Silence "no return value"/"unreachable statement" warnings.

ccxvii · ccxvii · commit b37173e52eb3 · 2014-03-26T14:27:53.000+01:00
clang incorrectly treats a default label as unreachable in a switch on
an enum that has all the cases covered. gcc and msvc complain about
missing return values if there is no default statement.

By making the default case fall through to the JS_TUNDEFINED case we
silence all the compilers and handle corrupt data (an enum that isn't
one of the enumerated values) safely.
diff --git a/Makefile b/Makefile
@@ -8,7 +8,7 @@ incdir ?= $(prefix)/include
 libdir ?= $(prefix)/lib
 
 CC := clang
-CFLAGS := -std=c99 -pedantic -Wall -Wextra -Wunreachable-code -Wno-unused-parameter
+CFLAGS := -std=c99 -pedantic -Wall -Wextra -Wno-unused-parameter -Wunreachable-code
 
 ifeq "$(build)" "debug"
 CFLAGS += -g
diff --git a/jsi.h b/jsi.h
@@ -12,6 +12,7 @@
 #include <math.h>
 #include <float.h>
 
+/* Microsoft Visual C */
 #ifdef _MSC_VER
 #pragma warning(disable:4996) /* _CRT_SECURE_NO_WARNINGS */
 #pragma warning(disable:4244) /* implicit conversion from double to int */
diff --git a/jsrun.c b/jsrun.c
@@ -206,6 +206,7 @@ static const char *js_typeof(js_State *J, int idx)
 {
 	const js_Value *v = stackidx(J, idx);
 	switch (v->type) {
+	default:
 	case JS_TUNDEFINED: return "undefined";
 	case JS_TNULL: return "object";
 	case JS_TBOOLEAN: return "boolean";
diff --git a/jsvalue.c b/jsvalue.c
@@ -112,6 +112,7 @@ js_Value jsV_toprimitive(js_State *J, const js_Value *v, int preferred)
 int jsV_toboolean(js_State *J, const js_Value *v)
 {
 	switch (v->type) {
+	default:
 	case JS_TUNDEFINED: return 0;
 	case JS_TNULL: return 0;
 	case JS_TBOOLEAN: return v->u.boolean;
@@ -169,6 +170,7 @@ double jsV_stringtonumber(js_State *J, const char *s)
 double jsV_tonumber(js_State *J, const js_Value *v)
 {
 	switch (v->type) {
+	default:
 	case JS_TUNDEFINED: return NAN;
 	case JS_TNULL: return 0;
 	case JS_TBOOLEAN: return v->u.boolean;
@@ -242,6 +244,7 @@ const char *jsV_numbertostring(js_State *J, double f)
 const char *jsV_tostring(js_State *J, const js_Value *v)
 {
 	switch (v->type) {
+	default:
 	case JS_TUNDEFINED: return "undefined";
 	case JS_TNULL: return "null";
 	case JS_TBOOLEAN: return v->u.boolean ? "true" : "false";
@@ -283,6 +286,7 @@ static js_Object *jsV_newstring(js_State *J, const char *v)
 js_Object *jsV_toobject(js_State *J, const js_Value *v)
 {
 	switch (v->type) {
+	default:
 	case JS_TUNDEFINED: js_typeerror(J, "cannot convert undefined to object");
 	case JS_TNULL: js_typeerror(J, "cannot convert null to object");
 	case JS_TBOOLEAN: return jsV_newboolean(J, v->u.boolean);

Original file line number	Diff line number	Diff line change
`@@ -206,6 +206,7 @@ static const char js_typeof(js_State J, int idx)`
`206`	`206`	`{`
`207`	`207`	`const js_Value *v = stackidx(J, idx);`
`208`	`208`	`switch (v->type) {`
	`209`	`+ default:`
`209`	`210`	`case JS_TUNDEFINED: return "undefined";`
`210`	`211`	`case JS_TNULL: return "object";`
`211`	`212`	`case JS_TBOOLEAN: return "boolean";`