Magisk/native/jni/base/logging.cpp

#include <cstdio>
#include <cstdlib>

#include <android/log.h>

#include <flags.h>
#include <base.hpp>

// Just need to include it somewhere
#include <base-rs.cpp>

using namespace std;

static int fmt_and_log_with_rs(LogLevel level, const char *fmt, va_list ap) {
    char buf[4096];
    int ret = vsnprintf(buf, sizeof(buf), fmt, ap);
    log_with_rs(level, rust::Str(buf, ret));
    return ret;
}

int (*cpp_logger)(LogLevel level, const char *fmt, va_list ap) = fmt_and_log_with_rs;

// Used to override external C library logging
extern "C" int magisk_log_print(int prio, const char *tag, const char *fmt, ...) {
    LogLevel level;
    switch (prio) {
    case ANDROID_LOG_DEBUG:
        level = LogLevel::Debug;
        break;
    case ANDROID_LOG_INFO:
        level = LogLevel::Info;
        break;
    case ANDROID_LOG_WARN:
        level = LogLevel::Warn;
        break;
    case ANDROID_LOG_ERROR:
        level = LogLevel::Error;
        break;
    default:
        return 0;
    }

    char fmt_buf[4096];
    auto len = strlcpy(fmt_buf, tag, sizeof(fmt_buf));
    // Prevent format specifications in the tag
    std::replace(fmt_buf, fmt_buf + len, '%', '_');
    snprintf(fmt_buf + len, sizeof(fmt_buf) - len, ": %s", fmt);
    va_list argv;
    va_start(argv, fmt);
    int ret = cpp_logger(level, fmt_buf, argv);
    va_end(argv);
    return ret;
}

#define LOG_BODY(level) { \
    va_list argv;        \
    va_start(argv, fmt); \
    cpp_logger(LogLevel::level, fmt, argv); \
    va_end(argv);        \
}

// LTO will optimize out the NOP function
#if MAGISK_DEBUG
void LOGD(const char *fmt, ...) { LOG_BODY(Debug) }
#else
void LOGD(const char *fmt, ...) {}
#endif
void LOGI(const char *fmt, ...) { LOG_BODY(Info) }
void LOGW(const char *fmt, ...) { LOG_BODY(Warn) }
void LOGE(const char *fmt, ...) { LOG_BODY(Error) }

// Export raw symbol to fortify compat
extern "C" void __vloge(const char* fmt, va_list ap) {
    cpp_logger(LogLevel::Error, fmt, ap);
}