cmake: Use recommended add_compile_definitions command

Available in CMake 3.12+.

CMakeLists.txt

@@ -41,27 +41,27 @@ option(SECP256K1_INSTALL "Enable installation" ON)
 
 option(SECP256K1_ENABLE_MODULE_ECDH "Enable ECDH module." ON)
 if(SECP256K1_ENABLE_MODULE_ECDH)
-  add_definitions(-DENABLE_MODULE_ECDH=1)
+  add_compile_definitions(ENABLE_MODULE_ECDH=1)
 endif()
 
 option(SECP256K1_ENABLE_MODULE_RECOVERY "Enable ECDSA pubkey recovery module." OFF)
 if(SECP256K1_ENABLE_MODULE_RECOVERY)
-  add_definitions(-DENABLE_MODULE_RECOVERY=1)
+  add_compile_definitions(ENABLE_MODULE_RECOVERY=1)
 endif()
 
 option(SECP256K1_ENABLE_MODULE_EXTRAKEYS "Enable extrakeys module." ON)
 option(SECP256K1_ENABLE_MODULE_SCHNORRSIG "Enable schnorrsig module." ON)
 if(SECP256K1_ENABLE_MODULE_SCHNORRSIG)
   set(SECP256K1_ENABLE_MODULE_EXTRAKEYS ON)
-  add_definitions(-DENABLE_MODULE_SCHNORRSIG=1)
+  add_compile_definitions(ENABLE_MODULE_SCHNORRSIG=1)
 endif()
 if(SECP256K1_ENABLE_MODULE_EXTRAKEYS)
-  add_definitions(-DENABLE_MODULE_EXTRAKEYS=1)
+  add_compile_definitions(ENABLE_MODULE_EXTRAKEYS=1)
 endif()
 
 option(SECP256K1_USE_EXTERNAL_DEFAULT_CALLBACKS "Enable external default callback functions." OFF)
 if(SECP256K1_USE_EXTERNAL_DEFAULT_CALLBACKS)
-  add_definitions(-DUSE_EXTERNAL_DEFAULT_CALLBACKS=1)
+  add_compile_definitions(USE_EXTERNAL_DEFAULT_CALLBACKS=1)
 endif()
 
 set(SECP256K1_ECMULT_WINDOW_SIZE "AUTO" CACHE STRING "Window size for ecmult precomputation for verification, specified as integer in range [2..24]. \"AUTO\" is a reasonable setting for desktop machines (currently 15). [default=AUTO]")
@@ -71,22 +71,22 @@ check_string_option_value(SECP256K1_ECMULT_WINDOW_SIZE)
 if(SECP256K1_ECMULT_WINDOW_SIZE STREQUAL "AUTO")
   set(SECP256K1_ECMULT_WINDOW_SIZE 15)
 endif()
-add_definitions(-DECMULT_WINDOW_SIZE=${SECP256K1_ECMULT_WINDOW_SIZE})
+add_compile_definitions(ECMULT_WINDOW_SIZE=${SECP256K1_ECMULT_WINDOW_SIZE})
 
 set(SECP256K1_ECMULT_GEN_PREC_BITS "AUTO" CACHE STRING "Precision bits to tune the precomputed table size for signing, specified as integer 2, 4 or 8. \"AUTO\" is a reasonable setting for desktop machines (currently 4). [default=AUTO]")
 set_property(CACHE SECP256K1_ECMULT_GEN_PREC_BITS PROPERTY STRINGS "AUTO" 2 4 8)
 check_string_option_value(SECP256K1_ECMULT_GEN_PREC_BITS)
 if(SECP256K1_ECMULT_GEN_PREC_BITS STREQUAL "AUTO")
   set(SECP256K1_ECMULT_GEN_PREC_BITS 4)
 endif()
-add_definitions(-DECMULT_GEN_PREC_BITS=${SECP256K1_ECMULT_GEN_PREC_BITS})
+add_compile_definitions(ECMULT_GEN_PREC_BITS=${SECP256K1_ECMULT_GEN_PREC_BITS})
 
 set(SECP256K1_TEST_OVERRIDE_WIDE_MULTIPLY "OFF" CACHE STRING "Test-only override of the (autodetected by the C code) \"widemul\" setting. Legal values are: \"OFF\", \"int128_struct\", \"int128\" or \"int64\". [default=OFF]")
 set_property(CACHE SECP256K1_TEST_OVERRIDE_WIDE_MULTIPLY PROPERTY STRINGS "OFF" "int128_struct" "int128" "int64")
 check_string_option_value(SECP256K1_TEST_OVERRIDE_WIDE_MULTIPLY)
 if(SECP256K1_TEST_OVERRIDE_WIDE_MULTIPLY)
   string(TOUPPER "${SECP256K1_TEST_OVERRIDE_WIDE_MULTIPLY}" widemul_upper_value)
-  add_definitions(-DUSE_FORCE_WIDEMUL_${widemul_upper_value}=1)
+  add_compile_definitions(USE_FORCE_WIDEMUL_${widemul_upper_value}=1)
 endif()
 mark_as_advanced(FORCE SECP256K1_TEST_OVERRIDE_WIDE_MULTIPLY)
 
@@ -95,13 +95,13 @@ set_property(CACHE SECP256K1_ASM PROPERTY STRINGS "AUTO" "OFF" "x86_64" "arm")
 check_string_option_value(SECP256K1_ASM)
 if(SECP256K1_ASM STREQUAL "arm")
   enable_language(ASM)
-  add_definitions(-DUSE_EXTERNAL_ASM=1)
+  add_compile_definitions(USE_EXTERNAL_ASM=1)
 elseif(SECP256K1_ASM)
   include(Check64bitAssembly)
   check_64bit_assembly()
   if(HAS_64BIT_ASM)
     set(SECP256K1_ASM "x86_64")
-    add_definitions(-DUSE_ASM_X86_64=1)
+    add_compile_definitions(USE_ASM_X86_64=1)
   elseif(SECP256K1_ASM STREQUAL "AUTO")
     set(SECP256K1_ASM "OFF")
   else()
@@ -124,7 +124,7 @@ if(SECP256K1_VALGRIND)
   if(Valgrind_FOUND)
     set(SECP256K1_VALGRIND ON)
     include_directories(${Valgrind_INCLUDE_DIR})
-    add_definitions(-DVALGRIND)
+    add_compile_definitions(VALGRIND)
   elseif(SECP256K1_VALGRIND STREQUAL "AUTO")
     set(SECP256K1_VALGRIND OFF)
   else()