target: add debug_reason_name()

Provide and use debug_reason_name() instead of expecting targets
to call Jim_Nvp_value2name_simple().  Less dependency on Jim, and
the code becomes more clear too.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

src/target/armv4_5.c

@@ -595,8 +595,7 @@ int arm_arch_state(struct target *target)
 	LOG_USER("target halted in %s state due to %s, current mode: %s\n"
 			"cpsr: 0x%8.8" PRIx32 " pc: 0x%8.8" PRIx32 "%s",
 			arm_state_strings[armv4_5->core_state],
-			Jim_Nvp_value2name_simple(nvp_target_debug_reason,
-					target->debug_reason)->name,
+			debug_reason_name(target),
 			arm_mode_name(armv4_5->core_mode),
 			buf_get_u32(armv4_5->cpsr->value, 0, 32),
 			buf_get_u32(armv4_5->core_cache->reg_list[15].value,

src/target/armv7m.c

@@ -480,8 +480,7 @@ int armv7m_arch_state(struct target *target)
 
 	LOG_USER("target halted due to %s, current mode: %s %s\n"
 		"xPSR: %#8.8" PRIx32 " pc: %#8.8" PRIx32 " %csp: %#8.8" PRIx32,
-		Jim_Nvp_value2name_simple(nvp_target_debug_reason,
-				target->debug_reason)->name,
+		debug_reason_name(target),
 		armv7m_mode_strings[armv7m->core_mode],
 		armv7m_exception_string(armv7m->exception_number),
 		buf_get_u32(armv7m->core_cache->reg_list[ARMV7M_xPSR].value, 0, 32),

src/target/mips32.c

@@ -254,7 +254,7 @@ int mips32_arch_state(struct target *target)
 	}
 
 	LOG_USER("target halted due to %s, pc: 0x%8.8" PRIx32 "",
-		Jim_Nvp_value2name_simple(nvp_target_debug_reason, target->debug_reason)->name ,
+		debug_reason_name(target),
 		buf_get_u32(mips32->core_cache->reg_list[MIPS32_PC].value, 0, 32));
 
 	return ERROR_OK;

src/target/target.c

@@ -187,7 +187,7 @@ const Jim_Nvp nvp_target_state[] = {
 	{ .name = NULL, .value = -1 },
 };
 
-const Jim_Nvp nvp_target_debug_reason [] = {
+static const Jim_Nvp nvp_target_debug_reason [] = {
 	{ .name = "debug-request"            , .value = DBG_REASON_DBGRQ },
 	{ .name = "breakpoint"               , .value = DBG_REASON_BREAKPOINT },
 	{ .name = "watchpoint"               , .value = DBG_REASON_WATCHPOINT },
@@ -214,6 +214,19 @@ const Jim_Nvp nvp_reset_modes[] = {
 	{ .name = NULL     , .value = -1 },
 };
 
+const char *debug_reason_name(struct target *t)
+{
+	const char *cp;
+
+	cp = Jim_Nvp_value2name_simple(nvp_target_debug_reason,
+			t->debug_reason)->name;
+	if (!cp) {
+		LOG_ERROR("Invalid debug reason: %d", (int)(t->debug_reason));
+		cp = "(*BUG*unknown*BUG*)";
+	}
+	return cp;
+}
+
 const char *
 target_state_name( struct target *t )
 {

src/target/target.h

@@ -91,8 +91,6 @@ enum target_debug_reason
 	DBG_REASON_UNDEFINED = 6
 };
 
-extern const Jim_Nvp nvp_target_debug_reason[];
-
 enum target_endianess
 {
 	TARGET_ENDIAN_UNKNOWN = 0,
@@ -165,6 +163,8 @@ static inline const char *target_name(struct target *target)
 	return target->cmd_name;
 }
 
+const char *debug_reason_name(struct target *t);
+
 enum target_event
 {
 	/* LD historical names