snippet: avoid some -Wunused-function warnings

diff --git a/snippet/basic-handsum-decode.c b/snippet/basic-handsum-decode.c
index ed405e8..d58f715 100644
--- a/snippet/basic-handsum-decode.c
+++ b/snippet/basic-handsum-decode.c

@@ -33,6 +33,11 @@
 #ifndef BASIC_HANDSUM_DECODE_INCLUDE_GUARD
 #define BASIC_HANDSUM_DECODE_INCLUDE_GUARD
 
+#if defined(__GNUC__) || defined(__clang__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
 #if defined(BASIC_HANDSUM_DECODE_CONFIG__STATIC_FUNCTIONS)
 #define BASIC_HANDSUM_DECODE__MAYBE_STATIC static
 #else
@@ -483,4 +488,9 @@
 }
 
 #endif  // BASIC_HANDSUM_DECODE_IMPLEMENTATION
+
+#if defined(__GNUC__)
+#pragma GCC diagnostic pop
+#endif
+
 #endif  // BASIC_HANDSUM_DECODE_INCLUDE_GUARD

diff --git a/snippet/parse-color.c b/snippet/parse-color.c
index 40d98ef..70b57de 100644
--- a/snippet/parse-color.c
+++ b/snippet/parse-color.c

@@ -27,6 +27,11 @@
 #ifndef PARSE_COLOR_INCLUDE_GUARD
 #define PARSE_COLOR_INCLUDE_GUARD
 
+#if defined(__GNUC__) || defined(__clang__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
 #if defined(PARSE_COLOR_CONFIG__STATIC_FUNCTIONS)
 #define PARSE_COLOR__MAYBE_STATIC static
 #else
@@ -200,4 +205,9 @@
 }
 
 #endif  // PARSE_COLOR_IMPLEMENTATION
+
+#if defined(__GNUC__)
+#pragma GCC diagnostic pop
+#endif
+
 #endif  // PARSE_COLOR_INCLUDE_GUARD

diff --git a/snippet/uncompng.c b/snippet/uncompng.c
index c4a8ae4..3e89a6a 100644
--- a/snippet/uncompng.c
+++ b/snippet/uncompng.c

@@ -29,6 +29,11 @@
 #ifndef UNCOMPNG_INCLUDE_GUARD
 #define UNCOMPNG_INCLUDE_GUARD
 
+#if defined(__GNUC__) || defined(__clang__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
 #if defined(UNCOMPNG_CONFIG__STATIC_FUNCTIONS)
 #define UNCOMPNG__MAYBE_STATIC static
 #else
@@ -926,4 +931,9 @@
 }
 
 #endif  // UNCOMPNG_IMPLEMENTATION
+
+#if defined(__GNUC__)
+#pragma GCC diagnostic pop
+#endif
+
 #endif  // UNCOMPNG_INCLUDE_GUARD