improve build script

build.sh

@@ -7,12 +7,13 @@ projectNameUpper=$(printf '%s\n' "$projectName" | awk '{ print toupper($0) }')
 
 print_help() {
     echo "$scriptName - Configure, build, and install $(basename $scriptDir)"
+    echo "Usage: $scriptName [OPTION [ARGUMENT]]"
     echo "-h                : print this help and exit"
     echo "-p                : package after building"
     echo "-t build-type     : build type [Debug, Release, RelWithDebInfo] (default: Release)"
     echo "-b build-dir      : build directory"
     echo "-i install-dir    : install directory (python site package by default)"
-    echo "-c compiler       : C++ compiler to use"
+    echo "-o [opts]         : options/arguments to pass on to CMake. Semicolon (;) delimited, or defined repeatedly."
 }
 
 if ! command -v python3 &>/dev/null; then
@@ -30,11 +31,13 @@ package=0
 buildType="Release"
 buildDir="$scriptDir/build"
 installDir=$(get_site_packages_dir)
-compiler=g++
 generator="Unix Makefiles"
 cCacheFlag=""
+cmakeArguments=""
+cc="gcc"
+cxx="g++"
 
-while getopts "hpt:b:i:c:" arg; do
+while getopts ":h p t: b: i: c: o:" arg; do
     case "$arg" in
         h)  # Print help and exit without doing anything
             print_help
@@ -53,8 +56,8 @@ while getopts "hpt:b:i:c:" arg; do
         i)  # Set install directory
             installDir="$OPTARG"
             ;;
-        c)  # Set C++ compiler
-            compiler="$OPTARG"
+        o)  # Append CMake arguments
+            cmakeArguments="$cmakeArguments;$OPTARG"
             ;;
         \?) # Unrecognized argument
             print_help
@@ -64,6 +67,35 @@ while getopts "hpt:b:i:c:" arg; do
     esac
 done
 
+case "$(uname -s)" in
+    Linux*)
+        compilerFlags=""
+        ;;
+    Darwin*)
+        # Set clang from homebrew
+        if ! command -v brew &> /dev/null; then
+            echo "Error: $script_name requires Homebrew"
+            exit 1
+        fi
+
+        if ! brew list llvm >/dev/null 2>&1; then
+            echo "Error: missing dependency: llvm"
+            echo "Consider running 'brew install llvm'"
+            exit 1
+        fi
+
+        toolchainRoot="$(brew --prefix llvm)"
+        toolchainBin="${toolchainRoot}/bin"
+        toolchainLib="${toolchainRoot}/lib"
+        toolchainInclude="${toolchainRoot}/include"
+        export cc="$toolchainBin/clang"
+        export cxx="$toolchainBin/clang++"
+        ;;
+    \?)
+        echo "Error: unsupported OS $(uname -s)"
+        exit 1
+esac
+
 # Create or clear the build directory
 if ! [ -d "$buildDir" ]; then
     mkdir -p "$buildDir"
@@ -89,8 +121,11 @@ if ! cmake                                                  \
     "-B$buildDir"                                           \
     "-DCMAKE_INSTALL_PREFIX:STRING=$installDir"             \
     "-G${generator}"                                        \
+    "-DCMAKE_C_COMPILER:STRING=$cc"                         \
+    "-DCMAKE_CXX_COMPILER:STRING=$cxx"                      \
     "-DCMAKE_COLOR_DIAGNOSTICS:BOOL=ON"                     \
     "$cCacheFlag"                                           \
+    $(echo $cmakeArguments | tr '\;' '\n')                  \
     ; then
     exit 1
 fi
@@ -100,13 +135,15 @@ if ! cmake --build "$buildDir" --config "$buildType" --target install -j; then
     exit 1
 fi
 
+# Package
 if [ $package -eq 1 ]; then
     cd "$buildDir"
     if [ "$generator" = "Ninja" ]; then
         echo ninja package
         ninja package
         ninja package_source
     else
+        echo make package
         make package
         make package_source
     fi