Merge #162: cmake: Switch from tri-state options to boolean. Stage TWO

598eda8 cmake [KILL 3-STATE]: Switch `WITH_USDT` to boolean w/ default OFF (Hennadii Stepanov)
f3c2fea fixup! cmake: Add `systemtap-sdt` optional package support (Hennadii Stepanov)

Pull request description:

  Same as #161, but USDT-specific with refactoring of the USDT search logic into its own "FindUSDT" module.

  The first commit is a pure refactoring.

Top commit has no ACKs.

Tree-SHA512: 2d67c7e72509fc78eb906a8af93e7525b8125bdeb38a5f45ceda1c0c75f300c74501402c39d8d17de2585b2ed2939de0009a33231d1164438ce929236d4b742a

CMakeLists.txt

@@ -108,11 +108,11 @@ if(WITH_ZMQ)
   endif()
 endif()
 
-tristate_option(WITH_USDT
-  "Enable tracepoints for Userspace, Statically Defined Tracing."
-  "if sys/sdt.h is found."
-  AUTO
-)
+option(WITH_USDT "Enable tracepoints for Userspace, Statically Defined Tracing." OFF)
+if(WITH_USDT)
+  find_package(USDT MODULE REQUIRED)
+endif()
+
 cmake_dependent_option(WITH_EXTERNAL_SIGNER "Enable external signer support." ON "NOT WIN32" OFF)
 set(ENABLE_EXTERNAL_SIGNER ${WITH_EXTERNAL_SIGNER})
 

cmake/bitcoin-config.h.in

@@ -30,10 +30,6 @@
 /* Copyright year */
 #define COPYRIGHT_YEAR @COPYRIGHT_YEAR@
 
-/* Define to 1 to enable tracepoints for Userspace, Statically Defined Tracing
-   */
-#cmakedefine ENABLE_TRACING 1
-
 /* Define to 1 if you have the declaration of `fork', and to 0 if you don't.
    */
 #cmakedefine01 HAVE_DECL_FORK

cmake/module/FindUSDT.cmake

@@ -0,0 +1,64 @@
+# Copyright (c) 2024-present The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or https://opensource.org/license/mit/.
+
+#[=======================================================================[
+FindUSDT
+--------
+
+Finds the Userspace, Statically Defined Tracing header(s).
+
+Imported Targets
+^^^^^^^^^^^^^^^^
+
+This module provides imported target ``USDT::headers``, if
+USDT has been found.
+
+Result Variables
+^^^^^^^^^^^^^^^^
+
+This module defines the following variables:
+
+``USDT_FOUND``
+  "True" if USDT found.
+
+#]=======================================================================]
+
+find_path(USDT_INCLUDE_DIR
+  NAMES sys/sdt.h
+)
+mark_as_advanced(USDT_INCLUDE_DIR)
+
+if(USDT_INCLUDE_DIR)
+  include(CMakePushCheckState)
+  cmake_push_check_state(RESET)
+
+  include(CheckCXXSourceCompiles)
+  set(CMAKE_REQUIRED_INCLUDES ${USDT_INCLUDE_DIR})
+  check_cxx_source_compiles("
+    #include <sys/sdt.h>
+
+    int main()
+    {
+      DTRACE_PROBE(context, event);
+      int a, b, c, d, e, f, g;
+      DTRACE_PROBE7(context, event, a, b, c, d, e, f, g);
+    }
+    " HAVE_USDT_H
+  )
+
+  cmake_pop_check_state()
+endif()
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(USDT
+  REQUIRED_VARS USDT_INCLUDE_DIR HAVE_USDT_H
+)
+
+if(USDT_FOUND AND NOT TARGET USDT::headers)
+  add_library(USDT::headers INTERFACE IMPORTED)
+  set_target_properties(USDT::headers PROPERTIES
+    INTERFACE_INCLUDE_DIRECTORIES "${USDT_INCLUDE_DIR}"
+    INTERFACE_COMPILE_DEFINITIONS ENABLE_TRACING
+  )
+endif()

cmake/optional.cmake

@@ -50,46 +50,6 @@ if(CCACHE)
   mark_as_advanced(CCACHE_COMMAND)
 endif()
 
-if(WITH_USDT)
-  find_path(SystemTap_INCLUDE_DIR
-    NAMES sys/sdt.h
-  )
-  mark_as_advanced(SystemTap_INCLUDE_DIR)
-
-  if(SystemTap_INCLUDE_DIR)
-    include(CMakePushCheckState)
-    cmake_push_check_state(RESET)
-
-    include(CheckCXXSourceCompiles)
-    set(CMAKE_REQUIRED_INCLUDES ${SystemTap_INCLUDE_DIR})
-    check_cxx_source_compiles("
-      #include <sys/sdt.h>
-
-      int main()
-      {
-        DTRACE_PROBE(context, event);
-        int a, b, c, d, e, f, g;
-        DTRACE_PROBE7(context, event, a, b, c, d, e, f, g);
-      }
-      " HAVE_USDT_H
-    )
-
-    cmake_pop_check_state()
-  endif()
-
-  if(HAVE_USDT_H)
-    target_include_directories(core_interface INTERFACE
-      ${SystemTap_INCLUDE_DIR}
-    )
-    set(ENABLE_TRACING TRUE)
-    set(WITH_USDT ON)
-  elseif(WITH_USDT STREQUAL "AUTO")
-    set(WITH_USDT OFF)
-  else()
-    message(FATAL_ERROR "sys/sdt.h requested, but not found.")
-  endif()
-endif()
-
 if(ENABLE_WALLET)
   if(WITH_SQLITE)
     if(VCPKG_TARGET_TRIPLET)

depends/Makefile

@@ -291,7 +291,7 @@ $(host_prefix)/toolchain.cmake : toolchain.cmake.in $(host_prefix)/.stamp_$(fina
             -e 's|@no_sqlite@|$(NO_SQLITE)|' \
             -e 's|@no_upnp@|$(NO_UPNP)|' \
             -e 's|@no_natpmp@|$(NO_NATPMP)|' \
-            -e 's|@no_usdt@|$(NO_USDT)|' \
+            -e 's|@usdt_packages@|$(usdt_packages_)|' \
             -e 's|@no_harden@|$(NO_HARDEN)|' \
             -e 's|@multiprocess@|$(MULTIPROCESS)|' \
             $< > $@

depends/toolchain.cmake.in

@@ -158,8 +158,10 @@ else()
   set(WITH_NATPMP ON CACHE BOOL "")
 endif()
 
-if(NOT WITH_USDT AND "@no_usdt@" STREQUAL "1")
-  set(WITH_USDT OFF CACHE STRING "Enable tracepoints for Userspace, Statically Defined Tracing.")
+if("@usdt_packages@" STREQUAL "")
+  set(WITH_USDT OFF CACHE BOOL "")
+else()
+  set(WITH_USDT ON CACHE BOOL "")
 endif()
 
 if("@no_harden@")

src/CMakeLists.txt

@@ -123,6 +123,7 @@ target_link_libraries(bitcoin_common
     secp256k1
     Boost::headers
     $<TARGET_NAME_IF_EXISTS:libevent::libevent>
+    $<TARGET_NAME_IF_EXISTS:USDT::headers>
 )
 
 
@@ -258,6 +259,7 @@ target_link_libraries(bitcoin_node
     $<TARGET_NAME_IF_EXISTS:NATPMP::NATPMP>
     $<TARGET_NAME_IF_EXISTS:MiniUPnPc::MiniUPnPc>
     $<TARGET_NAME_IF_EXISTS:bitcoin_zmq>
+    $<TARGET_NAME_IF_EXISTS:USDT::headers>
 )
 
 

src/util/trace.h

@@ -5,10 +5,6 @@
 #ifndef BITCOIN_UTIL_TRACE_H
 #define BITCOIN_UTIL_TRACE_H
 
-#if defined(HAVE_CONFIG_H)
-#include <config/bitcoin-config.h>
-#endif
-
 #ifdef ENABLE_TRACING
 
 #include <sys/sdt.h>

src/wallet/CMakeLists.txt

@@ -38,6 +38,7 @@ target_link_libraries(bitcoin_wallet
     bitcoin_common
     univalue
     Boost::headers
+    $<TARGET_NAME_IF_EXISTS:USDT::headers>
 )
 
 if(NOT USE_SQLITE AND NOT USE_BDB)