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authorAlan Coopersmith <alan.coopersmith@oracle.com>2013-08-16 21:55:27 -0700
committerAlan Coopersmith <alan.coopersmith@oracle.com>2013-08-16 22:02:39 -0700
commit95ee49d90c28b15a3c3be54a233368fc69f3531a (patch)
tree59378ad229779805f13400a460e64d310f1f84bc
parentdb07706cb268d5fe1bc38ef5c0a9f49309068b2c (diff)
Add comments about sizes of dynamically allocated arrays
Many arrays have sz_* or size_* fields to list the number of entries allocated, and num_* fields to record the number of entries used. Others use num_* for the number allocated, or size based on max_key_code. And a few are just plain trying to mess with your head. (I'm looking at you XkbNamesRec & XkbKeyTypeRec.) It sure would have been nice if all the XKB authors could have picked a single convention and stuck to it, but we're 20 years too late for that now, so just document it so I can stop reverse engineering from the code every time I need to see if we got a bounds check right or not. Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
-rw-r--r--XKBgeom.h5
-rw-r--r--XKBstr.h21
2 files changed, 26 insertions, 0 deletions
diff --git a/XKBgeom.h b/XKBgeom.h
index f603852..cef78fa 100644
--- a/XKBgeom.h
+++ b/XKBgeom.h
@@ -95,6 +95,11 @@ typedef struct _XkbBounds {
#define XkbBoundsWidth(b) (((b)->x2)-((b)->x1))
#define XkbBoundsHeight(b) (((b)->y2)-((b)->y1))
+/*
+ * In the following structs, this pattern is used for dynamically sized arrays:
+ * foo is an array for which sz_foo entries are allocated & num_foo are used
+ */
+
typedef struct _XkbOutline {
unsigned short num_points;
unsigned short sz_points;
diff --git a/XKBstr.h b/XKBstr.h
index 25c0cec..1146908 100644
--- a/XKBstr.h
+++ b/XKBstr.h
@@ -92,9 +92,12 @@ typedef struct _XkbKeyType {
XkbModsRec mods;
unsigned char num_levels;
unsigned char map_count;
+ /* map is an array of map_count XkbKTMapEntryRec structs */
XkbKTMapEntryPtr map;
+ /* preserve is an array of map_count XkbModsRec structs */
XkbModsPtr preserve;
Atom name;
+ /* level_names is an array of num_levels Atoms */
Atom * level_names;
} XkbKeyTypeRec, *XkbKeyTypePtr;
@@ -298,10 +301,14 @@ typedef struct _XkbControls {
#define XkbAX_NeedFeedback(c,w) (XkbAX_AnyFeedback(c)&&XkbAX_NeedOption(c,w))
typedef struct _XkbServerMapRec {
+ /* acts is an array of XkbActions structs, with size_acts entries
+ allocated, and num_acts entries used. */
unsigned short num_acts;
unsigned short size_acts;
XkbAction *acts;
+ /* behaviors, key_acts, explicit, & vmodmap are all arrays with
+ (xkb->max_key_code + 1) entries allocated for each. */
XkbBehavior *behaviors;
unsigned short *key_acts;
#if defined(__cplusplus) || defined(c_plusplus)
@@ -328,15 +335,20 @@ typedef struct _XkbSymMapRec {
} XkbSymMapRec, *XkbSymMapPtr;
typedef struct _XkbClientMapRec {
+ /* types is an array of XkbKeyTypeRec structs, with size_types entries
+ allocated, and num_types entries used. */
unsigned char size_types;
unsigned char num_types;
XkbKeyTypePtr types;
+ /* syms is an array of size_syms KeySyms, in which num_syms are used */
unsigned short size_syms;
unsigned short num_syms;
KeySym *syms;
+ /* key_sym_map is an array of (max_key_code + 1) XkbSymMapRec structs */
XkbSymMapPtr key_sym_map;
+ /* modmap is an array of (max_key_code + 1) unsigned chars */
unsigned char *modmap;
} XkbClientMapRec, *XkbClientMapPtr;
@@ -364,6 +376,8 @@ typedef struct _XkbSymInterpretRec {
} XkbSymInterpretRec,*XkbSymInterpretPtr;
typedef struct _XkbCompatMapRec {
+ /* sym_interpret is an array of XkbSymInterpretRec structs,
+ in which size_si are allocated & num_si are used. */
XkbSymInterpretPtr sym_interpret;
XkbModsRec groups[XkbNumKbdGroups];
unsigned short num_si;
@@ -413,11 +427,15 @@ typedef struct _XkbNamesRec {
Atom vmods[XkbNumVirtualMods];
Atom indicators[XkbNumIndicators];
Atom groups[XkbNumKbdGroups];
+ /* keys is an array of (xkb->max_key_code + 1) XkbKeyNameRec entries */
XkbKeyNamePtr keys;
+ /* key_aliases is an array of num_key_aliases XkbKeyAliasRec entries */
XkbKeyAliasPtr key_aliases;
+ /* radio_groups is an array of num_rg Atoms */
Atom *radio_groups;
Atom phys_symbols;
+ /* num_keys seems to be unused in libX11 */
unsigned char num_keys;
unsigned char num_key_aliases;
unsigned short num_rg;
@@ -592,6 +610,7 @@ typedef struct _XkbDeviceInfo {
unsigned short supported;
unsigned short unsupported;
+ /* btn_acts is an array of num_btn XkbAction entries */
unsigned short num_btns;
XkbAction * btn_acts;
@@ -599,6 +618,8 @@ typedef struct _XkbDeviceInfo {
unsigned short num_leds;
unsigned short dflt_kbd_fb;
unsigned short dflt_led_fb;
+ /* leds is an array of XkbDeviceLedInfoRec in which
+ sz_leds entries are allocated and num_leds entries are used */
XkbDeviceLedInfoPtr leds;
} XkbDeviceInfoRec,*XkbDeviceInfoPtr;