From 93d936ce24edd383bfa834d5d3ca60e9c6700d36 Mon Sep 17 00:00:00 2001
From: Michele Guerini Rocco <m.guerinirocco2@campus.unimib.it>
Date: Wed, 15 Dec 2021 02:31:15 +0100
Subject: [PATCH] Makefile: ignore instrisic modules

This excludes intristic modules like `iso_fortran_env` from the
automatic generation of the prerequisites.
---
 Makefile | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 5760f73..5ee6d20 100644
--- a/Makefile
+++ b/Makefile
@@ -140,7 +140,9 @@ graph.svg: Makefile
 #         dependencies (ie. the dependency graph is a DAG);
 $(OBJDIR)/%.d: $(SRCDIR)/%.f90 | $(OBJDIR)
 	@printf '$(@:d=o): $< \\\n' > $@
-	@sed -n 's@^[^!].*use \([^,]\+\),.*@$(OBJDIR)/\1.o \\@p' '$<' | sort -u >> $@
+	@grep -v 'use iso_' '$<' | \
+	 sed -n 's@^[^!].*use \([^,]\+\),.*@$(OBJDIR)/\1.o \\@p' | \
+	 sort -u >> $@
 
 # Load the generated rules
 include $(DEPS)