travis vs FetchContent_MakeAvailable(): give up on a recent cmake

... Avoid using the modern cmake function, and go back to an earlier
approach. The ppc64le travis images was not dealing well with the
attempt to hoist a modern cmake into it:

https://travis-ci.com/github/lemire/fast_float/jobs/444278392

.travis.yml

@@ -2,11 +2,6 @@ language: cpp
 
 dist: bionic
 
-arch:
-  - amd64
-  - ppc64le
-  - s390x
-
 cache:
   directories:
     - $HOME/.dep_cache
@@ -15,9 +10,30 @@ env:
   global:
     - fastfloat_DEPENDENCY_CACHE_DIR=$HOME/.dep_cache
 
+
+# the ppc64le and s390x images use cmake 3.10, but fast_float requires 3.11.
+# so we compile cmake from source in those images.
+# - tried the kitware ppa but that is using 3.10 as well
+# - tried also using snap to get a more recent version but that failed with
+#   udev errors.
+
 matrix:
   include:
-    - os: linux
+    - arch: ppc64le
+      os: linux
+      env:
+        - CMAKE_SRC="https://github.com/Kitware/CMake/releases/download/v3.11.4/cmake-3.11.4.tar.gz"
+
+    - arch: s390x
+      os: linux
+      env:
+        - CMAKE_SRC="https://github.com/Kitware/CMake/releases/download/v3.11.4/cmake-3.11.4.tar.gz"
+
+    - arch: amd64
+      os: linux
+
+    - arch: amd64
+      os: linux
       addons:
         apt:
           sources:
@@ -28,7 +44,8 @@ matrix:
         - COMPILER="CC=gcc-8 && CXX=g++-8"
       compiler: gcc-8
 
-    - os: linux
+    - arch: amd64
+      os: linux
       addons:
         apt:
           sources:
@@ -39,7 +56,8 @@ matrix:
         - COMPILER="CC=gcc-9 && CXX=g++-9"
       compiler: gcc-9
 
-    - os: linux
+    - arch: amd64
+      os: linux
       addons:
         apt:
           sources:
@@ -50,7 +68,8 @@ matrix:
         - COMPILER="CC=gcc-10 && CXX=g++-10"
       compiler: gcc-10
 
-    - os: linux
+    - arch: amd64
+      os: linux
       addons:
         apt:
           sources:
@@ -62,7 +81,8 @@ matrix:
         - SANITIZE="on"
       compiler: gcc-10-sanitize
 
-    - os: linux
+    - arch: amd64
+      os: linux
       addons:
         apt:
           sources:
@@ -72,9 +92,10 @@ matrix:
       env:
         - COMPILER="CC=gcc-10 && CXX=g++-10"
         - STATIC="on"
-      compiler: gcc-10-static
+      acompiler: gcc-10-static
 
-    - os: linux
+    - arch: amd64
+      os: linux
       addons:
         apt:
           sources:
@@ -85,7 +106,8 @@ matrix:
         - COMPILER="CC=clang-6.0 && CXX=clang++-6.0"
       compiler: clang-6
 
-    - os: linux
+    - arch: amd64
+      os: linux
       addons:
         apt:
           sources:
@@ -96,7 +118,8 @@ matrix:
         - COMPILER="CC=clang-7 && CXX=clang++-7"
       compiler: clang-7
 
-    - os: linux
+    - arch: amd64
+      os: linux
       addons:
         apt:
           sources:
@@ -107,7 +130,8 @@ matrix:
         - COMPILER="CC=clang-8 && CXX=clang++-8"
       compiler: clang-8
 
-    - os: linux
+    - arch: amd64
+      os: linux
       addons:
         apt:
           sources:
@@ -118,7 +142,8 @@ matrix:
         - COMPILER="CC=clang-9 && CXX=clang++-9"
       compiler: clang-9
 
-    - os: linux
+    - arch: amd64
+      os: linux
       addons:
         apt:
           packages:
@@ -131,7 +156,8 @@ matrix:
         - COMPILER="CC=clang-10 && CXX=clang++-10"
       compiler: clang-10
 
-    - os: linux
+    - arch: amd64
+      os: linux
       addons:
         apt:
           packages:
@@ -145,7 +171,8 @@ matrix:
         - STATIC="on"
       compiler: clang-10-static
 
-    - os: linux
+    - arch: amd64
+      os: linux
       addons:
         apt:
           packages:
@@ -163,42 +190,36 @@ before_install:
   - eval "${COMPILER}"
 
 install:
-  # make sure we have a recent cmake version.
+  - |
-  # fastfloat itself does not require it, but the tests require >= 3.14.
+    if [ "$CMAKE_SRC" != "" ] ; then
-
+      set -x
-  # these architectures have a snap:
+      set -e
-  # https://gitlab.kitware.com/cmake/cmake/-/issues/20122
+      sudo -E apt remove --purge cmake
-  - sudo -E apt-get -y update
+      sudo -E apt-get update
-  - sudo -E apt-get -y install snapd
+      sudo -E apt-get install -y build-essential libssl-dev
-  - sudo -E snap install cmake --beta --classic
+      mkdir cmake_src
-  - export PATH=/snap/cmake/current/bin:$PATH
+      pushd cmake_src
-
+      wget "$CMAKE_SRC"
-  # ALTERNATIVE: does not work on s390 and ppc64le
+      tar xfz $(basename "$CMAKE_SRC")
-  ## https://github.com/kahypar/kahypar/blob/master/.travis.yml
+      pushd $(basename "$CMAKE_SRC" | sed "s:.tar.gz::")
-  #- echo ${TRAVIS_OS_NAME}
+      ./bootstrap
-  #- |
+      make -j2
-  #  if [ "${TRAVIS_OS_NAME}" == "linux" ]; then
+      sudo make install
-  #    pwd ;
+      popd
-  #    export DEPS_DIR="${HOME}/deps" ;
+      popd
-  #    mkdir -p ${DEPS_DIR} && cd ${DEPS_DIR} ;
+      set +x
-  #    export CMAKE_URL="https://github.com/Kitware/CMake/releases/download/v3.17.0/cmake-3.17.0-Linux-x86_64.tar.gz";
+    fi
-  #    mkdir cmake;
-  #    travis_retry wget --no-check-certificate -O - ${CMAKE_URL} | tar --strip-components=1 -xz -C cmake;
-  #    export PATH=${DEPS_DIR}/cmake/bin:${PATH};
-  #    cd - ;
-  #    pwd
-  #  else
-  #    brew install cmake || brew upgrade cmake;
-  #  fi
-
   - echo ${PATH}
   - which cmake
   - cmake --version
+  - which ${CC}
+  - ${CC} --version
+  - which ${CXX}
+  - ${CXX} --version
 
 script:
   - mkdir build
   - cd build
-  - cmake  -DFASTFLOAT_TEST=ON  ..
+  - cmake -DFASTFLOAT_TEST=ON  ..
-  - make
+  - make -j2
   - ctest --output-on-failure -R basictest
-

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.11)
+cmake_minimum_required(VERSION 3.9)
 
 project(fast_float VERSION 0.1.0 LANGUAGES CXX)
 set(CMAKE_CXX_STANDARD 11)

tests/CMakeLists.txt

@@ -1,13 +1,22 @@
-# FetchContent_MakeAvailable() was only introduced in 3.14
+# FetchContent requires cmake >=3.11
-# https://cmake.org/cmake/help/v3.14/release/3.14.html#modules
+# see https://cmake.org/cmake/help/v3.11/module/FetchContent.html
-cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+cmake_minimum_required(VERSION 3.11 FATAL_ERROR)
 
 include(FetchContent)
 
 FetchContent_Declare(doctest
   GIT_REPOSITORY https://github.com/onqtam/doctest.git
-  GIT_TAG master)
+  GIT_TAG 2.4.1)
-FetchContent_MakeAvailable(doctest)
+
+# FetchContent_MakeAvailable() was only introduced in 3.14
+# https://cmake.org/cmake/help/v3.14/release/3.14.html#modules
+# FetchContent_MakeAvailable(doctest)
+FetchContent_GetProperties(doctest)
+if(NOT doctest_POPULATED)
+  FetchContent_Populate(doctest)
+  add_subdirectory(${doctest_SOURCE_DIR} ${doctest_BINARY_DIR})
+endif()
+
 
 function(fast_float_add_cpp_test TEST_NAME)
     add_executable(${TEST_NAME} ${TEST_NAME}.cpp)