chore: Detect uninitialized variables in CMake files (#6247)

There were a few uninitialized variables in CMake files. This change will make sure we always check if a variable has been initialized before using them, or in come cases initialize them by default. This change will raise an error on CI if a developer introduced an uninitialized variable in CMake files.

CMakeLists.txt

@@ -8,7 +8,9 @@ if(POLICY CMP0077)
 endif()
 
 # Fix "unrecognized escape" issues when passing CMAKE_MODULE_PATH on Windows.
-file(TO_CMAKE_PATH "${CMAKE_MODULE_PATH}" CMAKE_MODULE_PATH)
+if(DEFINED CMAKE_MODULE_PATH)
+  file(TO_CMAKE_PATH "${CMAKE_MODULE_PATH}" CMAKE_MODULE_PATH)
+endif()
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
 
 project(xrpl)

cmake/CompilationEnv.cmake

@@ -13,6 +13,7 @@ include_guard(GLOBAL)
 set(is_clang FALSE)
 set(is_gcc FALSE)
 set(is_msvc FALSE)
+set(is_xcode FALSE)
 
 if(CMAKE_CXX_COMPILER_ID MATCHES ".*Clang") # Clang or AppleClang
   set(is_clang TRUE)
@@ -24,6 +25,11 @@ else()
   message(FATAL_ERROR "Unsupported C++ compiler: ${CMAKE_CXX_COMPILER_ID}")
 endif()
 
+# Xcode generator detection
+if(CMAKE_GENERATOR STREQUAL "Xcode")
+  set(is_xcode TRUE)
+endif()
+
 
 # --------------------------------------------------------------------
 # Operating system detection

cmake/XrplCore.cmake

@@ -32,14 +32,14 @@ target_protobuf_sources(xrpl.libpb xrpl/proto
 
 target_compile_options(xrpl.libpb
   PUBLIC
-    $<$<BOOL:${MSVC}>:-wd4996>
-    $<$<BOOL:${XCODE}>:
+    $<$<BOOL:${is_msvc}>:-wd4996>
+    $<$<BOOL:${is_xcode}>:
       --system-header-prefix="google/protobuf"
       -Wno-deprecated-dynamic-exception-spec
     >
   PRIVATE
-    $<$<BOOL:${MSVC}>:-wd4065>
-    $<$<NOT:$<BOOL:${MSVC}>>:-Wno-deprecated-declarations>
+    $<$<BOOL:${is_msvc}>:-wd4065>
+    $<$<NOT:$<BOOL:${is_msvc}>>:-Wno-deprecated-declarations>
 )
 
 target_link_libraries(xrpl.libpb

cmake/XrplInstall.cmake

@@ -4,6 +4,12 @@
 
 include(create_symbolic_link)
 
+# If no suffix is defined for executables (e.g. Windows uses .exe but Linux
+# and macOS use none), then explicitly set it to the empty string.
+if(NOT DEFINED suffix)
+  set(suffix "")
+endif()
+
 install (
   TARGETS
     common

cmake/XrplInterface.cmake

@@ -4,6 +4,11 @@
 
 include(CompilationEnv)
 
+# Set defaults for optional variables to avoid uninitialized variable warnings
+if(NOT DEFINED voidstar)
+  set(voidstar OFF)
+endif()
+
 add_library (opts INTERFACE)
 add_library (Xrpl::opts ALIAS opts)
 target_compile_definitions (opts
@@ -52,7 +57,7 @@ add_library (xrpl_syslibs INTERFACE)
 add_library (Xrpl::syslibs ALIAS xrpl_syslibs)
 target_link_libraries (xrpl_syslibs
   INTERFACE
-    $<$<BOOL:${MSVC}>:
+    $<$<BOOL:${is_msvc}>:
       legacy_stdio_definitions.lib
       Shlwapi
       kernel32
@@ -69,10 +74,10 @@ target_link_libraries (xrpl_syslibs
       odbccp32
       crypt32
     >
-    $<$<NOT:$<BOOL:${MSVC}>>:dl>
-    $<$<NOT:$<OR:$<BOOL:${MSVC}>,$<BOOL:${APPLE}>>>:rt>)
+    $<$<NOT:$<BOOL:${is_msvc}>>:dl>
+    $<$<NOT:$<OR:$<BOOL:${is_msvc}>,$<BOOL:${is_macos}>>>:rt>)
 
-if (NOT MSVC)
+if (NOT is_msvc)
   set (THREADS_PREFER_PTHREAD_FLAG ON)
   find_package (Threads)
   target_link_libraries (xrpl_syslibs INTERFACE Threads::Threads)

cmake/XrplSanitizers.cmake

@@ -43,7 +43,10 @@
 include(CompilationEnv)
 
 # Read environment variable
-set(SANITIZERS $ENV{SANITIZERS})
+set(SANITIZERS "")
+if(DEFINED ENV{SANITIZERS})
+  set(SANITIZERS "$ENV{SANITIZERS}")
+endif()
 
 # Set SANITIZERS_ENABLED flag for use in other modules
 if(SANITIZERS MATCHES "address|thread|undefinedbehavior")

cmake/XrplSettings.cmake

@@ -4,10 +4,11 @@
 
 include(CompilationEnv)
 
-if("$ENV{CI}" STREQUAL "true" OR "$ENV{CONTINUOUS_INTEGRATION}" STREQUAL "true")
-  set(is_ci TRUE)
-else()
-  set(is_ci FALSE)
+set(is_ci FALSE)
+if(DEFINED ENV{CI})
+  if("$ENV{CI}" STREQUAL "true")
+    set(is_ci TRUE)
+  endif()
 endif()
 
 get_directory_property(has_parent PARENT_DIRECTORY)