hla: Provide a directly property based api for property data element.

[simgear.git] / simgear / nasal / nasal.h

diff --git a/simgear/nasal/nasal.h b/simgear/nasal/nasal.h
index 29f2baabaa8d6550031e6160c3a08a8189fc69ae..a7741b49639657de8885d62ebe612856b90876d7 100644 (file)
--- a/simgear/nasal/nasal.h
+++ b/simgear/nasal/nasal.h
@@ -6,6 +6,15 @@ extern "C" {
 
 #include "naref.h"
 
+#if __GNUC__ > 2
+/* This marks the function as having no side effects and depending on
+ * nothing but its arguments, which allows the optimizer to avoid
+ * duplicate calls to naNil(). */
+#define GCC_PURE __attribute__((__pure__))
+#else
+#define GCC_PURE
+#endif
+
 typedef struct Context* naContext;
     
 // The function signature for an extension function:
@@ -27,7 +36,7 @@ naContext naSubContext(naContext super);
 // provision for sharing it, nor for validating the source or type of
 // the pointer returned.
 void naSetUserData(naContext c, void* p);
-void* naGetUserData(naContext c);
+void* naGetUserData(naContext c) GCC_PURE;
 
 // "Save" this object in the context, preventing it (and objects
 // referenced by it) from being garbage collected.
@@ -117,19 +126,19 @@ naRef naGetSourceFile(naContext ctx, int frame);
 char* naGetError(naContext ctx);
 
 // Type predicates
-int naIsNil(naRef r);
-int naIsNum(naRef r);
-int naIsString(naRef r);
-int naIsScalar(naRef r);
-int naIsVector(naRef r);
-int naIsHash(naRef r);
-int naIsCode(naRef r);
-int naIsFunc(naRef r);
-int naIsCCode(naRef r);
+int naIsNil(naRef r) GCC_PURE;
+int naIsNum(naRef r) GCC_PURE;
+int naIsString(naRef r) GCC_PURE;
+int naIsScalar(naRef r) GCC_PURE;
+int naIsVector(naRef r) GCC_PURE;
+int naIsHash(naRef r) GCC_PURE;
+int naIsCode(naRef r) GCC_PURE;
+int naIsFunc(naRef r) GCC_PURE;
+int naIsCCode(naRef r) GCC_PURE;
 
 // Allocators/generators:
-naRef naNil();
-naRef naNum(double num);
+naRef naNil() GCC_PURE;
+naRef naNum(double num) GCC_PURE;
 naRef naNewString(naContext c);
 naRef naNewVector(naContext c);
 naRef naNewHash(naContext c);
@@ -137,16 +146,16 @@ naRef naNewFunc(naContext c, naRef code);
 naRef naNewCCode(naContext c, naCFunction fptr);
 
 // Some useful conversion/comparison routines
-int naEqual(naRef a, naRef b);
-int naStrEqual(naRef a, naRef b);
-int naTrue(naRef b);
-naRef naNumValue(naRef n);
+int naEqual(naRef a, naRef b) GCC_PURE;
+int naStrEqual(naRef a, naRef b) GCC_PURE;
+int naTrue(naRef b) GCC_PURE;
+naRef naNumValue(naRef n) GCC_PURE;
 naRef naStringValue(naContext c, naRef n);
 
 // String utilities:
-int naStr_len(naRef s);
-char* naStr_data(naRef s);
-naRef naStr_fromdata(naRef dst, char* data, int len);
+int naStr_len(naRef s) GCC_PURE;
+char* naStr_data(naRef s) GCC_PURE;
+naRef naStr_fromdata(naRef dst, const char* data, int len);
 naRef naStr_concat(naRef dest, naRef s1, naRef s2);
 naRef naStr_substr(naRef dest, naRef str, int start, int len);
 naRef naInternSymbol(naRef sym);
@@ -170,7 +179,7 @@ void naHash_keys(naRef dst, naRef hash);
 
 // Ghost utilities:
 typedef struct naGhostType {
-    void (*destroy)(void* ghost);
+    void(*destroy)(void*);
     const char* name;
 } naGhostType;
 naRef        naNewGhost(naContext c, naGhostType* t, void* ghost);
@@ -180,16 +189,16 @@ int          naIsGhost(naRef r);
 
 // Acquires a "modification lock" on a context, allowing the C code to
 // modify Nasal data without fear that such data may be "lost" by the
-// garbage collector (nasal data the C stack is not examined in GC!).
-// This disallows garbage collection until the current thread can be
-// blocked.  The lock should be acquired whenever nasal objects are
-// being modified.  It need not be acquired when only read access is
-// needed, PRESUMING that the Nasal data being read is findable by the
-// collector (via naSave, for example) and that another Nasal thread
-// cannot or will not delete the reference to the data.  It MUST NOT
-// be acquired by naCFunction's, as those are called with the lock
-// already held; acquiring two locks for the same thread will cause a
-// deadlock when the GC is invoked.  It should be UNLOCKED by
+// garbage collector (nasal data on the C stack is not examined in
+// GC!).  This disallows garbage collection until the current thread
+// can be blocked.  The lock should be acquired whenever nasal objects
+// are being modified.  It need not be acquired when only read access
+// is needed, PRESUMING that the Nasal data being read is findable by
+// the collector (via naSave, for example) and that another Nasal
+// thread cannot or will not delete the reference to the data.  It
+// MUST NOT be acquired by naCFunction's, as those are called with the
+// lock already held; acquiring two locks for the same thread will
+// cause a deadlock when the GC is invoked.  It should be UNLOCKED by
 // naCFunction's when they are about to do any long term non-nasal
 // processing and/or blocking I/O.  Note that naModLock() may need to
 // block to allow garbage collection to occur, and that garbage