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ValueFlow: Improved analysis in the valueFlowAfterAssign

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This commit is contained in:
Daniel Marjamäki 2014-04-22 16:10:20 +02:00
parent 2c3807f089
commit fe80f858d1
2 changed files with 26 additions and 3 deletions
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19
lib/valueflow.cpp
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@ -527,17 +527,30 @@ static void valueFlowAfterAssign(TokenList *tokenlist, ErrorLogger *errorLogger,
continue; continue;
std::list<ValueFlow::Value> values = tok->astOperand2()->values; std::list<ValueFlow::Value> values = tok->astOperand2()->values;
const bool constValue = tok->astOperand2()->isNumber();
int indentlevel = 0;
unsigned int number_of_if = 0; unsigned int number_of_if = 0;
int varusagelevel = -1;
for (Token *tok2 = tok; tok2 && tok2 != endToken; tok2 = tok2->next()) { for (Token *tok2 = tok; tok2 && tok2 != endToken; tok2 = tok2->next()) {
if (indentlevel >= 0 && tok2->str() == "{")
++indentlevel;
else if (indentlevel >= 0 && tok2->str() == "}")
--indentlevel;
if (Token::Match(tok2, "sizeof|typeof|typeid (")) if (Token::Match(tok2, "sizeof|typeof|typeid ("))
tok2 = tok2->linkAt(1); tok2 = tok2->linkAt(1);
// conditional block of code that assigns variable.. // conditional block of code that assigns variable..
if (Token::Match(tok2, "%var% (") && Token::simpleMatch(tok2->linkAt(1), ") {")) { else if (Token::Match(tok2, "%var% (") && Token::simpleMatch(tok2->linkAt(1), ") {")) {
Token * const start = tok2->linkAt(1)->next(); Token * const start = tok2->linkAt(1)->next();
Token * const end = start->link(); Token * const end = start->link();
if (Token::findmatch(start, "%varid%", end, varid)) { bool varusage = (indentlevel >= 0 && constValue && number_of_if == 0U) ?
isVariableChanged(start,end,varid) :
(nullptr != Token::findmatch(start, "%varid%", end, varid));
if (varusage) {
varusagelevel = indentlevel;
// TODO: don't check noreturn scopes // TODO: don't check noreturn scopes
if (number_of_if > 0U || Token::findmatch(tok2, "%varid%", start, varid)) { if (number_of_if > 0U || Token::findmatch(tok2, "%varid%", start, varid)) {
if (settings->debugwarnings) if (settings->debugwarnings)
@ -586,7 +599,7 @@ static void valueFlowAfterAssign(TokenList *tokenlist, ErrorLogger *errorLogger,
} }
} }
else if (tok2->str() == "}") { else if (tok2->str() == "}" && indentlevel == varusagelevel) {
++number_of_if; ++number_of_if;
// Set "conditional" flag for all values // Set "conditional" flag for all values

10
test/testvalueflow.cpp
View File

@ -594,6 +594,16 @@ private:
"}"; "}";
TODO_ASSERT_EQUALS(true, false, testValueOfX(code, 4U, 32)); TODO_ASSERT_EQUALS(true, false, testValueOfX(code, 4U, 32));
code = "void f() {\n"
" int x = 32;\n"
" if (a==1) { z=x+12; }\n"
" if (a==2) { z=x+32; }\n"
" z = x;\n"
"}";
ASSERT_EQUALS(true, testValueOfX(code, 3U, 32));
ASSERT_EQUALS(true, testValueOfX(code, 4U, 32));
ASSERT_EQUALS(true, testValueOfX(code, 5U, 32));
code = "void f() {\n" // #5656 - FP code = "void f() {\n" // #5656 - FP
" int x = 0;\n" " int x = 0;\n"
" if (!x) {\n" " if (!x) {\n"