Cannot make gpu-enabled chapel

Users
12

Hi Nelson -

It looks like you are using 2.1. If it were me, I would test the patch by trying it on a clone of Chapel (because it makes it easier to keep track of whether you have patched the sources / what version you have). If you wait a bit (until my PR is merged, later today), you can make a clone with git clone https://github.com/chapel-lang/chapel and then you can bring that up to date now or in the future with git pull.

Patching

If you want to try to patch 2.1, you can try that now. Save the following to a file, say patch.txt:

diff --git a/util/chplenv/chpl_llvm.py b/util/chplenv/chpl_llvm.py
index c29da81c40..7f898b5adf 100755
--- a/util/chplenv/chpl_llvm.py
+++ b/util/chplenv/chpl_llvm.py
@@ -649,7 +649,7 @@ def llvm_enabled():
     return False
 
 @memoize
-def get_gcc_prefix():
+def get_gcc_prefix_dir():
     gcc_prefix = overrides.get('CHPL_LLVM_GCC_PREFIX', '')
 
     # allow CHPL_LLVM_GCC_PREFIX=none to disable inferring it
@@ -710,6 +710,12 @@ def get_gcc_prefix():
 
     return gcc_prefix
 
+@memoize
+def get_gcc_install_dir():
+    gcc_dir = overrides.get('CHPL_LLVM_GCC_INSTALL_DIR', '')
+
+    return gcc_dir
+
 
 # The bundled LLVM does not currently know to look in a particular Mac OS X SDK
 # so we provide a -isysroot arg to indicate which is used.
@@ -808,9 +814,13 @@ def get_system_llvm_built_sdkroot():
 def get_clang_basic_args():
     clang_args = [ ]
 
-    gcc_prefix = get_gcc_prefix()
-    if gcc_prefix:
-        clang_args.append('--gcc-toolchain=' + gcc_prefix)
+    gcc_install_dir = get_gcc_install_dir();
+    if gcc_install_dir:
+        clang_args.append('--gcc-install-dir=' + gcc_install_dir)
+    else:
+        gcc_prefix = get_gcc_prefix_dir()
+        if gcc_prefix:
+            clang_args.append('--gcc-toolchain=' + gcc_prefix)
 
     sysroot_args = get_sysroot_resource_dir_args()
     if sysroot_args:

Then, cd to your chapel-2.1.0 directory and then run patch -p1 < patch.txt.

Using the patch

To understand what to set CHPL_LLVM_GCC_INSTALL_DIR to, try a test compile:

  • echo 'int main() { return 0; }' > hello.cc
  • clang++ -v hello.cc

This will print out lines along these lines:

  Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/11
  Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/12
  Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/13
  Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/14
  Selected GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/14

The paths printed here are suitable for use with CHPL_LLVM_GCC_INSTALL_DIR. Since you want to use GCC 13 (since it is the system default), you should pick that one.

For me, it amounts to doing

export CHPL_LLVM_GCC_INSTALL_DIR=/usr/bin/../lib/gcc/x86_64-linux-gnu/13

You can check if all of this is working by running printchplenv --all. You should see CHPL_TARGET_CC / CHPL_TARGET_CXX / CHPL_TARGET_LD lines that include --gcc-install-dir options with the path you have selected.

For me:

./util/printchplenv  --all

 machine info: Linux iris 6.8.0-44-generic #44-Ubuntu SMP PREEMPT_DYNAMIC Tue Aug 13 13:35:26 UTC 2024 x86_64
CHPL_HOME: /home/mppf/chapel-old-versions/chapel-2.1.0
script location: /home/mppf/chapel-old-versions/chapel-2.1.0/util/chplenv
CHPL_HOST_PLATFORM: linux64
CHPL_HOST_COMPILER: gnu
  CHPL_HOST_CC: gcc
  CHPL_HOST_CXX: g++
CHPL_HOST_ARCH: x86_64
CHPL_TARGET_PLATFORM: linux64
CHPL_TARGET_COMPILER: llvm
  CHPL_TARGET_CC: /usr/lib/llvm-18/bin/clang --gcc-install-dir=/usr/bin/../lib/gcc/x86_64-linux-gnu/13
  CHPL_TARGET_CXX: /usr/lib/llvm-18/bin/clang++ --gcc-install-dir=/usr/bin/../lib/gcc/x86_64-linux-gnu/13
  CHPL_TARGET_LD: /usr/lib/llvm-18/bin/clang++ --gcc-install-dir=/usr/bin/../lib/gcc/x86_64-linux-gnu/13
...
[Chapel Merge] Add CHPL_LLVM_GCC_INSTALL_DIR as an alternative to CHPL_LLVM_GCC_PREFIX