build: opt-in FLB_SMALL for optimising for binary size (~50% reduction)

Signed-off-by: Nigel Stewart <[email protected]>

Author: Nigel Stewart

CMakeLists.txt

@@ -45,6 +45,7 @@ set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/library")
 # Build Options
 option(FLB_ALL                "Enable all features"           No)
 option(FLB_DEBUG              "Build with debug symbols"      No)
+option(FLB_SMALL              "Optimise for small size"       No)
 option(FLB_COVERAGE           "Build with code-coverage"      No)
 option(FLB_JEMALLOC           "Build with Jemalloc support"   No)
 option(FLB_REGEX              "Build with Regex support"     Yes)
@@ -223,6 +224,10 @@ if(CMAKE_SYSTEM_NAME MATCHES "Darwin")
   endif()
 endif()
 
+if(FLB_SMALL)
+  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Os -g0 -s -fno-stack-protector -fomit-frame-pointer -DNDEBUG")
+endif()
+
 if(FLB_COVERAGE)
   set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g -O0 --coverage -fprofile-arcs -ftest-coverage")
   set(CMAKE_BUILD_TYPE "Debug")

cmake/onigmo.cmake

@@ -19,6 +19,17 @@ endif()
 
 # Onigmo (UNIX)
 # =============
+if(FLB_SMALL)
+ExternalProject_Add(onigmo
+  BUILD_IN_SOURCE TRUE
+  EXCLUDE_FROM_ALL TRUE
+  SOURCE_DIR ${ONIGMO_SRC}
+  INSTALL_DIR ${ONIGMO_DEST}
+  CONFIGURE_COMMAND ./configure ${AUTOCONF_HOST_OPT} --with-pic --disable-shared --enable-static --prefix=${ONIGMO_DEST}
+  CFLAGS=-std=gnu99\ -Wall\ -pipe\ -Os\ -g0\ -s\ -fno-stack-protector\ -fomit-frame-pointer\ -DNDEBUG
+  BUILD_COMMAND $(MAKE)
+  INSTALL_COMMAND $(MAKE) install)
+else()
 ExternalProject_Add(onigmo
   BUILD_IN_SOURCE TRUE
   EXCLUDE_FROM_ALL TRUE
@@ -28,6 +39,7 @@ ExternalProject_Add(onigmo
   CFLAGS=-std=gnu99\ -Wall\ -pipe\ -g3\ -O3\ -funroll-loops
   BUILD_COMMAND $(MAKE)
   INSTALL_COMMAND $(MAKE) install)
+endif()
 
 # Onigmo (Windows)
 # ================