Add more CMake options (#1715)

* Enable colored diagnostics

A well-known limitation of using ninja is that it requires the user to
pass -fcolor-diagnostics=always flag to the compiler to get colored
diagnostics. Starting from version 3.24, CMake can do this for us if we
set CMAKE_COLOR_DIAGNOSTICS flag to a truthful value.

* Add CMake option to disable GDB backtrace on fatal signal

Backtraces we produce are very verbose and somewhat useless. They also
are sometimes so long that they fill all of terminal scrollback and hide
the actual error.

* Add an off-by-default CMake option for using LLD as a linker

Using LLD gives a 3-fold link-time improvement on my machine.

Author: DanShaders

CMakeLists.txt

@@ -33,6 +33,8 @@ set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED TRUE)
 set(CMAKE_CXX_EXTENSIONS FALSE)
 
+set(CMAKE_COLOR_DIAGNOSTICS TRUE)
+
 #BEGIN internal
 option(BUILD_SHARED_LIBS "Use \"ON\" to build shared libraries instead of static where it's not specified (not recommended)" OFF)
 option(USE_EMSCRIPTEN "Use \"ON\" for config building wasm." OFF)
@@ -56,6 +58,16 @@ option(TON_USE_TSAN "Use \"ON\" to enable ThreadSanitizer." OFF)
 option(TON_USE_UBSAN "Use \"ON\" to enable UndefinedBehaviorSanitizer." OFF)
 set(TON_ARCH "native" CACHE STRING "Architecture, will be passed to -march=")
 
+option(TON_PRINT_BACKTRACE_ON_CRASH "Attempt to print a backtrace when a fatal signal is caught" ON)
+
+option(TON_USE_LLD "Use LLD for linking" OFF)
+
+if (TON_USE_LLD)
+    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -fuse-ld=lld")
+    set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -fuse-ld=lld")
+    set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -fuse-ld=lld")
+endif()
+
 #BEGIN M1 support
 EXECUTE_PROCESS( COMMAND uname -m COMMAND tr -d '\n' OUTPUT_VARIABLE ARCHITECTURE )
 

tdutils/CMakeLists.txt

@@ -319,6 +319,10 @@ set(TDUTILS_TEST_SOURCE
   PARENT_SCOPE
 )
 
+if (NOT TON_PRINT_BACKTRACE_ON_CRASH)
+  set_source_files_properties(td/utils/port/signals.cpp PROPERTIES COMPILE_DEFINITIONS TON_DISABLE_BACKTRACE)
+endif()
+
 #RULES
 #LIBRARIES
 add_library(tdutils STATIC ${TDUTILS_SOURCE})

tdutils/td/utils/port/signals.cpp

@@ -317,7 +317,7 @@ static void block_stdin() {
 #endif
 }
 
-static void default_failure_signal_handler(int sig) {
+[[maybe_unused]] static void default_failure_signal_handler(int sig) {
   Stacktrace::init();
   signal_safe_write_signal_number(sig);
 
@@ -334,9 +334,11 @@ Status set_default_failure_signal_handler() {
   Stdin();  // init static variables before atexit
 #endif
   std::atexit(block_stdin);
+#ifndef TON_DISABLE_BACKTRACE
   TRY_STATUS(setup_signals_alt_stack());
   TRY_STATUS(set_signal_handler(SignalType::Abort, default_failure_signal_handler));
   TRY_STATUS(set_signal_handler(SignalType::Error, default_failure_signal_handler));
+#endif
   return Status::OK();
 }