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Fix #14717 (FP: same exprId for different expressions leads to wrong redundantAssignment) #8520

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Fix #14717 (FP: same exprId for different expressions leads to wrong redundantAssignment) #8520

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Fix #14717 (FP: same exprId for different expressions leads to wrong …
danmar May 2, 2026
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danmar May 2, 2026
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37 changes: 22 additions & 15 deletions lib/symboldatabase.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1643,10 +1643,30 @@ namespace {
continue;
}

const auto getExprIdForOperand = [](const Token* tok) -> int {
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@pfultz2 pfultz2 May 2, 2026

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This could just be a function since it does capture anything.

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@danmar danmar May 2, 2026

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sure I will fix

if (!tok)
return 0;

int otherExprId = 0;

// Look through all referenced tokens.
// If two exprIds are found and one matches tok->exprId(), return the other.
// Otherwise, default to returning tok->exprId().
for (const auto& ref: followAllReferences(tok)) {
const int refExprId = ref.token->exprId();
if (refExprId != 0 && refExprId != tok->exprId()) {
if (otherExprId != 0 && otherExprId != refExprId)
return tok->exprId();
otherExprId = refExprId;
}
}
return otherExprId != 0 ? otherExprId : tok->exprId();
};

ExprIdKey key;
key.parentOp = tok->astParent()->str();
key.operand1 = op1 ? op1->exprId() : 0;
key.operand2 = op2 ? op2->exprId() : 0;
key.operand1 = getExprIdForOperand(op1);
key.operand2 = getExprIdForOperand(op2);

if (tok->astParent()->isCast() && tok->astParent()->str() == "(") {
const Token* typeStartToken;
Expand All @@ -1665,19 +1685,6 @@ namespace {
key.parentOp += type;
}

for (const auto& ref: followAllReferences(op1)) {
if (ref.token->exprId() != 0) { // cppcheck-suppress useStlAlgorithm
key.operand1 = ref.token->exprId();
break;
}
}
for (const auto& ref: followAllReferences(op2)) {
if (ref.token->exprId() != 0) { // cppcheck-suppress useStlAlgorithm
key.operand2 = ref.token->exprId();
break;
}
}

if (key.operand1 > key.operand2 && key.operand2 &&
Token::Match(tok->astParent(), "%or%|%oror%|+|*|&|&&|^|==|!=")) {
// In C++ the order of operands of + might matter
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19 changes: 19 additions & 0 deletions test/testvarid.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -262,6 +262,7 @@ class TestVarID : public TestFixture {
TEST_CASE(exprid12);
TEST_CASE(exprid13);
TEST_CASE(exprid14);
TEST_CASE(exprid15);

TEST_CASE(structuredBindings);
}
Expand Down Expand Up @@ -4518,6 +4519,24 @@ class TestVarID : public TestFixture {
ASSERT_EQUALS(exp, tokenize(code, s)); // don't crash
}

void exprid15()
{
// #14717
const char code[] = "#define MAX(a, b) (((a) > (b)) ? (a) : (b))\n"
"\n"
"void f(char *d) {\n"
" const char *p = &d[0];\n"
" int a = 1 / MAX(1, p[0]);\n"
" a = 1 / MAX(1, p[1]);\n"
"}\n";
const char exp[] = "3: void f ( char * d ) {\n"
"4: const char * p@2 ; p@2 =@UNIQUE &@UNIQUE d@1 [@UNIQUE 0 ] ;\n"
"5: int a@3 ; a@3 =@UNIQUE 1 /@UNIQUE $( $( 1 $>@UNIQUE $( p@2 [@9 0 ] $) $) $?@UNIQUE $( 1 $) $:@UNIQUE $( p@2 [@9 0 ] $) $) ;\n"
"6: a@3 =@UNIQUE 1 /@UNIQUE $( $( 1 $>@UNIQUE $( p@2 [@15 1 ] $) $) $?@UNIQUE $( 1 $) $:@UNIQUE $( p@2 [@15 1 ] $) $) ;\n"
"7: }\n";
ASSERT_EQUALS(exp, tokenizeExpr(code));
}

void structuredBindings() {
const char code[] = "int foo() { auto [x,y] = xy(); return x+y; }";
ASSERT_EQUALS("1: int foo ( ) { auto [ x@1 , y@2 ] = xy ( ) ; return x@1 + y@2 ; }\n",
Expand Down
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