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valueflow: better handling of increment/decrement

This commit is contained in:
Daniel Marjamäki 2014-01-17 19:28:28 +01:00
parent 18d6285ad2
commit 57d318b2e5
2 changed files with 26 additions and 2 deletions
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13
lib/valueflow.cpp
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@ -184,7 +184,7 @@ static void valueFlowBeforeCondition(TokenList *tokenlist, ErrorLogger *errorLog
continue; continue;
// extra logic for unsigned variables 'i>=1' => possible value can also be 0 // extra logic for unsigned variables 'i>=1' => possible value can also be 0
const ValueFlow::Value val(tok, num); ValueFlow::Value val(tok, num);
ValueFlow::Value val2; ValueFlow::Value val2;
if (num==1U && Token::Match(tok,"<=|>=")) { if (num==1U && Token::Match(tok,"<=|>=")) {
bool isunsigned = false; bool isunsigned = false;
@ -214,6 +214,17 @@ static void valueFlowBeforeCondition(TokenList *tokenlist, ErrorLogger *errorLog
break; break;
} }
// increment/decrement
if (Token::Match(tok2->previous(), "[;{}] %var% ++|-- ;"))
val.intvalue += (tok2->strAt(1)=="++") ? -1 : 1;
else if (Token::Match(tok2->tokAt(-2), "[;{}] ++|-- %var% ;"))
val.intvalue += (tok2->strAt(-1)=="++") ? -1 : 1;
else if (Token::Match(tok2->previous(), "++|-- %var%") || Token::Match(tok2, "%var% ++|--")) {
if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok2, "increment/decrement of " + tok2->str());
break;
}
// bailout: variable is used in rhs in assignment to itself // bailout: variable is used in rhs in assignment to itself
if (bailoutSelfAssignment(tok2)) { if (bailoutSelfAssignment(tok2)) {
if (settings->debugwarnings) if (settings->debugwarnings)

15
test/testvalueflow.cpp
View File

@ -109,7 +109,7 @@ private:
"}"; "}";
ASSERT_EQUALS(true, testValueOfX(code, 3U, 123)); ASSERT_EQUALS(true, testValueOfX(code, 3U, 123));
// assignment // assignment / increment
code = "void f(int x) {\n" code = "void f(int x) {\n"
" x = 2 + x;\n" " x = 2 + x;\n"
" if (x == 65);\n" " if (x == 65);\n"
@ -122,6 +122,19 @@ private:
"}"; "}";
ASSERT_EQUALS(false, testValueOfX(code, 2U, 65)); ASSERT_EQUALS(false, testValueOfX(code, 2U, 65));
code = "void f(int x) {\n"
" a[x++] = 0;\n"
" if (x == 5);\n"
"}";
ASSERT_EQUALS(false, testValueOfX(code, 2U, 5));
code = "void f(int x) {\n"
" a = x;\n"
" x++;\n"
" if (x == 4);\n"
"}";
ASSERT_EQUALS(true, testValueOfX(code, 2U, 3));
// guarding by && // guarding by &&
code = "void f(int x) {\n" code = "void f(int x) {\n"
" if (!x || \n" // <- x can be 0 " if (!x || \n" // <- x can be 0