Mark globals as const (php#10303)

This moves them from ``.data`` to ``.rodata`` and allows more compiler optimizations.

* ext/opcache/zend_accelerator_hash: make prime_numbers const

* Zend/zend_signal: make zend_sigs const

* ext/dba: make dba_handler pointers const

* ext/exif: make php_tiff_bytes_per_format and other globals const

* ext/intl/grapheme: make grapheme_extract_iters const

* ext/mstring: make rare_codepoint_bitvec const

* ext/snmp: make objid_mib const

* ext/opcache: make all zend_shared_memory_handlers const

Author: MaxKellermann

Zend/zend_signal.c

@@ -71,7 +71,7 @@ static int zend_signal_register(int signo, void (*handler)(int, siginfo_t*, void
 #define TIMEOUT_SIG SIGPROF
 #endif
 
-static int zend_sigs[] = { TIMEOUT_SIG, SIGHUP, SIGINT, SIGQUIT, SIGTERM, SIGUSR1, SIGUSR2 };
+static const int zend_sigs[] = { TIMEOUT_SIG, SIGHUP, SIGINT, SIGQUIT, SIGTERM, SIGUSR1, SIGUSR2 };
 
 #define SA_FLAGS_MASK ~(SA_NODEFER | SA_RESETHAND)
 

ext/dba/dba.c

@@ -55,8 +55,8 @@ PHP_MSHUTDOWN_FUNCTION(dba);
 PHP_MINFO_FUNCTION(dba);
 
 ZEND_BEGIN_MODULE_GLOBALS(dba)
-	char *default_handler;
-	dba_handler *default_hptr;
+	const char *default_handler;
+	const dba_handler *default_hptr;
 ZEND_END_MODULE_GLOBALS(dba)
 
 ZEND_DECLARE_MODULE_GLOBALS(dba)
@@ -159,7 +159,7 @@ static zend_string* php_dba_make_key(HashTable *key)
 
 /* {{{ globals */
 
-static dba_handler handler[] = {
+static const dba_handler handler[] = {
 #ifdef DBA_GDBM
 	DBA_HND(gdbm, DBA_LOCK_EXT) /* Locking done in library if set */
 #endif
@@ -249,7 +249,7 @@ PHPAPI void dba_fetch_resource(dba_info **pinfo, zval **id)
 /* {{{ dba_get_handler
 PHPAPI dba_handler *dba_get_handler(const char* handler_name)
 {
-	dba_handler *hptr;
+	const dba_handler *hptr;
 	for (hptr = handler; hptr->name && strcasecmp(hptr->name, handler_name); hptr++);
 	return hptr;
 }
@@ -320,7 +320,7 @@ static void dba_close_pe_rsrc(zend_resource *rsrc)
 /* {{{ PHP_INI */
 ZEND_INI_MH(OnUpdateDefaultHandler)
 {
-	dba_handler *hptr;
+	const dba_handler *hptr;
 
 	if (!ZSTR_LEN(new_value)) {
 		DBA_G(default_hptr) = NULL;
@@ -377,7 +377,7 @@ PHP_MSHUTDOWN_FUNCTION(dba)
 /* {{{ PHP_MINFO_FUNCTION */
 PHP_MINFO_FUNCTION(dba)
 {
-	dba_handler *hptr;
+	const dba_handler *hptr;
 	smart_str handlers = {0};
 
 	for(hptr = handler; hptr->name; hptr++) {
@@ -461,7 +461,7 @@ static void php_dba_open(INTERNAL_FUNCTION_PARAMETERS, bool persistent)
 {
 	dba_mode_t modenr;
 	dba_info *info, *other;
-	dba_handler *hptr;
+	const dba_handler *hptr;
 	char *error = NULL;
 	int lock_mode, lock_flag = 0;
 	char *file_mode;
@@ -1165,7 +1165,7 @@ PHP_FUNCTION(dba_sync)
 /* {{{ List configured database handlers */
 PHP_FUNCTION(dba_handlers)
 {
-	dba_handler *hptr;
+	const dba_handler *hptr;
 	bool full_info = 0;
 
 	if (zend_parse_parameters(ZEND_NUM_ARGS(), "|b", &full_info) == FAILURE) {

ext/dba/php_dba.h

@@ -48,7 +48,7 @@ typedef struct dba_info {
 	zend_long driver_flags;
 	/* private */
 	int flags; /* whether and how dba did locking and other flags*/
-	struct dba_handler *hnd;
+	const struct dba_handler *hnd;
 	dba_lock lock;
 } dba_info;
 
@@ -85,7 +85,7 @@ typedef struct dba_handler {
 	zend_string* (*nextkey)(dba_info *);
 	zend_result (*optimize)(dba_info *);
 	zend_result (*sync)(dba_info *);
-	char* (*info)(struct dba_handler *hnd, dba_info *);
+	char* (*info)(const struct dba_handler *hnd, dba_info *);
 		/* dba_info==NULL: Handler info, dba_info!=NULL: Database info */
 } dba_handler;
 
@@ -112,7 +112,7 @@ typedef struct dba_handler {
 #define DBA_SYNC_FUNC(x) \
 	zend_result dba_sync_##x(dba_info *info)
 #define DBA_INFO_FUNC(x) \
-	char *dba_info_##x(dba_handler *hnd, dba_info *info)
+	char *dba_info_##x(const dba_handler *hnd, dba_info *info)
 
 #define DBA_FUNCS(x) \
 	DBA_OPEN_FUNC(x); \

ext/exif/exif.c

@@ -230,10 +230,10 @@ static size_t php_strnlen(char* str, size_t maxlen) {
 /* }}} */
 
 /* {{{ error messages */
-static const char * EXIF_ERROR_FILEEOF   = "Unexpected end of file reached";
-static const char * EXIF_ERROR_CORRUPT   = "File structure corrupted";
-static const char * EXIF_ERROR_THUMBEOF  = "Thumbnail goes IFD boundary or end of file reached";
-static const char * EXIF_ERROR_FSREALLOC = "Illegal reallocating of undefined file section";
+static const char *const EXIF_ERROR_FILEEOF   = "Unexpected end of file reached";
+static const char *const EXIF_ERROR_CORRUPT   = "File structure corrupted";
+static const char *const EXIF_ERROR_THUMBEOF  = "Thumbnail goes IFD boundary or end of file reached";
+static const char *const EXIF_ERROR_FSREALLOC = "Illegal reallocating of undefined file section";
 
 #define EXIF_ERRLOG_FILEEOF(ImageInfo)    exif_error_docref(NULL EXIFERR_CC, ImageInfo, E_WARNING, "%s", EXIF_ERROR_FILEEOF);
 #define EXIF_ERRLOG_CORRUPT(ImageInfo)    exif_error_docref(NULL EXIFERR_CC, ImageInfo, E_WARNING, "%s", EXIF_ERROR_CORRUPT);
@@ -244,7 +244,7 @@ static const char * EXIF_ERROR_FSREALLOC = "Illegal reallocating of undefined fi
 /* {{{ format description defines
    Describes format descriptor
 */
-static int php_tiff_bytes_per_format[] = {0, 1, 1, 2, 4, 8, 1, 1, 2, 4, 8, 4, 8, 1};
+static const int php_tiff_bytes_per_format[] = {0, 1, 1, 2, 4, 8, 1, 1, 2, 4, 8, 4, 8, 1};
 #define NUM_FORMATS 13
 
 #define TAG_FMT_BYTE       1

ext/intl/grapheme/grapheme_string.c

@@ -679,7 +679,7 @@ grapheme_extract_count_iter(UBreakIterator *bi, int32_t size, unsigned char *pst
 /* {{{ grapheme extract iter function pointer array */
 typedef int32_t (*grapheme_extract_iter)(UBreakIterator * /*bi*/, int32_t /*size*/, unsigned char * /*pstr*/, int32_t /*str_len*/);
 
-static grapheme_extract_iter grapheme_extract_iters[] = {
+static const grapheme_extract_iter grapheme_extract_iters[] = {
 	&grapheme_extract_count_iter,
 	&grapheme_extract_bytecount_iter,
 	&grapheme_extract_charcount_iter,

ext/mbstring/gen_rare_cp_bitvec.php

@@ -40,7 +40,7 @@
  * as less likely to be the correct one.
  */
 
-static uint32_t rare_codepoint_bitvec[] = {
+static const uint32_t rare_codepoint_bitvec[] = {
 HEADER;
 
 for ($i = 0; $i < 0xFFFF / 32; $i++) {

ext/mbstring/rare_cp_bitvec.h

@@ -9,7 +9,7 @@
  * as less likely to be the correct one.
  */
 
-static uint32_t rare_codepoint_bitvec[] = {
+static const uint32_t rare_codepoint_bitvec[] = {
 0xffffd9ff, 0x00000000, 0x00000000, 0x80000000, 0xffffffff, 0x00002001, 0x00000000, 0x00000000,
 0x70ff0f0f, 0xfffcffff, 0x70fcfe61, 0x81fc3fcc, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff,
 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff,

ext/opcache/shared_alloc_mmap.c

@@ -276,7 +276,7 @@ static size_t segment_type_size(void)
 	return sizeof(zend_shared_segment);
 }
 
-zend_shared_memory_handlers zend_alloc_mmap_handlers = {
+const zend_shared_memory_handlers zend_alloc_mmap_handlers = {
 	create_segments,
 	detach_segment,
 	segment_type_size

ext/opcache/shared_alloc_posix.c

@@ -89,7 +89,7 @@ static size_t segment_type_size(void)
 	return sizeof(zend_shared_segment_posix);
 }
 
-zend_shared_memory_handlers zend_alloc_posix_handlers = {
+const zend_shared_memory_handlers zend_alloc_posix_handlers = {
 	(create_segments_t)create_segments,
 	(detach_segment_t)detach_segment,
 	segment_type_size

ext/opcache/shared_alloc_shm.c

@@ -135,7 +135,7 @@ static size_t segment_type_size(void)
 	return sizeof(zend_shared_segment_shm);
 }
 
-zend_shared_memory_handlers zend_alloc_shm_handlers = {
+const zend_shared_memory_handlers zend_alloc_shm_handlers = {
 	(create_segments_t)create_segments,
 	(detach_segment_t)detach_segment,
 	segment_type_size

ext/opcache/shared_alloc_win32.c

@@ -352,7 +352,7 @@ static size_t segment_type_size(void)
 	return sizeof(zend_shared_segment);
 }
 
-zend_shared_memory_handlers zend_alloc_win32_handlers = {
+const zend_shared_memory_handlers zend_alloc_win32_handlers = {
 	create_segments,
 	detach_segment,
 	segment_type_size

ext/opcache/zend_accelerator_hash.c

@@ -25,9 +25,9 @@
 #include "zend_shared_alloc.h"
 
 /* Generated on an Octa-ALPHA 300MHz CPU & 2.5GB RAM monster */
-static uint32_t prime_numbers[] =
+static const uint32_t prime_numbers[] =
 	{5, 11, 19, 53, 107, 223, 463, 983, 1979, 3907, 7963, 16229, 32531, 65407, 130987, 262237, 524521, 1048793 };
-static uint32_t num_prime_numbers = sizeof(prime_numbers) / sizeof(uint32_t);
+static const uint32_t num_prime_numbers = sizeof(prime_numbers) / sizeof(uint32_t);
 
 void zend_accel_hash_clean(zend_accel_hash *accel_hash)
 {

ext/opcache/zend_shared_alloc.h

@@ -91,7 +91,7 @@ typedef struct {
 
 typedef struct _handler_entry {
 	const char                  *name;
-	zend_shared_memory_handlers *handler;
+	const zend_shared_memory_handlers *handler;
 } zend_shared_memory_handler_entry;
 
 typedef struct _zend_shared_memory_state {
@@ -197,19 +197,19 @@ const char *zend_accel_get_shared_model(void);
 void zend_accel_shared_protect(int mode);
 
 #ifdef USE_MMAP
-extern zend_shared_memory_handlers zend_alloc_mmap_handlers;
+extern const zend_shared_memory_handlers zend_alloc_mmap_handlers;
 #endif
 
 #ifdef USE_SHM
-extern zend_shared_memory_handlers zend_alloc_shm_handlers;
+extern const zend_shared_memory_handlers zend_alloc_shm_handlers;
 #endif
 
 #ifdef USE_SHM_OPEN
-extern zend_shared_memory_handlers zend_alloc_posix_handlers;
+extern const zend_shared_memory_handlers zend_alloc_posix_handlers;
 #endif
 
 #ifdef ZEND_WIN32
-extern zend_shared_memory_handlers zend_alloc_win32_handlers;
+extern const zend_shared_memory_handlers zend_alloc_win32_handlers;
 void zend_shared_alloc_create_lock(void);
 void zend_shared_alloc_lock_win32(void);
 void zend_shared_alloc_unlock_win32(void);

ext/snmp/snmp.c

@@ -91,7 +91,7 @@ ZEND_DECLARE_MODULE_GLOBALS(snmp)
 static PHP_GINIT_FUNCTION(snmp);
 
 /* constant - can be shared among threads */
-static oid objid_mib[] = {1, 3, 6, 1, 2, 1};
+static const oid objid_mib[] = {1, 3, 6, 1, 2, 1};
 
 /* Handlers */
 static zend_object_handlers php_snmp_object_handlers;
@@ -765,7 +765,7 @@ static bool php_snmp_parse_oid(
 				return false;
 			}
 		} else {
-			memmove((char *)objid_query->vars[0].name, (char *)objid_mib, sizeof(objid_mib));
+			memmove((char *)objid_query->vars[0].name, (const char *)objid_mib, sizeof(objid_mib));
 			objid_query->vars[0].name_length = sizeof(objid_mib) / sizeof(oid);
 		}
 	} else {