Add a cmake option

CMakeLists.txt

@@ -64,6 +64,7 @@ include(cmake/bundle_static.cmake)
 # compatability.
 option(BUILD_SHARED_LIBS "Build shared instead of static library" ${PROJECT_IS_TOP_LEVEL})
 option(UNICORN_FUZZ "Enable fuzzing" OFF)
+option(UNICORN_LOGGING "Enable logging" OFF)
 option(UNICORN_BUILD_TESTS "Build unicorn tests" ${PROJECT_IS_TOP_LEVEL})
 option(UNICORN_INSTALL "Enable unicorn installation" ${PROJECT_IS_TOP_LEVEL})
 set(UNICORN_ARCH "x86;arm;aarch64;riscv;mips;sparc;m68k;ppc;s390x;tricore" CACHE STRING "Enabled unicorn architectures")
@@ -92,6 +93,11 @@ include_directories(
     qemu/tcg
 )
 
+# QEMU logging facility
+if (UNICORN_LOGGING)
+    add_compile_options(-DUNICORN_LOGGING)
+endif()
+
 # Some distributions on some rare architecures don't auto link atomic for us and
 # we do this manually by adding flags.
 set(ATOMIC_LINKAGE_FIX FALSE)

docs/FAQ.md

@@ -134,7 +134,7 @@ However, the qemu logs are partially commented-out and incomplete, but give it a
 You might want to dig deeper - and add your own log messages where you expect or try to find the bug.
 
 See the `unicorn/qemu/include/qemu/log.h` file for details.
-To enable logs, you must recompile Unicorn with the enabled `LOGGING_ENABLED` define.
+To enable logs, you must recompile Unicorn with the enabled `UNICORN_LOGGING` define.
 
 Logs are written in different log levels, which might result into a very verbose logging if enabled.
 To control the log level information, two environment variables could be used.

qemu/include/qemu/log.h

@@ -31,15 +31,16 @@
 /* Logging functions: */
 
 /* To verbose logging, enable the next line. */
-//#define LOGGING_ENABLED // to enable logging
+//#define UNICORN_LOGGING // to enable logging
 
-#ifdef LOGGING_ENABLED
+#ifdef UNICORN_LOGGING
 
 #include <stdint.h>
 #include <string.h>
 #include <stdlib.h>
 #include <stdarg.h>
 #include <stdio.h>
+#include <stdbool.h>
 
 /**
  * Reads the @p env_name and tries to parse the value into an uint32_t.
@@ -222,7 +223,7 @@ static inline bool is_log_level_active(uint32_t level)
 
     return false;
 }
-#endif /* LOGGING_ENABLED */
+#endif /* UNICORN_LOGGING */
 
 /**
  * Logs only if the right log level is set.