GCC Code Coverage Report

Directory: ./
File: firmware/ext/lua/lmem.c
Date: 2025-10-24 14:26:41
Coverage Exec Excl Total
Lines: 67.8% 40 0 59
Functions: 75.0% 6 0 8
Branches: 46.9% 15 0 32
Decisions: 39.1% 9 - 23
Line Branch Decision Exec Source
1 /*
2 ** $Id: lmem.c $
3 ** Interface to Memory Manager
4 ** See Copyright Notice in lua.h
5 */
6
7 #define lmem_c
8 #define LUA_CORE
9
10 #include "lprefix.h"
11
12
13 #include <stddef.h>
14
15 #include "lua.h"
16
17 #include "ldebug.h"
18 #include "ldo.h"
19 #include "lgc.h"
20 #include "lmem.h"
21 #include "lobject.h"
22 #include "lstate.h"
23
24
25
26 /*
27 ** About the realloc function:
28 ** void *frealloc (void *ud, void *ptr, size_t osize, size_t nsize);
29 ** ('osize' is the old size, 'nsize' is the new size)
30 **
31 ** - frealloc(ud, p, x, 0) frees the block 'p' and returns NULL.
32 ** Particularly, frealloc(ud, NULL, 0, 0) does nothing,
33 ** which is equivalent to free(NULL) in ISO C.
34 **
35 ** - frealloc(ud, NULL, x, s) creates a new block of size 's'
36 ** (no matter 'x'). Returns NULL if it cannot create the new block.
37 **
38 ** - otherwise, frealloc(ud, b, x, y) reallocates the block 'b' from
39 ** size 'x' to size 'y'. Returns NULL if it cannot reallocate the
40 ** block to the new size.
41 */
42
43
44 /*
45 ** Macro to call the allocation function.
46 */
47 #define callfrealloc(g,block,os,ns) ((*g->frealloc)(g->ud, block, os, ns))
48
49
50 /*
51 ** When an allocation fails, it will try again after an emergency
52 ** collection, except when it cannot run a collection. The GC should
53 ** not be called while the state is not fully built, as the collector
54 ** is not yet fully initialized. Also, it should not be called when
55 ** 'gcstopem' is true, because then the interpreter is in the middle of
56 ** a collection step.
57 */
58 #define cantryagain(g) (completestate(g) && !g->gcstopem)
59
60
61
62
63 #if defined(EMERGENCYGCTESTS)
64 /*
65 ** First allocation will fail except when freeing a block (frees never
66 ** fail) and when it cannot try again; this fail will trigger 'tryagain'
67 ** and a full GC cycle at every allocation.
68 */
69 static void *firsttry (global_State *g, void *block, size_t os, size_t ns) {
70 if (ns > 0 && cantryagain(g))
71 return NULL; /* fail */
72 else /* normal allocation */
73 return callfrealloc(g, block, os, ns);
74 }
75 #else
76 #define firsttry(g,block,os,ns) callfrealloc(g, block, os, ns)
77 #endif
78
79
80
81
82
83 /*
84 ** {==================================================================
85 ** Functions to allocate/deallocate arrays for the Parser
86 ** ===================================================================
87 */
88
89 /*
90 ** Minimum size for arrays during parsing, to avoid overhead of
91 ** reallocating to size 1, then 2, and then 4. All these arrays
92 ** will be reallocated to exact sizes or erased when parsing ends.
93 */
94 #define MINSIZEARRAY 4
95
96
97 20761 void *luaM_growaux_ (lua_State *L, void *block, int nelems, int *psize,
98 int size_elems, int limit, const char *what) {
99 void *newblock;
100 20761 int size = *psize;
101
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 20761 if (nelems + 1 <= size) /* does one extra element still fit? */
102 16380 return block; /* nothing to be done */
103
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 4381 if (size >= limit / 2) { /* cannot double it? */
104 ✗ if (l_unlikely(size >= limit)) /* cannot grow even a little? */
105 ✗ luaG_runerror(L, "too many %s (limit is %d)", what, limit);
106 ✗ size = limit; /* still have at least one free place */
107 }
108 else {
109 4381 size *= 2;
110
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 4381 if (size < MINSIZEARRAY)
111 2291 size = MINSIZEARRAY; /* minimum size */
112 }
113 lua_assert(nelems + 1 <= size && size <= limit);
114 /* 'limit' ensures that multiplication will not overflow */
115 4381 newblock = luaM_saferealloc_(L, block, cast_sizet(*psize) * size_elems,
116 4381 cast_sizet(size) * size_elems);
117 4381 *psize = size; /* update only when everything else is OK */
118 4381 return newblock;
119 }
120
121
122 /*
123 ** In prototypes, the size of the array is also its number of
124 ** elements (to save memory). So, if it cannot shrink an array
125 ** to its number of elements, the only option is to raise an
126 ** error.
127 */
128 3577 void *luaM_shrinkvector_ (lua_State *L, void *block, int *size,
129 int final_n, int size_elem) {
130 void *newblock;
131 3577 size_t oldsize = cast_sizet((*size) * size_elem);
132 3577 size_t newsize = cast_sizet(final_n * size_elem);
133 lua_assert(newsize <= oldsize);
134 3577 newblock = luaM_saferealloc_(L, block, oldsize, newsize);
135 3577 *size = final_n;
136 3577 return newblock;
137 }
138
139 /* }================================================================== */
140
141
142 ✗ l_noret luaM_toobig (lua_State *L) {
143 ✗ luaG_runerror(L, "memory allocation error: block too big");
144 }
145
146
147 /*
148 ** Free memory
149 */
150 97570 void luaM_free_ (lua_State *L, void *block, size_t osize) {
151 97570 global_State *g = G(L);
152 lua_assert((osize == 0) == (block == NULL));
153 97570 callfrealloc(g, block, osize, 0);
154 97570 g->GCdebt -= osize;
155 97570 }
156
157
158 /*
159 ** In case of allocation fail, this function will do an emergency
160 ** collection to free some memory and then try the allocation again.
161 */
162 ✗ static void *tryagain (lua_State *L, void *block,
163 size_t osize, size_t nsize) {
164 ✗ global_State *g = G(L);
165 ✗ if (cantryagain(g)) {
166 ✗ luaC_fullgc(L, 1); /* try to free some memory... */
167 ✗ return callfrealloc(g, block, osize, nsize); /* try again */
168 }
169 ✗ else return NULL; /* cannot run an emergency collection */
170 }
171
172
173 /*
174 ** Generic allocation routine.
175 */
176 23299 void *luaM_realloc_ (lua_State *L, void *block, size_t osize, size_t nsize) {
177 void *newblock;
178 23299 global_State *g = G(L);
179 lua_assert((osize == 0) == (block == NULL));
180 23299 newblock = firsttry(g, block, osize, nsize);
181
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 23299 if (l_unlikely(newblock == NULL && nsize > 0)) {
182 ✗ newblock = tryagain(L, block, osize, nsize);
183 ✗ if (newblock == NULL) /* still no memory? */
184 ✗ return NULL; /* do not update 'GCdebt' */
185 }
186 lua_assert((nsize == 0) == (newblock == NULL));
187 23299 g->GCdebt = (g->GCdebt + nsize) - osize;
188 23299 return newblock;
189 }
190
191
192 8552 void *luaM_saferealloc_ (lua_State *L, void *block, size_t osize,
193 size_t nsize) {
194 8552 void *newblock = luaM_realloc_(L, block, osize, nsize);
195
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 8552 if (l_unlikely(newblock == NULL && nsize > 0)) /* allocation failed? */
196 ✗ luaM_error(L);
197 8552 return newblock;
198 }
199
200
201 86158 void *luaM_malloc_ (lua_State *L, size_t size, int tag) {
202
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 86158 if (size == 0)
203 ✗ return NULL; /* that's all */
204 else {
205 86158 global_State *g = G(L);
206 86158 void *newblock = firsttry(g, NULL, tag, size);
207
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 86158 if (l_unlikely(newblock == NULL)) {
208 ✗ newblock = tryagain(L, NULL, tag, size);
209 ✗ if (newblock == NULL)
210 ✗ luaM_error(L);
211 }
212 86158 g->GCdebt += size;
213 86158 return newblock;
214 }
215 }
216