Merge commit '5a40295c4cf0af5ea8da9ced04a4ce7d3621a080' as 'flatcc'

1 files changed, 477 insertions, 0 deletions

diff --git a/flatcc/config/config.h b/flatcc/config/config.h
new file mode 100644
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--- /dev/null
+++ b/flatcc/config/config.h
@@ -0,0 +1,477 @@
+#ifndef CONFIG_H
+#define CONFIG_H
+
+#include "flatcc/flatcc_version.h"
+
+/*
+ * This is an alternative implementation to googles `flatc` compiler.
+ * This configuration enables or disable features which can be used
+ * to closer match the flatc behavior. The current flatc version
+ * may evolve over time, so the comments on flatc behavior should
+ * be seen as how things were when this file was last updated.
+ *
+ * One notable, but convenient, difference is that structs and enums are
+ * not required to be defined in a specific order here (as of June 2020
+ * flatc supports out of order enums). The schema can be rearranged by
+ * the user to support the flatc compiler without changing the
+ * underlying. This does put an extra restraint on struct depth as
+ * recursion must have set maximum level, but this also applies to
+ * target C compilers, e.g. clang has a limit of about 100-200 nestings.
+ *
+ * Another more significant difference is that structs are allowed as
+ * root objects. This is important if a query should return a partial
+ * result from a stored buffer but it isn't currently supported by
+ * flatc, although the documentation hints that it might be possible.
+ *
+ * Value overflows and conversions of enums and default values are
+ * checked more than by flatc, and this could break some schemas.
+ * However, hopefully it will not break any production schemas since the
+ * results would not be well-defined.
+ *
+ * Struct fields may be deprecated by padding. This isn't supported by
+ * flatc but was added because it seemed inconsistent to not have it
+ * when deprecated table fields are possible.
+ *
+ * Enums can be used in structs, but this is not supported by flatc.
+ * The reason might be either the additional work in the parser, or
+ * because it adds a burden to code generators, for example, C output
+ * must place enums before structs. However, they make perfect sense in
+ * the format.
+ */
+
+#define FLATCC_INFO_TEXT "FlatBuffers schema compiler for C by dvide.com"
+#define FLATCC_TITLE_TEXT "flatcc " FLATCC_INFO_TEXT
+#define FLATCC_GENERATED_BY "Generated by flatcc " FLATCC_VERSION_TEXT " " FLATCC_INFO_TEXT
+
+/* Include portability layer here since all other files depend on it. */
+#ifdef FLATCC_PORTABLE
+#include "flatcc/portable/portable.h"
+#endif
+
+/*
+ * Limit the input buffer or file size being parsed to prevent brining
+ * the whole system down on invalid or malicous content. This limit
+ * is covers the accumulated size of all included files. 0 is unlimited.
+ */
+#ifndef FLATCC_MAX_SCHEMA_SIZE
+#define FLATCC_MAX_SCHEMA_SIZE 1000000
+#endif
+
+/*
+ * Max nesting level of includes - the affects recursion on the call
+ * stack. 0 is unlimited.
+ */
+#ifndef FLATCC_MAX_INCLUDE_DEPTH
+#define FLATCC_MAX_INCLUDE_DEPTH 100
+#endif
+
+/*
+ * Max number of include files allowed regardless of how they are
+ * nested. This affects memory usage but it may be very large. It should
+ * not normally affect the number of open file handles since files are
+ * opened and closed individually, depending on the interfacing driver
+ * logic. 0 is unlimited.
+ */
+#ifndef FLATCC_MAX_INCLUDE_COUNT
+#define FLATCC_MAX_INCLUDE_COUNT 100
+#endif
+
+/*
+ * Limit parser recursion depth when analyzing dependent structs.
+ * The grammar itself does not contain recursion.
+ */
+#ifndef FLATCC_NESTING_MAX
+#define FLATCC_NESTING_MAX 100
+#endif
+
+#ifndef FLATCC_MAX_ERRORS
+#define FLATCC_MAX_ERRORS 10
+#endif
+
+/* Used when truncating some error messages. */
+#ifndef FLATCC_MAX_IDENT_SHOW
+#define FLATCC_MAX_IDENT_SHOW 50
+#endif
+
+/*
+ * Allow FlatBuffer schema reserved keywords
+ * to be used as field identifiers. This can
+ * be confusing, but also important for use with
+ * JSON where the field names are visible
+ * externally.
+ */
+#ifndef FLATCC_ALLOW_KW_FIELDS
+#define FLATCC_ALLOW_KW_FIELDS 1
+#endif
+
+/*
+ * Applies to the members of an enum. These
+ * names a visible in JSON. Using reserved
+ * names prevent them from being used in
+ * field default values.
+ */
+#ifndef FLATCC_ALLOW_KW_ENUMS
+#define FLATCC_ALLOW_KW_ENUMS 1
+#endif
+
+/*
+ * Artificial limit on grammar attributes to prevent abuse.
+ */
+#ifndef FLATCC_ATTR_MAX
+#define FLATCC_ATTR_MAX 100
+#endif
+
+#ifndef FLATCC_FORCE_ALIGN_MAX
+#define FLATCC_FORCE_ALIGN_MAX 256
+#endif
+
+/*
+ * sizeof(uoffset_t), sizeof(soffset_t) in FlatBuffers file format.
+ * Permissible values are 2, 4 (default), and 8.
+ */
+#ifndef FLATCC_OFFSET_SIZE
+#define FLATCC_OFFSET_SIZE 4
+#endif
+
+/*
+ * sizeof(voffset_t) in FlatBuffers file format.
+ * Permissible values are 2 (default), 4, and 8.
+ */
+#ifndef FLATCC_VOFFSET_SIZE
+#define FLATCC_VOFFSET_SIZE 2
+#endif
+
+/*
+ * DO NOT CHANGE
+ * The union type field type.
+ * This is hardcoded in many places and difficult
+ * to change since size = 1 does not require
+ * endian conversion. Config only placed here
+ * for consistency and clarity.
+ */
+#ifndef FLATCC_UTYPE_SIZE
+#define FLATCC_UTYPE_SIZE 1
+#endif
+
+/*
+ * DO NOT CHANGE, see also FLATCC_UTYPE_SIZE
+ */
+#ifndef FLATCC_BOOL_SIZE
+#define FLATCC_BOOL_SIZE 1
+#endif
+
+/*
+ * There are no hard limits on structs, but
+ * they cannot be effectively handled by tables
+ * if larger than 64K and 64K-1 allows us to store
+ * the size in short where needed. Internally
+ * we can handle 64 bits.
+ */
+#ifndef FLATCC_STRUCT_MAX_SIZE
+#define FLATCC_STRUCT_MAX_SIZE ((1 << 16) - 1)
+#endif
+
+#ifndef FLATCC_NAMESPACE_MAX
+#define FLATCC_NAMESPACE_MAX 100
+#endif
+
+/* Reserve space for trailing _ and \0. */
+#define FLATCC_NAMESPACE_BUFSIZ (FLATCC_NAMESPACE_MAX + 2)
+#define FLATCC_NAME_BUFSIZ (2 * FLATCC_NAMESPACE_BUFSIZ)
+
+#ifndef FLATCC_FILENAME_MAX
+#define FLATCC_FILENAME_MAX 256
+#endif
+
+/*
+ * If set, enum fields initialized with a numeric constant must match an
+ * existing enum value. This only applies to the schema intializers, not
+ * values assigned during buffer construction. It may be useful to allow
+ * non-existing values (and expensive to enforce), but for schema
+ * intializers, it could easily break future changes if inconsistent
+ * values are being used.
+ */
+#ifndef FLATCC_STRICT_ENUM_INIT
+#define FLATCC_STRICT_ENUM_INIT 1
+#endif
+
+/*
+ * flatc requires ascending enums, and it does simplify code generation
+ * to multiple languages, and name mapping of enums, so we require this
+ * by default, but C code generator handles both cases fine.
+ * As of June 2020 flatc supports out of order enums.
+ */
+#ifndef FLATCC_ASCENDING_ENUM
+#define FLATCC_ASCENDING_ENUM 0
+#endif
+
+/*
+ * flatc tool accepts any integer as bool because it
+ * doesn't do range check. By enabling this flag we get more compatible,
+ * but still only accepts 1 or 0 as bool, and also allow assignment of
+ * bool to other types (useful in enums that are not bool because
+ * official flatc has no boolean enum type.
+ *
+ * However, there appears to be no strong reason for mixing boolean types
+ * with other types, but since `flatc` supports, it is enabled by
+ * default.
+ */
+#ifndef FLATCC_ALLOW_BOOLEAN_CONVERSION
+#define FLATCC_ALLOW_BOOLEAN_CONVERSION 1
+#endif
+
+/* flatc does not recognize later defined enums, be we do by default. */
+#ifndef FLATCC_HIDE_LATER_ENUM
+#define FLATCC_HIDE_LATER_ENUM 0
+#endif
+
+/*
+ * The flatc parser does not recognize later structs.
+ * If disabled dependent structs will be topologically
+ * sorted to the set maximum recursion depth.
+ */
+#ifndef FLATCC_HIDE_LATER_STRUCT
+#define FLATCC_HIDE_LATER_STRUCT 0
+#endif
+
+/*
+ * In all cases we permit at most one root type per file.
+ * flatc allows none, or multiple, but apparently only generates
+ * accessors for the last seen.
+ */
+#ifndef FLATCC_REQUIRE_ROOT_TYPE
+#define FLATCC_REQUIRE_ROOT_TYPE 0
+#endif
+
+/*
+ * This also applies to nested_flatbuffers.
+ * flatc does not allow structs.
+ */
+#ifndef FLATCC_ALLOW_STRUCT_ROOT
+#define FLATCC_ALLOW_STRUCT_ROOT 1
+#endif
+
+/*
+ * pad deprecated struct fields with __depracedx[size] i C output.
+ * flatc does not permit deprecated struct fields.
+ */
+#ifndef FLATCC_ALLOW_STRUCT_FIELD_DEPRECATE
+#define FLATCC_ALLOW_STRUCT_FIELD_DEPRECATE 1
+#endif
+
+/*
+ * flatc only allows one key on table fields, which makes sense in
+ * C++ STL where a vector can have on comparison operator,
+ * but in C output we can easily have multiple <structname>_find_by_<fieldname>.
+ * Vectors can only be sorted by one field at a time, but e.g. an
+ * octree- or trie-like data-structure might choose to sort on different
+ * coordinates at different levels.
+ */
+#ifndef FLATCC_ALLOW_MULTIPLE_KEY_FIELDS
+#define FLATCC_ALLOW_MULTIPLE_KEY_FIELDS 1
+#endif
+
+/*
+ * flatc does not have a primary_key field attribute but it is useful
+ * when having multiple keys. Without a primary_key the field with the
+ * lowest id becomes the default, or primary, key. This key has a
+ * simpler find syntax and is also used by default when sorting.
+ * When there is only one keyed field on a table it is better to use
+ * the key attribute for compatibility reasons. It will automatically
+ * become primary.
+ */
+#ifndef FLATCC_ALLOW_PRIMARY_KEY
+#define FLATCC_ALLOW_PRIMARY_KEY 1
+#endif
+
+/*
+ * flatcc has scan functions which are equivalent to find except they
+ * don't require arrays to be sorted by field and have O(N) complexity.
+ * It makes sense to generate these functions by default for all fields,
+ * not just ones marked as key.
+ */
+
+#ifndef FLATCC_ALLOW_SCAN_FOR_ALL_FIELDS
+#define FLATCC_ALLOW_SCAN_FOR_ALL_FIELDS 1
+#endif
+
+/* flatc currently does not allow keys on structs, but it makes sense to have them. */
+#ifndef FLATCC_ALLOW_STRUCT_FIELD_KEY
+#define FLATCC_ALLOW_STRUCT_FIELD_KEY 1
+#endif
+
+/*
+ * Structs cannot have defaults. If an enum does not define a 0 value
+ * this is not considered an error when used with a struct.
+ * The flatc compiler does not accept enums on structs.
+ */
+#ifndef FLATCC_ALLOW_ENUM_STRUCT_FIELD
+#define FLATCC_ALLOW_ENUM_STRUCT_FIELD 1
+#endif
+
+/*
+ * flatc currrently only allows scalar and strings as keys,
+ * but enums are really a kind of scalar and it makes sense to support
+ * them.
+ */
+#ifndef FLATCC_ALLOW_ENUM_KEY
+#define FLATCC_ALLOW_ENUM_KEY 1
+#endif
+
+/*
+ * String keys are allowed (and actively used in refletion.fbs) by
+ * flatc, but they are more tricky to support in code generation
+ * so allow them to be disabled.
+ */
+#ifndef FLATCC_ALLOW_STRING_KEY
+#define FLATCC_ALLOW_STRING_KEY 1
+#endif
+
+/* Code gen specific. */
+
+#ifndef FLATCC_DEFAULT_SCHEMA_EXT
+#define FLATCC_DEFAULT_SCHEMA_EXT ".fbs"
+#endif
+
+#ifndef FLATCC_DEFAULT_BIN_SCHEMA_EXT
+#define FLATCC_DEFAULT_BIN_SCHEMA_EXT ".bfbs"
+#endif
+
+/* Schema file extensions do not carry a dot by convention, do the same here. */
+#ifndef FLATCC_DEFAULT_BIN_EXT
+#define FLATCC_DEFAULT_BIN_EXT "bin"
+#endif
+
+#ifndef FLATCC_DEFAULT_DEP_EXT
+#define FLATCC_DEFAULT_DEP_EXT ".fbs.d"
+#endif
+
+/*
+ * A depends file sometimes needs a single file to hook
+ * the include file dependencies onto.
+ */
+#ifndef FLATCC_DEFAULT_DEP_TARGET_SUFFIX
+#define FLATCC_DEFAULT_DEP_TARGET_SUFFIX "_reader.h"
+#endif
+
+#ifndef FLATCC_DEFAULT_FILENAME
+#define FLATCC_DEFAULT_FILENAME "test"
+#endif
+
+#ifndef FLATCC_DEFAULT_NAMESPACE
+#define FLATCC_DEFAULT_NAMESPACE ""
+#endif
+
+#ifndef FLATCC_DEFAULT_NAMESPACE_COMMON
+#define FLATCC_DEFAULT_NAMESPACE_COMMON "flatbuffers"
+#endif
+
+/* rpc attributes aren't spec'ed at this point, so we flag the code. */
+/* Similar to attributes after table name (no runtime option). */
+#ifndef FLATCC_ALLOW_RPC_SERVICE_ATTRIBUTES
+#define FLATCC_ALLOW_RPC_ATTRIBUTES 1
+#endif
+ 
+/* Similar to attributes after a tables field name (no runtime option). */
+#ifndef FLATCC_ALLOW_RPC_METHOD_ATTRIBUTES
+#define FLATCC_ALLOW_RPC_METHOD_ATTRIBUTES 1
+#endif
+
+/* Only takes effect if rpc method attributes are allowed (no runtime option). */
+#ifndef FLATCC_ALLOW_DEPRECATED_RPC_METHOD
+#define FLATCC_ALLOW_DEPRECATED_RPC_METHOD 1
+#endif
+
+
+/*
+ * This inserts #pragma pack(1) and padding fields instead
+ * of using alignas on field members.
+ */
+#define FLATCC_CGEN_PAD 0
+
+
+/* ---- CGEN are flagss specific the C code generator. ---- */
+
+/*
+ * Generate support code for sorting arrays.
+ */
+#ifndef FLATCC_CGEN_SORT
+#define FLATCC_CGEN_SORT 1
+#endif
+
+/* Disable warnings for known compilers */
+#ifndef FLATCC_CGEN_PRAGMAS
+#define FLATCC_CGEN_PRAGMAS 1
+#endif
+
+/* Default spacing when generating auto idented code. */
+#ifndef FLATCC_CGEN_SPACING
+#define FLATCC_CGEN_SPACING 4
+#endif
+
+/*
+ * Field names risk conflict with other names when
+ * generated symbols do not all have a suffix.
+ * This can avoid by only generating accessors
+ * with the `_get` suffix, rather than both with
+ * and without like:
+ * `Monster_name(monster)`
+ * `Monster_name_get(monster)`.
+ *
+ * Note: test code might break if enabled.
+ */
+#ifndef FLATCC_CGEN_NO_CONFLICTS
+#define FLATCC_CGEN_NO_CONFLICTS 0
+#endif
+
+/* ---- BGEN are flags specific to the binary schema generator. ---- */
+
+/*
+ * If disabled, no binary schema support is compiled in.
+ * This may be useful when generection reflection headers
+ * are no longer compatible with the current build. Disabling
+ * reflection makes it possible to still build the compiler and
+ * thus generate new reflection headers.
+ *
+ * This flag is enabled by the build system so files can also be
+ * excluded or included.
+ *
+ * #ifndef FLATCC_REFLECTION
+ * #define FLATCC_REFLECTION 0
+ * #endif
+*/
+
+/* Export option for --schema. */
+#ifndef FLATCC_BGEN_BFBS
+#define FLATCC_BGEN_BFBS 0
+#endif
+
+/*
+ * Add uoffset length field before buffer. This is not a valid buffer
+ * then but can be used to outfileenate multiple files and it is
+ * compatible with the layout of nested buffers that have a similar
+ * prefix. The prefix is a uoffset_t field.
+ */
+#ifndef FLATCC_BGEN_LENGTH_PREFIX
+#define FLATCC_BGEN_LENGTH_PREFIX 0
+#endif
+
+/* Prefix type names with namespace during schema export.
+ * flatc does not include the namespace prefix. */
+#ifndef FLATCC_BGEN_QUALIFY_NAMES
+#define FLATCC_BGEN_QUALIFY_NAMES 1
+#endif
+
+
+/* ---- JSON related code generation. ---- */
+
+/*
+ * Translate enum values to symbolic names. Ditto union types.
+ * This is also a runtime option but disabling it here uses
+ * a faster code path.
+ */
+#ifndef FLATCC_JSON_PRINT_MAP_ENUMS
+#define FLATCC_JSON_PRINT_MAP_ENUMS 1
+#endif
+
+#endif /* CONFIG_H */