Use go-pointer instead of uintptr hacks. (#814)

* Use go-pointer instead of uintptr hacks.

Fixes #791

* Do same of go-pointer

* Drop older verion of Go

* Fix build

* Fix build

3 files changed, 47 insertions, 53 deletions

diff --git a/callback.go b/callback.go
index 6450575..c3ce752 100644
--- a/callback.go
+++ b/callback.go
@@ -35,56 +35,55 @@ import (
 //export callbackTrampoline
 func callbackTrampoline(ctx *C.sqlite3_context, argc int, argv **C.sqlite3_value) {
 	args := (*[(math.MaxInt32 - 1) / unsafe.Sizeof((*C.sqlite3_value)(nil))]*C.sqlite3_value)(unsafe.Pointer(argv))[:argc:argc]
-	fi := lookupHandle(uintptr(C.sqlite3_user_data(ctx))).(*functionInfo)
+	fi := lookupHandle(C.sqlite3_user_data(ctx)).(*functionInfo)
 	fi.Call(ctx, args)
 }
 
 //export stepTrampoline
 func stepTrampoline(ctx *C.sqlite3_context, argc C.int, argv **C.sqlite3_value) {
 	args := (*[(math.MaxInt32 - 1) / unsafe.Sizeof((*C.sqlite3_value)(nil))]*C.sqlite3_value)(unsafe.Pointer(argv))[:int(argc):int(argc)]
-	ai := lookupHandle(uintptr(C.sqlite3_user_data(ctx))).(*aggInfo)
+	ai := lookupHandle(C.sqlite3_user_data(ctx)).(*aggInfo)
 	ai.Step(ctx, args)
 }
 
 //export doneTrampoline
 func doneTrampoline(ctx *C.sqlite3_context) {
-	handle := uintptr(C.sqlite3_user_data(ctx))
-	ai := lookupHandle(handle).(*aggInfo)
+	ai := lookupHandle(C.sqlite3_user_data(ctx)).(*aggInfo)
 	ai.Done(ctx)
 }
 
 //export compareTrampoline
-func compareTrampoline(handlePtr uintptr, la C.int, a *C.char, lb C.int, b *C.char) C.int {
+func compareTrampoline(handlePtr unsafe.Pointer, la C.int, a *C.char, lb C.int, b *C.char) C.int {
 	cmp := lookupHandle(handlePtr).(func(string, string) int)
 	return C.int(cmp(C.GoStringN(a, la), C.GoStringN(b, lb)))
 }
 
 //export commitHookTrampoline
-func commitHookTrampoline(handle uintptr) int {
+func commitHookTrampoline(handle unsafe.Pointer) int {
 	callback := lookupHandle(handle).(func() int)
 	return callback()
 }
 
 //export rollbackHookTrampoline
-func rollbackHookTrampoline(handle uintptr) {
+func rollbackHookTrampoline(handle unsafe.Pointer) {
 	callback := lookupHandle(handle).(func())
 	callback()
 }
 
 //export updateHookTrampoline
-func updateHookTrampoline(handle uintptr, op int, db *C.char, table *C.char, rowid int64) {
+func updateHookTrampoline(handle unsafe.Pointer, op int, db *C.char, table *C.char, rowid int64) {
 	callback := lookupHandle(handle).(func(int, string, string, int64))
 	callback(op, C.GoString(db), C.GoString(table), rowid)
 }
 
 //export authorizerTrampoline
-func authorizerTrampoline(handle uintptr, op int, arg1 *C.char, arg2 *C.char, arg3 *C.char) int {
+func authorizerTrampoline(handle unsafe.Pointer, op int, arg1 *C.char, arg2 *C.char, arg3 *C.char) int {
 	callback := lookupHandle(handle).(func(int, string, string, string) int)
 	return callback(op, C.GoString(arg1), C.GoString(arg2), C.GoString(arg3))
 }
 
 //export preUpdateHookTrampoline
-func preUpdateHookTrampoline(handle uintptr, dbHandle uintptr, op int, db *C.char, table *C.char, oldrowid int64, newrowid int64) {
+func preUpdateHookTrampoline(handle unsafe.Pointer, dbHandle uintptr, op int, db *C.char, table *C.char, oldrowid int64, newrowid int64) {
 	hval := lookupHandleVal(handle)
 	data := SQLitePreUpdateData{
 		Conn:         hval.db,
@@ -105,33 +104,27 @@ type handleVal struct {
 }
 
 var handleLock sync.Mutex
-var handleVals = make(map[uintptr]handleVal)
-var handleIndex uintptr = 100
+var handleVals = make(map[unsafe.Pointer]handleVal)
 
-func newHandle(db *SQLiteConn, v interface{}) uintptr {
+func newHandle(db *SQLiteConn, v interface{}) unsafe.Pointer {
 	handleLock.Lock()
 	defer handleLock.Unlock()
-	i := handleIndex
-	handleIndex++
-	handleVals[i] = handleVal{db, v}
-	return i
+	val := handleVal{db: db, val: v}
+	var p unsafe.Pointer = C.malloc(C.size_t(1))
+	if p == nil {
+		panic("can't allocate 'cgo-pointer hack index pointer': ptr == nil")
+	}
+	handleVals[p] = val
+	return p
 }
 
-func lookupHandleVal(handle uintptr) handleVal {
+func lookupHandleVal(handle unsafe.Pointer) handleVal {
 	handleLock.Lock()
 	defer handleLock.Unlock()
-	r, ok := handleVals[handle]
-	if !ok {
-		if handle >= 100 && handle < handleIndex {
-			panic("deleted handle")
-		} else {
-			panic("invalid handle")
-		}
-	}
-	return r
+	return handleVals[handle]
 }
 
-func lookupHandle(handle uintptr) interface{} {
+func lookupHandle(handle unsafe.Pointer) interface{} {
 	return lookupHandleVal(handle).val
 }
 
@@ -141,6 +134,7 @@ func deleteHandles(db *SQLiteConn) {
 	for handle, val := range handleVals {
 		if val.db == db {
 			delete(handleVals, handle)
+			C.free(handle)
 		}
 	}
 }
diff --git a/sqlite3.go b/sqlite3.go
index 86c0f64..ababcfd 100644
--- a/sqlite3.go
+++ b/sqlite3.go
@@ -473,7 +473,7 @@ func (c *SQLiteConn) RegisterCollation(name string, cmp func(string, string) int
 	handle := newHandle(c, cmp)
 	cname := C.CString(name)
 	defer C.free(unsafe.Pointer(cname))
-	rv := C.sqlite3_create_collation(c.db, cname, C.SQLITE_UTF8, unsafe.Pointer(handle), (*[0]byte)(unsafe.Pointer(C.compareTrampoline)))
+	rv := C.sqlite3_create_collation(c.db, cname, C.SQLITE_UTF8, handle, (*[0]byte)(unsafe.Pointer(C.compareTrampoline)))
 	if rv != C.SQLITE_OK {
 		return c.lastError()
 	}
@@ -491,7 +491,7 @@ func (c *SQLiteConn) RegisterCommitHook(callback func() int) {
 	if callback == nil {
 		C.sqlite3_commit_hook(c.db, nil, nil)
 	} else {
-		C.sqlite3_commit_hook(c.db, (*[0]byte)(C.commitHookTrampoline), unsafe.Pointer(newHandle(c, callback)))
+		C.sqlite3_commit_hook(c.db, (*[0]byte)(C.commitHookTrampoline), newHandle(c, callback))
 	}
 }
 
@@ -504,7 +504,7 @@ func (c *SQLiteConn) RegisterRollbackHook(callback func()) {
 	if callback == nil {
 		C.sqlite3_rollback_hook(c.db, nil, nil)
 	} else {
-		C.sqlite3_rollback_hook(c.db, (*[0]byte)(C.rollbackHookTrampoline), unsafe.Pointer(newHandle(c, callback)))
+		C.sqlite3_rollback_hook(c.db, (*[0]byte)(C.rollbackHookTrampoline), newHandle(c, callback))
 	}
 }
 
@@ -521,7 +521,7 @@ func (c *SQLiteConn) RegisterUpdateHook(callback func(int, string, string, int64
 	if callback == nil {
 		C.sqlite3_update_hook(c.db, nil, nil)
 	} else {
-		C.sqlite3_update_hook(c.db, (*[0]byte)(C.updateHookTrampoline), unsafe.Pointer(newHandle(c, callback)))
+		C.sqlite3_update_hook(c.db, (*[0]byte)(C.updateHookTrampoline), newHandle(c, callback))
 	}
 }
 
@@ -535,7 +535,7 @@ func (c *SQLiteConn) RegisterAuthorizer(callback func(int, string, string, strin
 	if callback == nil {
 		C.sqlite3_set_authorizer(c.db, nil, nil)
 	} else {
-		C.sqlite3_set_authorizer(c.db, (*[0]byte)(C.authorizerTrampoline), unsafe.Pointer(newHandle(c, callback)))
+		C.sqlite3_set_authorizer(c.db, (*[0]byte)(C.authorizerTrampoline), newHandle(c, callback))
 	}
 }
 
@@ -616,8 +616,8 @@ func (c *SQLiteConn) RegisterFunc(name string, impl interface{}, pure bool) erro
 	return nil
 }
 
-func sqlite3CreateFunction(db *C.sqlite3, zFunctionName *C.char, nArg C.int, eTextRep C.int, pApp uintptr, xFunc unsafe.Pointer, xStep unsafe.Pointer, xFinal unsafe.Pointer) C.int {
-	return C._sqlite3_create_function(db, zFunctionName, nArg, eTextRep, C.uintptr_t(pApp), (*[0]byte)(xFunc), (*[0]byte)(xStep), (*[0]byte)(xFinal))
+func sqlite3CreateFunction(db *C.sqlite3, zFunctionName *C.char, nArg C.int, eTextRep C.int, pApp unsafe.Pointer, xFunc unsafe.Pointer, xStep unsafe.Pointer, xFinal unsafe.Pointer) C.int {
+	return C._sqlite3_create_function(db, zFunctionName, nArg, eTextRep, C.uintptr_t(uintptr(pApp)), (*[0]byte)(xFunc), (*[0]byte)(xStep), (*[0]byte)(xFinal))
 }
 
 // RegisterAggregator makes a Go type available as a SQLite aggregation function.
@@ -804,7 +804,7 @@ func (c *SQLiteConn) exec(ctx context.Context, query string, args []namedValue)
 		if s.(*SQLiteStmt).s != nil {
 			stmtArgs := make([]namedValue, 0, len(args))
 			na := s.NumInput()
-			if len(args) - start < na {
+			if len(args)-start < na {
 				s.Close()
 				return nil, fmt.Errorf("not enough args to execute query: want %d got %d", na, len(args))
 			}
@@ -864,8 +864,8 @@ func (c *SQLiteConn) query(ctx context.Context, query string, args []namedValue)
 		}
 		s.(*SQLiteStmt).cls = true
 		na := s.NumInput()
-		if len(args) - start < na {
-			return nil, fmt.Errorf("not enough args to execute query: want %d got %d", na, len(args) - start)
+		if len(args)-start < na {
+			return nil, fmt.Errorf("not enough args to execute query: want %d got %d", na, len(args)-start)
 		}
 		// consume the number of arguments used in the current
 		// statement and append all named arguments not contained
diff --git a/sqlite3_opt_vtable.go b/sqlite3_opt_vtable.go
index 1af1c60..c0a6214 100644
--- a/sqlite3_opt_vtable.go
+++ b/sqlite3_opt_vtable.go
@@ -353,7 +353,7 @@ func mPrintf(format, arg string) *C.char {
 
 //export goMInit
 func goMInit(db, pClientData unsafe.Pointer, argc C.int, argv **C.char, pzErr **C.char, isCreate C.int) C.uintptr_t {
-	m := lookupHandle(uintptr(pClientData)).(*sqliteModule)
+	m := lookupHandle(pClientData).(*sqliteModule)
 	if m.c.db != (*C.sqlite3)(db) {
 		*pzErr = mPrintf("%s", "Inconsistent db handles")
 		return 0
@@ -379,12 +379,12 @@ func goMInit(db, pClientData unsafe.Pointer, argc C.int, argv **C.char, pzErr **
 	}
 	vt := sqliteVTab{m, vTab}
 	*pzErr = nil
-	return C.uintptr_t(newHandle(m.c, &vt))
+	return C.uintptr_t(uintptr(newHandle(m.c, &vt)))
 }
 
 //export goVRelease
 func goVRelease(pVTab unsafe.Pointer, isDestroy C.int) *C.char {
-	vt := lookupHandle(uintptr(pVTab)).(*sqliteVTab)
+	vt := lookupHandle(pVTab).(*sqliteVTab)
 	var err error
 	if isDestroy == 1 {
 		err = vt.vTab.Destroy()
@@ -399,7 +399,7 @@ func goVRelease(pVTab unsafe.Pointer, isDestroy C.int) *C.char {
 
 //export goVOpen
 func goVOpen(pVTab unsafe.Pointer, pzErr **C.char) C.uintptr_t {
-	vt := lookupHandle(uintptr(pVTab)).(*sqliteVTab)
+	vt := lookupHandle(pVTab).(*sqliteVTab)
 	vTabCursor, err := vt.vTab.Open()
 	if err != nil {
 		*pzErr = mPrintf("%s", err.Error())
@@ -407,12 +407,12 @@ func goVOpen(pVTab unsafe.Pointer, pzErr **C.char) C.uintptr_t {
 	}
 	vtc := sqliteVTabCursor{vt, vTabCursor}
 	*pzErr = nil
-	return C.uintptr_t(newHandle(vt.module.c, &vtc))
+	return C.uintptr_t(uintptr(newHandle(vt.module.c, &vtc)))
 }
 
 //export goVBestIndex
 func goVBestIndex(pVTab unsafe.Pointer, icp unsafe.Pointer) *C.char {
-	vt := lookupHandle(uintptr(pVTab)).(*sqliteVTab)
+	vt := lookupHandle(pVTab).(*sqliteVTab)
 	info := (*C.sqlite3_index_info)(icp)
 	csts := constraints(info)
 	res, err := vt.vTab.BestIndex(csts, orderBys(info))
@@ -455,7 +455,7 @@ func goVBestIndex(pVTab unsafe.Pointer, icp unsafe.Pointer) *C.char {
 
 //export goVClose
 func goVClose(pCursor unsafe.Pointer) *C.char {
-	vtc := lookupHandle(uintptr(pCursor)).(*sqliteVTabCursor)
+	vtc := lookupHandle(pCursor).(*sqliteVTabCursor)
 	err := vtc.vTabCursor.Close()
 	if err != nil {
 		return mPrintf("%s", err.Error())
@@ -465,13 +465,13 @@ func goVClose(pCursor unsafe.Pointer) *C.char {
 
 //export goMDestroy
 func goMDestroy(pClientData unsafe.Pointer) {
-	m := lookupHandle(uintptr(pClientData)).(*sqliteModule)
+	m := lookupHandle(pClientData).(*sqliteModule)
 	m.module.DestroyModule()
 }
 
 //export goVFilter
 func goVFilter(pCursor unsafe.Pointer, idxNum C.int, idxName *C.char, argc C.int, argv **C.sqlite3_value) *C.char {
-	vtc := lookupHandle(uintptr(pCursor)).(*sqliteVTabCursor)
+	vtc := lookupHandle(pCursor).(*sqliteVTabCursor)
 	args := (*[(math.MaxInt32 - 1) / unsafe.Sizeof((*C.sqlite3_value)(nil))]*C.sqlite3_value)(unsafe.Pointer(argv))[:argc:argc]
 	vals := make([]interface{}, 0, argc)
 	for _, v := range args {
@@ -490,7 +490,7 @@ func goVFilter(pCursor unsafe.Pointer, idxNum C.int, idxName *C.char, argc C.int
 
 //export goVNext
 func goVNext(pCursor unsafe.Pointer) *C.char {
-	vtc := lookupHandle(uintptr(pCursor)).(*sqliteVTabCursor)
+	vtc := lookupHandle(pCursor).(*sqliteVTabCursor)
 	err := vtc.vTabCursor.Next()
 	if err != nil {
 		return mPrintf("%s", err.Error())
@@ -500,7 +500,7 @@ func goVNext(pCursor unsafe.Pointer) *C.char {
 
 //export goVEof
 func goVEof(pCursor unsafe.Pointer) C.int {
-	vtc := lookupHandle(uintptr(pCursor)).(*sqliteVTabCursor)
+	vtc := lookupHandle(pCursor).(*sqliteVTabCursor)
 	err := vtc.vTabCursor.EOF()
 	if err {
 		return 1
@@ -510,7 +510,7 @@ func goVEof(pCursor unsafe.Pointer) C.int {
 
 //export goVColumn
 func goVColumn(pCursor, cp unsafe.Pointer, col C.int) *C.char {
-	vtc := lookupHandle(uintptr(pCursor)).(*sqliteVTabCursor)
+	vtc := lookupHandle(pCursor).(*sqliteVTabCursor)
 	c := (*SQLiteContext)(cp)
 	err := vtc.vTabCursor.Column(c, int(col))
 	if err != nil {
@@ -521,7 +521,7 @@ func goVColumn(pCursor, cp unsafe.Pointer, col C.int) *C.char {
 
 //export goVRowid
 func goVRowid(pCursor unsafe.Pointer, pRowid *C.sqlite3_int64) *C.char {
-	vtc := lookupHandle(uintptr(pCursor)).(*sqliteVTabCursor)
+	vtc := lookupHandle(pCursor).(*sqliteVTabCursor)
 	rowid, err := vtc.vTabCursor.Rowid()
 	if err != nil {
 		return mPrintf("%s", err.Error())
@@ -532,7 +532,7 @@ func goVRowid(pCursor unsafe.Pointer, pRowid *C.sqlite3_int64) *C.char {
 
 //export goVUpdate
 func goVUpdate(pVTab unsafe.Pointer, argc C.int, argv **C.sqlite3_value, pRowid *C.sqlite3_int64) *C.char {
-	vt := lookupHandle(uintptr(pVTab)).(*sqliteVTab)
+	vt := lookupHandle(pVTab).(*sqliteVTab)
 
 	var tname string
 	if n, ok := vt.vTab.(interface {
@@ -652,7 +652,7 @@ func (c *SQLiteConn) CreateModule(moduleName string, module Module) error {
 	mname := C.CString(moduleName)
 	defer C.free(unsafe.Pointer(mname))
 	udm := sqliteModule{c, moduleName, module}
-	rv := C._sqlite3_create_module(c.db, mname, C.uintptr_t(newHandle(c, &udm)))
+	rv := C._sqlite3_create_module(c.db, mname, C.uintptr_t(uintptr(newHandle(c, &udm))))
 	if rv != C.SQLITE_OK {
 		return c.lastError()
 	}