10 files changed, 60 insertions, 15 deletions
diff --git a/cmake/FindANTLR3.cmake b/cmake/FindANTLR3.cmake
index 5429be99a..3ed3c5376 100644
--- a/cmake/FindANTLR3.cmake
+++ b/cmake/FindANTLR3.cmake
@@ -34,7 +34,11 @@ if(ANTLR3_JAR AND ANTLR3_INCLUDE_DIR AND ANTLR3_RUNTIME)
 endif()
 
 if(NOT ANTLR3_FOUND_SYSTEM)
-    check_auto_download("ANTLR3" "")
+    check_ep_downloaded("ANTLR3-EP-jar")
+    if(NOT ANTLR3-EP-jar_DOWNLOADED)
+      check_auto_download("ANTLR3" "")
+    endif()
+
     include(ExternalProject)
 
     set(ANTLR3_VERSION "3.4")
diff --git a/cmake/FindCLN.cmake b/cmake/FindCLN.cmake
index 5a2295c4b..b5b37ec59 100644
--- a/cmake/FindCLN.cmake
+++ b/cmake/FindCLN.cmake
@@ -34,7 +34,11 @@ if(CLN_INCLUDE_DIR AND CLN_LIBRARIES)
 endif()
 
 if(NOT CLN_FOUND_SYSTEM)
-  check_auto_download("CLN" "--no-cln")
+  check_ep_downloaded("CLN-EP")
+  if(NOT CLN-EP_DOWNLOADED)
+    check_auto_download("CLN" "--no-cln")
+  endif()
+
   include(ExternalProject)
 
   fail_if_cross_compiling("Windows" "" "CLN" "autoconf fails")
diff --git a/cmake/FindCaDiCaL.cmake b/cmake/FindCaDiCaL.cmake
index 82737a0ac..7c70a066c 100644
--- a/cmake/FindCaDiCaL.cmake
+++ b/cmake/FindCaDiCaL.cmake
@@ -39,7 +39,11 @@ if(CaDiCaL_INCLUDE_DIR AND CaDiCaL_LIBRARIES)
 endif()
 
 if(NOT CaDiCaL_FOUND_SYSTEM)
-  check_auto_download("CaDiCaL" "--no-cadical")
+  check_ep_downloaded("CaDiCaL-EP")
+  if(NOT CaDiCaL-EP_DOWNLOADED)
+    check_auto_download("CaDiCaL" "--no-cadical")
+  endif()
+
   include(CheckSymbolExists)
   include(ExternalProject)
 
@@ -102,5 +106,4 @@ if(CaDiCaL_FOUND_SYSTEM)
   message(STATUS "Found CaDiCaL ${CaDiCaL_VERSION}: ${CaDiCaL_LIBRARIES}")
 else()
   message(STATUS "Building CaDiCaL ${CaDiCaL_VERSION}: ${CaDiCaL_LIBRARIES}")
-  add_dependencies(CaDiCaL CaDiCaL-EP)
 endif()
diff --git a/cmake/FindCryptoMiniSat.cmake b/cmake/FindCryptoMiniSat.cmake
index 08cb6f6a1..9599f645f 100644
--- a/cmake/FindCryptoMiniSat.cmake
+++ b/cmake/FindCryptoMiniSat.cmake
@@ -22,6 +22,7 @@ find_package(cryptominisat5 ${CryptoMiniSat_FIND_VERSION} QUIET)
 
 set(CryptoMiniSat_FOUND_SYSTEM FALSE)
 if(cryptominisat5_FOUND)
+  set(CryptoMiniSat_VERSION ${cryptominisat5_VERSION})
   set(CryptoMiniSat_FOUND_SYSTEM TRUE)
   add_library(CryptoMiniSat INTERFACE IMPORTED GLOBAL)
   target_link_libraries(CryptoMiniSat INTERFACE cryptominisat5)
@@ -31,15 +32,18 @@ if(cryptominisat5_FOUND)
     CryptoMiniSat PROPERTIES INTERFACE_INCLUDE_DIRECTORIES
                              "${CRYPTOMINISAT5_INCLUDE_DIRS}"
   )
-
 endif()
 
 if(NOT CryptoMiniSat_FOUND_SYSTEM)
-  check_auto_download("CryptoMiniSat" "--no-cryptominisat")
-  include(ExternalProject)
-
   set(CryptoMiniSat_VERSION "5.8.0")
 
+  check_ep_downloaded("CryptoMiniSat-EP")
+  if(NOT CryptoMiniSat-EP_DOWNLOADED)
+    check_auto_download("CryptoMiniSat" "--no-cryptominisat")
+  endif()
+
+  include(ExternalProject)
+
   ExternalProject_Add(
     CryptoMiniSat-EP
     ${COMMON_EP_CONFIG}
diff --git a/cmake/FindGMP.cmake b/cmake/FindGMP.cmake
index f5447f95d..c554197b9 100644
--- a/cmake/FindGMP.cmake
+++ b/cmake/FindGMP.cmake
@@ -43,7 +43,11 @@ if(GMP_INCLUDE_DIR AND GMP_LIBRARIES)
 endif()
 
 if(NOT GMP_FOUND_SYSTEM)
-  check_auto_download("GMP" "")
+  check_ep_downloaded("GMP-EP")
+  if(NOT GMP-EP_DOWNLOADED)
+    check_auto_download("GMP" "")
+  endif()
+
   include(ExternalProject)
 
   set(GMP_VERSION "6.2.1")
diff --git a/cmake/FindGTest.cmake b/cmake/FindGTest.cmake
index bc12e44ba..d36829784 100644
--- a/cmake/FindGTest.cmake
+++ b/cmake/FindGTest.cmake
@@ -25,7 +25,11 @@ if(GTest_INCLUDE_DIR AND GTest_LIBRARIES AND GTest_MAIN_LIBRARIES)
 endif()
 
 if(NOT GTest_FOUND_SYSTEM)
-    check_auto_download("GTest" "")
+    check_ep_downloaded("GTest-EP")
+    if(NOT GTest-EP_DOWNLOADED)
+      check_auto_download("GTest" "")
+    endif()
+
     include(ExternalProject)
 
     set(GTest_VERSION "1.10.0")
diff --git a/cmake/FindKissat.cmake b/cmake/FindKissat.cmake
index 62aa5eeec..08b214961 100644
--- a/cmake/FindKissat.cmake
+++ b/cmake/FindKissat.cmake
@@ -39,7 +39,11 @@ if(Kissat_INCLUDE_DIR AND Kissat_LIBRARIES)
 endif()
 
 if(NOT Kissat_FOUND_SYSTEM)
-  check_auto_download("Kissat" "--no-kissat")
+  check_ep_downloaded("Kissat-EP")
+  if(NOT Kissat-EP_DOWNLOADED)
+    check_auto_download("Kissat" "--no-kissat")
+  endif()
+
   include(ExternalProject)
 
   fail_if_include_missing("sys/resource.h" "Kissat")
diff --git a/cmake/FindPoly.cmake b/cmake/FindPoly.cmake
index 2030ca806..0a5780585 100644
--- a/cmake/FindPoly.cmake
+++ b/cmake/FindPoly.cmake
@@ -38,7 +38,11 @@ if(Poly_INCLUDE_DIR
 endif()
 
 if(NOT Poly_FOUND_SYSTEM)
-  check_auto_download("Poly" "--no-poly")
+  check_ep_downloaded("Poly-EP")
+  if(NOT Poly-EP_DOWNLOADED)
+    check_auto_download("Poly" "--no-poly")
+  endif()
+
   include(ExternalProject)
 
   set(Poly_VERSION "0.1.9")
diff --git a/cmake/FindSymFPU.cmake b/cmake/FindSymFPU.cmake
index be5b1eacb..5a2ac5111 100644
--- a/cmake/FindSymFPU.cmake
+++ b/cmake/FindSymFPU.cmake
@@ -24,7 +24,11 @@ if(SymFPU_INCLUDE_DIR)
 endif()
 
 if(NOT SymFPU_FOUND_SYSTEM)
-  check_auto_download("SymFPU" "--no-symfpu")
+  check_ep_downloaded("SymFPU-EP")
+  if(NOT SymFPU-EP_DOWNLOADED)
+    check_auto_download("SymFPU" "--no-symfpu")
+  endif()
+
   include(ExternalProject)
   include(deps-helper)
 
diff --git a/cmake/deps-helper.cmake b/cmake/deps-helper.cmake
index f044c2706..f37ccb1f2 100644
--- a/cmake/deps-helper.cmake
+++ b/cmake/deps-helper.cmake
@@ -47,11 +47,11 @@ macro(check_auto_download name disable_option)
             set(depname "${name}")
         endif()
         if("${disable_option}" STREQUAL "")
-            message(FATAL_ERROR "Could not find the required dependency
+            message(FATAL_ERROR "Could not find the required dependency \
 ${depname} in the system. Please install it yourself or use --auto-download to \
 let us download and build it for you.")
         else()
-            message(FATAL_ERROR "Could not find the optional dependency
+            message(FATAL_ERROR "Could not find the optional dependency \
 ${depname} in the system. You can disable this dependency with \
 ${disable_option}, install it yourself or use --auto-download to let us \
 download and build it for you.")
@@ -59,6 +59,16 @@ download and build it for you.")
     endif()
 endmacro(check_auto_download)
 
+# Check if the given external project was already set up in a previous
+# configure call.
+macro(check_ep_downloaded name)
+  if(EXISTS "${DEPS_PREFIX}/src/${name}")
+    set(${name}_DOWNLOADED TRUE)
+  else()
+    set(${name}_DOWNLOADED FALSE)
+  endif()
+endmacro()
+
 macro(check_system_version name)
     # find_package sets this variable when called with a version
     # https://cmake.org/cmake/help/latest/command/find_package.html#version-selection