configure: Rework HAVE_CAPSTONE #define

Autotools and the current build system define HAVE_* macros only when
the corresponding feature is available, leaving them undefined otherwise.

HAVE_CAPSTONE is an exception, align it with this convention to make the
build system more consistent and slightly simpler.

Change-Id: I0b71743a687802b905e3fe1e17cad815a7febb14
Signed-off-by: Marc Schink <dev@zapb.de>
Reviewed-on: https://review.openocd.org/c/openocd/+/9540
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

configure.ac

@@ -527,10 +527,6 @@ AS_IF([test "x$enable_capstone" != xno], [
 	])
 ])
 
-AS_IF([test "x$enable_capstone" == xno], [
-	AC_DEFINE([HAVE_CAPSTONE], [0], [0 if you don't have Capstone disassembly framework.])
-])
-
 for hidapi_lib in hidapi hidapi-hidraw hidapi-libusb; do
 	PKG_CHECK_MODULES([HIDAPI],[$hidapi_lib],[
 		use_hidapi=yes

src/target/a64_disassembler.c

@@ -13,7 +13,7 @@
 #include "target.h"
 #include "a64_disassembler.h"
 
-#if HAVE_CAPSTONE
+#ifdef HAVE_CAPSTONE
 
 #include <capstone.h>
 

src/target/arm_disassembler.c

@@ -15,7 +15,7 @@
 #include "arm_disassembler.h"
 #include <helper/log.h>
 
-#if HAVE_CAPSTONE
+#ifdef HAVE_CAPSTONE
 #include <capstone.h>
 #endif
 
@@ -3019,7 +3019,7 @@ int arm_access_size(struct arm_instruction *instruction)
 	}
 }
 
-#if HAVE_CAPSTONE
+#ifdef HAVE_CAPSTONE
 static void print_opcode(struct command_invocation *cmd, const cs_insn *insn)
 {
 	uint32_t opcode = 0;

src/target/arm_disassembler.h

@@ -187,7 +187,7 @@ int arm_evaluate_opcode(uint32_t opcode, uint32_t address,
 int thumb_evaluate_opcode(uint16_t opcode, uint32_t address,
 		struct arm_instruction *instruction);
 int arm_access_size(struct arm_instruction *instruction);
-#if HAVE_CAPSTONE
+#ifdef HAVE_CAPSTONE
 int arm_disassemble(struct command_invocation *cmd, struct target *target,
 		target_addr_t address, size_t count, bool thumb_mode);
 #endif

src/target/armv4_5.c

@@ -952,7 +952,7 @@ COMMAND_HANDLER(handle_arm_core_state_command)
 
 COMMAND_HANDLER(handle_arm_disassemble_command)
 {
-#if HAVE_CAPSTONE
+#ifdef HAVE_CAPSTONE
 	struct target *target = get_current_target(CMD_CTX);
 
 	if (!target) {