[CMake] Refactor libsolc linker flag for EXPORTED_FUNCTIONS and make it more readable.

Author: christianparpart

cmake/EthUtils.cmake

@@ -48,3 +48,11 @@ function(detect_stray_source_files FILELIST DIRECTORY)
 		message(SEND_ERROR "The following source files are present but are not compiled: ${sources}")
 	endif()
 endfunction(detect_stray_source_files)
+
+# CreateExportedFunctionsForEMSDK(OUTPUT_VARIABLE Symbol1 Symbol2 ... SymbolN)
+function(CreateExportedFunctionsForEMSDK OUTPUT_VARIABLE)
+	list(TRANSFORM ARGN PREPEND "\"_")
+	list(TRANSFORM ARGN APPEND "\"")
+	list(JOIN ARGN "," ARGN)
+	set(${OUTPUT_VARIABLE} "[${ARGN}]" PARENT_SCOPE)
+endfunction()

libsolc/CMakeLists.txt

@@ -1,8 +1,17 @@
 if (EMSCRIPTEN)
+	CreateExportedFunctionsForEMSDK(
+		ExportedFunctions
+		solidity_license
+		solidity_version
+		solidity_compile
+		solidity_alloc
+		solidity_free
+		solidity_reset
+	)
 	# Specify which functions to export in soljson.js.
 	# Note that additional Emscripten-generated methods needed by solc-js are
 	# defined to be exported in cmake/EthCompilerSettings.cmake.
-	set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -s EXPORTED_FUNCTIONS='[\"_solidity_license\",\"_solidity_version\",\"_solidity_compile\",\"_solidity_alloc\",\"_solidity_free\",\"_solidity_reset\"]'")
+	set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -s EXPORTED_FUNCTIONS='${ExportedFunctions}'")
 	add_executable(soljson libsolc.cpp libsolc.h)
 	target_link_libraries(soljson PRIVATE solidity)
 else()