From 6acaaac7692561c19a544c505d79917d7ecad70f Mon Sep 17 00:00:00 2001
From: David Anderson <dvander@alliedmods.net>
Date: Fri, 15 Jun 2007 20:23:40 +0000
Subject: [PATCH] added a hacky way to get NULL references

--HG--
extra : convert_revision : svn%3A39bc706e-5318-0410-9160-8a85361fbb7c/trunk%40944
---
 core/sourcemod.cpp            |  3 ++-
 core/vm/sp_vm_basecontext.cpp | 21 +++++++++++++++++++++
 core/vm/sp_vm_basecontext.h   |  2 ++
 plugins/include/core.inc      | 10 ++++++----
 public/sourcepawn/sp_vm_api.h | 21 ++++++++++++++++++++-
 5 files changed, 51 insertions(+), 6 deletions(-)

diff --git a/core/sourcemod.cpp b/core/sourcemod.cpp
index d21467a5..2544bde1 100644
--- a/core/sourcemod.cpp
+++ b/core/sourcemod.cpp
@@ -200,7 +200,8 @@ bool SourceModBase::InitializeSourceMod(char *error, size_t maxlength, bool late
 	}
 
 	unsigned int api = g_pVM->GetAPIVersion();
-	if (api != SOURCEPAWN_VM_API_VERSION)
+	/* :TODO: clean this up (see amb398) */
+	if (api > SOURCEPAWN_VM_API_VERSION || api < 2)
 	{
 		ShutdownJIT();
 		if (error && maxlength)
diff --git a/core/vm/sp_vm_basecontext.cpp b/core/vm/sp_vm_basecontext.cpp
index dbd4f07a..da987ed5 100644
--- a/core/vm/sp_vm_basecontext.cpp
+++ b/core/vm/sp_vm_basecontext.cpp
@@ -72,6 +72,17 @@ BaseContext::BaseContext(sp_context_t *_ctx)
 	} else {
 		m_pub_funcs = NULL;
 	}
+
+	/* Initialize the null references */
+	uint32_t index;
+	if (FindPubvarByName("NULL_VECTOR", &index) == SP_ERROR_NONE)
+	{
+		sp_pubvar_t *pubvar;
+		GetPubvarByIndex(index, &pubvar);
+		m_pNullVec = pubvar->offs;
+	} else {
+		m_pNullVec = NULL;
+	}
 }
 
 void BaseContext::FlushFunctionCache()
@@ -991,4 +1002,14 @@ void BaseContext::SetIdentity(SourceMod::IdentityToken_t *token)
 {
 	m_pToken = token;
 }
+
+cell_t *BaseContext::GetNullRef(SP_NULL_TYPE type)
+{
+	if (type == SP_NULL_VECTOR)
+	{
+		return m_pNullVec;
+	}
+
+	return NULL;
+}
 #endif
diff --git a/core/vm/sp_vm_basecontext.h b/core/vm/sp_vm_basecontext.h
index 15977543..938b9f55 100644
--- a/core/vm/sp_vm_basecontext.h
+++ b/core/vm/sp_vm_basecontext.h
@@ -69,6 +69,7 @@ namespace SourcePawn
 #if defined SOURCEMOD_BUILD
 		SourceMod::IdentityToken_t *GetIdentity();
 		void SetIdentity(SourceMod::IdentityToken_t *token);
+		cell_t *GetNullRef(SP_NULL_TYPE type);
 #endif
 	public: //IPluginDebugInfo
 		int LookupFile(ucell_t addr, const char **filename);
@@ -84,6 +85,7 @@ namespace SourcePawn
 		sp_context_t *ctx;
 #if defined SOURCEMOD_BUILD
 		SourceMod::IdentityToken_t *m_pToken;
+		cell_t *m_pNullVec;
 #endif
 		char m_MsgCache[1024];
 		bool m_CustomMsg;
diff --git a/plugins/include/core.inc b/plugins/include/core.inc
index 5fd5634a..4e56a03f 100644
--- a/plugins/include/core.inc
+++ b/plugins/include/core.inc
@@ -85,11 +85,13 @@ enum PluginInfo
  */
 struct Extension
 {
-	const String:name[],	/* Short name */
-	const String:file[],	/* Default file name */
-	bool:autoload,			/* Whether or not to auto-load */
-	bool:required,			/* Whether or not to require */
+	const String:name[],	/**< Short name */
+	const String:file[],	/**< Default file name */
+	bool:autoload,			/**< Whether or not to auto-load */
+	bool:required,			/**< Whether or not to require */
 };
 
+public Float:NULL_VECTOR[3];	/**< Pass this into certain functions to act as a C++ NULL */
+
 #define AUTOLOAD_EXTENSIONS
 #define REQUIRE_EXTENSIONS
diff --git a/public/sourcepawn/sp_vm_api.h b/public/sourcepawn/sp_vm_api.h
index f4da9310..66584910 100644
--- a/public/sourcepawn/sp_vm_api.h
+++ b/public/sourcepawn/sp_vm_api.h
@@ -28,7 +28,7 @@
 #include "sp_vm_types.h"
 
 /** SourcePawn VM API Version */
-#define SOURCEPAWN_VM_API_VERSION		2
+#define SOURCEPAWN_VM_API_VERSION		3
 
 #if !defined SOURCEMOD_BUILD
 #define SOURCEMOD_BUILD
@@ -49,6 +49,16 @@ namespace SourcePawn
 	#define SM_PARAM_STRING_UTF8	(1<<0)		/**< String should be UTF-8 handled */
 	#define SM_PARAM_STRING_COPY	(1<<1)		/**< String should be copied into the plugin */
 
+#if defined SOURCEMOD_BUILD
+	/**
+	 * @brief Pseudo-NULL reference types.
+	 */
+	enum SP_NULL_TYPE
+	{
+		SP_NULL_VECTOR = 0,		/**< Float[3] reference */
+	};
+#endif
+
 	/**
 	 * @brief Represents what a function needs to implement in order to be callable.
 	 */
@@ -536,6 +546,15 @@ namespace SourcePawn
 		 * @return			Identity token.
 		 */
 		virtual SourceMod::IdentityToken_t *GetIdentity() =0;
+
+		/**
+		 * @brief Returns a NULL reference based on one of the available NULL
+		 * reference types.
+		 *
+		 * @param type		NULL reference type.
+		 * @return			cell_t address to compare to.
+		 */
+		virtual cell_t *GetNullRef(SP_NULL_TYPE type) =0;
 #endif
 	};