Rewrite PDO result binding

Instead of requiring the type to be determined in advance by the
describer function and then requiring get_col to return a buffer
of appropriate type, allow get_col to return an arbitrary zval.
See UPGRADING.INTERNALS for a more detailed description of the
change.

This makes the result fetching simpler, more efficient and more
flexible. The general possibility already existed via the special
PDO_PARAM_ZVAL type, but the usage was very inconvenient and/or
inefficient. Now it's possible to easily implement behavior like
"return int if it fits, otherwise string" and to avoid any kind
of complex management of temporary buffers.

This also fixes bug #40913 (our second highest voted bug of all
time, for some reason). PARAM_LOB result bindings will now
consistently return a stream resource, independently of the used
database driver.

I've tried my best to update all PDO drivers for this change, but
some of the changes may be broken, as I cannot test or even build
some of these drivers (in particular PDO dblib and PDO oci).
Fixes are appreciated -- a working CI setup would be even more
appreciated ;)

1 files changed, 12 insertions, 57 deletions

diff --git a/ext/pdo_dblib/dblib_stmt.c b/ext/pdo_dblib/dblib_stmt.c
index 0dca4c79cf..03e69a4ac0 100644
--- a/ext/pdo_dblib/dblib_stmt.c
+++ b/ext/pdo_dblib/dblib_stmt.c
@@ -251,7 +251,6 @@ static int pdo_dblib_stmt_describe(pdo_stmt_t *stmt, int colno)
 	}
 
 	col->maxlen = dbcollen(H->link, colno+1);
-	col->param_type = PDO_PARAM_ZVAL;
 
 	return 1;
 }
@@ -304,14 +303,12 @@ static int pdo_dblib_stmt_should_stringify_col(pdo_stmt_t *stmt, int coltype)
 	return 0;
 }
 
-static void pdo_dblib_stmt_stringify_col(int coltype, LPBYTE data, DBINT data_len, zval **ptr)
+static void pdo_dblib_stmt_stringify_col(int coltype, LPBYTE data, DBINT data_len, zval *zv)
 {
 	DBCHAR *tmp_data;
-	DBINT tmp_data_len;
-	zval *zv;
 
 	/* FIXME: We allocate more than we need here */
-	tmp_data_len = 32 + (2 * (data_len));
+	DBINT tmp_data_len = 32 + (2 * (data_len));
 
 	switch (coltype) {
 		case SQLDATETIME:
@@ -326,7 +323,6 @@ static void pdo_dblib_stmt_stringify_col(int coltype, LPBYTE data, DBINT data_le
 	tmp_data = emalloc(tmp_data_len);
 	data_len = dbconvert(NULL, coltype, data, data_len, SQLCHAR, (LPBYTE) tmp_data, tmp_data_len);
 
-	zv = emalloc(sizeof(zval));
 	if (data_len > 0) {
 		/* to prevent overflows, tmp_data_len is provided as a dest len for dbconvert()
 		 * this code previously passed a dest len of -1
@@ -342,12 +338,9 @@ static void pdo_dblib_stmt_stringify_col(int coltype, LPBYTE data, DBINT data_le
 	}
 
 	efree(tmp_data);
-
-	*ptr = zv;
 }
 
-static int pdo_dblib_stmt_get_col(pdo_stmt_t *stmt, int colno, char **ptr,
-	 zend_ulong *len, int *caller_frees)
+static int pdo_dblib_stmt_get_col(pdo_stmt_t *stmt, int colno, zval *zv, enum pdo_param_type *type)
 {
 
 	pdo_dblib_stmt *S = (pdo_dblib_stmt*)stmt->driver_data;
@@ -357,7 +350,6 @@ static int pdo_dblib_stmt_get_col(pdo_stmt_t *stmt, int colno, char **ptr,
 	LPBYTE data;
 	DBCHAR *tmp_data;
 	DBINT data_len, tmp_data_len;
-	zval *zv = NULL;
 
 	coltype = dbcoltype(H->link, colno+1);
 	data = dbdata(H->link, colno+1);
@@ -365,10 +357,8 @@ static int pdo_dblib_stmt_get_col(pdo_stmt_t *stmt, int colno, char **ptr,
 
 	if (data_len != 0 || data != NULL) {
 		if (pdo_dblib_stmt_should_stringify_col(stmt, coltype) && dbwillconvert(coltype, SQLCHAR)) {
-			pdo_dblib_stmt_stringify_col(coltype, data, data_len, &zv);
-		}
-
-		if (!zv) {
+			pdo_dblib_stmt_stringify_col(coltype, data, data_len, zv);
+		} else {
 			switch (coltype) {
 				case SQLCHAR:
 				case SQLVARCHAR:
@@ -382,7 +372,6 @@ static int pdo_dblib_stmt_get_col(pdo_stmt_t *stmt, int colno, char **ptr,
 				case SQLVARBINARY:
 				case SQLBINARY:
 				case SQLIMAGE: {
-					zv = emalloc(sizeof(zval));
 					ZVAL_STRINGL(zv, (DBCHAR *) data, data_len);
 
 					break;
@@ -407,50 +396,31 @@ static int pdo_dblib_stmt_get_col(pdo_stmt_t *stmt, int colno, char **ptr,
 #endif
 					);
 
-					zv = emalloc(sizeof(zval));
 					ZVAL_STRINGL(zv, tmp_data, dl);
 
 					efree(tmp_data);
 
 					break;
 				}
-				case SQLFLT4: {
-					zv = emalloc(sizeof(zval));
+				case SQLFLT4:
 					ZVAL_DOUBLE(zv, *(DBFLT4 *) data);
-
 					break;
-				}
-				case SQLFLT8: {
-					zv = emalloc(sizeof(zval));
+				case SQLFLT8:
 					ZVAL_DOUBLE(zv, *(DBFLT8 *) data);
-
 					break;
-				}
-				case SQLINT8: {
-					zv = emalloc(sizeof(zval));
+				case SQLINT8:
 					ZVAL_LONG(zv, *(DBBIGINT *) data);
-
 					break;
-				}
-				case SQLINT4: {
-					zv = emalloc(sizeof(zval));
+				case SQLINT4:
 					ZVAL_LONG(zv, *(DBINT *) data);
-
 					break;
-				}
-				case SQLINT2: {
-					zv = emalloc(sizeof(zval));
+				case SQLINT2:
 					ZVAL_LONG(zv, *(DBSMALLINT *) data);
-
 					break;
-				}
 				case SQLINT1:
-				case SQLBIT: {
-					zv = emalloc(sizeof(zval));
+				case SQLBIT:
 					ZVAL_LONG(zv, *(DBTINYINT *) data);
-
 					break;
-				}
 				case SQLDECIMAL:
 				case SQLNUMERIC:
 				case SQLMONEY:
@@ -458,10 +428,7 @@ static int pdo_dblib_stmt_get_col(pdo_stmt_t *stmt, int colno, char **ptr,
 				case SQLMONEYN: {
 					DBFLT8 float_value;
 					dbconvert(NULL, coltype, data, 8, SQLFLT8, (LPBYTE) &float_value, -1);
-
-					zv = emalloc(sizeof(zval));
 					ZVAL_DOUBLE(zv, float_value);
-
 					break;
 				}
 
@@ -472,12 +439,10 @@ static int pdo_dblib_stmt_get_col(pdo_stmt_t *stmt, int colno, char **ptr,
 						tmp_data = safe_emalloc(tmp_data_len, sizeof(char), 1);
 						data_len = dbconvert(NULL, SQLUNIQUE, data, data_len, SQLCHAR, (LPBYTE) tmp_data, tmp_data_len);
 						php_strtoupper(tmp_data, data_len);
-						zv = emalloc(sizeof(zval));
 						ZVAL_STRINGL(zv, tmp_data, data_len);
 						efree(tmp_data);
 					} else {
 						/* 16-byte binary representation */
-						zv = emalloc(sizeof(zval));
 						ZVAL_STRINGL(zv, (DBCHAR *) data, 16);
 					}
 					break;
@@ -485,7 +450,7 @@ static int pdo_dblib_stmt_get_col(pdo_stmt_t *stmt, int colno, char **ptr,
 
 				default: {
 					if (dbwillconvert(coltype, SQLCHAR)) {
-						pdo_dblib_stmt_stringify_col(coltype, data, data_len, &zv);
+						pdo_dblib_stmt_stringify_col(coltype, data, data_len, zv);
 					}
 
 					break;
@@ -494,16 +459,6 @@ static int pdo_dblib_stmt_get_col(pdo_stmt_t *stmt, int colno, char **ptr,
 		}
 	}
 
-	if (zv != NULL) {
-		*ptr = (char*)zv;
-		*len = sizeof(zval);
-	} else {
-		*ptr = NULL;
-		*len = 0;
-	}
-
-	*caller_frees = 1;
-
 	return 1;
 }