{
 		return -1;
 	}
diff --git a/src/shell_cmds_lib.c b/src/shell_cmds_lib.c
index bb402cf..14b6f78 100644
--- a/src/shell_cmds_lib.c
+++ b/src/shell_cmds_lib.c
@@ -1,4 +1,5 @@
 #include "shell_cmds_lib.h"
+extern int errno;
 
 /** Utility for @ref asmsh_cmd_parse_addr() parsing an operand
  * @param const char* the string representation of operand
diff --git a/tests/tests_asm_env.c b/tests/tests_asm_env.c
index 8898d1c..01257b3 100644
--- a/tests/tests_asm_env.c
+++ b/tests/tests_asm_env.c
@@ -290,7 +290,7 @@ START_TEST(test_env_write_mem)
 	set_ptrace_record();
 	wr_addr = (uintptr_t)env->code_write_ptr;
 	ck_assert_int_eq(
-		asmsh_env_write_mem(env, (void**)&wr_addr, value, value_sz),
+		asmsh_env_write_mem(env, &wr_addr, value, value_sz),
 		0);
 	ck_assert_int_eq(wr_addr, (uintptr_t)env->code_write_ptr + value_sz);
 	ck_assert_int_eq(ptrace_calls.calls_sz, 2);
@@ -303,7 +303,7 @@ START_TEST(test_env_write_mem)
 	//unalligned write
 	wr_addr = (uintptr_t)env->code_write_ptr + 1;
 	ck_assert_int_eq(
-		asmsh_env_write_mem(env, (void**)&wr_addr, value, value_sz),
+		asmsh_env_write_mem(env, &wr_addr, value, value_sz),
 		0);
 	ck_assert_int_eq(wr_addr, (uintptr_t)env->code_write_ptr + value_sz + 1);
 	ck_assert_int_eq(ptrace_calls.calls_sz, 2 + 1 + 1);
@@ -331,12 +331,12 @@ START_TEST(testloop_env_write_mem_ptrace_fails)
 	
 	set_ptrace_fails_in("asmsh_env_write_mem", _i);
 	wr_addr = (uintptr_t)env->code_write_ptr;
-	ret = asmsh_env_write_mem(env, (void**)&wr_addr, value, value_sz);
+	ret = asmsh_env_write_mem(env, &wr_addr, value, value_sz);
 	ck_assert_int_eq(ret, reset_ptrace_fails_in() < 0 ? -1 : 0);
 
 	set_ptrace_fails_in("asmsh_env_write_mem", _i);
 	wr_addr = (uintptr_t)env->code_write_ptr + 1;
-	ret = asmsh_env_write_mem(env, (void**)&wr_addr, value, value_sz);
+	ret = asmsh_env_write_mem(env, &wr_addr, value, value_sz);
 	ck_assert_int_eq(ret, reset_ptrace_fails_in() < 0 ? -1 : 0);
 }
 END_TEST