From: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Date: Fri, 3 Feb 2023 18:59:23 +0000 (-0500)
Subject: Build fix: filter parser fails to build with -Werror
X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=9f2a20195dbdc0e69e1e33abb642242ec7c3e244

Build fix: filter parser fails to build with -Werror

Using bison 3.8.2 and clang 15.0.7, the project fails to build with
-Werror as building the generated parser results in the following
warning:

  CXX      filter/libfilter_la-filter-parser.lo
  filter/filter-parser.cpp:1552:9: error: variable 'yynerrs' set but not used [-Werror,-Wunused-but-set-variable]
      int yynerrs = 0;
          ^

A pragma directive is inserted to silence the warning and allow the
build to go through.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I4c46a5df91bdeca6ad4e2a8ff7f2a98ee94c4f1d
---

diff --git a/src/common/filter/filter-parser.ypp b/src/common/filter/filter-parser.ypp
index 0f11c234d..fedf0e830 100644
--- a/src/common/filter/filter-parser.ypp
+++ b/src/common/filter/filter-parser.ypp
@@ -29,6 +29,14 @@
 #define WIDTH_x64_SCANF_IS_A_BROKEN_API	"17"
 #define WIDTH_lg_SCANF_IS_A_BROKEN_API	"4096"	/* Hugely optimistic approximation */
 
+/*
+ * bison 3.8.2 produces a parser with unused, but set, which results in warnings
+ * at build time.
+ */
+#ifdef __clang__
+#pragma clang diagnostic ignored "-Wunused-but-set-variable"
+#endif /* __clang__ */
+
 #ifdef DEBUG
 static const int print_xml = 1;
 #define dbg_printf(fmt, args...)	\