X-Git-Url: http://git.draconx.ca/gitweb/upkg.git/blobdiff_plain/dc739f280f430ad323594ab38adf1e85b5ac0efd..07c7ad2a8ae59fd0159c52c27c263f034aa7746a:/src/libupkg.c

diff --git a/src/libupkg.c b/src/libupkg.c
index 004cb46..b87c5dd 100644
--- a/src/libupkg.c
+++ b/src/libupkg.c
@@ -25,6 +25,19 @@
 
 #define MIN(a, b) ((a) < (b) ? (a) : (b))
 
+/*
+ * Print a message and execute some statement(s) if the expression evaluates
+ * to zero.  Intended to help verify that assumed constraints on the file
+ * format actually are not violated.
+ */
+#define format_assert(expr, body) do { \
+	if (!(expr)) { \
+		fprintf(stderr, "%s: %d: %s: format assertion failed: %s\n", \
+		                __FILE__, __LINE__, __func__, #expr); \
+		body; \
+	} \
+} while (0)
+
 struct upkg_name {
 	unsigned long flags;
 	char *name;
@@ -61,27 +74,27 @@ struct upkg_private {
 /* Default I/O operations for ordinary files. */
 static size_t file_read(void *buf, size_t size, void *handle)
 {
-	return fread(buf, 1, size, handle);
+	return fread(buf, 1, size, (FILE *)handle);
 }
 
 static int file_seek(void *handle, long offset, int whence)
 {
-	return fseek(handle, offset, whence);
+	return fseek((FILE *)handle, offset, whence);
 }
 
 static long file_tell(void *handle)
 {
-	return ftell(handle);
+	return ftell((FILE *)handle);
 }
 
 static int file_eof(void *handle)
 {
-	return feof(handle);
+	return feof((FILE *)handle);
 }
 
 static int file_close(void *handle)
 {
-	return fclose(handle);
+	return fclose((FILE *)handle);
 }
 
 const struct upkg_file_ops upkg_default_fops = {
@@ -357,12 +370,12 @@ static int pkg_init_imports(struct upkg *pkg)
 
 		len = 0;
 		rc = upkg_decode_index(&tmp, buf+len, nbuf-len);
-		if (rc == 0 || len < 0 || len >= pkg->name_count) goto err;
+		if (rc == 0 || len >= pkg->name_count) goto err;
 		import->class_package = pkg->priv->names[tmp].name;
 		len += rc;
 
 		rc = upkg_decode_index(&tmp, buf+len, nbuf-len);
-		if (rc == 0 || len < 0 || len >= pkg->name_count) goto err;
+		if (rc == 0 || len >= pkg->name_count) goto err;
 		import->class_name = pkg->priv->names[tmp].name;
 		len += rc;
 
@@ -371,7 +384,7 @@ static int pkg_init_imports(struct upkg *pkg)
 		len += 4;
 
 		rc = upkg_decode_index(&tmp, buf+len, nbuf-len);
-		if (rc == 0 || len < 0 || len >= pkg->name_count) goto err;
+		if (rc == 0 || len >= pkg->name_count) goto err;
 		import->object_name = pkg->priv->names[tmp].name;
 		len += rc;
 
@@ -481,13 +494,17 @@ const char *upkg_get_name(struct upkg *pkg, unsigned long idx)
 	return pkg->priv->names[idx].name;
 }
 
-long upkg_export_find(struct upkg *pkg, const char *name)
+long upkg_export_find(struct upkg *pkg, long parent, const char *name)
 {
-	/* This is wrong.
-	 * Export names are not necessarily unique within a package. */
-	for (unsigned i = 0; i < pkg->export_count; i++) {
-		struct upkg_export *export = &pkg->priv->exports[i];
-		if (strcmp(export->name, name) == 0) {
+	/* This only makes sense if the assertion below is not violated. */
+	long package = parent < 0 ? 0 : parent + 1;
+
+	for (unsigned long i = 0; i < pkg->export_count; i++) {
+		struct upkg_export *e = &pkg->priv->exports[i];
+
+		/* Assertion: an object's package is an export. */
+		format_assert(e->package >= 0, continue);
+		if (e->package == package && strcmp(e->name, name) == 0) {
 			return i;
 		}
 	}
@@ -521,11 +538,8 @@ const char *upkg_export_class(struct upkg *pkg, unsigned long idx,
 
 	export = &pkg->priv->exports[idx];
 
-	/* ASSUMPTION: class references are always imports */
-	if (export->class > 0) {
-		fprintf(stderr, "Assumption Violated: class not import\n");
-		return NULL;
-	}
+	/* Assumption: class references are always imports. */
+	format_assert(export->class <= 0, return NULL);
 
 	/* Get the class. */
 	if (export->class == 0) {
@@ -538,17 +552,12 @@ const char *upkg_export_class(struct upkg *pkg, unsigned long idx,
 		return NULL;
 	iclass = &pkg->priv->imports[pkg_idx];
 
-	/* ASSUMPTION: Class references are always Core.Class */
-	if (strcmp(iclass->class_name, "Class") || strcmp(iclass->class_package, "Core")) {
-		fprintf(stderr, "Assumption Violated: class not Core.Class\n");
-		return NULL;
-	}
+	/* Assumption: class references are always Core.Class. */
+	format_assert(!strcmp(iclass->class_package, "Core"), return NULL);
+	format_assert(!strcmp(iclass->class_name, "Class"), return NULL);
 
-	/* ASSUMPTION: Package references are always imports */
-	if (iclass->package >= 0) {
-		fprintf(stderr, "Assumption Violated: package not import\n");
-		return NULL;
-	}
+	/* Assumption: package references are always imports. */
+	format_assert(iclass->package <= 0, return NULL);
 
 	/* Get the package. */
 	pkg_idx = -(iclass->package + 1);
@@ -556,11 +565,9 @@ const char *upkg_export_class(struct upkg *pkg, unsigned long idx,
 		return NULL;
 	ipackage = &pkg->priv->imports[pkg_idx];
 
-	/* ASSUMPTION: Package references are always Core.Package */
-	if (strcmp(ipackage->class_name, "Package") || strcmp(ipackage->class_package, "Core")) {
-		fprintf(stderr, "Assumption Violated: package not Core.Package\n");
-		return NULL;
-	}
+	/* Assumption: package references are always Core.Package. */
+	format_assert(!strcmp(ipackage->class_package, "Core"), return NULL);
+	format_assert(!strcmp(ipackage->class_name, "Package"), return NULL);
 
 	if (package) *package = ipackage->object_name;
 	return iclass->object_name;