Add build_environment

Author: scaronni

dkms.8.in

@@ -953,6 +953,27 @@ Run no more than this number of jobs in parallel.
 .B compress_gzip_opts, compress_xz_opts, compress_zstd_opts
 Control how modules are compressed. By default, the highest available level of compression is used.
 .TP
+.B build_environment
+If the directive is set to any non null-value, the content of the directive will be imported into the DKMS shell with the
+.B source
+command when building modules.
+
+Can be used to specify a custom
+.B gcc
+installed in a custom path; and the variable
+.B $kernelver
+can be used to represent the target kernel version. Some examples:
+
+Define a custom script to point to a specific GCC (
+.B CC=/opt/gcc12/bin/gcc
+):
+.B build_environment="/opt/gcc12/env"
+
+Enable the software collection
+.B gcc-toolset-11
+and use it for building an UEK kernel on Oracle Linux:
+.B build_environment="/opt/rh/gcc-toolset-11/enable"
+.TP
 .B post_transaction
 If the directive is set to any non null-value, the content of the directive will be executed with any command that change the content of the kernel modules folder, that is
 .B dkms autoinstall, dkms install

dkms.in

@@ -103,8 +103,7 @@ show_deprecation_warnings=0
 # All of the variables not related to signing we will accept from framework.conf.
 readonly dkms_framework_nonsigning_variables="source_tree dkms_tree install_tree tmp_location
    verbose symlink_modules autoinstall_all_kernels modprobe_on_install parallel_jobs
-   compress_gzip_opts compress_xz_opts compress_zstd_opts
-   post_transaction"
+   compress_gzip_opts compress_xz_opts compress_zstd_opts build_environment post_transaction"
 # All of the signing related variables we will accept from framework.conf.
 readonly dkms_framework_signing_variables="sign_file mok_signing_key mok_certificate"
 
@@ -1381,6 +1380,12 @@ do_build()
 {
     [[ $kernelver && $arch ]] || die 16 "do_build: Empty \$kernelver or \$arch"
 
+    # Source build environment file if specified
+    if [[ -n "$build_environment" && -f "$build_environment" ]]; then
+        # shellcheck disable=SC1090
+        source "$build_environment"
+    fi
+
     # If the module has not been added, try to add it.
     if ! is_module_added "$module" "$module_version" ; then
         add_module
@@ -3302,7 +3307,6 @@ addon_modules_dir="${ADDON_MODULES_DIR}"
 # Source in configuration not related to signing
 read_framework_conf "$dkms_framework_nonsigning_variables"
 
-
 # Clear out command line argument variables
 module=""
 module_version=""

dkms_framework.conf.in

@@ -56,6 +56,10 @@
 # compress_xz_opts="--check=crc32 --lzma2=dict=1MiB -6"
 # compress_zstd_opts="-q --rm -T0 -3"
 
+# Path to a file containing environment variables to be sourced by DKMS.
+# This file will be sourced for the build command.
+# build_environment=""
+
 # Command to run at the end of every DKMS transaction, for example after a new
 # kernel has been installed on the system and all modules have been successfully
 # built and installed.