7903666: Jextract should report issues with missing dependencies

README.md

@@ -119,6 +119,30 @@ jextract -t org.jextract @includes.txt point.h
 
 It is easy to see how this mechanism allows developers to look into the set of symbols seen by `jextract` while parsing, and then process the generated include file, so as to prevent code generation for otherwise unused symbols.
 
+Users should exercise caution when filtering symbols, as it is relatively easy to filter out a declaration that is depended on by one or more declarations:
+
+```c
+// test.h
+struct A {
+   int x;
+}
+struct A aVar;
+```
+
+Here, we could run `jextract` and filter out `A`, like so:
+
+```
+jextract --include-var aVar test.h
+```
+
+However, doing so would lead to broken generated code, as the layout of the global variable `aVar` depends on the layout of the excluded struct `A`.
+
+In such cases, `jextract` will report the missing dependency and terminate without generating any bindings:
+
+```
+ERROR: aVar depends on A which has been excluded
+```
+
 #### Tracing support
 
 It is sometimes useful to inspect the parameters passed to a native call, especially when diagnosing application

src/main/java/org/openjdk/jextract/JextractTool.java

@@ -46,15 +46,12 @@
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.text.MessageFormat;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.List;
-import java.util.Locale;
 import java.util.Optional;
-import java.util.ResourceBundle;
 import java.util.spi.ToolProvider;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -71,11 +68,12 @@ public final class JextractTool {
 
     // error codes
     private static final int SUCCESS       = 0;
-    private static final int OPTION_ERROR  = 1;
-    private static final int INPUT_ERROR   = 2;
-    private static final int CLANG_ERROR   = 3;
-    private static final int RUNTIME_ERROR = 4;
-    private static final int OUTPUT_ERROR  = 5;
+    private static final int FAILURE       = 1;
+    private static final int OPTION_ERROR  = 2;
+    private static final int INPUT_ERROR   = 3;
+    private static final int CLANG_ERROR   = 4;
+    private static final int FATAL_ERROR   = 5;
+    private static final int OUTPUT_ERROR  = 6;
 
     private final Logger logger;
 
@@ -502,7 +500,7 @@ private int run(String[] args) {
             return CLANG_ERROR;
         } catch (RuntimeException re) {
             logger.fatal(re);
-            return RUNTIME_ERROR;
+            return FATAL_ERROR;
         }
 
         try {
@@ -519,10 +517,12 @@ private int run(String[] args) {
             }
         } catch (RuntimeException re) {
             logger.fatal(re);
-            return RUNTIME_ERROR;
+            return FATAL_ERROR;
         }
 
-        return SUCCESS;
+        return logger.hasErrors() ?
+                FAILURE :
+                SUCCESS;
     }
 
     /**

test/lib/testlib/JextractToolRunner.java

@@ -67,11 +67,12 @@ public class JextractToolRunner {
 
     // (private) exit codes from jextract tool. Copied from JextractTool.
     protected static final int SUCCESS       = 0;
-    protected static final int OPTION_ERROR  = 1;
-    protected static final int INPUT_ERROR   = 2;
-    protected static final int CLANG_ERROR   = 3;
-    protected static final int RUNTIME_ERROR = 4;
-    protected static final int OUTPUT_ERROR  = 5;
+    protected static final int FAILURE       = 1;
+    protected static final int OPTION_ERROR  = 2;
+    protected static final int INPUT_ERROR   = 3;
+    protected static final int CLANG_ERROR   = 4;
+    protected static final int RUNTIME_ERROR = 5;
+    protected static final int OUTPUT_ERROR  = 6;
 
     private static String safeFileName(String filename) {
         int ext = filename.lastIndexOf('.');

test/testng/org/openjdk/jextract/test/toolprovider/includeDeps/TestBadIncludes.java

@@ -44,6 +44,7 @@ public void before() {
                 "--include-struct", "C",
                 "--include-function", "n",
                 outputH.toString());
+        result.checkFailure(FAILURE);
     }
 
     @Test(dataProvider = "cases")