Fix erroneous warning on unused stock variables.

Bug: issue #976
Test: new test cases
Signed-off-by: David Anderson <[email protected]>

compiler/semantics.cpp

@@ -2311,6 +2311,15 @@ bool Semantics::CheckExprStmt(ExprStmt* stmt) {
     return true;
 }
 
+bool Semantics::IsIncluded(Decl* sym) {
+    const auto fileno = cc_.sources()->GetSourceFileIndex(sym->pos());
+    return !cc_.sources()->opened_files()[fileno]->is_main_file();
+}
+
+bool Semantics::IsIncludedStock(VarDeclBase* sym) {
+    return sym->vclass() == sGLOBAL && sym->is_stock() && IsIncluded(sym);
+}
+
 /*  testsymbols - test for unused local or global variables
  *
  *  "Public" functions are excluded from the check, since these
@@ -2359,9 +2368,14 @@ bool Semantics::TestSymbol(Decl* sym, bool testconst) {
         default: {
             auto var = sym->as<VarDeclBase>();
             /* a variable */
-            if (!var->is_used() && !var->is_public()) {
-                report(sym, 203) << sym->name(); /* symbol isn't used (and not public) */
-            } else if (!var->is_public() && !var->is_read()) {
+
+            // We ignore variables that are marked as public or stock that was included.
+            if (var->is_public() || IsIncludedStock(var))
+                break;
+
+            if (!var->is_used()) {
+                report(sym, 203) << sym->name(); /* symbol isn't used (and not public/stock) */
+            } else if (!var->is_read()) {
                 report(sym, 204) << sym->name(); /* value assigned to symbol is never used */
             }
         }

compiler/semantics.h

@@ -253,6 +253,9 @@ class Semantics final
     bool CheckScalarType(Expr* expr);
     bool IsThisAtom(sp::Atom* atom);
 
+    bool IsIncluded(Decl* expr);
+    bool IsIncludedStock(VarDeclBase* expr);
+
   private:
     CompileContext& cc_;
     TypeManager* types_ = nullptr;

tests/compile-only/fail-stock-array-unused.sp

@@ -0,0 +1,9 @@
+// warnings_are_errors: true
+
+stock const char messages[2][] =
+{
+    "first",
+    "second"
+};
+
+public void main() {}

tests/compile-only/fail-stock-array-unused.txt

@@ -0,0 +1 @@
+(3) : error 203: symbol is never used: "messages"

tests/compile-only/fail-stock-var-unused.sp

@@ -0,0 +1,5 @@
+// warnings_are_errors: true
+
+stock const int X = 1;
+
+public void main() {}

tests/compile-only/fail-stock-var-unused.txt

@@ -0,0 +1 @@
+(3) : error 204: symbol is assigned a value that is never used: "X"

tests/compile-only/ok-included-stock-array-unused.inc

@@ -0,0 +1,5 @@
+stock const char messages[2][] =
+{
+    "first",
+    "second"
+};

tests/compile-only/ok-included-stock-array-unused.sp

@@ -0,0 +1,5 @@
+// warnings_are_errors: true
+
+#include "ok-included-stock-array-unused.inc"
+
+public void main() {}

tests/compile-only/ok-included-stock-var-unused.inc

@@ -0,0 +1 @@
+stock const int X = 1;

tests/compile-only/ok-included-stock-var-unused.sp

@@ -0,0 +1,5 @@
+// warnings_are_errors: true
+
+#include "ok-included-stock-var-unused.inc"
+
+public void main() {}