Avoid error with old Bison versions

`api.token.raw` is only defined starting with Bison 3.5
Since it's not essential, define it on the command-line iff the Bison
version is sufficient.

src/CMakeLists.txt

@@ -12,9 +12,7 @@ set(common_src
     "version.c"
     )
 
-find_package(BISON REQUIRED)
 find_package(PkgConfig)
-
 if(NOT PKG_CONFIG_FOUND)
   # fallback to find_package
   find_package(PNG REQUIRED)
@@ -22,8 +20,15 @@ else()
   pkg_check_modules(LIBPNG REQUIRED libpng)
 endif()
 
+find_package(BISON REQUIRED)
+set(BISON_FLAGS "")
+# Set sompe optimization flags on versions that support them
+if(BISON_VERSION VERSION_GREATER_EQUAL "3.5")
+  set(BISON_FLAGS "${BISON_FLAGS} -Dapi.token.raw=true")
+endif()
 BISON_TARGET(PARSER "asm/parser.y"
              "${PROJECT_SOURCE_DIR}/src/asm/parser.c"
+             COMPILE_FLAGS "${BISON_FLAGS}"
              DEFINES_FILE "${PROJECT_SOURCE_DIR}/src/asm/parser.h"
              )
 

src/asm/parser.y

@@ -166,8 +166,6 @@ static inline void failAssertMsg(enum AssertionType type, char const *msg)
 
 %}
 
-%define api.token.raw true
-
 %union
 {
 	char tzSym[MAXSYMLEN + 1];

src/check_bison_ver.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+bison -V | awk '
+/^bison.*[0-9]+(\.[0-9]+){1,2}$/ {
+	match($0, /[0-9]+(\.[0-9]+){1,2}$/);
+	split(substr($0, RSTART), ver, ".");
+	if (ver[1] == major && ver[2] >= minor) { exit 0 } else { exit 1 }
+}' major="$1" minor="$2"