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ValueFlow: Fix uninitvar false positive after initialization '*((int*)&x) = ..' #5142

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Merged
danmar merged 2 commits into from
Jun 10, 2023
Merged

ValueFlow: Fix uninitvar false positive after initialization '*((int*)&x) = ..' #5142

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ValueFlow: Fix uninitvar false positive after initialization '*((int*…
danmar Jun 10, 2023
03c1f1e
fix
danmar Jun 10, 2023
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8 changes: 8 additions & 0 deletions lib/valueflow.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -7924,6 +7924,14 @@ static Token* findStartToken(const Variable* var, Token* start, const Library* l
Token* first = uses.front();
if (Token::findmatch(start, "goto|asm|setjmp|longjmp", first))
return start;
if (first != var->nameToken()) {
// if this is lhs in assignment then set first to the first token in LHS expression
Token* temp = first;
while (Token::Match(temp->astParent(), "[&*(]") && precedes(temp->astParent(), temp))
temp = temp->astParent();
if (Token::simpleMatch(temp->astParent(), "=") && precedes(temp, temp->astParent()))
first = temp;
}
// If there is only one usage
if (uses.size() == 1)
return first->previous();
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12 changes: 12 additions & 0 deletions test/testvalueflow.cpp
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Expand Up @@ -5292,6 +5292,18 @@ class TestValueFlow : public TestFixture {
"}";
ASSERT_EQUALS(0U, tokenValues(code, "x )").size());

// initialization
code = "int foo() {\n"
" int x;\n"
" *((int *)(&x)) = 12;"
" a = x + 1;\n"
"}";
values = tokenValues(code, "x +");
ASSERT_EQUALS(true, values.empty());
// ASSERT_EQUALS(1U, values.size());
// ASSERT(values.front().isIntValue());
// ASSERT_EQUALS(12, values.front().intvalue);

// #8036
code = "void foo() {\n"
" int x;\n"
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