Merge pull request #2370 from acqn/VisibilityFix

[cc65] Fixed visibility of undeclared functions and objects

test/err/bug2304-var-use.c

@@ -0,0 +1,15 @@
+/* Bug 2304 - Visibility of objects/functions undeclared in file scope but 'extern'-declared in unrelated block scopes */
+
+void f1(void)
+{
+    extern int a;
+}
+
+/* 'a' is still invisible in the file scope */
+
+int main(void)
+{
+    return a * 0;   /* Usage of 'a' should be an error */
+}
+
+int a = 42;

test/misc/Makefile

@@ -133,6 +133,12 @@ $(WORKDIR)/goto.$1.$2.prg: goto.c $(ISEQUAL) | $(WORKDIR)
 	$(CC65) -t sim$2 -$1 -o $$@ $$< 2>$(WORKDIR)/goto.$1.$2.out
 	$(ISEQUAL) $(WORKDIR)/goto.$1.$2.out goto.ref
 
+# this one requires failure with --std=c89, it fails with --std=cc65 due to
+# stricter checks
+$(WORKDIR)/bug2304-implicit-func.$1.$2.prg: bug2304-implicit-func.c | $(WORKDIR)
+	$(if $(QUIET),echo misc/bug2304-implicit-func.$1.$2.prg)
+	$(NOT) $(CC65) --standard c89 -t sim$2 -$1 -o $$@ $$< $(NULLERR)
+
 # should not compile until 3-byte struct by value tests are re-enabled
 $(WORKDIR)/struct-by-value.$1.$2.prg: struct-by-value.c | $(WORKDIR)
 	$(if $(QUIET),echo misc/struct-by-value.$1.$2.prg)

test/misc/bug2304-implicit-func.c

@@ -0,0 +1,21 @@
+/* Bug 2304 - Visibility of objects/functions undeclared in file scope but 'extern'-declared in unrelated block scopes */
+
+/* This one should fail even in C89 */
+
+void f1(void)
+{
+    extern unsigned int f();
+}
+
+/* 'f' is still invisible in the file scope */
+
+int main(void)
+{
+    f();        /* Should be a conflict since the implicit function type is incompatible */
+    return 0;
+}
+
+unsigned int f()
+{
+    return 42;
+}