Centralized backend list; AsAvailable->AUTO

src/backends/CMakeLists.txt

@@ -1,42 +1,74 @@
-set(SOCI_EMPTY ${PROJECT_IS_TOP_LEVEL} CACHE STRING "Include the 'empty' backend. Can be bool-valued or one of 'Enabled', 'Disabled' and 'AsAvailable'")
+set(SOCI_EXISTING_BACKENDS
+  "Empty"
 
-set(SOCI_DB2 "AsAvailable" CACHE STRING "Include the 'DB2' backend. Can be bool-valued or one of 'Enabled', 'Disabled' and 'AsAvailable'")
-set(SOCI_FIREBIRD "AsAvailable" CACHE STRING "Include the 'Firebird' backend. Can be bool-valued or one of 'Enabled', 'Disabled' and 'AsAvailable'")
-set(SOCI_MYSQL "AsAvailable" CACHE STRING "Include the 'MySQL' backend. Can be bool-valued or one of 'Enabled', 'Disabled' and 'AsAvailable'")
-set(SOCI_ODBC "AsAvailable" CACHE STRING "Include the 'ODBC' backend. Can be bool-valued or one of 'Enabled', 'Disabled' and 'AsAvailable'")
-set(SOCI_ORACLE "AsAvailable" CACHE STRING "Include the 'Oracle' backend. Can be bool-valued or one of 'Enabled', 'Disabled' and 'AsAvailable'")
-set(SOCI_POSTGRESQL "AsAvailable" CACHE STRING "Include the 'Postgresql' backend. Can be bool-valued or one of 'Enabled', 'Disabled' and 'AsAvailable'")
-set(SOCI_SQLITE3 "AsAvailable" CACHE STRING "Include the 'SQLite3' backend. Can be bool-valued or one of 'Enabled', 'Disabled' and 'AsAvailable'")
+  "DB2"
+  "Firebird"
+  "MySQL"
+  "ODBC"
+  "Oracle"
+  "PostgreSQL"
+  "SQLite3"
+)
+set(SOCI_ENABLED_BACKENDS "")
 
+foreach(CURRENT_BACKEND IN LISTS SOCI_EXISTING_BACKENDS)
+  string(TOUPPER "${CURRENT_BACKEND}" CURRENT_BACKEND_UPPER)
+  string(TOLOWER "${CURRENT_BACKEND}" CURRENT_BACKEND_LOWER)
 
-foreach(CURRENT IN ITEMS "db2" "empty" "firebird" "mysql" "odbc" "oracle" "postgresql" "sqlite3")
-  string(TOUPPER "${CURRENT}" CURRENT_UPPER)
+  set(CURRENT_ENABLED_VAR "SOCI_${CURRENT_BACKEND_UPPER}")
+
+  # Add option to enable/disable the current backend. Note: if the cache variable already exists
+  # (e.g. because it has been specified on the command line), this will NOT overwrite the
+  # explicitly specified value
+  set(
+    ${CURRENT_ENABLED_VAR}
+    "AUTO"
+    CACHE
+    STRING
+    "Whether to include the '${CURRENT_BACKEND}' backend. Can be a boolean value or 'AUTO' indicating that it shall be included unless its dependencies can't be satisfied."
+  )
 
   # Backwards compatibility with the old cmake setup that used WITH_* variables
   # These are now only defined if the user specified them.
-  if (DEFINED WITH_${CURRENT_UPPER})
-    message(DEPRECATION "Use of the WITH_${CURRENT_UPPER} option is deprecated - use the new SOCI_${CURRENT_UPPER} instead")
-    set(SOCI_${CURRENT_UPPER} "${WITH_${CURRENT_UPPER}}" CACHE STRING "")
+  if (DEFINED WITH_${CURRENT_BACKEND_UPPER})
+    message(DEPRECATION "Use of the WITH_${CURRENT_BACKEND_UPPER} option is deprecated - use the new ${CURRENT_ENABLED_VAR} instead")
+    if (WITH_${CURRENT_BACKEND_UPPER} AND ${CURRENT_ENABLED_VAR})
+      # Overwrite the new-style enable-option unless that was set to disable the current backend
+      # (Note that non-empty string - in particular "AUTO" - also convert to a true expression).
+      # However, the legacy behavior was to only include the backend, if its dependencies are met,
+      # so we set to AUTO rather than ON.
+      set(${CURRENT_ENABLED_VAR} "AUTO" CACHE STRING "" FORCE)
+    endif()
     # Delete the legacy variable from cache
-    unset(WITH_${CURRENT_UPPER} CACHE)
+    unset(WITH_${CURRENT_BACKEND_UPPER} CACHE)
   endif()
 
-  set(SOCI_${CURRENT_UPPER}_AS_AVAILABLE OFF CACHE INTERNAL "" FORCE)
-
-  if (SOCI_${CURRENT_UPPER} STREQUAL "Enabled")
-    set(SOCI_${CURRENT_UPPER} ON CACHE BOOL "" FORCE)
-  elseif(SOCI_${CURRENT_UPPER} STREQUAL "Disabled")
-    set(SOCI_${CURRENT_UPPER} OFF CACHE BOOL "" FORCE)
-  elseif(SOCI_${CURRENT_UPPER} STREQUAL "AsAvailable")
-    set(SOCI_${CURRENT_UPPER} ON CACHE BOOL "" FORCE)
-    set(SOCI_${CURRENT_UPPER}_AS_AVAILABLE ON CACHE INTERNAL "" FORCE)
-  elseif(SOCI_${CURRENT_UPPER} MATCHES "[Oo][Nn]|[Oo][Ff][Ff]|[Tt][Rr][Uu][Ee]|[Ff][Aa][Ll][Ss][Ee]|[Yy][Ee][Ss]|[Nn][Oo]|[YyNn01]")
-    # Do nothing - these are already booleans
+
+  # Internal variable indicating whether the current backend's include mode is AUTO
+  set(CURRENT_AUTO_VAR "SOCI_${CURRENT_BACKEND_UPPER}_AUTO")
+  set(${CURRENT_AUTO_VAR} OFF CACHE INTERNAL "" FORCE)
+
+  # Convert the value of the current backend's include flag to uppercase
+  string(TOUPPER "${${CURRENT_ENABLED_VAR}}" ${CURRENT_ENABLED_VAR})
+
+  set(INCLUDE_CURRENT_BACKEND OFF)
+  if (${CURRENT_ENABLED_VAR} STREQUAL "AUTO")
+    set(INCLUDE_CURRENT_BACKEND ON)
+    set(${CURRENT_AUTO_VAR} ON)
+  elseif(${CURRENT_ENABLED_VAR} MATCHES "^(ON|OFF|TRUE|FALSE|YES|NO|[YN01])$")
+    set(INCLUDE_CURRENT_BACKEND ${${CURRENT_ENABLED_VAR}})
   else()
-    message(FATAL_ERROR "Unsupported value '${SOCI_${CURRENT_UPPER}}' for option SOCI_${CURRENT_UPPER}")
+    message(FATAL_ERROR "Invalid value '${${CURRENT_ENABLED_VAR}}' for option '${CURRENT_ENABLED_VAR}'")
   endif()
 
-  if (SOCI_${CURRENT_UPPER})
-    add_subdirectory(${CURRENT})
+  if (${CURRENT_ENABLED_VAR})
+    add_subdirectory(${CURRENT_BACKEND_LOWER})
+
+    # Verify that the backend hasn't been disabled (happens if include mode is AUTO and there are
+    # unmet dependencies.
+    if (${CURRENT_ENABLED_VAR})
+      list(APPEND SOCI_ENABLED_BACKENDS "${CURRENT_BACKEND}")
+    endif()
   endif()
 endforeach()
+

src/backends/db2/CMakeLists.txt

@@ -1,4 +1,4 @@
-if (SOCI_DB2_AS_AVAILABLE)
+if (SOCI_DB2_AUTO)
   set(REQUIRED_FLAG "")
 else()
   set(REQUIRED_FLAG "REQUIRED")

src/backends/firebird/CMakeLists.txt

@@ -1,6 +1,6 @@
 option(SOCI_FIREBIRD_EMBEDDED "Use the embedded version of Firebird" OFF)
 
-if (SOCI_FIREBIRD_AS_AVAILABLE)
+if (SOCI_FIREBIRD_AUTO)
   set(REQUIRED_FLAG "")
 else()
   set(REQUIRED_FLAG "REQUIRED")

src/backends/mysql/CMakeLists.txt

@@ -1,4 +1,4 @@
-if (SOCI_MYSQL_AS_AVAILABLE)
+if (SOCI_MYSQL_AUTO)
   set(REQUIRED_FLAG "")
 else()
   set(REQUIRED_FLAG "REQUIRED")

src/backends/odbc/CMakeLists.txt

@@ -1,4 +1,4 @@
-if (SOCI_ODBC_AS_AVAILABLE)
+if (SOCI_ODBC_AUTO)
   set(REQUIRED_FLAG "")
 else()
   set(REQUIRED_FLAG "REQUIRED")

src/backends/oracle/CMakeLists.txt

@@ -1,4 +1,4 @@
-if (SOCI_ORACLE_AS_AVAILABLE)
+if (SOCI_ORACLE_AUTO)
   set(REQUIRED_FLAG "")
 else()
   set(REQUIRED_FLAG "REQUIRED")

src/backends/postgresql/CMakeLists.txt

@@ -1,4 +1,4 @@
-if (SOCI_POSTGRESQL_AS_AVAILABLE)
+if (SOCI_POSTGRESQL_AUTO)
   set(REQUIRED_FLAG "")
 else()
   set(REQUIRED_FLAG "REQUIRED")

src/backends/sqlite3/CMakeLists.txt

@@ -1,4 +1,4 @@
-if (SOCI_SQLITE3_AS_AVAILABLE)
+if (SOCI_SQLITE3_AUTO)
   set(REQUIRED_FLAG "")
 else()
   set(REQUIRED_FLAG "REQUIRED")

tests/CMakeLists.txt

@@ -2,10 +2,13 @@
 add_subdirectory(common)
 
 
-foreach (CURRENT_BACKEND IN ITEMS "db2" "empty" "firebird" "mysql" "odbc" "oracle" "postgresql" "sqlite3")
+foreach (CURRENT_BACKEND IN LISTS SOCI_ENABLED_BACKENDS)
   string(TOUPPER "${CURRENT_BACKEND}" CURRENT_BACKEND_UPPER)
+  string(TOLOWER "${CURRENT_BACKEND}" CURRENT_BACKEND_LOWER)
 
-  if (SOCI_${CURRENT_BACKEND_UPPER} AND NOT SOCI_${CURRENT_BACKEND_UPPER}_DO_NOT_TEST)
+  set(SOCI_${CURRENT_BACKEND_UPPER}_SKIP_TESTS OFF CACHE BOOL "Whether to skip tests for backend '${CURRENT_BACKEND}'")
+
+  if (NOT SOCI_${CURRENT_BACKEND_UPPER}_SKIP_TESTS)
     add_subdirectory(${CURRENT_BACKEND})
   endif()
 endforeach()