From 4ff750609549a99f6b318ce600c42c90d4f2e480 Mon Sep 17 00:00:00 2001
From: Simon Marchi <simon.marchi@efficios.com>
Date: Fri, 20 Aug 2021 16:10:37 -0400
Subject: [PATCH] common: move append_str to string-utils
MIME-Version: 1.0
Content-Type: text/plain; charset=utf8
Content-Transfer-Encoding: 8bit

Move the append_str function from filter-visitor-generate-bytecode.c to
the string-utils lib, so that it can be re-used elsewhere.

Change-Id: Ica09cb750ac7f3f2d6f3fb5fc786b683ceb6f79a
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---
 .../filter-visitor-generate-bytecode.cpp      | 30 ++++---------------
 src/common/string-utils/string-utils.cpp      | 22 ++++++++++++++
 src/common/string-utils/string-utils.h        | 10 +++++++
 3 files changed, 37 insertions(+), 25 deletions(-)

diff --git a/src/common/filter/filter-visitor-generate-bytecode.cpp b/src/common/filter/filter-visitor-generate-bytecode.cpp
index 7b418acdc..c7e1be782 100644
--- a/src/common/filter/filter-visitor-generate-bytecode.cpp
+++ b/src/common/filter/filter-visitor-generate-bytecode.cpp
@@ -19,6 +19,7 @@
 #include "common/bytecode/bytecode.h"
 #include "common/compat/string.h"
 #include "common/macros.h"
+#include "common/string-utils/string-utils.h"
 #include "filter-ast.h"
 #include "filter-ir.h"
 
@@ -59,27 +60,6 @@ int visit_node_root(struct filter_parser_ctx *ctx, struct ir_op *node)
 	return bytecode_push(&ctx->bytecode, &insn, 1, sizeof(insn));
 }
 
-static
-int append_str(char **s, const char *append)
-{
-	char *old_str = *s;
-	char *new_str;
-	size_t oldlen = (old_str == NULL) ? 0 : strlen(old_str);
-	size_t appendlen = strlen(append);
-
-	new_str = (char *) calloc(oldlen + appendlen + 1, 1);
-	if (!new_str) {
-		return -ENOMEM;
-	}
-	if (oldlen) {
-		strcpy(new_str, old_str);
-	}
-	strcat(new_str, append);
-	*s = new_str;
-	free(old_str);
-	return 0;
-}
-
 /*
  * 1: match
  * 0: no match
@@ -97,14 +77,14 @@ int load_expression_legacy_match(const struct ir_load_expression *exp,
 	switch (op->type) {
 	case IR_LOAD_EXPRESSION_GET_CONTEXT_ROOT:
 		*op_type = BYTECODE_OP_GET_CONTEXT_REF;
-		if (append_str(symbol, "$ctx.")) {
+		if (strutils_append_str(symbol, "$ctx.")) {
 			return -ENOMEM;
 		}
 		need_dot = false;
 		break;
 	case IR_LOAD_EXPRESSION_GET_APP_CONTEXT_ROOT:
 		*op_type = BYTECODE_OP_GET_CONTEXT_REF;
-		if (append_str(symbol, "$app.")) {
+		if (strutils_append_str(symbol, "$app.")) {
 			return -ENOMEM;
 		}
 		need_dot = false;
@@ -130,10 +110,10 @@ int load_expression_legacy_match(const struct ir_load_expression *exp,
 		case IR_LOAD_EXPRESSION_LOAD_FIELD:
 			goto end;
 		case IR_LOAD_EXPRESSION_GET_SYMBOL:
-			if (need_dot && append_str(symbol, ".")) {
+			if (need_dot && strutils_append_str(symbol, ".")) {
 				return -ENOMEM;
 			}
-			if (append_str(symbol, op->u.symbol)) {
+			if (strutils_append_str(symbol, op->u.symbol)) {
 				return -ENOMEM;
 			}
 			break;
diff --git a/src/common/string-utils/string-utils.cpp b/src/common/string-utils/string-utils.cpp
index 3051644f3..8dcc6b2aa 100644
--- a/src/common/string-utils/string-utils.cpp
+++ b/src/common/string-utils/string-utils.cpp
@@ -10,6 +10,8 @@
 #include <string.h>
 #include <stdbool.h>
 #include <type_traits>
+#include <assert.h>
+#include <errno.h>
 
 #include "string-utils.h"
 #include "../macros.h"
@@ -373,3 +375,23 @@ size_t strutils_array_of_strings_len(char * const *array)
 
 	return count;
 }
+
+int strutils_append_str(char **s, const char *append)
+{
+	char *old = *s;
+	char *new_str;
+	size_t oldlen = (old == NULL) ? 0 : strlen(old);
+	size_t appendlen = strlen(append);
+
+	new_str = (char *) zmalloc(oldlen + appendlen + 1);
+	if (!new_str) {
+		return -ENOMEM;
+	}
+	if (oldlen) {
+		strcpy(new_str, old);
+	}
+	strcat(new_str, append);
+	*s = new_str;
+	free(old);
+	return 0;
+}
diff --git a/src/common/string-utils/string-utils.h b/src/common/string-utils/string-utils.h
index 1cf31e9d4..8f47abbc3 100644
--- a/src/common/string-utils/string-utils.h
+++ b/src/common/string-utils/string-utils.h
@@ -27,4 +27,14 @@ void strutils_free_null_terminated_array_of_strings(char **array);
 
 size_t strutils_array_of_strings_len(char * const *array);
 
+/*
+ * Append `append` to the malloc-end string `str`.
+ *
+ * On success, `str` is free'd (if not NULL) and assigned a new malloc-ed
+ * string.  On failure, `str` is not modified.
+ *
+ * Return 0 on success, -ENOMEM on failure.
+ */
+int strutils_append_str(char **str, const char *append);
+
 #endif /* _STRING_UTILS_H */
-- 
2.34.1