# Internal-only.  Do not use.  Expand a variable and strip the flags
# not suitable to extension builders.
%__extension_strip_flags() %{lua:
--the only argument to this macro is the "name" of the flags we strip (e.g. cflags, ldflags, etc.)
local name = rpm.expand("%{1}")
--store all the individual flags in a variable as a continuous string
local flags = rpm.expand("%{build_" .. name .. "}")
--create an empty table for the minimal set of flags we wanna preserve
local stripped_flags = { }
--iterate over the individual flags and store the ones we want in the table as unique keys
for flag in flags:gmatch("%S+") do
  if flag:find("^%-fexceptions") or flag:find("^%-fcf%-protection") then
    stripped_flags[flag] = true end
  end
--print out the finalized set of flags for use by the extension builders
for k,_ in pairs(stripped_flags) do print(k .. " ") end
}

# Variants of CFLAGS, CXXFLAGS, FFLAGS, LDFLAGS for use within
# extension builders.
%extension_cflags %{__extension_strip_flags cflags}
%extension_cxxflags %{__extension_strip_flags cxxflags}
%extension_fflags %{__extension_strip_flags fflags}
%extension_ldflags %{__extension_strip_flags ldflags}