1/* @ajax/wasm-module: a decoded module (what @ajax/wasm-decode produces, @ajax/wasm-validate checks
2 * and @ajax/wasm-interp runs). Everything points into the binary it came from, which must outlive
3 * the module; only the arrays are owned. Index spaces put imports first, as the spec does. */
4#ifndef WASM_MODULE_H
5#define WASM_MODULE_H
6
7#include "wasm/types.h"
8
9#include <stdbool.h>
10#include <stddef.h>
11#include <stdint.h>
12
13typedef struct {
14    uint32_t nparams, nresults;
15    const wasm_valtype *params;  /* into the binary */
16    const wasm_valtype *results; /* into the binary */
17} wasm_functype;
18
19typedef struct {
20    uint64_t min, max; /* max only when flags has WASM_LIMITS_HAS_MAX */
21    uint8_t flags;
22} wasm_limits;
23
24typedef struct {
25    wasm_valtype elem;
26    wasm_limits limits;
27} wasm_tabletype;
28
29typedef struct {
30    wasm_valtype type;
31    bool mut;
32} wasm_globaltype;
33
34/* A constant expression or a function body: bytes up to and including its final `end`. */
35typedef struct {
36    const uint8_t *start;
37    size_t len;
38    size_t offset; /* of start in the binary */
39} wasm_expr;
40
41typedef struct {
42    const uint8_t *module, *name; /* UTF-8, not NUL-terminated */
43    uint32_t module_len, name_len;
44    uint8_t kind; /* WASM_EXTERN_* */
45    uint32_t func_type;
46    wasm_tabletype table;
47    wasm_limits mem;
48    wasm_globaltype global;
49} wasm_import;
50
51typedef struct {
52    const uint8_t *name;
53    uint32_t name_len;
54    uint8_t kind;
55    uint32_t index;
56} wasm_export;
57
58enum { WASM_SEG_ACTIVE, WASM_SEG_PASSIVE, WASM_SEG_DECLARATIVE };
59
60typedef struct {
61    uint8_t mode;
62    uint32_t table;
63    wasm_expr offset;   /* active only */
64    wasm_valtype type;  /* WASM_FUNCREF or WASM_EXTERNREF */
65    uint32_t count;
66    uint32_t *funcs;    /* function indices (flags 0-3), or NULL */
67    wasm_expr *exprs;   /* element expressions (flags 4-7), or NULL */
68    size_t offset_in_binary;
69} wasm_elem;
70
71typedef struct {
72    uint8_t mode; /* active or passive */
73    uint32_t mem;
74    wasm_expr offset;
75    const uint8_t *bytes;
76    uint32_t len;
77    size_t offset_in_binary;
78} wasm_data;
79
80typedef struct {
81    uint32_t count;
82    wasm_valtype type;
83} wasm_localgroup;
84
85typedef struct {
86    wasm_localgroup *locals;
87    uint32_t nlocal_groups;
88    uint64_t nlocals; /* declared locals, parameters not included */
89    wasm_expr body;   /* the instructions after the local declarations */
90    size_t offset;    /* of the entry (its size field) in the binary */
91} wasm_code;
92
93typedef struct wasm_module {
94    const uint8_t *bytes;
95    size_t len;
96    wasm_functype *types;
97    uint32_t ntypes;
98    wasm_import *imports;
99    uint32_t nimports;
100    uint32_t *funcs; /* type index of every function, imports first */
101    uint32_t nfuncs, nfunc_imports;
102    wasm_tabletype *tables;
103    uint32_t ntables, ntable_imports;
104    wasm_limits *mems;
105    uint32_t nmems, nmem_imports;
106    wasm_globaltype *globals;
107    uint32_t nglobals, nglobal_imports;
108    wasm_expr *global_inits; /* defined globals only: global i's at [i - nglobal_imports] */
109    wasm_export *exports;
110    uint32_t nexports;
111    bool has_start;
112    uint32_t start;
113    wasm_elem *elems;
114    uint32_t nelems;
115    bool has_datacount;
116    uint32_t datacount;
117    wasm_code *codes; /* defined functions: function i's at [i - nfunc_imports] */
118    uint32_t ncodes;
119    wasm_data *datas;
120    uint32_t ndatas;
121    /* Offsets of the code section's start, for messages. */
122    size_t code_section_offset;
123} wasm_module;
124
125/* Frees the arrays (not the binary). Safe on a zeroed or partly decoded module. */
126void wasm_module_free(wasm_module *m);
127
128/* The type of function f (imports first). */
129static inline const wasm_functype *wasm_func_type(const wasm_module *m, uint32_t f) { return &m->types[m->funcs[f]]; }
130
131/* The export named name of kind, or NULL. */
132const wasm_export *wasm_module_export(const wasm_module *m, const char *name, uint8_t kind);
133
134#endif