From 146da1d4094ef541ff7eb249910735de233cf5ca Mon Sep 17 00:00:00 2001
From: Nick Dingle <nick.dingle@arm.com>
Date: Wed, 23 Jul 2025 11:05:22 +0100
Subject: [PATCH] Capture module file dependencies in CMake

The modulefile la_xisnan.F90 depends on the modulefile
la_constants.f90 but this dependency is not expressed in the CMake
rules. In some parallel builds we have observed failures where
compilation of objects that depend on la_constants.mod starts before
compilation of la_constants.f90 has finished.

This patch modifies CMakeLists.txt to ensure that la_constants.mod is
built before any other object or modulefile that depends on it.
---
 SRC/CMakeLists.txt | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/SRC/CMakeLists.txt b/SRC/CMakeLists.txt
index be426cecd..676397e76 100644
--- a/SRC/CMakeLists.txt
+++ b/SRC/CMakeLists.txt
@@ -36,7 +36,9 @@
 #
 #######################################################################
 
-set(ALLMOD la_xisnan.F90 la_constants.f90)
+set(CONSTMOD la_constants.f90)
+
+set(NANMOD la_xisnan.F90)
 
 set(ALLAUX ilaenv.f ilaenv2stage.f ieeeck.f lsamen.f iparmq.f iparam2stage.F
    ilaprec.f ilatrans.f ilauplo.f iladiag.f chla_transtype.f
@@ -519,7 +521,14 @@ list(REMOVE_DUPLICATES SOURCES)
 
 # Use special target for MOD files to guarantee they are built before
 # any other files that depend on them
-add_library(mod_files OBJECT ${ALLMOD})
+add_library(const_mod_file OBJECT ${CONSTMOD})
+set_target_properties(
+  const_mod_file PROPERTIES
+  POSITION_INDEPENDENT_CODE ON
+  Fortran_PREPROCESS ON
+  )
+
+add_library(mod_files OBJECT ${NANMOD} $<TARGET_OBJECTS:const_mod_file>)
 set_target_properties(
   mod_files PROPERTIES
   POSITION_INDEPENDENT_CODE ON