LibCpp: Move parser tests to Userland/Libraries/LibCpp/Tests/parser

Userland/Libraries/LibCpp/Tests/parser/strace.cpp

@@ -0,0 +1,145 @@
+static int g_pid = -1;
+
+static void handle_sigint(int)
+{
+    if (g_pid == -1)
+        return;
+
+    if (ptrace(PT_DETACH, g_pid, 0, 0) == -1) {
+        perror("detach");
+    }
+}
+
+int main(int argc, char** argv)
+{
+    if (pledge("stdio wpath cpath proc exec ptrace sigaction", nullptr) < 0) {
+        perror("pledge");
+        return 1;
+    }
+
+    Vector<const char*> child_argv;
+
+    const char* output_filename = nullptr;
+    auto trace_file = Core::File::standard_error();
+
+    Core::ArgsParser parser;
+    parser.set_general_help(
+        "Trace all syscalls and their result.");
+    parser.add_option(g_pid, "Trace the given PID", "pid", 'p', "pid");
+    parser.add_option(output_filename, "Filename to write output to", "output", 'o', "output");
+    parser.add_positional_argument(child_argv, "Arguments to exec", "argument", Core::ArgsParser::Required::No);
+
+    parser.parse(argc, argv);
+
+    if (output_filename != nullptr) {
+        auto open_result = Core::File::open(output_filename, Core::OpenMode::WriteOnly);
+        if (open_result.is_error()) {
+            outln(stderr, "Failed to open output file: {}", open_result.error());
+            return 1;
+        }
+        trace_file = open_result.value();
+    }
+
+    if (pledge("stdio proc exec ptrace sigaction", nullptr) < 0) {
+        perror("pledge");
+        return 1;
+    }
+
+    int status;
+    if (g_pid == -1) {
+        if (child_argv.is_empty()) {
+            outln(stderr, "strace: Expected either a pid or some arguments\n");
+            return 1;
+        }
+
+        child_argv.append(nullptr);
+        int pid = fork();
+        if (pid < 0) {
+            perror("fork");
+            return 1;
+        }
+
+        if (!pid) {
+            if (ptrace(PT_TRACE_ME, 0, 0, 0) == -1) {
+                perror("traceme");
+                return 1;
+            }
+            int rc = execvp(child_argv.first(), const_cast<char**>(child_argv.data()));
+            if (rc < 0) {
+                perror("execvp");
+                exit(1);
+            }
+            VERIFY_NOT_REACHED();
+        }
+
+        g_pid = pid;
+        if (waitpid(pid, &status, WSTOPPED | WEXITED) != pid || !WIFSTOPPED(status)) {
+            perror("waitpid");
+            return 1;
+        }
+    }
+
+    struct sigaction sa;
+    memset(&sa, 0, sizeof(struct sigaction));
+    sa.sa_handler = handle_sigint;
+    sigaction(SIGINT, &sa, nullptr);
+
+    if (ptrace(PT_ATTACH, g_pid, 0, 0) == -1) {
+        perror("attach");
+        return 1;
+    }
+    if (waitpid(g_pid, &status, WSTOPPED | WEXITED) != g_pid || !WIFSTOPPED(status)) {
+        perror("waitpid");
+        return 1;
+    }
+
+    for (;;) {
+        if (ptrace(PT_SYSCALL, g_pid, 0, 0) == -1) {
+            perror("syscall");
+            return 1;
+        }
+        if (waitpid(g_pid, &status, WSTOPPED | WEXITED) != g_pid || !WIFSTOPPED(status)) {
+            perror("wait_pid");
+            return 1;
+        }
+        PtraceRegisters regs = {};
+        if (ptrace(PT_GETREGS, g_pid, &regs, 0) == -1) {
+            perror("getregs");
+            return 1;
+        }
+        u32 syscall_index = regs.eax;
+        u32 arg1 = regs.edx;
+        u32 arg2 = regs.ecx;
+        u32 arg3 = regs.ebx;
+
+        if (ptrace(PT_SYSCALL, g_pid, 0, 0) == -1) {
+            perror("syscall");
+            return 1;
+        }
+        if (waitpid(g_pid, &status, WSTOPPED | WEXITED) != g_pid || !WIFSTOPPED(status)) {
+            perror("wait_pid");
+            return 1;
+        }
+
+        if (ptrace(PT_GETREGS, g_pid, &regs, 0) == -1) {
+            perror("getregs");
+            return 1;
+        }
+
+        u32 res = regs.eax;
+
+        auto string = String::formatted("{}({:#08x}, {:#08x}, {:#08x})\t={}\n",
+            Syscall::to_string((Syscall::Function)syscall_index),
+            arg1,
+            arg2,
+            arg3,
+            res);
+
+        if (!trace_file->write(string)) {
+            warnln("write: {}", trace_file->error_string());
+            return 1;
+        }
+    }
+
+    return 0;
+}