cmake: Bump CMake minimum required version up to 3.18

.github/workflows/ci.yml

@@ -864,5 +864,5 @@ jobs:
           CI_BUILD: ${{ runner.temp }}/${{ github.run_id }}${{ github.action }}/build
           CI_INSTALL: ${{ runner.temp }}/${{ github.run_id }}${{ github.action }}/install
         run: |
-          cmake -B ${{ env.CI_BUILD }} -DCMAKE_INSTALL_PREFIX=${{ env.CI_INSTALL }} && cmake --build ${{ env.CI_BUILD }} --target install && ls -RlAh ${{ env.CI_INSTALL }}
+          cmake -B ${{ env.CI_BUILD }} -DCMAKE_INSTALL_PREFIX=${{ env.CI_INSTALL }} && cmake --install ${{ env.CI_BUILD }} && ls -RlAh ${{ env.CI_INSTALL }}
           gcc -o ecdsa examples/ecdsa.c -I ${{ env.CI_INSTALL }}/include -L ${{ env.CI_INSTALL }}/lib*/ -l secp256k1 -Wl,-rpath,"${{ env.CI_INSTALL }}/lib",-rpath,"${{ env.CI_INSTALL }}/lib64" && ./ecdsa

CMakeLists.txt

@@ -1,11 +1,4 @@
-cmake_minimum_required(VERSION 3.13)
-
-if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.15)
-  # MSVC runtime library flags are selected by the CMAKE_MSVC_RUNTIME_LIBRARY abstraction.
-  cmake_policy(SET CMP0091 NEW)
-  # MSVC warning flags are not in CMAKE_<LANG>_FLAGS by default.
-  cmake_policy(SET CMP0092 NEW)
-endif()
+cmake_minimum_required(VERSION 3.18)
 
 project(libsecp256k1
   # The package (a.k.a. release) version is based on semantic versioning 2.0.0 of

README.md

@@ -82,7 +82,7 @@ To maintain a pristine source tree, CMake encourages to perform an out-of-source
     $ cmake ..
     $ cmake --build .
     $ ctest  # run the test suite
-    $ sudo cmake --build . --target install  # optional
+    $ sudo cmake --install .  # optional
 
 To compile optional modules (such as Schnorr signatures), you need to run `cmake` with additional flags (such as `-DSECP256K1_ENABLE_MODULE_SCHNORRSIG=ON`). Run `cmake .. -LH` to see the full list of available flags.
 

doc/release-process.md

@@ -31,7 +31,7 @@ Perform these checks when reviewing the release PR (see below):
    ```shell
    dir=$(mktemp -d)
    build=$(mktemp -d)
-   cmake -B $build -DCMAKE_INSTALL_PREFIX=$dir && cmake --build $build --target install && ls -RlAh $dir
+   cmake -B $build -DCMAKE_INSTALL_PREFIX=$dir && cmake --install $build && ls -RlAh $dir
    gcc -o ecdsa examples/ecdsa.c -I $dir/include -L $dir/lib*/ -l secp256k1 -Wl,-rpath,"$dir/lib",-rpath,"$dir/lib64" && ./ecdsa
    ```
 4. Use the [`check-abi.sh`](/tools/check-abi.sh) tool to verify that there are no unexpected ABI incompatibilities and that the version number and the release notes accurately reflect all potential ABI changes. To run this tool, the `abi-dumper` and `abi-compliance-checker` packages are required.

src/CMakeLists.txt

@@ -48,20 +48,12 @@ if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
     VERSION ${${PROJECT_NAME}_soversion}.${${PROJECT_NAME}_LIB_VERSION_AGE}.${${PROJECT_NAME}_LIB_VERSION_REVISION}
   )
 elseif(APPLE)
-  if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.17)
-    math(EXPR ${PROJECT_NAME}_compatibility_version "${${PROJECT_NAME}_LIB_VERSION_CURRENT} + 1")
-    set_target_properties(secp256k1 PROPERTIES
-      MACHO_COMPATIBILITY_VERSION ${${PROJECT_NAME}_compatibility_version}
-      MACHO_CURRENT_VERSION ${${PROJECT_NAME}_compatibility_version}.${${PROJECT_NAME}_LIB_VERSION_REVISION}
-    )
-    unset(${PROJECT_NAME}_compatibility_version)
-  elseif(BUILD_SHARED_LIBS)
-    message(WARNING
-      "The 'compatibility version' and 'current version' values of the DYLIB "
-      "will diverge from the values set by the GNU Libtool. To ensure "
-      "compatibility, it is recommended to upgrade CMake to at least version 3.17."
-    )
-  endif()
+  math(EXPR ${PROJECT_NAME}_compatibility_version "${${PROJECT_NAME}_LIB_VERSION_CURRENT} + 1")
+  set_target_properties(secp256k1 PROPERTIES
+    MACHO_COMPATIBILITY_VERSION ${${PROJECT_NAME}_compatibility_version}
+    MACHO_CURRENT_VERSION ${${PROJECT_NAME}_compatibility_version}.${${PROJECT_NAME}_LIB_VERSION_REVISION}
+  )
+  unset(${PROJECT_NAME}_compatibility_version)
 elseif(CMAKE_SYSTEM_NAME STREQUAL "Windows")
   set(${PROJECT_NAME}_windows "secp256k1")
   if(MSVC)