M2 Mac（Ventura 13.3.1）下R与data.table的OpenMP配置求助

问题概述 #

• OpenMP已正确安装
• 已按官方指南更新~/.R/Makevars文件
• ~/.R/Makevars未在R中加载生效
• 附R SessionInfo详情

OpenMP已正确安装 #

通过以下代码验证OpenMP相关文件均存在：

file.exists(
  "/usr/local/lib/libomp.dylib",
  "/usr/local/include/ompt.h",
  "/usr/local/include/omp.h",
  "/usr/local/include/omp-tools.h"
)
# 输出：TRUE TRUE TRUE TRUE

编译并运行openmp_test.c测试程序：

#include <stdio.h>
#include <omp.h>

int main() {
    #pragma omp parallel
    {
        int thread_id = omp_get_thread_num();
        printf("Hello from thread %d\n", thread_id);
    }
    return 0;
}

使用命令clang -Xclang -fopenmp -lomp openmp_test.c -o openmp_test编译，运行./openmp_test得到多线程输出，确认OpenMP可正常工作。

已按指南更新~/.R/Makevars文件 #

文件内容如下：

readLines("~/.R/Makevars")
# [1] "CPPFLAGS += -Xclang -fopenmp"
# [2] "LDFLAGS += -lomp"            
# [3] "TEST = test1234"               

~/.R/Makevars未在R中加载 #

在R中查询相关环境变量均为空：

Sys.getenv("CPPFLAGS")
# [1] ""
Sys.getenv("LDFLAGS")
# [1] ""
Sys.getenv("TEST")
# [1] ""

在Shell中查看文件权限：

ls -al ~/.R/Makevars
# -rw-------  1 chandler  62 May 31 07:08 /Users/chandler/.R/Makevars

尝试修改权限为chmod 600 ~/.R/Makevars，并在.Renviron中添加R_MAKEVARS_USER=~/.R/Makevars，确认Sys.getenv("R_MAKEVARS_USER")已生效，但问题仍未解决。

R SessionInfo #

R version 4.3.0 (2023-04-21)
Platform: aarch64-apple-darwin20 (64-bit)
Running under: macOS Ventura 13.3.1

Matrix products: default
BLAS:   /Library/Frameworks/R.framework/Versions/4.3-arm64/Resources/lib/libRblas.0.dylib 
LAPACK: /Library/Frameworks/R.framework/Versions/4.3-arm64/Resources/lib/libRlapack.dylib;  LAPACK version 3.11.0

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

time zone: America/Denver
tzcode source: internal

attached base packages:
[1] stats     graphics  grDevices
[4] utils     datasets  methods  
[7] base     

loaded via a namespace (and not attached):
[1] compiler_4.3.0

内容的提问来源于stack exchange，提问作者chandler