From: Michael Tremer <michael.tremer@ipfire.org>
Date: Mon, 24 May 2021 13:00:17 +0000 (+0000)
Subject: parser: Implement fetching recursive variables
X-Git-Tag: 0.9.28~1285^2~85
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f4d930714790b39ab1efd4aa8a8f021e693360fa;p=pakfire.git

parser: Implement fetching recursive variables

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/libpakfire/include/pakfire/util.h b/src/libpakfire/include/pakfire/util.h
index 74c4f5f33..e861c61f0 100644
--- a/src/libpakfire/include/pakfire/util.h
+++ b/src/libpakfire/include/pakfire/util.h
@@ -41,6 +41,7 @@ void pakfire_parse_deps(Pakfire pakfire, PakfirePackage pkg,
 
 int pakfire_string_startswith(const char* s, const char* prefix);
 int pakfire_string_endswith(const char* s, const char* suffix);
+int pakfire_string_matches(const char* s, const char* pattern);
 char* pakfire_unquote_in_place(char* s);
 int pakfire_string_partition(const char* s, const char* delim, char** s1, char** s2);
 char* pakfire_string_replace(const char* s, const char* pattern, const char* repl);
diff --git a/src/libpakfire/parser.c b/src/libpakfire/parser.c
index 2ac993925..99991038c 100644
--- a/src/libpakfire/parser.c
+++ b/src/libpakfire/parser.c
@@ -202,6 +202,11 @@ static struct pakfire_parser_declaration* pakfire_parser_get_declaration(
 	if (!namespace)
 		namespace = "";
 
+	if (namespace)
+		DEBUG(parser->pakfire, "Looking up %s.%s\n", namespace, name);
+	else
+		DEBUG(parser->pakfire, "Looking up %s\n", name);
+
 	struct pakfire_parser_declaration* d;
 	for (unsigned i = 0; i < parser->num_declarations; i++) {
 		d = parser->declarations[i];
@@ -305,7 +310,7 @@ static const char* pakfire_parser_get_raw(PakfireParser parser, const char* name
 	d = pakfire_parser_get_declaration(parser, namespace, name);
 
 	// Return a match when it actually contains a string
-	if (d)
+	if (d && d->value)
 		return d->value;
 
 	// We are done, if the namespace is empty
@@ -321,7 +326,7 @@ static const char* pakfire_parser_get_raw(PakfireParser parser, const char* name
 
 		if (*template) {
 			d = pakfire_parser_get_declaration(parser, template, name);
-			if (d)
+			if (d && d->value)
 				return d->value;
 		}
 	}
@@ -334,7 +339,7 @@ static const char* pakfire_parser_get_raw(PakfireParser parser, const char* name
 		pakfire_parser_strip_namespace(&n);
 
 		d = pakfire_parser_get_declaration(parser, n, name);
-		if (d)
+		if (d && d->value)
 			return d->value;
 
 		// End if we have exhausted the namespace
@@ -504,6 +509,11 @@ static int pakfire_parser_expand_variables(PakfireParser parser,
 			break;
 		}
 
+		// Find the entire matched pattern
+		r = pcre2_substring_get_bynumber(match, 0, &pattern, &pattern_length);
+		if (r)
+			goto ERROR;
+
 		// Find the variable name
 		r = pcre2_substring_get_bynumber(match, 1, &variable, &variable_length);
 		if (r)
@@ -514,6 +524,23 @@ static int pakfire_parser_expand_variables(PakfireParser parser,
 		// Search for a declaration of this variable
 		const char* repl = pakfire_parser_get_raw(parser, namespace, (const char*)variable);
 
+		// Is this a recursive pattern?
+		if (repl && pakfire_string_matches(repl, (const char*)pattern)) {
+			DEBUG(parser->pakfire, "Recursion detected in %s\n", pattern);
+
+			// Move up one step and lookup there
+			if (namespace && *namespace) {
+				char* parent_namespace = strdupa(namespace);
+				pakfire_parser_strip_namespace(&parent_namespace);
+
+				repl = pakfire_parser_get_raw(parser, parent_namespace, (const char*)variable);
+
+			// If we have already reached the top namespace, we replace with an empty string
+			} else {
+				repl = NULL;
+			}
+		}
+
 		// What is its value?
 		if (repl) {
 			DEBUG(parser->pakfire, "Replacing %%{%s} with '%s'\n", variable, repl);
@@ -521,11 +548,6 @@ static int pakfire_parser_expand_variables(PakfireParser parser,
 			DEBUG(parser->pakfire, "Replacing %%{%s} with an empty string\n", variable);
 		}
 
-		// Find the entire matched pattern
-		r = pcre2_substring_get_bynumber(match, 0, &pattern, &pattern_length);
-		if (r)
-			goto ERROR;
-
 		// Replace all occurrences
 		char* tmp = pakfire_string_replace(*buffer, (const char*)pattern, (repl) ? repl : "");
 		if (!tmp)
diff --git a/src/libpakfire/parser/grammar.y b/src/libpakfire/parser/grammar.y
index 83ca76c59..b94b11b0d 100644
--- a/src/libpakfire/parser/grammar.y
+++ b/src/libpakfire/parser/grammar.y
@@ -314,11 +314,7 @@ subparser					: subparser_name T_EOL block T_END T_EOL
 								int r = pakfire_string_partition($1, ":", &key, &value);
 								if (r == 0) {
 									if (strcmp("package", key) == 0) {
-										char* name = pakfire_parser_expand($$, NULL, value);
-										if (name) {
-											pakfire_parser_set($$, NULL, "name", name);
-											free(name);
-										}
+										pakfire_parser_set($$, NULL, "name", value);
 									}
 
 									if (key)
diff --git a/src/libpakfire/util.c b/src/libpakfire/util.c
index fd29b683b..383359997 100644
--- a/src/libpakfire/util.c
+++ b/src/libpakfire/util.c
@@ -164,6 +164,10 @@ int pakfire_string_endswith(const char* s, const char* suffix) {
 	return !strcmp(s + strlen(s) - strlen(suffix), suffix);
 }
 
+int pakfire_string_matches(const char* s, const char* pattern) {
+	return !!strstr(s, pattern);
+}
+
 char* pakfire_unquote_in_place(char* s) {
 	if (!s || !*s)
 		return s;