From de13ca2874e673b426efcf04f734ae6625635396 Mon Sep 17 00:00:00 2001
From: Simon Tatham <anakin@pobox.com>
Date: Thu, 15 Jun 2023 07:40:14 +0100
Subject: [PATCH] Add a 'core' library alongside 'common'.

The 'core' library contains almost all the same objects as 'common',
but leaves out hat.c. And the auxiliary program 'hatgen' now links
against that slightly reduced core library instead of 'common'.

This avoids a dependency loop: one of hatgen's jobs is to generate
hat-tables.h, but hat-tables.h is a dependency of it.

Of course, the generated hat-tables.h is already committed, so this
doesn't present a bootstrapping problem in a normal build. But if
someone modifies hatgen.c in order to regenerate hat-tables.h, and
does so in a way that makes it uncompilable, they can't rebuild hatgen
and try again! Of course you can always revert changes with git, but
it's annoying to have to. Better to keep the dependencies non-cyclic
in the first place.
---
 CMakeLists.txt           |  9 +++++----
 auxiliary/CMakeLists.txt |  2 +-
 cmake/setup.cmake        | 10 ++++++++--
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 481294f..d0d6077 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,11 +5,12 @@ project(puzzles
 
 include(cmake/setup.cmake)
 
-add_library(common
+add_library(core_obj OBJECT
   combi.c divvy.c drawing.c dsf.c findloop.c grid.c latin.c
-  laydomino.c loopgen.c malloc.c matching.c midend.c misc.c penrose.c hat.c
-  ps.c random.c sort.c tdq.c tree234.c version.c
-  ${platform_common_sources})
+  laydomino.c loopgen.c malloc.c matching.c midend.c misc.c penrose.c
+  ps.c random.c sort.c tdq.c tree234.c version.c ${platform_common_sources})
+add_library(core $<TARGET_OBJECTS:core_obj>)
+add_library(common $<TARGET_OBJECTS:core_obj> hat.c)
 
 include_directories(${CMAKE_CURRENT_SOURCE_DIR})
 
diff --git a/auxiliary/CMakeLists.txt b/auxiliary/CMakeLists.txt
index f475812..b9c1067 100644
--- a/auxiliary/CMakeLists.txt
+++ b/auxiliary/CMakeLists.txt
@@ -1,6 +1,6 @@
 cliprogram(combi-test combi-test.c)
 cliprogram(divvy-test divvy-test.c)
-cliprogram(hatgen hatgen.c COMPILE_DEFINITIONS TEST_HAT)
+cliprogram(hatgen hatgen.c CORE_LIB COMPILE_DEFINITIONS TEST_HAT)
 cliprogram(hat-test hat-test.c)
 cliprogram(latin-test latin-test.c)
 cliprogram(matching matching.c)
diff --git a/cmake/setup.cmake b/cmake/setup.cmake
index 3c91285..3b73739 100644
--- a/cmake/setup.cmake
+++ b/cmake/setup.cmake
@@ -148,12 +148,18 @@ endfunction()
 # a command-line helper tool.
 function(cliprogram NAME)
   cmake_parse_arguments(OPT
-    "" "" "COMPILE_DEFINITIONS" ${ARGN})
+    "CORE_LIB" "" "COMPILE_DEFINITIONS" ${ARGN})
+
+  if(OPT_CORE_LIB)
+    set(lib core)
+  else()
+    set(lib common)
+  endif()
 
   if(build_cli_programs)
     add_executable(${NAME} ${CMAKE_SOURCE_DIR}/nullfe.c
       ${OPT_UNPARSED_ARGUMENTS})
-    target_link_libraries(${NAME} common ${platform_libs})
+    target_link_libraries(${NAME} ${lib} ${platform_libs})
     if(OPT_COMPILE_DEFINITIONS)
       target_compile_definitions(${NAME} PRIVATE ${OPT_COMPILE_DEFINITIONS})
     endif()