Merge pull request #2658 from kugelfuhr/kugelfuhr/fix-2655

Fix -W -unreachable-code not working in all cases

src/cc65/error.c

@@ -379,6 +379,18 @@ void PPWarning (const char* Format, ...)
 
 
 
+void UnreachableCodeWarning (void)
+/* Print a warning about unreachable code at the current location if these
+** warnings are enabled.
+*/
+{
+    if (IS_Get (&WarnUnreachableCode)) {
+        Warning ("Unreachable code");
+    }
+}
+
+
+
 IntStack* FindWarning (const char* Name)
 /* Search for a warning in the WarnMap table and return a pointer to the
 ** intstack that holds its state. Return NULL if there is no such warning.

src/cc65/error.h

@@ -127,6 +127,11 @@ void LIWarning (errcat_t EC, LineInfo* LI, const char* Format, ...) attribute ((
 void PPWarning (const char* Format, ...) attribute ((format (printf, 1, 2)));
 /* Print a warning message. For use within the preprocessor */
 
+void UnreachableCodeWarning (void);
+/* Print a warning about unreachable code at the current location if these
+** warnings are enabled.
+*/
+
 IntStack* FindWarning (const char* Name);
 /* Search for a warning in the WarnMap table and return a pointer to the
 ** intstack that holds its state. Return NULL if there is no such warning.

src/cc65/stmt.c

@@ -188,8 +188,8 @@ static int IfStatement (void)
         /* If the if expression was always true, the code in the else branch
         ** is never executed. Output a warning if this is the case.
         */
-        if (TestResult == TESTEXPR_TRUE && IS_Get (&WarnUnreachableCode)) {
-            Warning ("Unreachable code");
+        if (TestResult == TESTEXPR_TRUE) {
+            UnreachableCodeWarning ();
         }
 
         /* Define the target for the first test */

src/cc65/testexpr.c

@@ -76,7 +76,7 @@ unsigned Test (unsigned Label, int Invert)
         /* Constant rvalue */
         if (!Invert && Expr.IVal == 0) {
             g_jump (Label);
-            Warning ("Unreachable code");
+            UnreachableCodeWarning ();
         } else if (Invert && Expr.IVal != 0) {
             g_jump (Label);
         }

test/misc/Makefile

@@ -134,6 +134,11 @@ $(WORKDIR)/endless.$1.$2.prg: endless.c | $(WORKDIR)
 
 # these need reference data that can't be generated by a host-compiled program,
 # in a useful way
+$(WORKDIR)/bug2655.$1.$2.prg: bug2655.c $(ISEQUAL) | $(WORKDIR)
+	$(if $(QUIET),echo misc/bug2655.$1.$2.prg)
+	$(CC65) -t sim$2 -$1 -o $$@ $$< 2>$(WORKDIR)/bug2655.$1.$2.out
+	$(ISEQUAL) $(WORKDIR)/bug2655.$1.$2.out bug2655.ref
+
 $(WORKDIR)/limits.$1.$2.prg: limits.c $(ISEQUAL) | $(WORKDIR)
 	$(if $(QUIET),echo misc/limits.$1.$2.prg)
 	$(CC65) -t sim$2 -$1 -o $$(@:.prg=.s) $$< $(NULLERR)

test/misc/bug2655.c

@@ -0,0 +1,18 @@
+void f1(void)
+{
+    if (1) {
+        f1();
+    } else {
+        f1();
+    }
+}
+
+void f2(void)
+{
+    if (0) {
+        f2();
+    } else {
+        f2();
+    }
+}
+

test/misc/bug2655.ref

@@ -0,0 +1,2 @@
+bug2655.c:5: Warning: Unreachable code
+bug2655.c:12: Warning: Unreachable code