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/**
 * @test
 * @bug 8366138
 * @summary C2: jump_switch_ranges could cause stack overflow when compiling
 *          huge switch statement with zero-count profiling data.
 * @library /test/lib /
 * @run main/othervm ${test.main.class}
 * @run main/othervm -Xbatch -XX:CompileOnly=Test::test -XX:-DontCompileHugeMethods -XX:CompilerThreadStackSize=512 ${test.main.class}
 * @run main/othervm -Xbatch -XX:CompileOnly=Test::test -XX:+DontCompileHugeMethods -XX:CompilerThreadStackSize=512 ${test.main.class}
 */

package compiler.c2;

import java.util.stream.Stream;

import compiler.lib.compile_framework.CompileFramework;
import compiler.lib.template_framework.Template;
import static compiler.lib.template_framework.Template.scope;

public class TestSwitchStackOverflow {
    // Template method exceeds HugeMethodLimit, hence -XX:-DontCompileHugeMethods.
    // 5000 cases + CompilerThreadStackSize=512 reliably overflows without the fix.
    static final int NUM_CASES = 5000;

    // Generate a class with a large tableswitch method and a main that
    // triggers recompilation with zero-count profiling data:
    //   Phase 1: warm up with default-only path -> C2 compiles
    //   Phase 2: hit a case -> triggers unstable_if deopt
    //   Phase 3: recompile with all counts zero (except the default case)
    static String generate() {
        var caseTemplate = Template.make("i", (Integer i) -> scope(
            """
            case #i:
                return #i;
            """
        ));
        var test = Template.make(() -> scope(
            """
            public class Test {
                static int test(int x) {
                    switch (x) {
                    """,
                    Stream.iterate(0, i -> i + 1)
                          .limit(NUM_CASES)
                          .map(i -> caseTemplate.asToken(i))
                          .toList(),
                    """
                        default: return -1;
                    }
                }

                public static void main(String[] args) {
                    for (int i = 0; i < 10_000; i++) {
                        test(-1);
                    }
                    test(42);
                    for (int i = 0; i < 10_000; i++) {
                        test(-1);
                    }
                    System.out.println("Done");
                }
            }
            """
        ));

        return test.render();
    }

    public static void main(String[] args) {
        CompileFramework comp = new CompileFramework();
        comp.addJavaSourceCode("Test", generate());
        comp.compile();
        comp.invoke("Test", "main", new Object[] { new String[0] });
    }
}