Update configuration for Travis CI; add configuration for AppVeyor CI

Exclude the branch "libpng16" from testing. It's identical to "master".
Also exclude the other (non-current) "libpng[0-1][0-7]" branches.

Parallelize the builds and the unit tests.

For Travis CI, update the build matrix as follows:
 * On Linux, use both clang and gcc.
 * On macOS, use clang only, with and without Xcode.

For AppVeyor CI, add a build matrix as follows:
 * On Windows, use Microsoft Visual Studio 2019 on x86, x64 and arm64.
 * Also on Windows, use MSYS2 on x86 and x64.

Use the new scripts/ci_*.sh; remove the old scripts/travis.sh.

.appveyor.yml

@@ -0,0 +1,71 @@
+version: 1.6.x-{build}
+
+branches:
+  except:
+    - /libpng[0-1][0-7]/
+
+image:
+  - Visual Studio 2019
+
+shallow_clone: true
+
+environment:
+  matrix:
+    - TOOLCHAIN: vstudio
+      AUTOMATION: cmake
+      CI_CMAKE_GENERATOR: Visual Studio 16 2019
+      CI_CMAKE_GENERATOR_PLATFORM: Win32
+    - TOOLCHAIN: vstudio
+      AUTOMATION: cmake
+      CI_CMAKE_GENERATOR: Visual Studio 16 2019
+      CI_CMAKE_GENERATOR_PLATFORM: X64
+    - TOOLCHAIN: vstudio
+      AUTOMATION: cmake
+      CI_CMAKE_GENERATOR: Visual Studio 16 2019
+      CI_CMAKE_GENERATOR_PLATFORM: ARM64
+      CI_NO_TEST: 1
+    - TOOLCHAIN: msys2
+      AUTOMATION: cmake
+      CI_CMAKE_GENERATOR: Unix Makefiles
+      CI_CC: i686-w64-mingw32-gcc
+    - TOOLCHAIN: msys2
+      AUTOMATION: cmake
+      CI_CMAKE_GENERATOR: Unix Makefiles
+      CI_CC: x86_64-w64-mingw32-gcc
+    - TOOLCHAIN: msys2
+      AUTOMATION: autotools
+      CI_CC: i686-w64-mingw32-gcc
+    - TOOLCHAIN: msys2
+      AUTOMATION: autotools
+      CI_CC: x86_64-w64-mingw32-gcc
+    - TOOLCHAIN: msys2
+      AUTOMATION: legacy
+      CI_LEGACY_MAKEFILES: scripts/makefile.gcc scripts/makefile.msys
+      CI_CC: i686-w64-mingw32-gcc
+    - TOOLCHAIN: msys2
+      AUTOMATION: legacy
+      CI_LEGACY_MAKEFILES: scripts/makefile.gcc scripts/makefile.msys
+      CI_CC: x86_64-w64-mingw32-gcc
+
+install:
+  - 'if "%TOOLCHAIN%"=="vstudio" if "%CI_CMAKE_GENERATOR_PLATFORM%"=="Win32" C:\tools\vcpkg\vcpkg.exe install zlib:x86-windows'
+  - 'if "%TOOLCHAIN%"=="vstudio" if "%CI_CMAKE_GENERATOR_PLATFORM%"=="X64" C:\tools\vcpkg\vcpkg.exe install zlib:x64-windows'
+  - 'if "%TOOLCHAIN%"=="vstudio" if "%CI_CMAKE_GENERATOR_PLATFORM%"=="ARM64" C:\tools\vcpkg\vcpkg.exe install zlib:arm64-windows'
+  - 'if "%TOOLCHAIN%"=="vstudio" C:\tools\vcpkg\vcpkg.exe integrate install'
+
+before_build:
+  - 'if "%TOOLCHAIN%"=="vstudio" set CI_CMAKE_VARS=-DCMAKE_TOOLCHAIN_FILE=C:\tools\vcpkg\scripts\buildsystems\vcpkg.cmake'
+  - 'if "%TOOLCHAIN%"=="msys2" if "%CI_CC%"=="i686-w64-mingw32-gcc" set PATH=C:\msys64\mingw32\bin;%PATH%'
+  - 'if "%TOOLCHAIN%"=="msys2" if "%CI_CC%"=="x86_64-w64-mingw32-gcc" set PATH=C:\msys64\mingw64\bin;%PATH%'
+  - 'set CI_CMAKE_BUILD_FLAGS=--parallel 2'
+  - 'set CI_CTEST_FLAGS=--parallel 2'
+  - 'set CI_MAKE_FLAGS=-j2'
+
+build_script:
+  - 'if "%TOOLCHAIN%"=="vstudio" C:\msys64\usr\bin\bash.exe -l "%APPVEYOR_BUILD_FOLDER%\scripts\ci_cmake.sh"'
+  - 'if "%TOOLCHAIN%"=="msys2" if "%AUTOMATION%"=="cmake" C:\msys64\usr\bin\bash.exe -l "%APPVEYOR_BUILD_FOLDER%\scripts\ci_cmake.sh"'
+  - 'if "%TOOLCHAIN%"=="msys2" if "%AUTOMATION%"=="autotools" C:\msys64\usr\bin\bash.exe -l "%APPVEYOR_BUILD_FOLDER%\scripts\ci_autotools.sh"'
+  - 'if "%TOOLCHAIN%"=="msys2" if "%AUTOMATION%"=="legacy" C:\msys64\usr\bin\bash.exe -l "%APPVEYOR_BUILD_FOLDER%\scripts\ci_legacy.sh"'
+
+cache:
+  - C:\tools\vcpkg\installed

.travis.yml

@@ -1,23 +1,43 @@
+branches:
+  except:
+    - /libpng[0-1][0-7]/
+
 language: c
 
-compiler:
-  - clang
-
-env:
-  - USE_CMAKE=1 DISABLE_TESTS=1
-  - USE_CMAKE=1 ENABLE_SANITIZERS="address,undefined" EXTRA_ARGS="-DPNG_HARDWARE_OPTIMIZATIONS=ON"
-  - USE_CMAKE=1 ENABLE_SANITIZERS="address,undefined" EXTRA_ARGS="-DPNG_HARDWARE_OPTIMIZATIONS=OFF"
-  - USE_CONFIGURE=1 DISABLE_TESTS=1
-  - USE_CONFIGURE=1 EXTRA_ARGS="--enable-hardware-optimizations"
-  - USE_CONFIGURE=1 EXTRA_ARGS="--disable-hardware-optimizations"
-  - USE_LEGACY_MAKEFILES=1 DISABLE_TESTS=1
-  - USE_LEGACY_MAKEFILES=1 ENABLE_SANITIZERS="address,undefined"
-
 os:
   - linux
   - osx
 
+compiler:
+  - clang
+  - gcc
+
+env:
+  - AUTOMATION=cmake CI_NO_TEST=1
+  - AUTOMATION=cmake CI_CMAKE_VARS="-DPNG_HARDWARE_OPTIMIZATIONS=ON" CI_SANITIZERS="address,undefined"
+  - AUTOMATION=cmake CI_CMAKE_VARS="-DPNG_HARDWARE_OPTIMIZATIONS=OFF" CI_SANITIZERS="address,undefined"
+  - AUTOMATION=cmake CI_CMAKE_GENERATOR=Xcode
+  - AUTOMATION=autotools CI_NO_TEST=1
+  - AUTOMATION=autotools CI_CONFIGURE_FLAGS="--enable-hardware-optimizations"
+  - AUTOMATION=autotools CI_CONFIGURE_FLAGS="--disable-hardware-optimizations"
+  - AUTOMATION=legacy CI_NO_TEST=1
+  - AUTOMATION=legacy CI_SANITIZERS="address,undefined"
+
+matrix:
+  exclude:
+    - os: osx
+      compiler: gcc
+    - os: linux
+      env: AUTOMATION=cmake CI_CMAKE_GENERATOR=Xcode
+
+before_script:
+  - 'export CI_CMAKE_BUILD_FLAGS="--parallel 2"'
+  - 'export CI_CTEST_FLAGS="--parallel 2"'
+  - 'export CI_MAKE_FLAGS=-j2'
+  - 'export CI_CC=$TRAVIS_COMPILER'
+  - 'export CI_LEGACY_MAKEFILES="scripts/makefile.$TRAVIS_COMPILER"'
+
 script:
-  - bash ./scripts/travis.sh
+  - './scripts/ci_$AUTOMATION.sh'
 
 sudo: false

scripts/travis.sh

@@ -1,37 +0,0 @@
-#!/bin/bash
-
-set -e
-
-if [[ $ENABLE_SANITIZERS ]]; then
-    LOCAL_CMAKE_EXTRA_ARGS="-DCMAKE_C_FLAGS=-fsanitize=$ENABLE_SANITIZERS"
-    LOCAL_MAKE_EXTRA_ARGS="CFLAGS=-fsanitize=$ENABLE_SANITIZERS LDFLAGS=-fsanitize=$ENABLE_SANITIZERS"
-fi
-
-if [[ $USE_CMAKE ]]; then
-    echo "$0: using cmake + make:" $LOCAL_CMAKE_EXTRA_ARGS $EXTRA_ARGS
-    mkdir build-cmake
-    cd build-cmake
-    cmake $LOCAL_CMAKE_EXTRA_ARGS $EXTRA_ARGS ..
-    make
-    [[ $DISABLE_TESTS ]] || make test
-    make clean
-fi
-
-if [[ $USE_CONFIGURE ]]; then
-    mkdir build-configure
-    cd build-configure
-    echo "$0: using configure + make:" $LOCAL_MAKE_EXTRA_ARGS $EXTRA_ARGS
-    ../configure $LOCAL_MAKE_EXTRA_ARGS $EXTRA_ARGS
-    make
-    [[ $DISABLE_TESTS ]] || make test
-    make clean
-    make distclean
-fi
-
-if [[ $USE_LEGACY_MAKEFILES ]]; then
-    echo "$0: using scripts/makefile.$CC:" $LOCAL_MAKE_EXTRA_ARGS $EXTRA_ARGS
-    make -f scripts/makefile.$CC $LOCAL_MAKE_EXTRA_ARGS $EXTRA_ARGS
-    [[ $DISABLE_TESTS ]] || make -f scripts/makefile.$CC $LOCAL_MAKE_EXTRA_ARGS $EXTRA_ARGS test
-    make -f scripts/makefile.$CC $LOCAL_MAKE_EXTRA_ARGS $EXTRA_ARGS clean
-    # TODO: use scripts/makefile.std, etc.
-fi