reduce repetition in pcre2 error message reporting

src/vmod_pcre2.c

@@ -110,14 +110,32 @@ errmsg(VRT_CTX, const char *fmt, ...)
 	va_end(args);
 }
 
-static inline int
-get_pcre2_errmsg(struct ws * const restrict ws, int errcode,
-		 char * restrict * const restrict buf)
+static void
+report_pcre2_err(VRT_CTX, int errcode, const char * const restrict msg,
+		 const char * const restrict post)
 {
-	unsigned bytes = WS_Reserve(ws, 0);
-	*buf = WS_Front(ws);
-	return pcre2_get_error_message(errcode, (PCRE2_UCHAR *)*buf,
+	int ret;
+
+	uintptr_t snap = WS_Snapshot(ctx->ws);
+	unsigned bytes = WS_Reserve(ctx->ws, 0);
+	char *buf = WS_Front(ctx->ws);
+
+	ret = pcre2_get_error_message(errcode, (PCRE2_UCHAR *)buf,
 				      (PCRE2_SIZE)bytes);
+	if (ret == PCRE2_ERROR_BADDATA) {
+		WS_ReleaseP(ctx->ws, buf);
+		VERR(ctx, "%s (unknown error code)%s", msg, post);
+	}
+	else if (ret == PCRE2_ERROR_NOMEMORY) {
+		WS_Release(ctx->ws, strlen(buf) + 1);
+		VERR(ctx, "%s: %s (truncated error message)%s", msg, buf,
+		     post);
+	}
+	else {
+		WS_Release(ctx->ws, ret);
+		VERR(ctx, "%s: %s%s", msg, buf, post);
+	}
+	WS_Reset(ctx->ws, snap);
 }
 
 /* Event function */
@@ -293,26 +311,17 @@ vmod_regex__init(VRT_CTX, struct vmod_pcre2_regex **regexp,
 	code = pcre2_compile((PCRE2_SPTR)pattern, PCRE2_ZERO_TERMINATED,
 			     options, &err_code, &err_offset, ccontext);
 	if (code == NULL) {
-		char *buf;
+		char *msg, *offset_msg;
 		uintptr_t snap = WS_Snapshot(ctx->ws);
-		ret = get_pcre2_errmsg(ctx->ws, err_code, &buf);
-		if (ret == PCRE2_ERROR_BADDATA) {
-			WS_ReleaseP(ctx->ws, buf);
-			VERR(ctx, "Cannot compile '%s' in %s constructor "
-			     "(unknown error code)", pattern, vcl_name);
-		}
-		else if (ret == PCRE2_ERROR_NOMEMORY) {
-			WS_Release(ctx->ws, strlen(buf) + 1);
-			VERR(ctx, "Cannot compile '%s' in %s constructor: %s"
-			     "(truncated error message) at offset %zu", pattern,
-			     vcl_name, err_offset);
-		}
-		else {
-			WS_Release(ctx->ws, ret);
-			VERR(ctx, "Cannot compile '%s' in %s constructor: %s "
-			     "at offset %zu", pattern, vcl_name, buf,
-			     err_offset);
-		}
+
+		if ((msg = WS_Printf(ctx->ws,
+				     "Cannot compile '%s' in %s constructor",
+				     pattern, vcl_name)) == NULL)
+			msg = "";
+		if ((offset_msg = WS_Printf(ctx->ws, " at offset %zu",
+					    err_offset)) == NULL)
+			offset_msg = "";
+		report_pcre2_err(ctx, err_code, msg, offset_msg);
 		WS_Reset(ctx->ws, snap);
 		pcre2_compile_context_free(ccontext);
 		return;
@@ -323,27 +332,14 @@ vmod_regex__init(VRT_CTX, struct vmod_pcre2_regex **regexp,
 		options |= PCRE2_JIT_COMPLETE;
 		ret = pcre2_jit_compile(code, options);
 		if (ret != 0) {
-			char *buf;
+			char *msg;
 			uintptr_t snap = WS_Snapshot(ctx->ws);
-			ret = get_pcre2_errmsg(ctx->ws, ret, &buf);
-			if (ret == PCRE2_ERROR_BADDATA) {
-				WS_ReleaseP(ctx->ws, buf);
-				VERR(ctx, "Cannot jit-compile '%s' in %s "
-				     "constructor (unknown error code)",
-				     pattern, vcl_name);
-			}
-			else if (ret == PCRE2_ERROR_NOMEMORY) {
-				WS_Release(ctx->ws, strlen(buf) + 1);
-				VERR(ctx, "Cannot jit-compile '%s' in %s "
-				     "constructor: %s (truncated error message)",
-				     pattern, vcl_name);
-			}
-			else {
-				WS_Release(ctx->ws, ret);
-				VERR(ctx, "Cannot jit-compile '%s' in %s "
-				     "constructor: %s ", pattern, vcl_name,
-				     buf);
-			}
+
+			if ((msg = WS_Printf(ctx->ws, "Cannot jit-compile '%s' "
+					     "in %s constructor", pattern,
+					     vcl_name)) == NULL)
+				msg = "";
+			report_pcre2_err(ctx, ret, msg, "");
 			WS_Reset(ctx->ws, snap);
 			pcre2_compile_context_free(ccontext);
 			return;
@@ -390,6 +386,8 @@ vmod_regex_match(VRT_CTX, struct vmod_pcre2_regex *regex,
 	struct vmod_priv *match_task = NULL;
 	struct match_call *match_opts;
 	int ret;
+	char *msg;
+	uintptr_t snap;
 
 	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
 	CHECK_OBJ_NOTNULL(regex, VMOD_PCRE2_REGEX_MAGIC);
@@ -504,23 +502,11 @@ vmod_regex_match(VRT_CTX, struct vmod_pcre2_regex *regex,
 	if (ret >= 0)
 		return 1;
 
-	char *buf;
-	uintptr_t snap = WS_Snapshot(ctx->ws);
-	ret = get_pcre2_errmsg(ctx->ws, ret, &buf);
-	if (ret == PCRE2_ERROR_BADDATA) {
-		WS_ReleaseP(ctx->ws, buf);
-		VERR(ctx, "in %s.match() (unknown error code)",
-		     regex->vcl_name);
-	}
-	else if (ret == PCRE2_ERROR_NOMEMORY) {
-		WS_Release(ctx->ws, strlen(buf) + 1);
-		VERR(ctx, "in %s.match(): %s (truncated error message)",
-		     regex->vcl_name, buf);
-	}
-	else {
-		WS_Release(ctx->ws, ret);
-		VERR(ctx, "in %s.match(): %s ", regex->vcl_name, buf);
-	}
+	snap = WS_Snapshot(ctx->ws);
+	if ((msg = WS_Printf(ctx->ws, "in %s.match()", regex->vcl_name))
+	    == NULL)
+		msg = "";
+	report_pcre2_err(ctx, ret, msg, "");
 	WS_Reset(ctx->ws, snap);
 	return 0;
 }