From 0011fb5a365f4b3b1b660f65d1ed62b18d5d1d91 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Tue, 24 Sep 2019 22:22:16 +0200
Subject: [PATCH] ExprEngine: Temporary hardcoding for calloc

---
 lib/exprengine.cpp      | 27 +++++++++++++++++++++++++--
 lib/exprengine.h        | 17 +++++++++++++----
 test/testexprengine.cpp |  6 ++++++
 3 files changed, 44 insertions(+), 6 deletions(-)

diff --git a/lib/exprengine.cpp b/lib/exprengine.cpp
index 7ef2416a8..fc1dc847c 100644
--- a/lib/exprengine.cpp
+++ b/lib/exprengine.cpp
@@ -191,7 +191,7 @@ namespace {
             unsigned int size = 1;
             for (const auto &dim : tok->variable()->dimensions())
                 size *= dim.num;
-            auto val = std::make_shared<ExprEngine::ArrayValue>(getNewSymbolName(), size);
+            auto val = std::make_shared<ExprEngine::ArrayValue>(getNewSymbolName(), size, size);
             memory[tok->varId()] = val;
             return val;
         }
@@ -249,6 +249,13 @@ void ExprEngine::ArrayValue::assign(ExprEngine::ValuePtr index, ExprEngine::Valu
     }
 }
 
+void ExprEngine::ArrayValue::clear()
+{
+    auto zero = std::make_shared<ExprEngine::IntRange>("0", 0, 0);
+    for (int i = 0; i < data.size(); ++i)
+        data[i] = zero;
+}
+
 ExprEngine::ValuePtr ExprEngine::ArrayValue::read(ExprEngine::ValuePtr index)
 {
     auto i1 = std::dynamic_pointer_cast<ExprEngine::IntRange>(index);
@@ -602,8 +609,10 @@ static ExprEngine::ValuePtr executeAssign(const Token *tok, Data &data)
 
 static ExprEngine::ValuePtr executeFunctionCall(const Token *tok, Data &data)
 {
+    std::vector<ExprEngine::ValuePtr> argValues;
     for (const Token *argtok : getArguments(tok)) {
         auto val = executeExpression(argtok, data);
+        argValues.push_back(val);
         if (!argtok->valueType() || (argtok->valueType()->constness & 1) == 1)
             continue;
         if (auto arrayValue = std::dynamic_pointer_cast<ExprEngine::ArrayValue>(val)) {
@@ -619,6 +628,20 @@ static ExprEngine::ValuePtr executeFunctionCall(const Token *tok, Data &data)
                 data.memory[addressOf->varId] = getValueRangeFromValueType(data.getNewSymbolName(), &vt, *data.settings);
         }
     }
+
+    // TODO Fix this hardcoding..
+    if (Token::simpleMatch(tok->astOperand1(), "calloc (") && argValues.size() == 2 && argValues[0] && argValues[1]) {
+        auto bufferSize = std::make_shared<ExprEngine::BinOpResult>("*", argValues[0], argValues[1]);
+        ExprEngine::BinOpResult::IntOrFloatValue minValue, maxValue;
+        bufferSize->getRange(&minValue, &maxValue);
+        if (!minValue.isFloat()) {
+            auto buffer = std::make_shared<ExprEngine::ArrayValue>(data.getNewSymbolName(), minValue.intValue, maxValue.intValue);
+            buffer->clear();
+            call(data.callbacks, tok, buffer);
+            return buffer;
+        }
+    }
+
     auto val = getValueRangeFromValueType(data.getNewSymbolName(), tok->valueType(), *data.settings);
     call(data.callbacks, tok, val);
     return val;
@@ -764,7 +787,7 @@ static void execute(const Token *start, const Token *end, Data &data)
             data.trackProgramState(tok);
         if (tok->variable() && tok->variable()->nameToken() == tok) {
             if (tok->variable()->isArray() && tok->variable()->dimensions().size() == 1 && tok->variable()->dimensions()[0].known) {
-                data.memory[tok->varId()] = std::make_shared<ExprEngine::ArrayValue>(data.getNewSymbolName(), tok->variable()->dimension(0));
+                data.memory[tok->varId()] = std::make_shared<ExprEngine::ArrayValue>(data.getNewSymbolName(), tok->variable()->dimension(0), tok->variable()->dimension(0));
             }
             if (Token::Match(tok, "%name% ["))
                 tok = tok->linkAt(1);
diff --git a/lib/exprengine.h b/lib/exprengine.h
index d4fbfb8b4..e46aedc4a 100644
--- a/lib/exprengine.h
+++ b/lib/exprengine.h
@@ -158,10 +158,16 @@ namespace ExprEngine {
     public:
         const int MAXSIZE = 0x100000;
 
-        ArrayValue(const std::string &name, size_t size)
-            : Value(name) {
-            data.resize((size < MAXSIZE) ? size : MAXSIZE,
-                        std::make_shared<UninitValue>());
+        ArrayValue(const std::string &name, int minSize, int maxSize)
+            : Value(name)
+            , minSize(minSize)
+            , maxSize(maxSize) {
+            if (minSize < 1)
+                minSize = 1;
+            // Known size..
+            if (minSize == maxSize)
+                data.resize((minSize < MAXSIZE) ? minSize : MAXSIZE,
+                            std::make_shared<UninitValue>());
         }
 
         ValueType type() const override {
@@ -170,9 +176,12 @@ namespace ExprEngine {
         std::string getRange() const override;
 
         void assign(ValuePtr index, ValuePtr value);
+        void clear();
         ValuePtr read(ValuePtr index);
 
         std::vector<ValuePtr> data;
+        int minSize;
+        int maxSize;
     };
 
     class StringLiteralValue: public Value {
diff --git a/test/testexprengine.cpp b/test/testexprengine.cpp
index 028cfa1b4..3a948d900 100644
--- a/test/testexprengine.cpp
+++ b/test/testexprengine.cpp
@@ -36,6 +36,8 @@ private:
         TEST_CASE(argSmartPointer);
         TEST_CASE(argStruct);
 
+        TEST_CASE(dynamicAllocation1);
+
         TEST_CASE(expr1);
         TEST_CASE(expr2);
         TEST_CASE(expr3);
@@ -110,6 +112,10 @@ private:
                                "void f(struct S s) { return s.a + s.b; }", "s.a+s.b"));
     }
 
+    void dynamicAllocation1() {
+        ASSERT_EQUALS("[0]", getRange("char *f() { char *p = calloc(1,1); return p; }", "p"));
+    }
+
     void expr1() {
         ASSERT_EQUALS("-32768:32767", getRange("void f(short x) { a = x; }", "x"));
     }