Merge #192: cmake: Switch to libsecp256k1 upstream build system

458d54c cmake: Run secp256k1 tests (Hennadii Stepanov)
bfe7c4d [FIXUP] cmake: Enable tests before adding subdirectories (Hennadii Stepanov)
70ec2d9 cmake: Reorder subdirectories (Hennadii Stepanov)
cdd843a cmake: Override build configurations for libsecp256k1 (Hennadii Stepanov)
65f15d1 cmake: Pass to secp256k1 build system only sanitizer flags (Hennadii Stepanov)
469e1ad cmake: Remove C stuff from summary (Hennadii Stepanov)
c3134b0 cmake: Let libsecp256k1 manage config-specific C flags (Hennadii Stepanov)
f0aec78 cmake: Switch to libsecp256k1 upstream build system (Hennadii Stepanov)

Pull request description:

  To test this PR, one can compare the ouputs of the following commands:
  - Autotools:
  ```
  $ make -C src/secp256k1 libsecp256k1.la V=1
  ```
  - CMake:
  ```
  $ cmake --build build -t secp256k1 --verbose
  ```

  Also sets of the libsecp256k1-specific tests can be compared between `make check` and `ctest`.

ACKs for top commit:
  real-or-random:
    utACK 458d54c as far as the secp256k1 config is concerned

Tree-SHA512: 212830a31832fb4af609eb7799ad140a22a2bc13c0685286dc58a25d9e5767394e94cbc969268a4e6adcf3c6a0b059f0f74dd7220e30dbbcbfebd1647279e5bd

CMakeLists.txt

@@ -322,11 +322,13 @@ target_link_libraries(core_base_interface INTERFACE
   Threads::Threads
 )
 
+add_library(sanitize_interface INTERFACE)
+target_link_libraries(core_base_interface INTERFACE sanitize_interface)
 if(SANITIZERS)
   # First check if the compiler accepts flags. If an incompatible pair like
   # -fsanitize=address,thread is used here, this check will fail. This will also
   # fail if a bad argument is passed, e.g. -fsanitize=undfeined
-  try_append_cxx_flags("-fsanitize=${SANITIZERS}" TARGET core_base_interface
+  try_append_cxx_flags("-fsanitize=${SANITIZERS}" TARGET sanitize_interface
     RESULT_VAR cxx_supports_sanitizers
     SKIP_LINK
   )
@@ -353,7 +355,7 @@ if(SANITIZERS)
     message(FATAL_ERROR "Linker did not accept requested flags, you are missing required libraries.")
   endif()
 endif()
-target_link_options(core_base_interface INTERFACE ${SANITIZER_LDFLAGS})
+target_link_options(sanitize_interface INTERFACE ${SANITIZER_LDFLAGS})
 
 include(AddBoostIfNeeded)
 add_boost_if_needed()
@@ -369,7 +371,6 @@ include(cmake/ccache.cmake)
 include(cmake/crc32c.cmake)
 include(cmake/leveldb.cmake)
 include(cmake/minisketch.cmake)
-include(cmake/secp256k1.cmake)
 
 add_library(warn_interface INTERFACE)
 target_link_libraries(core_interface INTERFACE warn_interface)
@@ -429,15 +430,12 @@ target_compile_definitions(core_interface_debug INTERFACE
 )
 # We leave assertions on.
 if(MSVC)
-  remove_c_flag_from_all_configs(/DNDEBUG)
   remove_cxx_flag_from_all_configs(/DNDEBUG)
 else()
-  remove_c_flag_from_all_configs(-DNDEBUG)
   remove_cxx_flag_from_all_configs(-DNDEBUG)
 
-  # Adjust flags used by the C/CXX compiler during RELEASE builds.
+  # Adjust flags used by the CXX compiler during RELEASE builds.
   # Prefer -O2 optimization level. (-O3 is CMake's default for Release for many compilers.)
-  replace_c_flag_in_config(Release -O3 -O2)
   replace_cxx_flag_in_config(Release -O3 -O2)
 
   are_flags_overridden(CMAKE_CXX_FLAGS_DEBUG cxx_flags_debug_overridden)
@@ -447,6 +445,7 @@ else()
     if(compiler_supports_g3)
       replace_cxx_flag_in_config(Debug -g -g3)
     endif()
+    unset(compiler_supports_g3)
 
     try_append_cxx_flags("-ftrapv" RESULT_VAR compiler_supports_ftrapv)
     if(compiler_supports_ftrapv)
@@ -463,24 +462,6 @@ else()
     )
   endif()
   unset(cxx_flags_debug_overridden)
-
-  are_flags_overridden(CMAKE_C_FLAGS_DEBUG c_flags_debug_overridden)
-  if(NOT c_flags_debug_overridden)
-    # Redefine flags used by the C compiler during DEBUG builds.
-    if(compiler_supports_g3)
-      replace_c_flag_in_config(Debug -g -g3)
-    endif()
-
-    string(PREPEND CMAKE_C_FLAGS_DEBUG "-O0 ")
-
-    set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG}"
-      CACHE STRING
-      "Flags used by the C compiler during DEBUG builds."
-      FORCE
-    )
-  endif()
-  unset(compiler_supports_g3)
-  unset(c_flags_debug_overridden)
 endif()
 
 set(CMAKE_CXX_FLAGS_COVERAGE "-Og --coverage")
@@ -599,6 +580,9 @@ if(DEFINED ENV{LDFLAGS})
   deduplicate_flags(CMAKE_EXE_LINKER_FLAGS)
 endif()
 
+if(BUILD_TESTS)
+  enable_testing()
+endif()
 # TODO: The `CMAKE_SKIP_BUILD_RPATH` variable setting can be deleted
 #       in the future after reordering Guix script commands to
 #       perform binary checks after the installation step.
@@ -607,10 +591,11 @@ endif()
 # - https://github.com/bitcoin/bitcoin/pull/30312#issuecomment-2191235833
 set(CMAKE_SKIP_BUILD_RPATH TRUE)
 set(CMAKE_SKIP_INSTALL_RPATH TRUE)
-add_subdirectory(src)
 add_subdirectory(test)
 add_subdirectory(doc)
 
+add_subdirectory(src)
+
 include(cmake/tests.cmake)
 
 include(Maintenance)
@@ -664,7 +649,6 @@ else()
   set(cross_status "FALSE")
 endif()
 message("Cross compiling ....................... ${cross_status}")
-message("C compiler ............................ ${CMAKE_C_COMPILER_ID} ${CMAKE_C_COMPILER_VERSION}, ${CMAKE_C_COMPILER}")
 message("C++ compiler .......................... ${CMAKE_CXX_COMPILER_ID} ${CMAKE_CXX_COMPILER_VERSION}, ${CMAKE_CXX_COMPILER}")
 include(FlagsSummary)
 flags_summary()

cmake/module/FlagsSummary.cmake

@@ -22,17 +22,6 @@ function(print_flags_per_config config indent_num)
   get_target_interface(definitions ${config} core_interface COMPILE_DEFINITIONS)
   indent_message("Preprocessor defined macros ..........." "${definitions}" ${indent_num})
 
-  string(STRIP "${CMAKE_C_FLAGS} ${CMAKE_C_FLAGS_${config_uppercase}}" combined_c_flags)
-  string(STRIP "${combined_c_flags} ${CMAKE_C${CMAKE_C_STANDARD}_STANDARD_COMPILE_OPTION}" combined_c_flags)
-  if(CMAKE_POSITION_INDEPENDENT_CODE)
-    string(JOIN " " combined_c_flags ${combined_c_flags} ${CMAKE_C_COMPILE_OPTIONS_PIC})
-  endif()
-  get_target_interface(core_c_flags ${config} core_base_interface COMPILE_OPTIONS)
-  string(STRIP "${combined_c_flags} ${core_c_flags}" combined_c_flags)
-  string(STRIP "${combined_c_flags} ${APPEND_CPPFLAGS}" combined_c_flags)
-  string(STRIP "${combined_c_flags} ${APPEND_CFLAGS}" combined_c_flags)
-  indent_message("C compiler flags ......................" "${combined_c_flags}" ${indent_num})
-
   string(STRIP "${CMAKE_CXX_FLAGS} ${CMAKE_CXX_FLAGS_${config_uppercase}}" combined_cxx_flags)
   string(STRIP "${combined_cxx_flags} ${CMAKE_CXX${CMAKE_CXX_STANDARD}_STANDARD_COMPILE_OPTION}" combined_cxx_flags)
   if(CMAKE_POSITION_INDEPENDENT_CODE)

cmake/module/ProcessConfigurations.cmake

@@ -84,23 +84,6 @@ function(set_default_config config)
   endif()
 endfunction()
 
-function(remove_c_flag_from_all_configs flag)
-  get_all_configs(all_configs)
-  foreach(config IN LISTS all_configs)
-    string(TOUPPER "${config}" config_uppercase)
-    set(flags "${CMAKE_C_FLAGS_${config_uppercase}}")
-    separate_arguments(flags)
-    list(FILTER flags EXCLUDE REGEX "${flag}")
-    list(JOIN flags " " new_flags)
-    set(CMAKE_C_FLAGS_${config_uppercase} "${new_flags}" PARENT_SCOPE)
-    set(CMAKE_C_FLAGS_${config_uppercase} "${new_flags}"
-      CACHE STRING
-      "Flags used by the C compiler during ${config_uppercase} builds."
-      FORCE
-    )
-  endforeach()
-endfunction()
-
 function(remove_cxx_flag_from_all_configs flag)
   get_all_configs(all_configs)
   foreach(config IN LISTS all_configs)
@@ -118,17 +101,6 @@ function(remove_cxx_flag_from_all_configs flag)
   endforeach()
 endfunction()
 
-function(replace_c_flag_in_config config old_flag new_flag)
-  string(TOUPPER "${config}" config_uppercase)
-  string(REGEX REPLACE "(^| )${old_flag}( |$)" "\\1${new_flag}\\2" new_flags "${CMAKE_C_FLAGS_${config_uppercase}}")
-  set(CMAKE_C_FLAGS_${config_uppercase} "${new_flags}" PARENT_SCOPE)
-  set(CMAKE_C_FLAGS_${config_uppercase} "${new_flags}"
-    CACHE STRING
-    "Flags used by the C compiler during ${config_uppercase} builds."
-    FORCE
-  )
-endfunction()
-
 function(replace_cxx_flag_in_config config old_flag new_flag)
   string(TOUPPER "${config}" config_uppercase)
   string(REGEX REPLACE "(^| )${old_flag}( |$)" "\\1${new_flag}\\2" new_flags "${CMAKE_CXX_FLAGS_${config_uppercase}}")

cmake/tests.cmake

@@ -2,8 +2,6 @@
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or https://opensource.org/license/mit/.
 
-include(CTest)
-
 if(TARGET bitcoin-util AND TARGET bitcoin-tx AND PYTHON_COMMAND)
   add_test(NAME util_test_runner
     COMMAND ${CMAKE_COMMAND} -E env BITCOINUTIL=$<TARGET_FILE:bitcoin-util> BITCOINTX=$<TARGET_FILE:bitcoin-tx> ${PYTHON_COMMAND} ${CMAKE_BINARY_DIR}/test/util/test_runner.py

src/CMakeLists.txt

@@ -1,6 +1,6 @@
-# Copyright (c) 2023 The Bitcoin Core developers
+# Copyright (c) 2023-present The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
-# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+# file COPYING or https://opensource.org/license/mit/.
 
 include(GNUInstallDirs)
 include(AddWindowsResources)
@@ -38,6 +38,38 @@ if(WITH_MULTIPROCESS)
   add_subdirectory(ipc)
 endif()
 
+#=============================
+# secp256k1 subtree
+#=============================
+message("")
+message("Configuring secp256k1 subtree...")
+set(SECP256K1_DISABLE_SHARED ON CACHE BOOL "" FORCE)
+set(SECP256K1_ENABLE_MODULE_ECDH OFF CACHE BOOL "" FORCE)
+set(SECP256K1_ENABLE_MODULE_RECOVERY ON CACHE BOOL "" FORCE)
+set(SECP256K1_ECMULT_GEN_KB 86 CACHE STRING "" FORCE)
+set(SECP256K1_BUILD_BENCHMARK OFF CACHE BOOL "" FORCE)
+set(SECP256K1_BUILD_TESTS ${BUILD_TESTS} CACHE BOOL "" FORCE)
+set(SECP256K1_BUILD_EXHAUSTIVE_TESTS ${BUILD_TESTS} CACHE BOOL "" FORCE)
+set(SECP256K1_BUILD_CTIME_TESTS OFF CACHE BOOL "" FORCE)
+set(SECP256K1_BUILD_EXAMPLES OFF CACHE BOOL "" FORCE)
+include(GetTargetInterface)
+# -fsanitize and related flags apply to both C++ and C,
+# so we can pass them down to libsecp256k1 as CFLAGS.
+get_target_interface(core_sanitizer_cxx_flags "" sanitize_interface COMPILE_OPTIONS)
+set(SECP256K1_LATE_CFLAGS ${core_sanitizer_cxx_flags} CACHE STRING "" FORCE)
+unset(core_sanitizer_cxx_flags)
+# We want to build libsecp256k1 with the most tested RelWithDebInfo configuration.
+enable_language(C)
+foreach(config IN LISTS CMAKE_BUILD_TYPE CMAKE_CONFIGURATION_TYPES)
+  if(config STREQUAL "")
+    continue()
+  endif()
+  string(TOUPPER "${config}" config)
+  set(CMAKE_C_FLAGS_${config} "${CMAKE_C_FLAGS_RELWITHDEBINFO}")
+endforeach()
+add_subdirectory(secp256k1)
+set_target_properties(secp256k1 PROPERTIES EXPORT_COMPILE_COMMANDS OFF)
+string(APPEND CMAKE_C_COMPILE_OBJECT " ${APPEND_CPPFLAGS} ${APPEND_CFLAGS}")
 
 # Stable, backwards-compatible consensus functionality.
 add_library(bitcoin_consensus STATIC EXCLUDE_FROM_ALL