Allow CUDA build with bazel

BUILD.bazel

@@ -1,5 +1,7 @@
+load("@bazel_skylib//rules:common_settings.bzl", "bool_flag")
 load("@bazel_skylib//rules:copy_file.bzl", "copy_file")
 load("@rules_cc//cc:defs.bzl", "cc_binary", "cc_library", "cc_test")
+load("@rules_cuda//cuda:defs.bzl", "cuda_library", "requires_cuda")
 
 copy_file(
     name = "highs-config",
@@ -8,12 +10,43 @@ copy_file(
     visibility = ["//visibility:public"],
 )
 
+bool_flag(
+    name = "cupdlp_gpu",
+    build_setting_default = False,
+    visibility = ["//visibility:public"],
+)
+
+config_setting(
+    name = "cupdlp_gpu_enabled",
+    flag_values = {
+        "@rules_cuda//cuda:enable": "True",
+        "@local_cuda//:valid_toolchain_found": "True",
+        ":cupdlp_gpu": "True",
+    },
+)
+
 cc_library(
     name = "config",
     srcs = ["HConfig.h"],
     visibility = ["//visibility:public"],
 )
 
+cuda_library(
+    name = "cupdlp",
+    srcs = glob([
+        "highs/pdlp/cupdlp/cuda/*.cu",
+    ]),
+    hdrs = glob([
+        "highs/pdlp/cupdlp/cuda/*.cuh",
+    ]),
+    defines = ["CUPDLP_GPU"],
+    target_compatible_with = requires_cuda(),
+    deps = [
+        "@local_cuda//:cublas",
+        "@local_cuda//:cusparse",
+    ],
+)
+
 cc_library(
     name = "highs",
     srcs = ["highs/interfaces/highs_c_api.cpp"] + glob([
@@ -49,6 +82,10 @@ cc_library(
             "-Wno-unused-but-set-variable",
         ],
     }),
+    defines = select({
+        ":cupdlp_gpu_enabled": ["CUPDLP_GPU"],
+        "//conditions:default": ["CUPDLP_CPU"],
+    }),
     includes = [
         "extern",
         # "extern/filereaderlp",
@@ -66,7 +103,6 @@ cc_library(
         # "highs/simplex",
         # "highs/test_kkt",
         # "highs/util",
-        "bazel-bin",
     ],
     linkopts = select({
         "@rules_cc//cc/compiler:msvc-cl": ["-DEFAULTLIB:shell32.lib"],
@@ -76,7 +112,10 @@ cc_library(
     deps = [
         "//:config",
         "@zlib",
-    ],
+    ] + select({
+        ":cupdlp_gpu_enabled": [":cupdlp"],
+        "//conditions:default": [],
+    }),
 )
 
 cc_library(

MODULE.bazel

@@ -19,3 +19,14 @@ bazel_dep(
     name = "zlib",
     version = "1.3.1.bcr.5",
 )
+
+bazel_dep(
+    name = "rules_cuda",
+    version = "0.2.5",
+)
+
+local_cuda = use_extension("@rules_cuda//cuda:extensions.bzl", "toolchain")
+local_cuda.local_toolchain(
+    toolkit_path = "",
+)
+use_repo(local_cuda, "local_cuda")

highs/HConfig.h.bazel.in

@@ -3,7 +3,6 @@
 
 #define FAST_BUILD
 /* #undef ZLIB_FOUND */
-#define CUPDLP_CPU
 #define CMAKE_BUILD_TYPE "RELEASE"
 #define HiGHSRELEASE
 /* #undef HIGHSINT64 */

highs/pdlp/README.md

@@ -46,8 +46,18 @@ When both work, on Linux, you should check that `/usr/local/cuda` exists.
 
 #### Build
 
+##### CMake
+
 ```
 cmake -S . -B build -DCUPDLP_GPU=ON -DALL_TESTS=ON ..
 cmake --build build --parallel
 ```
 
+##### Bazel
+
+```bash
+# Will NOT build with CUDA, only CPU support
+bazel build //:highs 
+# Will build with CUDA if a CUDA toolchain is detected
+bazel build //:highs --//:cupdlp_gpu
+```