From f2719ec6ca346e9db42e9b6b1046a87724c27d75 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Sun, 23 Apr 2017 10:51:31 +0200
Subject: [PATCH] Refactoring CheckString::sprintfOverlappingData. Use AST,
 isSameExpression(), getArguments(), ..

---
 Makefile            |  2 +-
 lib/checkstring.cpp | 39 +++++++++++++++------------------------
 2 files changed, 16 insertions(+), 25 deletions(-)

diff --git a/Makefile b/Makefile
index 27bf781ba..c92f9387a 100644
--- a/Makefile
+++ b/Makefile
@@ -366,7 +366,7 @@ $(SRCDIR)/checksizeof.o: lib/checksizeof.cpp lib/cxx11emu.h lib/checksizeof.h li
 $(SRCDIR)/checkstl.o: lib/checkstl.cpp lib/cxx11emu.h lib/checkstl.h lib/config.h lib/check.h lib/token.h lib/valueflow.h lib/mathlib.h lib/tokenize.h lib/errorlogger.h lib/suppressions.h lib/tokenlist.h lib/settings.h lib/library.h lib/standards.h lib/platform.h lib/importproject.h lib/timer.h lib/symboldatabase.h lib/checknullpointer.h lib/utils.h
 	$(CXX) ${INCLUDE_FOR_LIB} $(CPPFLAGS) $(CFG) $(CXXFLAGS) $(UNDEF_STRICT_ANSI) -c -o $(SRCDIR)/checkstl.o $(SRCDIR)/checkstl.cpp
 
-$(SRCDIR)/checkstring.o: lib/checkstring.cpp lib/cxx11emu.h lib/checkstring.h lib/config.h lib/check.h lib/token.h lib/valueflow.h lib/mathlib.h lib/tokenize.h lib/errorlogger.h lib/suppressions.h lib/tokenlist.h lib/settings.h lib/library.h lib/standards.h lib/platform.h lib/importproject.h lib/timer.h lib/symboldatabase.h lib/utils.h
+$(SRCDIR)/checkstring.o: lib/checkstring.cpp lib/cxx11emu.h lib/checkstring.h lib/config.h lib/check.h lib/token.h lib/valueflow.h lib/mathlib.h lib/tokenize.h lib/errorlogger.h lib/suppressions.h lib/tokenlist.h lib/settings.h lib/library.h lib/standards.h lib/platform.h lib/importproject.h lib/timer.h lib/symboldatabase.h lib/astutils.h lib/utils.h
 	$(CXX) ${INCLUDE_FOR_LIB} $(CPPFLAGS) $(CFG) $(CXXFLAGS) $(UNDEF_STRICT_ANSI) -c -o $(SRCDIR)/checkstring.o $(SRCDIR)/checkstring.cpp
 
 $(SRCDIR)/checktype.o: lib/checktype.cpp lib/cxx11emu.h lib/checktype.h lib/config.h lib/check.h lib/token.h lib/valueflow.h lib/mathlib.h lib/tokenize.h lib/errorlogger.h lib/suppressions.h lib/tokenlist.h lib/settings.h lib/library.h lib/standards.h lib/platform.h lib/importproject.h lib/timer.h lib/symboldatabase.h
diff --git a/lib/checkstring.cpp b/lib/checkstring.cpp
index 09dd49933..5d0d05f9e 100644
--- a/lib/checkstring.cpp
+++ b/lib/checkstring.cpp
@@ -20,6 +20,7 @@
 //---------------------------------------------------------------------------
 #include "checkstring.h"
 #include "symboldatabase.h"
+#include "astutils.h"
 #include "utils.h"
 
 //---------------------------------------------------------------------------
@@ -321,6 +322,7 @@ void CheckString::incorrectStringBooleanError(const Token *tok, const std::strin
 
 //---------------------------------------------------------------------------
 // Overlapping source and destination passed to sprintf().
+// TODO: Library configuration for overlapping arguments
 //---------------------------------------------------------------------------
 void CheckString::sprintfOverlappingData()
 {
@@ -329,34 +331,23 @@ void CheckString::sprintfOverlappingData()
     for (std::size_t i = 0; i < functions; ++i) {
         const Scope * scope = symbolDatabase->functionScopes[i];
         for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
-            // Get variable id of target buffer..
-            unsigned int varid = 0;
-
-            if (Token::Match(tok, "sprintf|snprintf|swprintf ( %var% ,"))
-                varid = tok->tokAt(2)->varId();
-
-            else if (Token::Match(tok, "sprintf|snprintf|swprintf ( %name% . %var% ,"))
-                varid = tok->tokAt(4)->varId();
-
-            else
+            if (!Token::Match(tok, "sprintf|snprintf|swprintf ("))
                 continue;
 
-            // goto next argument
-            const Token *tok2 = tok->tokAt(2)->nextArgument();
+            const std::vector<const Token *> args = getArguments(tok);
 
-            if (tok->str() == "snprintf" || tok->str() == "swprintf") { // Jump over second parameter for snprintf and swprintf
-                tok2 = tok2->nextArgument();
-                if (!tok2)
-                    continue;
-            }
-
-            // is any source buffer overlapping the target buffer?
-            do {
-                if (Token::Match(tok2, "%varid% [,)]", varid)) {
-                    sprintfOverlappingDataError(tok2, tok2->str());
-                    break;
+            const int formatString = Token::Match(tok, "sprintf") ? 1 : 2;
+            for (unsigned int argnr = formatString + 1; argnr < args.size(); ++argnr) {
+                bool same = isSameExpression(_tokenizer->isCPP(),
+                                             false,
+                                             args[0],
+                                             args[argnr],
+                                             _settings->library,
+                                             true);
+                if (same) {
+                    sprintfOverlappingDataError(args[argnr], args[argnr]->expressionString());
                 }
-            } while (nullptr != (tok2 = tok2->nextArgument()));
+            }
         }
     }
 }