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ExprEngine: Better handling of pointer aliasing

This commit is contained in:
Daniel Marjamäki 2019-09-22 15:58:55 +02:00
parent ec4b7c1f4b
commit 5c07cfd2e8
2 changed files with 36 additions and 5 deletions
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16
lib/exprengine.cpp
View File

@ -476,6 +476,22 @@ static ExprEngine::ValuePtr executeAssign(const Token *tok, Data &data)
auto val = std::dynamic_pointer_cast<ExprEngine::AddressOfValue>(pval);
if (val)
data.memory[val->varId] = rhsValue;
} else if (pval && pval->type() == ExprEngine::ValueType::BinOpResult) {
auto b = std::dynamic_pointer_cast<ExprEngine::BinOpResult>(pval);
if (b && b->binop == "+") {
std::shared_ptr<ExprEngine::ArrayValue> arr;
ExprEngine::ValuePtr offset;
if (b->op1->type() == ExprEngine::ValueType::ArrayValue) {
arr = std::dynamic_pointer_cast<ExprEngine::ArrayValue>(b->op1);
offset = b->op2;
} else {
arr = std::dynamic_pointer_cast<ExprEngine::ArrayValue>(b->op2);
offset = b->op1;
}
if (arr && offset) {
arr->assign(offset, rhsValue);
}
}
}
}
return rhsValue;

25
test/testexprengine.cpp
View File

@ -57,9 +57,11 @@ private:
TEST_CASE(pointerAlias1);
TEST_CASE(pointerAlias2);
TEST_CASE(pointerAlias3);
TEST_CASE(pointerAlias4);
}
std::string getRange(const char code[], const std::string &str) {
std::string getRange(const char code[], const std::string &str, int linenr = 0) {
Settings settings;
settings.platform(cppcheck::Platform::Unix64);
settings.library.smartPointers.insert("std::shared_ptr");
@ -68,7 +70,7 @@ private:
tokenizer.tokenize(istr, "test.cpp");
std::string ret;
std::function<void(const Token *, const ExprEngine::Value &)> f = [&](const Token *tok, const ExprEngine::Value &value) {
if (tok->expressionString() == str) {
if ((linenr == 0 || linenr == tok->linenr()) && tok->expressionString() == str) {
if (!ret.empty())
ret += ",";
ret += value.getRange();
@ -162,15 +164,28 @@ private:
}
void localArrayUninit() {
ASSERT_EQUALS("?", getRange("inf f() { int arr[10]; return arr[4]; }", "arr[4]"));
ASSERT_EQUALS("?", getRange("int f() { int arr[10]; return arr[4]; }", "arr[4]"));
}
void pointerAlias1() {
ASSERT_EQUALS("3", getRange("inf f() { int x; int *p = &x; x = 3; return *p; }", "return*p"));
ASSERT_EQUALS("3", getRange("int f() { int x; int *p = &x; x = 3; return *p; }", "return*p"));
}
void pointerAlias2() {
ASSERT_EQUALS("1", getRange("inf f() { int x; int *p = &x; *p = 1; return *p; }", "return*p"));
ASSERT_EQUALS("1", getRange("int f() { int x; int *p = &x; *p = 1; return *p; }", "return*p"));
}
void pointerAlias3() {
ASSERT_EQUALS("7", getRange("int f() {\n"
" int x = 18;\n"
" int *p = &x;\n"
" *p = 7;\n"
" return x;\n"
"}", "x", 5));
}
void pointerAlias4() {
ASSERT_EQUALS("71", getRange("int f() { int x[10]; int *p = x+3; *p = 71; return x[3]; }", "x[3]"));
}
};