Squashed 'src/secp256k1/' changes from 4187a46649..c82d84bb86

c82d84bb86 build: add CMake option for disabling symbol visibility attributes
ce7923874f build: Add SECP256K1_NO_API_VISIBILITY_ATTRIBUTES
e5297f6d79 build: Refactor visibility logic
c498779096 Merge bitcoin-core/secp256k1#1687: cmake: support the use of launchers in ctest -S scripts
0dfe387dbe cmake: support the use of launchers in ctest -S scripts
89096c234d Merge bitcoin-core/secp256k1#1692: cmake: configure libsecp256k1.pc during install
7106dce6fd cmake: configure libsecp256k1.pc during install
29e73f4ba5 Merge bitcoin-core/secp256k1#1685: cmake: Emulate Libtool's behavior on FreeBSD
746e36b141 Merge bitcoin-core/secp256k1#1678: cmake: add a helper for linking into static libs
a28c2ffa5c Merge bitcoin-core/secp256k1#1683: README: add link to musig example
2a9d374735 Merge bitcoin-core/secp256k1#1690: ci: Bump GCC snapshot major version to 16
add146e101 ci: Bump GCC snapshot major version to 16
145ae3e28d cmake: add a helper for linking into static libs
819210974b README: add link to musig example, generalize module enabling hint
95db29b144 Merge bitcoin-core/secp256k1#1679: cmake: Use `PUBLIC_HEADER` target property in installation logic
37dd422b5c cmake: Emulate Libtool's behavior on FreeBSD
f24b838bed Merge bitcoin-core/secp256k1#1680: doc: Promote "Building with CMake" to standard procedure
3f31ac43e0 doc: Promote "Building with CMake" to standard procedure
6f67151ee2 cmake: Use `PUBLIC_HEADER` target property
c32715b2a0 cmake, move-only: Move module option processing to `src/CMakeLists.txt`
201b2b8f06 Merge bitcoin-core/secp256k1#1675: cmake: Bump minimum required CMake version to 3.22
3af71987a8 cmake: Bump minimum required CMake version to 3.22
92394476e9 Merge bitcoin-core/secp256k1#1673: Assert field magnitude at control-flow join
3a4f448cb4 Assert field magnitude at control-flow join
9fab425256 Merge bitcoin-core/secp256k1#1668: bench_ecmult: add benchmark for ecmult_const_xonly
05445377f4 bench_ecmult: add benchmark for ecmult_const_xonly
bb597b3d39 Merge bitcoin-core/secp256k1#1670: tests: update wycheproof files
d73ed99479 tests: update wycheproof files

git-subtree-dir: src/secp256k1
git-subtree-split: c82d84bb86f9769a4f9d958f40e86cd99e071bc7

Author: hebasto

CHANGELOG.md

@@ -115,7 +115,7 @@ We strongly recommend updating to 0.3.1 if you use or plan to use Clang >=14 to
  - Fix "constant-timeness" issue with Clang >=14 that could leave applications using libsecp256k1 vulnerable to a timing side-channel attack. The fix avoids secret-dependent control flow and secret-dependent memory accesses in conditional moves of memory objects when libsecp256k1 is compiled with Clang >=14.
 
 #### Added
-  - Added tests against [Project Wycheproof's](https://github.com/google/wycheproof/) set of ECDSA test vectors (Bitcoin "low-S" variant), a fixed set of test cases designed to trigger various edge cases.
+  - Added tests against [Project Wycheproof's](https://github.com/C2SP/wycheproof/) set of ECDSA test vectors (Bitcoin "low-S" variant), a fixed set of test cases designed to trigger various edge cases.
 
 #### Changed
  - Increased minimum required CMake version to 3.13. CMake builds remain experimental.

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.16)
+cmake_minimum_required(VERSION 3.22)
 
 #=============================
 # Project / Package metadata
@@ -13,19 +13,9 @@ project(libsecp256k1
   LANGUAGES C
 )
 enable_testing()
+include(CTestUseLaunchers) # Allow users to set CTEST_USE_LAUNCHERS in custom `ctest -S` scripts.
 list(APPEND CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake)
 
-if(CMAKE_VERSION VERSION_LESS 3.21)
-  # Emulates CMake 3.21+ behavior.
-  if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
-    set(PROJECT_IS_TOP_LEVEL ON)
-    set(${PROJECT_NAME}_IS_TOP_LEVEL ON)
-  else()
-    set(PROJECT_IS_TOP_LEVEL OFF)
-    set(${PROJECT_NAME}_IS_TOP_LEVEL OFF)
-  endif()
-endif()
-
 # The library version is based on libtool versioning of the ABI. The set of
 # rules for updating the version can be found here:
 # https://www.gnu.org/software/libtool/manual/html_node/Updating-version-info.html
@@ -52,6 +42,8 @@ endif()
 
 option(SECP256K1_INSTALL "Enable installation." ${PROJECT_IS_TOP_LEVEL})
 
+option(SECP256K1_ENABLE_API_VISIBILITY_ATTRIBUTES "Enable visibility attributes in the API." ON)
+
 ## Modules
 
 # We declare all options before processing them, to make sure we can express
@@ -63,40 +55,6 @@ option(SECP256K1_ENABLE_MODULE_SCHNORRSIG "Enable schnorrsig module." ON)
 option(SECP256K1_ENABLE_MODULE_MUSIG "Enable musig module." ON)
 option(SECP256K1_ENABLE_MODULE_ELLSWIFT "Enable ElligatorSwift module." ON)
 
-# Processing must be done in a topological sorting of the dependency graph
-# (dependent module first).
-if(SECP256K1_ENABLE_MODULE_ELLSWIFT)
-  add_compile_definitions(ENABLE_MODULE_ELLSWIFT=1)
-endif()
-
-if(SECP256K1_ENABLE_MODULE_MUSIG)
-  if(DEFINED SECP256K1_ENABLE_MODULE_SCHNORRSIG AND NOT SECP256K1_ENABLE_MODULE_SCHNORRSIG)
-    message(FATAL_ERROR "Module dependency error: You have disabled the schnorrsig module explicitly, but it is required by the musig module.")
-  endif()
-  set(SECP256K1_ENABLE_MODULE_SCHNORRSIG ON)
-  add_compile_definitions(ENABLE_MODULE_MUSIG=1)
-endif()
-
-if(SECP256K1_ENABLE_MODULE_SCHNORRSIG)
-  if(DEFINED SECP256K1_ENABLE_MODULE_EXTRAKEYS AND NOT SECP256K1_ENABLE_MODULE_EXTRAKEYS)
-    message(FATAL_ERROR "Module dependency error: You have disabled the extrakeys module explicitly, but it is required by the schnorrsig module.")
-  endif()
-  set(SECP256K1_ENABLE_MODULE_EXTRAKEYS ON)
-  add_compile_definitions(ENABLE_MODULE_SCHNORRSIG=1)
-endif()
-
-if(SECP256K1_ENABLE_MODULE_EXTRAKEYS)
-  add_compile_definitions(ENABLE_MODULE_EXTRAKEYS=1)
-endif()
-
-if(SECP256K1_ENABLE_MODULE_RECOVERY)
-  add_compile_definitions(ENABLE_MODULE_RECOVERY=1)
-endif()
-
-if(SECP256K1_ENABLE_MODULE_ECDH)
-  add_compile_definitions(ENABLE_MODULE_ECDH=1)
-endif()
-
 option(SECP256K1_USE_EXTERNAL_DEFAULT_CALLBACKS "Enable external default callback functions." OFF)
 if(SECP256K1_USE_EXTERNAL_DEFAULT_CALLBACKS)
   add_compile_definitions(USE_EXTERNAL_DEFAULT_CALLBACKS=1)
@@ -356,6 +314,7 @@ else()
   set(cross_status "FALSE")
 endif()
 message("Cross compiling ....................... ${cross_status}")
+message("API visibility attributes ............. ${SECP256K1_ENABLE_API_VISIBILITY_ATTRIBUTES}")
 message("Valgrind .............................. ${SECP256K1_VALGRIND}")
 get_directory_property(definitions COMPILE_DEFINITIONS)
 string(REPLACE ";" " " definitions "${definitions}")

CMakePresets.json

@@ -1,5 +1,4 @@
 {
-  "cmakeMinimumRequired": {"major": 3, "minor": 21, "patch": 0}, 
   "version": 3,
   "configurePresets": [
     {

README.md

@@ -108,8 +108,8 @@ Building with Autotools
 
 To compile optional modules (such as Schnorr signatures), you need to run `./configure` with additional flags (such as `--enable-module-schnorrsig`). Run `./configure --help` to see the full list of available flags.
 
-Building with CMake (experimental)
-----------------------------------
+Building with CMake
+-------------------
 
 To maintain a pristine source tree, CMake encourages to perform an out-of-source build by using a separate dedicated build tree.
 
@@ -151,8 +151,9 @@ Usage examples can be found in the [examples](examples) directory. To compile th
   * [Schnorr signatures example](examples/schnorr.c)
   * [Deriving a shared secret (ECDH) example](examples/ecdh.c)
   * [ElligatorSwift key exchange example](examples/ellswift.c)
+  * [MuSig2 Schnorr multi-signatures example](examples/musig.c)
 
-To compile the Schnorr signature and ECDH examples, you also need to configure with `--enable-module-schnorrsig` and `--enable-module-ecdh`.
+To compile the examples, make sure the corresponding modules are enabled.
 
 Benchmark
 ------------

ci/linux-debian.Dockerfile

@@ -40,7 +40,7 @@ RUN apt-get update && apt-get install --no-install-recommends -y \
         apt-get clean && rm -rf /var/lib/apt/lists/*
 
 # Build and install gcc snapshot
-ARG GCC_SNAPSHOT_MAJOR=15
+ARG GCC_SNAPSHOT_MAJOR=16
 RUN apt-get update && apt-get install --no-install-recommends -y wget libgmp-dev libmpfr-dev libmpc-dev flex && \
     mkdir gcc && cd gcc && \
     wget --progress=dot:giga --https-only --recursive --accept '*.tar.xz' --level 1 --no-directories "https://gcc.gnu.org/pub/gcc/snapshots/LATEST-${GCC_SNAPSHOT_MAJOR}" && \

cmake/GeneratePkgConfigFile.cmake

@@ -1,8 +1,12 @@
 function(generate_pkg_config_file in_file)
-  set(prefix ${CMAKE_INSTALL_PREFIX})
+  set(prefix "@CMAKE_INSTALL_PREFIX@")
   set(exec_prefix \${prefix})
   set(libdir \${exec_prefix}/${CMAKE_INSTALL_LIBDIR})
   set(includedir \${prefix}/${CMAKE_INSTALL_INCLUDEDIR})
   set(PACKAGE_VERSION ${PROJECT_VERSION})
-  configure_file(${in_file} ${PROJECT_NAME}.pc @ONLY)
+  configure_file(${in_file} ${PROJECT_NAME}.pc.in @ONLY)
+  install(CODE "configure_file(
+  \"${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}.pc.in\"
+  \"${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}.pc\"
+  @ONLY)" ALL_COMPONENTS)
 endfunction()

include/secp256k1.h

@@ -121,45 +121,57 @@ typedef int (*secp256k1_nonce_function)(
 #endif
 
 /* Symbol visibility. */
-#if defined(_WIN32)
-  /* GCC for Windows (e.g., MinGW) accepts the __declspec syntax
-   * for MSVC compatibility. A __declspec declaration implies (but is not
-   * exactly equivalent to) __attribute__ ((visibility("default"))), and so we
-   * actually want __declspec even on GCC, see "Microsoft Windows Function
-   * Attributes" in the GCC manual and the recommendations in
-   * https://gcc.gnu.org/wiki/Visibility. */
-# if defined(SECP256K1_BUILD)
-#  if defined(DLL_EXPORT) || defined(SECP256K1_DLL_EXPORT)
-    /* Building libsecp256k1 as a DLL.
-     * 1. If using Libtool, it defines DLL_EXPORT automatically.
-     * 2. In other cases, SECP256K1_DLL_EXPORT must be defined. */
-#   define SECP256K1_API extern __declspec (dllexport)
-#  else
-    /* Building libsecp256k1 as a static library on Windows.
-     * No declspec is needed, and so we would want the non-Windows-specific
-     * logic below take care of this case. However, this may result in setting
-     * __attribute__ ((visibility("default"))), which is supposed to be a noop
-     * on Windows but may trigger warnings when compiling with -flto due to a
-     * bug in GCC, see
-     * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116478 . */
-#   define SECP256K1_API extern
-#  endif
-  /* The user must define SECP256K1_STATIC when consuming libsecp256k1 as a static
-   * library on Windows. */
-# elif !defined(SECP256K1_STATIC)
-   /* Consuming libsecp256k1 as a DLL. */
-#  define SECP256K1_API extern __declspec (dllimport)
-# endif
+#if !defined(SECP256K1_API) && defined(SECP256K1_NO_API_VISIBILITY_ATTRIBUTES)
+     /* The user has requested that we don't specify visibility attributes in
+      * the public API.
+      *
+      * Since all our non-API declarations use the static qualifier, this means
+      * that the user can use -fvisibility=<value> to set the visibility of the
+      * API symbols. For instance, -fvisibility=hidden can be useful *even for
+      * the API symbols*, e.g., when building a static library which is linked
+      * into a shared library, and the latter should not re-export the
+      * libsecp256k1 API.
+      *
+      * While visibility is a concept that applies only to shared libraries,
+      * setting visibility will still make a difference when building a static
+      * library: the visibility settings will be stored in the static library,
+      * solely for the potential case that the static library will be linked into
+      * a shared library. In that case, the stored visibility settings will
+      * resurface and be honored for the shared library. */
+#    define SECP256K1_API extern
 #endif
-#ifndef SECP256K1_API
-/* All cases not captured by the Windows-specific logic. */
-# if defined(__GNUC__) && (__GNUC__ >= 4) && defined(SECP256K1_BUILD)
-   /* Building libsecp256k1 using GCC or compatible. */
-#  define SECP256K1_API extern __attribute__ ((visibility ("default")))
-# else
-   /* Fall back to standard C's extern. */
-#  define SECP256K1_API extern
-# endif
+#if !defined(SECP256K1_API)
+#    if defined(SECP256K1_BUILD)
+         /* On Windows, assume a shared library only if explicitly requested.
+          *   1. If using Libtool, it defines DLL_EXPORT automatically.
+          *   2. In other cases, SECP256K1_DLL_EXPORT must be defined. */
+#        if defined(_WIN32) && (defined(SECP256K1_DLL_EXPORT) || defined(DLL_EXPORT))
+             /* GCC for Windows (e.g., MinGW) accepts the __declspec syntax for
+              * MSVC compatibility. A __declspec declaration implies (but is not
+              * exactly equivalent to) __attribute__ ((visibility("default"))),
+              * and so we actually want __declspec even on GCC, see "Microsoft
+              * Windows Function Attributes" in the GCC manual and the
+              * recommendations in https://gcc.gnu.org/wiki/Visibility . */
+#            define SECP256K1_API extern __declspec(dllexport)
+         /* Avoid __attribute__ ((visibility("default"))) on Windows to get rid
+          * of warnings when compiling with -flto due to a bug in GCC, see
+          * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116478 . */
+#        elif !defined(_WIN32) && defined (__GNUC__) && (__GNUC__ >= 4)
+#            define SECP256K1_API extern __attribute__ ((visibility("default")))
+#        else
+#            define SECP256K1_API extern
+#        endif
+#    else
+         /* On Windows, SECP256K1_STATIC must be defined when consuming
+          * libsecp256k1 as a static library. Note that SECP256K1_STATIC is a
+          * "consumer-only" macro, and it has no meaning when building
+          * libsecp256k1. */
+#        if defined(_WIN32) && !defined(SECP256K1_STATIC)
+#            define SECP256K1_API extern __declspec(dllimport)
+#        else
+#            define SECP256K1_API extern
+#        endif
+#    endif
 #endif
 
 /* Warning attributes