Closs-platform support

CMakeLists.txt

@@ -2,7 +2,8 @@ cmake_minimum_required(VERSION 3.10)
 
 project(bfjit)
 
-set(CMAKE_CXX_STANDARD 23)
+# C++23 triggers a bug in llvm16, fixed in llvm17
+set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED True)
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
@@ -33,15 +34,20 @@ find_package(fmt REQUIRED)
 # -DLLVM_DIR=/opt/homebrew/opt/llvm/lib/cmake/llvm
 find_package(LLVM REQUIRED)
 
-llvm_map_components_to_libnames(llvm_libs 
-  core
-  analysis
-  scalaropts
-  instcombine
-  transformutils
-  passes
-  orcjit
-  native)
+set(llvm_libs LLVM)
+
+if(APPLE)
+  llvm_map_components_to_libnames(llvm_libs 
+    core
+    analysis
+    scalaropts
+    instcombine
+    transformutils
+    passes
+    orcjit
+    native)
+endif()
+
 message(STATUS "LLVM found at: ${LLVM_DIR}")
 message(STATUS "LLVM lib list: ${llvm_libs}")
 

include/bfjit/io/file_chunk_iter.hpp

@@ -42,11 +42,12 @@ namespace bfjit::io {
       }
 
       {
-        int const enable = 1;
-        // signal sequential reading on macos
-        // on linux this would be posix_fadvise but cba
-        // to make this multiplatform
-        ::fcntl(file, F_RDAHEAD, &enable);
+        #ifdef __APPLE__
+          int const enable = 1;
+          ::fcntl(file, F_RDAHEAD, &enable);
+        #elif __linux__
+          ::posix_fadvise(file, 0, 0, POSIX_FADV_SEQUENTIAL);
+        #endif
       }
 
       // initialize the iter

src/bfjit/codegen/codegen.cpp

@@ -117,7 +117,7 @@ namespace bfjit::codegen {
         main_type,
         // external linkage per convention
         llvm::Function::ExternalLinkage,
-        "jit_main",
+        "main",
         &global_module.mod
       );
 

src/bfjit/jit/jit.cpp

@@ -23,6 +23,14 @@ namespace bfjit::jit {
 
     auto jit = llvm::cantFail(llvm::orc::LLJITBuilder().create());
 
+    // this one will make sure that symbols in the current process are
+    // available to the JIT code
+    // essentially to make sure that libc is available, e.g. getchar and putchar
+    jit->getMainJITDylib().addGenerator(
+      llvm::cantFail(
+        llvm::orc::DynamicLibrarySearchGenerator::GetForCurrentProcess(
+          jit->getDataLayout().getGlobalPrefix())));
+
     // fmt::println(
     //   "architecture: {}",
     //   jit->getTargetTriple().getArchName().str());
@@ -33,7 +41,7 @@ namespace bfjit::jit {
           std::move(smc.mod_impl),
           std::move(smc.ctx_impl))));
 
-    auto main_fn = llvm::cantFail(jit->lookup("jit_main"));
+    auto main_fn = llvm::cantFail(jit->lookup("main"));
     auto main_ptr = main_fn.toPtr<int32_t(*)()>();
 
     // for debugging: settings set plugin.jit-loader.gdb.enable on