add support for static linking of applications

By default, the pre-builts that are used during linking are shared
libraries. This changes seeks for their static counterparts and uses
them during linking. The '-static' flags also added to perform a
complete static link

Build: cmake -G Ninja -DBUILD_UHDR_SHARED_LIBS=0
Test: ./ultrahdr_app

CMakeLists.txt

@@ -160,6 +160,12 @@ if(BUILD_SHARED_LIBS)
   set(CMAKE_CXX_VISIBILITY_PRESET hidden)
   set(CMAKE_VISIBILITY_INLINES_HIDDEN YES)
   add_compile_options(-DUHDR_BUILDING_SHARED_LIBRARY)
+else()
+  if(WIN32)
+    set(CMAKE_FIND_LIBRARY_SUFFIXES .lib .a)
+  else()
+    set(CMAKE_FIND_LIBRARY_SUFFIXES .a)
+  endif()
 endif()
 if(UHDR_ENABLE_LOGS)
   add_compile_options(-DLOG_NDEBUG)
@@ -524,6 +530,9 @@ target_link_libraries(${UHDR_CORE_LIB_NAME} PRIVATE ${COMMON_LIBS_LIST} ${IMAGEI
 if(UHDR_BUILD_EXAMPLES)
   add_executable(ultrahdr_app "${EXAMPLES_DIR}/ultrahdr_app.cpp")
   add_dependencies(ultrahdr_app ${UHDR_CORE_LIB_NAME})
+  if(NOT BUILD_SHARED_LIBS AND NOT MSVC)
+    target_link_options(ultrahdr_app PRIVATE -static)
+  endif()
   if(UHDR_BUILD_FUZZERS)
     target_link_options(ultrahdr_app PRIVATE -fsanitize=fuzzer-no-link)
   endif()
@@ -553,6 +562,9 @@ if(UHDR_BUILD_TESTS)
     ${PRIVATE_INCLUDE_DIR}
     ${GTEST_INCLUDE_DIRS}
   )
+  if(NOT BUILD_SHARED_LIBS AND NOT MSVC)
+    target_link_options(ultrahdr_unit_test PRIVATE -static)
+  endif()
   if(UHDR_BUILD_FUZZERS)
     target_link_options(ultrahdr_unit_test PRIVATE -fsanitize=fuzzer-no-link)
   endif()
@@ -567,6 +579,9 @@ if(UHDR_BUILD_BENCHMARK)
     ${PRIVATE_INCLUDE_DIR}
     ${BENCHMARK_INCLUDE_DIR}
   )
+  if(NOT BUILD_SHARED_LIBS AND NOT MSVC)
+    target_link_options(ultrahdr_bm PRIVATE -static)
+  endif()
   if(UHDR_BUILD_FUZZERS)
     target_link_options(ultrahdr_bm PRIVATE -fsanitize=fuzzer-no-link)
   endif()
@@ -617,6 +632,9 @@ if(UHDR_BUILD_FUZZERS)
   else()
     target_link_options(ultrahdr_enc_fuzzer PRIVATE -fsanitize=fuzzer)
   endif()
+  if(NOT BUILD_SHARED_LIBS AND NOT MSVC)
+    target_link_options(ultrahdr_enc_fuzzer PRIVATE -static)
+  endif()
   target_link_libraries(ultrahdr_enc_fuzzer ${UHDR_CORE_LIB_NAME})
 
   add_executable(ultrahdr_dec_fuzzer ${FUZZERS_DIR}/ultrahdr_dec_fuzzer.cpp)
@@ -627,6 +645,9 @@ if(UHDR_BUILD_FUZZERS)
   else()
     target_link_options(ultrahdr_dec_fuzzer PRIVATE -fsanitize=fuzzer)
   endif()
+  if(NOT BUILD_SHARED_LIBS AND NOT MSVC)
+    target_link_options(ultrahdr_dec_fuzzer PRIVATE -static)
+  endif()
   target_link_libraries(ultrahdr_dec_fuzzer ${UHDR_CORE_LIB_NAME})
 endif()