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Unused var: Limit bailout for foreach loops. Only bailout if name contains 'foreach' or 'for_each'. Only bailout variables that are used more than once in the body. Ticket: #4155

This commit is contained in:
Daniel Marjamäki 2012-12-17 18:19:05 +01:00
parent 72ea94bf75
commit 1e2fb4f1a4
2 changed files with 40 additions and 8 deletions
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25
lib/checkunusedvar.cpp
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@ -20,7 +20,7 @@
//--------------------------------------------------------------------------- //---------------------------------------------------------------------------
#include "checkunusedvar.h" #include "checkunusedvar.h"
#include "symboldatabase.h" #include "symboldatabase.h"
#include <algorithm>
//--------------------------------------------------------------------------- //---------------------------------------------------------------------------
// Register this check class (by creating a static instance of it) // Register this check class (by creating a static instance of it)
@ -746,11 +746,24 @@ void CheckUnusedVar::checkFunctionVariableUsage_iterateScopes(const Scope* const
break; break;
} }
if (Token::Match(tok,"%var% (") && Token::simpleMatch(tok->linkAt(1),") {") && !Token::Match(tok, "for|while|if|catch")) { // bailout when for_each is used
const Token * const endTok = tok->linkAt(1)->linkAt(1); if (Token::Match(tok,"%var% (") && Token::simpleMatch(tok->linkAt(1),") {")) {
for (const Token *tok2 = endTok->link(); tok2 && tok2 != endTok; tok2 = tok2->next()) { // does the name contain "for_each" or "foreach"?
if (tok2->varId()) std::string name(tok->str());
variables.erase(tok2->varId()); std::transform(name.begin(),name.end(),name.begin(),static_cast<int(*)(int)>(std::tolower));
if (name.find("foreach") != std::string::npos || name.find("for_each") != std::string::npos) {
// bailout all variables in the body that are used more than once.
// TODO: there is no need to bailout if variable is only read or only written
std::set<unsigned int> varid;
const Token * const endTok = tok->linkAt(1)->linkAt(1);
for (const Token *tok2 = endTok->link(); tok2 && tok2 != endTok; tok2 = tok2->next()) {
if (tok2->varId()) {
if (varid.find(tok2->varId()) == varid.end())
varid.insert(tok2->varId());
else
variables.erase(tok2->varId());
}
}
} }
} }

23
test/testunusedvar.cpp
View File

@ -135,7 +135,7 @@ private:
TEST_CASE(localvarIfElse); // return tmp1 ? tmp2 : tmp3; TEST_CASE(localvarIfElse); // return tmp1 ? tmp2 : tmp3;
TEST_CASE(localvarOpAssign); // a |= b; TEST_CASE(localvarOpAssign); // a |= b;
TEST_CASE(localvarFor); // for ( ; var; ) TEST_CASE(localvarFor); // for ( ; var; )
TEST_CASE(localvarForEach); // BOOST_FOREACH, hlist_for_each, etc TEST_CASE(localvarForEach); // #4155 - BOOST_FOREACH, hlist_for_each, etc
TEST_CASE(localvarShift1); // 1 >> var TEST_CASE(localvarShift1); // 1 >> var
TEST_CASE(localvarShift2); // x = x >> 1 TEST_CASE(localvarShift2); // x = x >> 1
TEST_CASE(localvarShift3); // x << y TEST_CASE(localvarShift3); // x << y
@ -2949,7 +2949,7 @@ private:
ASSERT_EQUALS("", errout.str()); ASSERT_EQUALS("", errout.str());
} }
void localvarForEach() { void localvarForEach() { // #4155 - foreach
functionVariableUsage("void foo() {\n" functionVariableUsage("void foo() {\n"
" int i = -1;\n" " int i = -1;\n"
" int a[] = {1,2,3};\n" " int a[] = {1,2,3};\n"
@ -2959,6 +2959,25 @@ private:
" }\n" " }\n"
"}\n"); "}\n");
ASSERT_EQUALS("", errout.str()); ASSERT_EQUALS("", errout.str());
functionVariableUsage("void foo() {\n"
" int i = -1;\n"
" int a[] = {1,2,3};\n"
" FOREACH_X (int x, a) {\n"
" i = x;\n"
" }\n"
"}\n");
ASSERT_EQUALS("[test.cpp:5]: (style) Variable 'i' is assigned a value that is never used.\n", errout.str());
functionVariableUsage("void foo() {\n"
" int i = -1;\n"
" int a[] = {1,2,3};\n"
" X (int x, a) {\n"
" if (i==x) return x;\n"
" i = x;\n"
" }\n"
"}\n");
ASSERT_EQUALS("[test.cpp:6]: (style) Variable 'i' is assigned a value that is never used.\n", errout.str());
} }
void localvarShift1() { void localvarShift1() {