update from pre/postUpdate node to new forms

SqlInjection.ql

@@ -15,33 +15,17 @@ module SqliFlowConfig implements DataFlow::ConfigSig {
         // count = read(STDIN_FILENO, buf, BUFSIZE);
         exists(FunctionCall read |
             read.getTarget().getName() = "read" and
-            read.getArgument(1) = source.(DataFlow::PostUpdateNode).getPreUpdateNode().asIndirectArgument()
+            read.getArgument(1) = source.asDefiningArgument()
         )
     }
 
     predicate isBarrier(DataFlow::Node sanitizer) { none() }
 
-    predicate isAdditionalFlowStep(DataFlow::Node into, DataFlow::Node out) {
-        // Extra taint step
-        //     snprintf(query, bufsize, "INSERT INTO users VALUES (%d, '%s')", id, info);
-        // But snprintf is a macro on mac os.  The actual function's name is
-        //     #undef snprintf
-        //     #define snprintf(str, len, ...) \
-        //       __builtin___snprintf_chk (str, len, 0, __darwin_obsz(str), __VA_ARGS__)
-        //     #endif
-        exists(FunctionCall printf |
-            printf.getTarget().getName().matches("%snprintf%") and
-            printf.getArgument(0) = out.(DataFlow::PostUpdateNode).getPreUpdateNode().asIndirectArgument() and
-            // very specific: shifted index for macro.
-            printf.getArgument(6) = into.asExpr()
-        )
-    }
-
     predicate isSink(DataFlow::Node sink) {
         // rc = sqlite3_exec(db, query, NULL, 0, &zErrMsg);
         exists(FunctionCall exec |
             exec.getTarget().getName() = "sqlite3_exec" and
-            exec.getArgument(1) = sink.asExpr()
+            exec.getArgument(1) = sink.asIndirectArgument()
         )
     }
 }
@@ -52,3 +36,4 @@ import MyFlow::PathGraph
 from  MyFlow::PathNode source, MyFlow::PathNode sink
 where MyFlow::flowPath(source, sink)
 select sink, source, sink, "Possible SQL injection"
+

session.ql

@@ -1,17 +1,18 @@
-/**
- * @name SQLI Vulnerability
- * @description Using untrusted strings in a sql query allows sql injection attacks.
- * @kind path-problem
- * @id cpp/sqlivulnerable
- * @problem.severity warning
- */
-
 import cpp
 
 // 1. invalid input -- source
 //    count = read(STDIN_FILENO, buf, BUFSIZE - 1);
 //
-
+// 2. gets to a sql statement -- flow
+//    flow config
+//
+// 3. drops table -- sink
+//    rc = sqlite3_exec(db, query, NULL, 0, &zErrMsg);
+// All predicates and classes are using one of:
+// AST Abstract syntax tree
+// CFG Control flow graph
+// DFG Data flow graph
+// Type hierarchy
 class DataSource extends VariableAccess {
   DataSource() {
     exists(FunctionCall read |
@@ -21,70 +22,8 @@ class DataSource extends VariableAccess {
   }
 }
 
-// from DataSource buf
-// select buf
-  
-// 2. gets to a sql statement -- flow
-//    flow config
-//
-// 3. drops table -- sink
-//    rc = sqlite3_exec(db, query, NULL, 0, &zErrMsg);
-
-
-class DataSink extends Expr {
-    DataSink() {
-      exists(FunctionCall read |
-       read.getTarget().getName() = "sqlite3_exec" and
-       read.getArgument(1) = this
-      )
-    }
-  }
-
-// from DataSource ds
-// select ds
-
-
-// from FunctionCall exec, Expr query 
-// where exec.getTarget().getName() = "sqlite3_exec" and
-// exec.getArgument(1) = query
-// select query
-// from StmtParent st
-// where not (st instanceof VariableAccess)
-// select st
-
-
-
-// All predicates and classes are using one of:
-// AST Abstract syntax tree
-// CFG Control flow graph
-// DFG Data flow graph
-// Type hierarchy
-//
-
-
-import semmle.code.cpp.dataflow.new.TaintTracking
-
-
-module SqliFlowConfig implements DataFlow::ConfigSig {
-    predicate isSource(DataFlow::Node source) {
-        exists(DataSource ds |
-            source.asExpr() = ds
-            )
-    }
-
-    predicate isSink(DataFlow::Node sink) {
-        exists(DataSink ds |
-            sink.asExpr() = ds
-            )
-
-    }
-  
-}
-
-
-module MyFlow = TaintTracking::Global<SqliFlowConfig>;
-import MyFlow::PathGraph
-
-from  MyFlow::PathNode source, MyFlow::PathNode sink
-where MyFlow::flowPath(source, sink)
-select sink, source, sink, "Possible SQL injection"
+from FunctionCall read, VariableAccess buf
+where
+  read.getTarget().getName() = "read" and
+  read.getArgument(1) = buf
+select buf