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Fix 10647: FN knownConditionTrueFalse for impossible Boolean value #3968

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Merged
orbitcowboy merged 5 commits into from
Apr 3, 2022
Merged

Fix 10647: FN knownConditionTrueFalse for impossible Boolean value #3968

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e5856b5
Add impossible values for bool
pfultz2 Apr 3, 2022
2bb0fea
Fix valueflow tests
pfultz2 Apr 3, 2022
8fe69ab
Fix assertion failure
pfultz2 Apr 3, 2022
befd217
Add test
pfultz2 Apr 3, 2022
6d8d9a2
Format
pfultz2 Apr 3, 2022
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16 changes: 14 additions & 2 deletions lib/valueflow.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -374,7 +374,7 @@ static const Token *getCastTypeStartToken(const Token *parent)
// does the operation cause a loss of information?
static bool isNonInvertibleOperation(const Token* tok)
{
return tok->isComparisonOp() || Token::Match(tok, "%|/|&|%or%|<<|>>");
return tok->isComparisonOp() || Token::Match(tok, "%|/|&|%or%|<<|>>|%oror%|&&");
}

static bool isComputableValue(const Token* parent, const ValueFlow::Value& value)
Expand Down Expand Up @@ -1549,7 +1549,19 @@ static void valueFlowImpossibleValues(TokenList* tokenList, const Settings* sett
for (Token* tok = tokenList->front(); tok; tok = tok->next()) {
if (tok->hasKnownIntValue())
continue;
if (astIsUnsigned(tok) && !astIsPointer(tok)) {
if (Token::Match(tok, "true|false"))
continue;
if (astIsBool(tok) || Token::Match(tok, "%comp%")) {
ValueFlow::Value lower{-1};
lower.bound = ValueFlow::Value::Bound::Upper;
lower.setImpossible();
setTokenValue(tok, lower, settings);

ValueFlow::Value upper{2};
upper.bound = ValueFlow::Value::Bound::Lower;
upper.setImpossible();
setTokenValue(tok, upper, settings);
} else if (astIsUnsigned(tok) && !astIsPointer(tok)) {
std::vector<MathLib::bigint> minvalue = minUnsignedValue(tok);
if (minvalue.empty())
continue;
Expand Down
9 changes: 9 additions & 0 deletions test/testcondition.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -4008,6 +4008,15 @@ class TestCondition : public TestFixture {
" }\n"
"};\n");
ASSERT_EQUALS("", errout.str());

check("void f(const uint32_t u) {\n"
" const uint32_t v = u < 4;\n"
" if (v) {\n"
" const uint32_t w = v < 2;\n"
" if (w) {}\n"
" }\n"
"}\n");
ASSERT_EQUALS("[test.cpp:5]: (style) Condition 'w' is always true\n", errout.str());
}

void alwaysTrueSymbolic()
Expand Down
31 changes: 15 additions & 16 deletions test/testvalueflow.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -526,7 +526,7 @@ class TestValueFlow : public TestFixture {

#define valueOfTok(code, tokstr) valueOfTok_(code, tokstr, __FILE__, __LINE__)
ValueFlow::Value valueOfTok_(const char code[], const char tokstr[], const char* file, int line) {
std::list<ValueFlow::Value> values = tokenValues_(file, line, code, tokstr);
std::list<ValueFlow::Value> values = removeImpossible(tokenValues_(file, line, code, tokstr));
return values.size() == 1U && !values.front().isTokValue() ? values.front() : ValueFlow::Value();
}

Expand All @@ -552,8 +552,7 @@ class TestValueFlow : public TestFixture {
ASSERT_EQUALS(0, valueOfTok("x(NULL);", "NULL").intvalue);
ASSERT_EQUALS((int)('a'), valueOfTok("x='a';", "'a'").intvalue);
ASSERT_EQUALS((int)('\n'), valueOfTok("x='\\n';", "'\\n'").intvalue);
TODO_ASSERT_EQUALS(
0xFFFFFFFF00000000, -1, valueOfTok("x=0xFFFFFFFF00000000;", "0xFFFFFFFF00000000").intvalue); // #7701
TODO_ASSERT_EQUALS(0xFFFFFFFF00000000, 0, valueOfTok("x=0xFFFFFFFF00000000;", "0xFFFFFFFF00000000").intvalue); // #7701
ASSERT_EQUALS_DOUBLE(16, valueOfTok("x=(double)16;", "(").floatValue, 1e-5);
ASSERT_EQUALS_DOUBLE(0.0625, valueOfTok("x=1/(double)16;", "/").floatValue, 1e-5);

Expand Down Expand Up @@ -977,7 +976,7 @@ class TestValueFlow : public TestFixture {
" a = !x;\n"
" if (x==0) {}\n"
"}";
values = tokenValues(code,"!");
values = removeImpossible(tokenValues(code, "!"));
ASSERT_EQUALS(1U, values.size());
ASSERT_EQUALS(1, values.back().intvalue);

Expand Down Expand Up @@ -1077,22 +1076,22 @@ class TestValueFlow : public TestFixture {
}

// Comparison of string
values = tokenValues("f(\"xyz\" == \"xyz\");", "=="); // implementation defined
values = removeImpossible(tokenValues("f(\"xyz\" == \"xyz\");", "==")); // implementation defined
ASSERT_EQUALS(0U, values.size()); // <- no value

values = tokenValues("f(\"xyz\" == 0);", "==");
values = removeImpossible(tokenValues("f(\"xyz\" == 0);", "=="));
ASSERT_EQUALS(1U, values.size());
ASSERT_EQUALS(0, values.front().intvalue);

values = tokenValues("f(0 == \"xyz\");", "==");
values = removeImpossible(tokenValues("f(0 == \"xyz\");", "=="));
ASSERT_EQUALS(1U, values.size());
ASSERT_EQUALS(0, values.front().intvalue);

values = tokenValues("f(\"xyz\" != 0);", "!=");
values = removeImpossible(tokenValues("f(\"xyz\" != 0);", "!="));
ASSERT_EQUALS(1U, values.size());
ASSERT_EQUALS(1, values.front().intvalue);

values = tokenValues("f(0 != \"xyz\");", "!=");
values = removeImpossible(tokenValues("f(0 != \"xyz\");", "!="));
ASSERT_EQUALS(1U, values.size());
ASSERT_EQUALS(1, values.front().intvalue);
}
Expand Down Expand Up @@ -3771,7 +3770,7 @@ class TestValueFlow : public TestFixture {
" while (s.x < y)\n" // s.x does not have known value
" s.x++;\n"
"}";
values = tokenValues(code, "<");
values = removeImpossible(tokenValues(code, "<"));
ASSERT_EQUALS(1, values.size());
ASSERT(values.front().isPossible());
ASSERT_EQUALS(1, values.front().intvalue);
Expand Down Expand Up @@ -3811,7 +3810,7 @@ class TestValueFlow : public TestFixture {
" if (*b > 0) {\n" // *b does not have known value
" }\n"
"}";
values = tokenValues(code, ">");
values = removeImpossible(tokenValues(code, ">"));
ASSERT_EQUALS(1, values.size());
ASSERT(values.front().isPossible());
ASSERT_EQUALS(1, values.front().intvalue);
Expand All @@ -3824,7 +3823,7 @@ class TestValueFlow : public TestFixture {
" dostuff(&pvd);\n"
" } while (condition)\n"
"}";
values = tokenValues(code, "==");
values = removeImpossible(tokenValues(code, "=="));
ASSERT_EQUALS(1, values.size());
ASSERT(values.front().isPossible());
ASSERT_EQUALS(1, values.front().intvalue);
Expand All @@ -3834,7 +3833,7 @@ class TestValueFlow : public TestFixture {
"void foo(struct S s) {\n"
" for (s.x = 0; s.x < 127; s.x++) {}\n"
"}";
values = tokenValues(code, "<"); // TODO: comparison can be true or false
values = removeImpossible(tokenValues(code, "<")); // TODO: comparison can be true or false
ASSERT_EQUALS(true, values.empty());
}

Expand Down Expand Up @@ -5128,7 +5127,7 @@ class TestValueFlow : public TestFixture {
" if (b && i == j) return;\n"
" if(i != j) {}\n"
"}\n";
ASSERT_EQUALS(true, tokenValues(code, "!=").empty());
ASSERT_EQUALS(true, removeImpossible(tokenValues(code, "!=")).empty());

code = "void f(int i, int j) {\n"
" if (i == j) {\n"
Expand Down Expand Up @@ -5156,7 +5155,7 @@ class TestValueFlow : public TestFixture {
" if (i != j) {}\n"
" }\n"
"}\n";
ASSERT_EQUALS(true, tokenValues(code, "!=").empty());
ASSERT_EQUALS(true, removeImpossible(tokenValues(code, "!=")).empty());

code = "void f(bool b, int i, int j) {\n"
" if (b || i == j) {} else {\n"
Expand All @@ -5170,7 +5169,7 @@ class TestValueFlow : public TestFixture {
" if (i != j) {}\n"
" }\n"
"}\n";
ASSERT_EQUALS(true, tokenValues(code, "!=").empty());
ASSERT_EQUALS(true, removeImpossible(tokenValues(code, "!=")).empty());

code = "void foo()\n" // #8924
"{\n"
Expand Down