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Fix #11041 FN constVariable with array of pointers [regression] #4080

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merged 2 commits into from
May 5, 2022
Merged

Fix #11041 FN constVariable with array of pointers [regression] #4080

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214423c
Fix #11041 FN constVariable with array of pointers [regression]
chrchr-github May 4, 2022
3494045
Use std::vector for deterministic order of results, use helper variables
chrchr-github May 4, 2022
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40 changes: 21 additions & 19 deletions lib/checkother.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1540,60 +1540,62 @@ void CheckOther::checkConstPointer()
if (!mSettings->severity.isEnabled(Severity::style))
return;

std::set<const Variable *> pointers;
std::set<const Variable *> nonConstPointers;
std::vector<const Variable*> pointers, nonConstPointers;
for (const Token *tok = mTokenizer->tokens(); tok; tok = tok->next()) {
if (!tok->variable())
const Variable* const var = tok->variable();
if (!var)
continue;
if (!tok->variable()->isLocal() && !tok->variable()->isArgument())
if (!var->isLocal() && !var->isArgument())
continue;
const Token* const nameTok = tok->variable()->nameToken();
const Token* const nameTok = var->nameToken();
// declarations of (static) pointers are (not) split up, array declarations are never split up
if (tok == nameTok && (!tok->variable()->isStatic() || Token::simpleMatch(nameTok->next(), "[")) &&
if (tok == nameTok && (!var->isStatic() || Token::simpleMatch(nameTok->next(), "[")) &&
// range-based for loop
!(Token::simpleMatch(nameTok->astParent(), ":") && Token::simpleMatch(nameTok->astParent()->astParent(), "(")))
continue;
if (!tok->valueType())
const ValueType* const vt = tok->valueType();
if (!vt)
continue;
if (tok->valueType()->pointer != 1 || (tok->valueType()->constness & 1) || tok->valueType()->reference != Reference::None)
if (vt->pointer != 1 && !(vt->pointer == 2 && var->isArray()) || (vt->constness & 1) || vt->reference != Reference::None)
continue;
if (nonConstPointers.find(tok->variable()) != nonConstPointers.end())
if (std::find(nonConstPointers.begin(), nonConstPointers.end(), var) != nonConstPointers.end())
continue;
pointers.insert(tok->variable());
const Token *parent = tok->astParent();
pointers.emplace_back(var);
const Token* const parent = tok->astParent();
bool deref = false;
if (parent && parent->isUnaryOp("*"))
deref = true;
else if (Token::simpleMatch(parent, "[") && parent->astOperand1() == tok && parent->astOperand1() != nameTok)
else if (Token::simpleMatch(parent, "[") && parent->astOperand1() == tok && tok != nameTok)
deref = true;
if (deref) {
if (Token::Match(parent->astParent(), "%cop%") && !parent->astParent()->isUnaryOp("&") && !parent->astParent()->isUnaryOp("*"))
const Token* const gparent = parent->astParent();
if (Token::Match(gparent, "%cop%") && !gparent->isUnaryOp("&") && !gparent->isUnaryOp("*"))
continue;
if (Token::simpleMatch(parent->astParent(), "return"))
if (Token::simpleMatch(gparent, "return"))
continue;
else if (Token::Match(parent->astParent(), "%assign%") && parent == parent->astParent()->astOperand2()) {
else if (Token::Match(gparent, "%assign%") && parent == gparent->astOperand2()) {
bool takingRef = false;
const Token *lhs = parent->astParent()->astOperand1();
const Token *lhs = gparent->astOperand1();
if (lhs && lhs->variable() && lhs->variable()->isReference() && lhs->variable()->nameToken() == lhs)
takingRef = true;
if (!takingRef)
continue;
} else if (Token::simpleMatch(parent->astParent(), "[") && parent->astParent()->astOperand2() == parent)
} else if (Token::simpleMatch(gparent, "[") && gparent->astOperand2() == parent)
continue;
} else {
if (Token::Match(parent, "%oror%|%comp%|&&|?|!|-"))
continue;
else if (Token::simpleMatch(parent, "(") && Token::Match(parent->astOperand1(), "if|while"))
continue;
}
nonConstPointers.insert(tok->variable());
nonConstPointers.emplace_back(var);
}
for (const Variable *p: pointers) {
if (p->isArgument()) {
if (!p->scope() || !p->scope()->function || p->scope()->function->isImplicitlyVirtual(true) || p->scope()->function->hasVirtualSpecifier())
continue;
}
if (nonConstPointers.find(p) == nonConstPointers.end()) {
if (std::find(nonConstPointers.begin(), nonConstPointers.end(), p) == nonConstPointers.end()) {
const Token *start = (p->isArgument()) ? p->scope()->bodyStart : p->nameToken()->next();
const int indirect = p->isArray() ? p->dimensions().size() : 1;
if (isVariableChanged(start, p->scope()->bodyEnd, indirect, p->declarationId(), false, mSettings, mTokenizer->isCPP()))
Expand Down
15 changes: 14 additions & 1 deletion test/testother.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3059,6 +3059,19 @@ class TestOther : public TestFixture {
"};\n"
"S<int*> s;\n");
ASSERT_EQUALS("", errout.str());

check("void f(int i) {\n"
" const char *tmp;\n"
" char* a[] = { \"a\", \"aa\" };\n"
" static char* b[] = { \"b\", \"bb\" };\n"
" tmp = a[i];\n"
" printf(\"%s\", tmp);\n"
" tmp = b[i];\n"
" printf(\"%s\", tmp);\n"
"}\n");
ASSERT_EQUALS("[test.cpp:3]: (style) Variable 'a' can be declared with const\n"
"[test.cpp:4]: (style) Variable 'b' can be declared with const\n",
errout.str());
}

void switchRedundantAssignmentTest() {
Expand Down Expand Up @@ -9213,7 +9226,7 @@ class TestOther : public TestFixture {
" int local_argc = 0;\n"
" local_argv[local_argc++] = argv[0];\n"
"}\n", "test.c");
ASSERT_EQUALS("", errout.str());
ASSERT_EQUALS("[test.c:1]: (style) Parameter 'argv' can be declared with const\n", errout.str());

check("void f() {\n"
" int x = 0;\n"
Expand Down