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* Add new ClangMemoryMgmtExample in samples for LLVM (pull bytedeco#1522)
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‎CHANGELOG.md‎

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* Add new `ClangMemoryMgmtExample` in samples for LLVM ([pull #1522](https://github.com/bytedeco/javacpp-presets/pull/1522))
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* Enable `opencv_python3` module for `macosx-arm64` as well ([pull #1517](https://github.com/bytedeco/javacpp-presets/pull/1517))
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* Introduce `macosx-arm64` builds for CPython ([pull #1511](https://github.com/bytedeco/javacpp-presets/pull/1511)), NumPy ([pull #1515](https://github.com/bytedeco/javacpp-presets/pull/1515)), SciPy ([pull #1516](https://github.com/bytedeco/javacpp-presets/pull/1516))
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* Update and fix the sample code of the presets for LLVM ([pull #1501](https://github.com/bytedeco/javacpp-presets/pull/1501))

‎llvm/samples/clang/ClangMemoryMgmtExample.java‎

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import org.bytedeco.javacpp.BytePointer;
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import org.bytedeco.javacpp.Pointer;
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import org.bytedeco.javacpp.PointerPointer;
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import org.bytedeco.javacpp.PointerScope;
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import org.bytedeco.llvm.clang.CXClientData;
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import org.bytedeco.llvm.clang.CXCursor;
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import org.bytedeco.llvm.clang.CXCursorVisitor;
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import org.bytedeco.llvm.clang.CXIndex;
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import org.bytedeco.llvm.clang.CXSourceRange;
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import org.bytedeco.llvm.clang.CXString;
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import org.bytedeco.llvm.clang.CXToken;
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import org.bytedeco.llvm.clang.CXTranslationUnit;
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import org.bytedeco.llvm.clang.CXUnsavedFile;
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import org.bytedeco.llvm.global.clang;
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import java.net.URISyntaxException;
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import java.net.URL;
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import java.nio.file.Path;
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import java.nio.file.Paths;
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import java.util.List;
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import java.util.function.Consumer;
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import java.util.function.Supplier;
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import java.util.stream.IntStream;
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import static java.lang.System.out;
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import static java.util.Arrays.asList;
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import static java.util.Objects.requireNonNull;
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import static org.bytedeco.llvm.global.clang.CXChildVisit_Recurse;
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import static org.bytedeco.llvm.global.clang.CXError_Success;
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import static org.bytedeco.llvm.global.clang.CXTranslationUnit_None;
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import static org.bytedeco.llvm.global.clang.clang_Cursor_getTranslationUnit;
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import static org.bytedeco.llvm.global.clang.clang_createIndex;
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import static org.bytedeco.llvm.global.clang.clang_disposeIndex;
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import static org.bytedeco.llvm.global.clang.clang_disposeTokens;
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import static org.bytedeco.llvm.global.clang.clang_disposeTranslationUnit;
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import static org.bytedeco.llvm.global.clang.clang_getCursorExtent;
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import static org.bytedeco.llvm.global.clang.clang_getCursorKind;
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import static org.bytedeco.llvm.global.clang.clang_getCursorKindSpelling;
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import static org.bytedeco.llvm.global.clang.clang_getTokenKind;
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import static org.bytedeco.llvm.global.clang.clang_getTokenSpelling;
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import static org.bytedeco.llvm.global.clang.clang_getTranslationUnitCursor;
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import static org.bytedeco.llvm.global.clang.clang_parseTranslationUnit2;
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import static org.bytedeco.llvm.global.clang.clang_tokenize;
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import static org.bytedeco.llvm.global.clang.clang_visitChildren;
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/**
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* Demonstrates how to avoid memory leaks when traversing the AST and tokenizing
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* ranges.
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*
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* <p>
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* This includes:
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* <ul>
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* <li><em>Try-with-resources</em> for any {@link AutoCloseable} instances
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* (incl. {@link Pointer} descendants);</li>
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* <li>usage of {@link PointerScope} (see {@link #withPointerScope(Runnable)});</li>
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* <li>invocation of {@link clang#clang_disposeIndex(CXIndex)}, {@link
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* clang#clang_disposeTranslationUnit(CXTranslationUnit)}, and {@link
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* clang#clang_disposeTokens(CXTranslationUnit, CXToken, int)} where
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* appropriate.</li>
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* </ul>
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* </p>
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*
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* @see AutoCloseable
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* @see Pointer
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* @see PointerScope
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* @see #withPointerScope(Runnable)
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* @see clang#clang_disposeIndex(CXIndex)
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* @see clang#clang_disposeTranslationUnit(CXTranslationUnit)
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* @see clang#clang_disposeTokens(CXTranslationUnit, CXToken, int)
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* @author Andrey Shcheglov
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*/
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public final class ClangMemoryMgmtExample {
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private ClangMemoryMgmtExample() {
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assert false;
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}
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public static void main(final String... args) throws URISyntaxException {
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final URL codeUrl = requireNonNull(ClangMemoryMgmtExample.class.getResource("/sample1.cc"));
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final Path absoluteFile = Paths.get(codeUrl.toURI()).toAbsolutePath().normalize();
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parse(absoluteFile, asList("-std=gnu++20", "-fparse-all-comments"));
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}
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private static void parse(
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final Path absoluteFile,
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final List<String> commandLineArgs
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) {
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withPointerScope(() -> {
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withIndex(clang_createIndex(1, 0), index -> {
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withTranslationUnit(CXTranslationUnit::new, translationUnit -> {
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try (final BytePointer sourceFilename = new BytePointer(absoluteFile.toString())) {
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try (final PointerPointer<Pointer> commandLineArgsPtr = new PointerPointer<>(commandLineArgs.toArray(new String[0]))) {
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try (final CXUnsavedFile unsavedFiles = new CXUnsavedFile()) {
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final int unsavedFilesCount = 0;
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final int errorCode = clang_parseTranslationUnit2(
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index,
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sourceFilename,
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commandLineArgsPtr,
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commandLineArgs.size(),
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unsavedFiles,
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unsavedFilesCount,
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CXTranslationUnit_None,
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translationUnit
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);
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if (errorCode == CXError_Success) {
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try (final CXCursor rootCursor = clang_getTranslationUnitCursor(translationUnit)) {
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clang_visitChildren(rootCursor, new AstVisitor(), null);
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}
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} else {
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out.printf("Failed to parse %s; parser returned code %d%n", absoluteFile, errorCode);
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}
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}
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}
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}
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});
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});
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});
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}
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private static void withPointerScope(final Runnable block) {
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try (final PointerScope ignored = new PointerScope()) {
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block.run();
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}
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}
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private static void withIndex(
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final CXIndex index,
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final Consumer<CXIndex> block
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) {
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try (final CXIndex ignored = index) {
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try {
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block.accept(index);
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} finally {
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clang_disposeIndex(index);
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}
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}
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}
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private static void withTranslationUnit(
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final Supplier<CXTranslationUnit> lazyTranslationUnit,
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final Consumer<CXTranslationUnit> block
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) {
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try (final CXTranslationUnit translationUnit = lazyTranslationUnit.get()) {
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try {
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block.accept(translationUnit);
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} finally {
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clang_disposeTranslationUnit(translationUnit);
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}
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}
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}
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private static void forEachToken(
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final CXCursor cursor,
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final Consumer<? super CXToken> action
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) {
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try (final CXSourceRange extent = clang_getCursorExtent(cursor)) {
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try (final CXTranslationUnit translationUnit = clang_Cursor_getTranslationUnit(cursor)) {
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try (final CXToken tokens = new CXToken()) {
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final int[] tokenCountRef = new int[1];
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clang_tokenize(translationUnit, extent, tokens, tokenCountRef);
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final int tokenCount = tokenCountRef[0];
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try {
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IntStream.range(0, tokenCount)
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.mapToObj(tokens::position)
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.forEach(action);
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} finally {
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tokens.position(0L);
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clang_disposeTokens(translationUnit, tokens, tokenCount);
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}
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}
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}
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}
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}
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private static final class AstVisitor extends CXCursorVisitor {
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@Override
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public int call(final CXCursor cursor, final CXCursor parent, final CXClientData clientData) {
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try (final CXCursor c = cursor; final CXCursor p = parent; final CXClientData d = clientData) {
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/*-
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* Entering a new `PointerScope` here is 100% necessary,
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* probably because the outer ("lower") stack frame is a
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* native one (i.e. `call()` is directly invoked by the
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* native code).
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*
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* Despite previously registered ("outer") pointer scopes
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* are still visible, having only a single scope per
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* translation unit (i.e., AST tree) rather than per cursor
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* eventually results in 100% usage of all CPU cores -- in
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* the native code.
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*/
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withPointerScope(() -> {
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try (final CXString spelling = clang_getCursorKindSpelling(clang_getCursorKind(cursor))) {
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out.println(spelling.getString());
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}
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try (final CXTranslationUnit translationUnit = clang_Cursor_getTranslationUnit(cursor)) {
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forEachToken(cursor, token -> {
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final TokenKind kind = TokenKind.valueOf(clang_getTokenKind(token));
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try (final CXString spelling = clang_getTokenSpelling(translationUnit, token)) {
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out.printf("\t%s(\"%s\")%n", kind, spelling.getString());
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}
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});
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}
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});
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}
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return CXChildVisit_Recurse;
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}
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}
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private enum TokenKind {
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Punctuation,
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Keyword,
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Identifier,
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Literal,
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Comment,
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;
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private static TokenKind valueOf(final int ordinal) {
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return values()[ordinal];
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}
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}
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}

‎llvm/samples/clang/pom.xml‎

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<version>1.5.11-SNAPSHOT</version>
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<properties>
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<exec.mainClass>ClangASTVisitorExample</exec.mainClass>
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<maven.compiler.source>1.7</maven.compiler.source>
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<maven.compiler.target>1.7</maven.compiler.target>
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<maven.compiler.source>8</maven.compiler.source>
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<maven.compiler.target>8</maven.compiler.target>
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</properties>
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<dependencies>
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<dependency>
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</dependency>
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</dependencies>
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<build>
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<sourceDirectory>.</sourceDirectory>
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<sourceDirectory>${project.basedir}</sourceDirectory>
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<resources>
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<resource>
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<directory>${project.basedir}</directory>
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<includes>
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<include>**/*.cc</include>
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</includes>
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<excludes>
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<exclude>**/*.java</exclude>
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<exclude>**/pom.xml</exclude>
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<exclude>target/**/*</exclude>
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</excludes>
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</resource>
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</resources>
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</build>
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</project>

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