nostrdb: pull latest, adding flatcc and lmdb

nostrdb/flatcc/portable/pattributes.h

@@ -0,0 +1,84 @@
+
+/*
+ * C23 introduces an attribute syntax `[[<attribute>]]`. Prior to that
+ * other non-standard syntaxes such as `__attribute__((<attribute>))`
+ * and `__declspec(<attribute>)` have been supported by some compiler
+ * versions.
+ *
+ * See also:
+ * https://en.cppreference.com/w/c/language/attributes
+ *
+ * There is no portable way to use C23 attributes in older C standards
+ * so in order to use these portably, some macro name needs to be
+ * defined for each attribute that either maps to the older supported
+ * syntax, or ignores the attribute as appropriate.
+ *
+ * The Linux kernel defines certain attributes as macros, such as
+ * `fallthrough`. When adding attributes it seems reasonable to follow
+ * the Linux conventions in lack of any official standard. However, it
+ * is not the intention that this file should mirror the Linux
+ * attributes 1 to 1.
+ *
+ * See also:
+ * https://github.com/torvalds/linux/blob/master/include/linux/compiler_attributes.h
+ *
+ * There is a risk that exposed attribute names may lead to name
+ * conflicts. A conflicting name can be undefined and if necessary used
+ * using `pattribute(<attribute>)`. All attributes can be hidden by
+ * defining `PORTABLE_EXPOSE_ATTRIBUTES=0` in which case
+ * `pattribute(<attribute>)` can still be used and then if a specific
+ * attribute name still needs to be exposed, it can be defined manually
+ * like `#define fallthrough pattribute(fallthrough)`.
+ */
+
+
+#ifndef PATTRIBUTES_H
+#define PATTRIBUTES_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef PORTABLE_EXPOSE_ATTRIBUTES
+#define PORTABLE_EXPOSE_ATTRIBUTES 1
+#endif
+
+#ifdef __has_c_attribute
+# define PORTABLE_HAS_C_ATTRIBUTE(x) __has_c_attribute(x)
+#else
+# define PORTABLE_HAS_C_ATTRIBUTE(x) 0
+#endif
+
+#ifdef __has_attribute
+# define PORTABLE_HAS_ATTRIBUTE(x) __has_attribute(x)
+#else
+# define PORTABLE_HAS_ATTRIBUTE(x) 0
+#endif
+
+
+/* https://en.cppreference.com/w/c/language/attributes/fallthrough */
+#if PORTABLE_HAS_C_ATTRIBUTE(__fallthrough__)
+# define pattribute_fallthrough [[__fallthrough__]]
+#elif PORTABLE_HAS_ATTRIBUTE(__fallthrough__)
+# define pattribute_fallthrough __attribute__((__fallthrough__))
+#else
+# define pattribute_fallthrough ((void)0)
+#endif
+
+
+#define pattribute(x) pattribute_##x
+
+#if PORTABLE_EXPOSE_ATTRIBUTES
+
+#ifndef fallthrough
+# define fallthrough pattribute(fallthrough)
+#endif
+
+#endif
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* PATTRIBUTES_H */