diff --git a/src/hammer.c b/src/hammer.c
index dba530e66762b5e6dfccdc42ea63fbc7ed1e7300..2d34f9e041ea189e1ed39159e28135c35f539b50 100644
--- a/src/hammer.c
+++ b/src/hammer.c
@@ -139,6 +139,136 @@ void h_free_backend_with_params(HParserBackendWithParams *be_with_params) {
}
}
+/*
+ * Internal function to query name or descriptive text; the logic is
+ * the same in both cases.
+ */
+
+static const char * h_get_string_for_backend(
+ HParserBackend be, int description) {
+ /*
+ * For names, failure to resolve should return null - those are
+ * cases we can't look up by name either. Human readable descriptions
+ * should have human-readable error strings
+ */
+ const char *text = description ? "this is a bug!" : NULL;
+ const char **ptr;
+
+ if (be >= PB_MIN && be <= PB_MAX) {
+ /* the invalid backend is special */
+ if (be == PB_INVALID) {
+ text = description ? "invalid backend" : NULL;
+ } else {
+ if (backends[be] != backends[PB_INVALID]) {
+ /* Point to the name or description */
+ ptr = description ?
+ &(backends[be]->backend_description) :
+ &(backends[be]->backend_short_name);
+ /* See if the backend knows how to describe itself */
+ if (*ptr != NULL) {
+ text = *ptr;
+ } else {
+ /* nope */
+ text = description ? "no description available" : NULL;
+ }
+ } else {
+ /*
+ * This is the case for backends which weren't compiled into this
+ * library.
+ */
+ text = description ? "unsupported backend" : NULL;
+ }
+ }
+ } else {
+ text = description ? "bad backend number" : NULL;
+ }
+
+ return text;
+}
+
+/* Return an identifying name for this backend */
+
+const char * h_get_name_for_backend(HParserBackend be) {
+ /*
+ * call h_get_string_for_backend(), 0 indicates name
+ * rather than description requested
+ */
+ return h_get_string_for_backend(be, 0);
+}
+
+/*
+ * Return some human-readable descriptive text for this backend
+ */
+
+const char * h_get_descriptive_text_for_backend(HParserBackend be) {
+ /*
+ * call h_get_string_for_backend(), 1 indicates a
+ * description is requested.
+ */
+ return h_get_string_for_backend(be, 1);
+}
+
+/*
+ * Internal function to query name or descriptive text for a backend with
+ * params; the logic is the same in both cases.
+ */
+
+static char * h_get_string_for_backend_with_params__m(HAllocator *mm__,
+ HParserBackendWithParams *be_with_params, int description) {
+ char *text = NULL;
+ const char *generic_text = NULL;
+ HParserBackend be = PB_INVALID;
+ char * (**text_getter_func)(HAllocator *mm__,
+ HParserBackend be,
+ void *params) = NULL;
+
+
+ if (mm__ == NULL || be_with_params == NULL) goto done;
+
+ /* check if we can compute custom text with params for this backend */
+ be = be_with_params->backend;
+ if (be >= PB_MIN && be <= PB_MAX && be != PB_INVALID &&
+ backends[be] != backends[PB_INVALID]) {
+ text_getter_func = description ?
+ &(backends[be]->get_description_with_params) :
+ &(backends[be]->get_short_name_with_params);
+
+ if (*text_getter_func != NULL) {
+ text = (*text_getter_func)(mm__, be,
+ be_with_params->params);
+ }
+ }
+
+ /* got it? */
+ if (!text) {
+ /* fall back to the generic descriptive text */
+ generic_text = h_get_string_for_backend(be, description);
+ if (generic_text) {
+ text = h_new(char, strlen(generic_text) + 1);
+ strncpy(text, generic_text, strlen(generic_text) + 1);
+ }
+ }
+
+ done:
+ return text;
+}
+
+/*
+ * Allocate and return some human-readable descriptive text for this backend
+ * with parameters. The caller is responsible for freeing the result.
+ */
+
+char * h_get_descriptive_text_for_backend_with_params__m(HAllocator *mm__,
+ HParserBackendWithParams *be_with_params) {
+ return h_get_string_for_backend_with_params__m(mm__, be_with_params, 1);
+}
+
+char * h_get_descriptive_text_for_backend_with_params(
+ HParserBackendWithParams *be_with_params) {
+ return h_get_descriptive_text_for_backend_with_params__m(
+ &system_allocator, be_with_params);
+}
+
#define DEFAULT_ENDIANNESS (BIT_BIG_ENDIAN | BYTE_BIG_ENDIAN)
HParseResult* h_parse(const HParser* parser, const uint8_t* input, size_t length) {
diff --git a/src/hammer.h b/src/hammer.h
index e838720af187b28fec6eae03790cd627067a747d..687592943102c30bd9794a00f20784a5017b9bb1 100644
--- a/src/hammer.h
+++ b/src/hammer.h
@@ -306,6 +306,40 @@ HAMMER_FN_DECL(HParserBackendWithParams *, h_copy_backend_with_params,
void h_free_backend_with_params(HParserBackendWithParams *be_with_params);
+/**
+ * Get a name string for a backend; this is constant per backend and so
+ * need not be freed; it will resolve to the backend under
+ * h_get_backend_by_name().
+ */
+
+const char * h_get_name_for_backend(HParserBackend be);
+
+/**
+ * Get a name string for a backend with parameters; it is the caller's
+ * responsibility to free it later. This will resolve to the same
+ * backend and parameters under h_get_backend_with_params_by_name().
+ */
+
+HAMMER_FN_DECL(char *, h_get_name_for_backend_with_params,
+ HParserBackendWithParams *be_with_params);
+
+/**
+ * Get a human-readable descriptive string for a backend; this is constant
+ * per backend and so need not be freed.
+ */
+
+const char * h_get_descriptive_text_for_backend(HParserBackend be);
+
+/**
+ * Get a human-readable descriptive string for a backend with params; it is
+ * the caller's responsibility to free it later. Sorry, but it's allowed
+ * to depend on the params and putting keeping the buffer elsewhere and
+ * replacing it on the next call wouldn't be thread-safe.
+ */
+
+HAMMER_FN_DECL(char *, h_get_descriptive_text_for_backend_with_params,
+ HParserBackendWithParams *be_with_params);
+
/**
* Top-level function to call a parser that has been built over some
* piece of input (of known size).
diff --git a/src/internal.h b/src/internal.h
index 1ed77e7a021269d4d764af35c4af32a5aa9f2e6f..4fc9eb989ebd40e44f62ef3b90c164984b1e69da 100644
--- a/src/internal.h
+++ b/src/internal.h
@@ -252,6 +252,16 @@ typedef struct HParserBackendVTable_ {
* void ** and returning a status code (0 indicates success).
*/
int (*copy_params)(HAllocator *mm__, void **out, void *in);
+
+ /* Description/name handling */
+ const char *backend_short_name;
+ const char *backend_description;
+ char * (*get_description_with_params)(HAllocator *mm__,
+ HParserBackend be,
+ void *params);
+ char * (*get_short_name_with_params)(HAllocator *mm__,
+ HParserBackend be,
+ void *params);
} HParserBackendVTable;