MacOS: use llvm20

Author: howetuft

.github/workflows/build.yml

@@ -196,8 +196,21 @@ jobs:
         shell: bash
         run: |
             brew install ispc
-            #brew install llvm
-            #export PATH="/usr/local/opt/llvm/bin:$PATH"
+
+            # We make conan believe we use apple-clang (see profiles), but
+            # actually we use recent version of llvm, to get full compatibility
+            # with C++20
+            brew install llvm@20
+
+            LLVM_PREFIX=$(brew --prefix llvm@20)
+            echo "PATH=$LLVM_PREFIX/bin:$PATH" >> $GITHUB_ENV
+            echo "CC=clang" >> $GITHUB_ENV
+            echo "CXX=clang++" >> $GITHUB_ENV
+            echo "AR=llvm-ar" >> $GITHUB_ENV
+            echo "RANLIB=llvm-ranlib" >> $GITHUB_ENV
+            echo "LD=ld.lld" >> $GITHUB_ENV
+            echo "DYLD_LIBRARY_PATH=$LLVM_PREFIX/lib:$DYLD_LIBRARY_PATH" >> $GITHUB_ENV
+            export PATH="/usr/local/opt/llvm/bin:$PATH"
 
             bash ${{ env.WORKSPACE }}/install-conan.sh
 

conan-profiles/conan-profile-macOS-X64

@@ -9,6 +9,11 @@ compiler.version=14.0
 compiler.cppstd={{ os.getenv("CXX_VERSION") }}
 compiler.libcxx=libc++
 
+spdlog/*:compiler=clang
+spdlog/*:compiler.version=20
+spdlog/*:compiler.cppstd={{ os.getenv("CXX_VERSION") }}
+spdlog/*:compiler.libcxx=libc++
+
 [options]
 minizip-ng/*:with_zlib=True
 minizip-ng/*:with_libcomp=False