Add support for extended details

Signed-off-by: Mattias Andrée <maandree@kth.se>

5 files changed, 175 insertions, 19 deletions

diff --git a/README b/README
index 4d24223..e0efe29 100644
--- a/README
+++ b/README
@@ -6,8 +6,8 @@ specific, maybe multiple library, errors.
 The errors are thread-local, support error description, error
 source string (which function failed), and error code with
 error code group (e.g. "errno", "addrinfo" or a library name),
-as well as cause chains, and if linked together with
-liberror-backtrace, backtraces.
+as well as cause chains, extended details, and if linked
+together with liberror-backtrace, backtraces.
 
 
 The important functions are:
diff --git a/copy_error.c b/copy_error.c
index 8d93131..ebf71b4 100644
--- a/copy_error.c
+++ b/copy_error.c
@@ -2,6 +2,8 @@
 #include "internal.h"
 
 
+#define STRDUP(S) ((S) ? strdup(S) : NULL)
+
 struct liberror_error *
 liberror_copy_error(struct liberror_error *src)
 {
@@ -16,6 +18,7 @@ liberror_copy_error(struct liberror_error *src)
 		if (dest->backtrace)
 			dest->backtrace->refcount += 1;
 		dest->dynamically_allocated = 1;
+
 		if (src->cause) {
 			dest->cause = liberror_copy_error(src->cause);
 			if (!dest->cause) {
@@ -25,7 +28,39 @@ liberror_copy_error(struct liberror_error *src)
 				dest = NULL;
 			}
 		}
+
+		switch (dest->details_type) {
+		case LIBERROR_DETAILS_USER:
+			dest->details.user.data = dest->details.user.copy_data(dest->details.user.data);
+			if (!dest->details.user.data)
+				goto fail;
+			break;
+
+		case LIBERROR_DETAILS_ONE_FILE:
+			dest->details.one_file.name = STRDUP(src->details.one_file.name);
+			if (src->details.one_file.name && !dest->details.one_file.name)
+				goto fail;
+			break;
+
+		case LIBERROR_DETAILS_TWO_FILES:
+			dest->details.two_files.name1 = STRDUP(src->details.two_files.name1);
+			dest->details.two_files.name2 = STRDUP(src->details.two_files.name2);
+			if (src->details.two_files.name1 && !dest->details.two_files.name1)
+				goto fail;
+			if (src->details.two_files.name2 && !dest->details.two_files.name2)
+				goto fail;
+			break;
+
+		case LIBERROR_DETAILS_NONE:
+		default:
+			break;
+		}
 	}
 	errno = saved_errno;
 	return dest;
+
+fail:
+	liberror_free_error(dest);
+	errno = saved_errno;
+	return NULL;
 }
diff --git a/free_error.c b/free_error.c
index a15d36c..1af0104 100644
--- a/free_error.c
+++ b/free_error.c
@@ -5,11 +5,34 @@
 void
 liberror_free_error(struct liberror_error *error)
 {
-	if (!error)
-		return;
-	if (error->backtrace && !--error->backtrace->refcount)
-		free(error->backtrace);
-	liberror_free_error(error->cause);
-	if (error->dynamically_allocated)
-		free(error);
+	struct liberror_error *tmp;
+	while (error) {
+		if (error->backtrace && !--error->backtrace->refcount)
+			free(error->backtrace);
+
+		switch (error->details_type) {
+		case LIBERROR_DETAILS_USER:
+			if (error->details.user.data && error->details.user.free_data)
+				error->details.user.free_data(error->details.user.data);
+			break;
+
+		case LIBERROR_DETAILS_ONE_FILE:
+			free(error->details.one_file.name);
+			break;
+
+		case LIBERROR_DETAILS_TWO_FILES:
+			free(error->details.two_files.name1);
+			free(error->details.two_files.name2);
+			break;
+
+		case LIBERROR_DETAILS_NONE:
+		default:
+			break;
+		}
+
+		tmp = error;
+		error = error->cause;
+		if (tmp->dynamically_allocated)
+			free(tmp);
+	}
 }
diff --git a/liberror.h b/liberror.h
index 27c700d..508dbac 100644
--- a/liberror.h
+++ b/liberror.h
@@ -13,6 +13,53 @@
 struct liberror_backtrace;
 
 /**
+ * Value that specifies which feild in a
+ * `union liberror_details` that is used
+ */
+enum liberror_details_type {
+	LIBERROR_DETAILS_NONE,
+	LIBERROR_DETAILS_USER,
+	LIBERROR_DETAILS_ONE_FILE,
+	LIBERROR_DETAILS_TWO_FILES
+};
+
+/**
+ * Error details
+ */
+union liberror_details {
+	/**
+	 * For `LIBERROR_DETAILS_USER`
+	 */
+	struct {
+		const char *library;
+		void *data;
+		void (*free_data)(void *);
+		void *(*copy_data)(void *);
+	} user;
+
+	/**
+	 * For `LIBERROR_DETAILS_ONE_FILE`
+	 */
+	struct {
+		int fd;
+		char *name;
+		const char *role;
+	} one_file;
+
+	/**
+	 * For `LIBERROR_DETAILS_TWO_FILES`
+	 */
+	struct {
+		int fd1;
+		int fd2;
+		char *name1;
+		char *name2;
+		const char *role1;
+		const char *role2;
+	} two_files;
+};
+
+/**
  * Error structure
  */
 struct liberror_error {
@@ -63,6 +110,16 @@ struct liberror_error {
 	 * Whether the error is physically allocated
 	 */
 	int dynamically_allocated;
+
+	/**
+	 * Which value in `.details` that is used
+	 */
+	enum liberror_details_type details_type;
+
+	/**
+	 * Error detail
+	 */
+	union liberror_details details;
 };
 
 
diff --git a/print_error.c b/print_error.c
index 4675bab..245caa0 100644
--- a/print_error.c
+++ b/print_error.c
@@ -3,7 +3,7 @@
 
 
 static void
-print_error_description(struct liberror_error *error, FILE *fp, const char *prefix)
+print_error(struct liberror_error *error, FILE *fp, char *prefix)
 {
 	if (*error->description) {
 		if (*error->source)
@@ -15,6 +15,54 @@ print_error_description(struct liberror_error *error, FILE *fp, const char *pref
 	} else {
 		fprintf(fp, "%sError: %s error %lli\n", prefix, error->code_group, error->code);
 	}
+
+	*strchr(prefix, '\0') = ' ';
+
+	switch (error->details_type) {
+	case LIBERROR_DETAILS_ONE_FILE:
+		if (error->details.one_file.fd >= 0 || error->details.one_file.name) {
+			fprintf(fp, "%sDetails:\n", prefix);
+			if (error->details.one_file.name) {
+				fprintf(fp, "%s  %s name: %s\n", prefix,
+				        error->details.one_file.role, error->details.one_file.name);
+			}
+			if (error->details.one_file.fd >= 0) {
+				fprintf(fp, "%s  %s descriptor: %i\n", prefix,
+				        error->details.one_file.role, error->details.one_file.fd);
+			}
+		}
+		break;
+
+	case LIBERROR_DETAILS_TWO_FILES:
+		if (error->details.two_files.fd1 >= 0 || error->details.two_files.name1 ||
+		    error->details.two_files.fd2 >= 0 || error->details.two_files.name2) {
+			fprintf(fp, "%sDetails:\n", prefix);
+			if (error->details.two_files.fd1 >= 0) {
+				fprintf(fp, "%s  %s descriptor: %i\n", prefix,
+				        error->details.two_files.role1, error->details.two_files.fd1);
+			}
+			if (error->details.two_files.name1) {
+				fprintf(fp, "%s  %s name: %s\n", prefix,
+				        error->details.two_files.role1, error->details.two_files.name1);
+			}
+			if (error->details.two_files.fd2 >= 0) {
+				fprintf(fp, "%s  %s descriptor: %i\n", prefix,
+				        error->details.two_files.role2, error->details.two_files.fd2);
+			}
+			if (error->details.two_files.name2) {
+				fprintf(fp, "%s  %s name: %s\n", prefix,
+				        error->details.two_files.role2, error->details.two_files.name2);
+			}
+		}
+		break;
+
+	case LIBERROR_DETAILS_NONE:
+	case LIBERROR_DETAILS_USER:
+	default:
+		break;
+	}
+
+	liberror_print_backtrace(error, fp, prefix);
 }
 
 
@@ -43,20 +91,13 @@ liberror_print_error(struct liberror_error *error, FILE *fp, int reset, const ch
 		fp = stderr;
 
 	*p = *q = '\0';
-	print_error_description(err, fp, prefix);
-
-	*p = ' ';
-	liberror_print_backtrace(err, fp, prefix);
+	print_error(err, fp, prefix);
 
 	while ((err = err->cause)) {
 		*p = *q = '\0';
 		fprintf(fp, "%sCaused by:\n", prefix);
-
 		*p = ' ';
-		print_error_description(err, fp, prefix);
-		
-		*q = ' ';
-		liberror_print_backtrace(err, fp, prefix);
+		print_error(err, fp, prefix);
 	}
 
 	if (reset) {