From 1163570dd4873f9782d38e547bc1f7e974d8ea80 Mon Sep 17 00:00:00 2001
From: John Mulligan <jmulligan@redhat.com>
Date: Tue, 1 Nov 2022 14:51:57 -0400
Subject: [PATCH] script: add discover_compiler function to lib-build.sh

The discover_compiler function is an abstraction over the current
compiler detection code in run-make.sh. It is intended to be flexible
enough to work on {centos,rhel} systems, but currently is just an
updated version of the logic from run-make.sh. The intent is that this
function will grow and become useful for other scripts used for
building (possibly do_cmake.sh for example).

Signed-off-by: John Mulligan <jmulligan@redhat.com>
(cherry picked from commit 561bf4ea9b4dd8f6710a959c5bd38eb4085a9d52)
(cherry picked from commit 8dae1c161c4d3bc3a1ef3cd48de0da9a89e44e65)
---
 src/script/lib-build.sh | 49 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/src/script/lib-build.sh b/src/script/lib-build.sh
index a6ff447c99e..052df9e2860 100644
--- a/src/script/lib-build.sh
+++ b/src/script/lib-build.sh
@@ -31,3 +31,52 @@ function ci_debug() {
         echo "CI_DEBUG: $*"
     fi
 }
+<<<<<<< HEAD
+=======
+
+# get_processors returns 1/2 the value of the value returned by
+# the nproc program OR the value of the environment variable NPROC
+# allowing the user to tune the number of cores visible to the
+# build scripts.
+function get_processors() {
+    # get_processors() depends on coreutils nproc.
+    if [ -n "$NPROC" ]; then
+        echo "$NPROC"
+    else
+        if [ "$(nproc)" -ge 2 ]; then
+            echo "$(($(nproc) / 2))"
+        else
+            echo 1
+        fi
+    fi
+}
+
+# discover_compiler takes one argument, purpose, which may be used
+# to adjust the results for a specific need. It sets three environment
+# variables `discovered_c_compiler`, `discovered_cxx_compiler` and
+# `discovered_compiler_env`. The `discovered_compiler_env` variable
+# may be blank. If not, it will contain a file that needs to be sourced
+# prior to using the compiler.
+function discover_compiler() {
+    # nb: currently purpose is not used for detection
+    local purpose="$1"
+    ci_debug "Finding compiler for ${purpose}"
+
+    local compiler_env=""
+    local cxx_compiler=g++
+    local c_compiler=gcc
+    # ubuntu/debian ci builds prefer clang
+    for i in {14..10}; do
+        if type -t "clang-$i" > /dev/null; then
+            cxx_compiler="clang++-$i"
+            c_compiler="clang-$i"
+            break
+        fi
+    done
+
+    export discovered_c_compiler="${c_compiler}"
+    export discovered_cxx_compiler="${cxx_compiler}"
+    export discovered_compiler_env="${compiler_env}"
+    return 0
+}
+>>>>>>> 8dae1c161c4 (script: add discover_compiler function to lib-build.sh)
-- 
2.39.5