Add macros.build-constraints to the buildroot

SOURCES/macros.build-constraints

@@ -0,0 +1,42 @@
+# Macros to constrain resource use during the build process
+
+# outputs build flag overrides to be used in conjunction with
+# %%make_build, %%cmake_build etc.
+#
+# if no override is needed, this macro outputs nothing
+#
+# - m   memory limit in MBs per core; default is 1024
+#
+# Usage:
+# e.g. %make_build %{limit_build -m 2048}
+#   => /usr/bin/make -O -j16 V=1 VERBOSE=1
+#      %make_build %{limit_build -m 40960}
+#   => /usr/bin/make -O -j16 V=1 VERBOSE=1 -j1
+# 
+%limit_build(m:) %{lua:
+  local mem_per_process=rpm.expand("%{-m*}")
+  if mem_per_process == "" then
+    mem_per_process = 1024
+  else
+    mem_per_process = tonumber(mem_per_process)
+  end
+  local mem_total = 0
+  for line in io.lines('/proc/meminfo') do
+    if line:sub(1, 9) == "MemTotal:" then
+      local tokens = {}
+      for token in line:gmatch("%w+") do
+        tokens[#tokens + 1] = token
+      end
+      mem_total = tonumber(tokens[2])
+      break
+    end
+  end
+  local max_jobs = mem_total // (mem_per_process * 1024)
+  if max_jobs < 1 then
+    max_jobs = 1
+  end
+  cur_max_jobs=tonumber(rpm.expand("%{_smp_build_ncpus}"))
+  if cur_max_jobs > max_jobs then
+    print("-j" .. max_jobs)
+  end
+}

SPECS/epel-rpm-macros.spec

@@ -1,6 +1,6 @@
 Name:           epel-rpm-macros
 Version:        9
-Release:        14%{dist}
+Release:        14%{dist}.inferit
 Summary:        Extra Packages for Enterprise Linux RPM macros
 
 License:        GPLv2
@@ -15,6 +15,8 @@ Source2:        GPL
 #Add source for misc macros below here
 # https://src.fedoraproject.org/rpms/redhat-rpm-config/blob/rawhide/f/macros.shell-completions
 Source3:        macros.shell-completions
+# macros.build-constraints
+Source4:        macros.build-constraints
 
 
 BuildArch:      noarch
@@ -62,14 +64,21 @@ install -Dpm 644 %{SOURCE1} \
 install -Dpm 644 %{SOURCE3} \
     %{buildroot}%{_rpmmacrodir}/macros.shell-completions
 
+install -Dpm 644 %{SOURCE4} \
+    %{buildroot}%{_rpmmacrodir}/macros.build-constraints
+
 %files
 %license GPL
 %{_rpmmacrodir}/macros.epel-rpm-macros
 %{_sysconfdir}/rpm/macros.zzz-epel-override
 %{_rpmmacrodir}/macros.shell-completions
+%{_rpmmacrodir}/macros.build-constraints
 
 
 %changelog
+* Tue Aug 27 2024 Arkady L. Shane <tigro@msvsphere-os.ru> - 9-14.inferit
+- Add macros.build-constraints to the buildroot
+
 * Sat Mar 02 2024 Maxwell G <maxwell@gtmx.me> - 9-14
 - Add forge-srpm-macros to the buildroot