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dead code: fixed memory leaks, simplified code for empty do/while/if removing, removing of 'else' branch

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This commit is contained in:
mkoch
2024-01-14 15:36:52 +03:00
parent 5728736bc2
commit 4809857318
1 changed files with 29 additions and 51 deletions
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80
sapfor/experts/Sapfor_2017/_src/Transformations/dead_code.cpp
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@@ -10,6 +10,8 @@ using std::string;
using std::vector; using std::vector;
using std::set; using std::set;
#define PRINT_USELESS_STATEMENTS 1
static void updateUseDefForInstruction(SAPFOR::BasicBlock* block, SAPFOR::Instruction* instr, static void updateUseDefForInstruction(SAPFOR::BasicBlock* block, SAPFOR::Instruction* instr,
set<SAPFOR::Argument*>& use, set<SAPFOR::Argument*>& def, set<SAPFOR::Argument*>& use, set<SAPFOR::Argument*>& def,
vector<SAPFOR::Argument*>& formal_parameters, vector<SAPFOR::Argument*>& formal_parameters,
@@ -318,12 +320,6 @@ void removeDeadCode(SgStatement* func,
{ {
SgProgHedrStmt* prog = isSgProgHedrStmt(func); SgProgHedrStmt* prog = isSgProgHedrStmt(func);
if (prog)
__spf_print(1, "[analyze %s]\n", prog->name().identifier());
else
__spf_print(1, "[cannot resolve name of function]\n");
auto cfg = buildCFGforCurrentFunc(func, SAPFOR::CFG_Settings(true, false, false, false, false, false, false), commonBlocks, allFuncs); auto cfg = buildCFGforCurrentFunc(func, SAPFOR::CFG_Settings(true, false, false, false, false, false, false), commonBlocks, allFuncs);
if(cfg.size() != 1) if(cfg.size() != 1)
@@ -333,14 +329,14 @@ void removeDeadCode(SgStatement* func,
vector<SAPFOR::Argument*> func_parameters(cfg_pair.first->funcParams.countOfPars, NULL); vector<SAPFOR::Argument*> func_parameters(cfg_pair.first->funcParams.countOfPars, NULL);
DeadCodeAnalysis* analysis_object = new DeadCodeAnalysis(func_parameters); DeadCodeAnalysis analysis_object(func_parameters);
analysis_object->fit(cfg_pair.second); analysis_object.fit(cfg_pair.second);
analysis_object->analyze(); analysis_object.analyze();
set<SgStatement*> useful; set<SgStatement*> useful;
for (DeadCodeAnalysisNode* byNode : analysis_object->getNodes()) for (DeadCodeAnalysisNode* byNode : analysis_object.getNodes())
{ {
const auto& instructions = byNode->getBlock()->getInstructions(); const auto& instructions = byNode->getBlock()->getInstructions();
const auto& statuses = byNode->getResult(); const auto& statuses = byNode->getResult();
@@ -357,10 +353,7 @@ void removeDeadCode(SgStatement* func,
SgStatement* stmt = instructions[i]->getInstruction()->getOperator(); SgStatement* stmt = instructions[i]->getInstruction()->getOperator();
while(stmt && useful.insert(stmt).second) while(stmt && useful.insert(stmt).second)
{
__spf_print(1, "[Useful statement '%s' on line %d]\n", stmt->unparse(), stmt->lineNumber());
stmt = stmt->controlParent(); stmt = stmt->controlParent();
}
} }
} }
} }
@@ -372,65 +365,50 @@ void removeDeadCode(SgStatement* func,
ASSIGN_STAT ASSIGN_STAT
}; };
SgStatement* enclosing = st->controlParent();
SgStatement* encl_end = enclosing ? enclosing->lastNodeOfStmt() : NULL;
while (st != end) while (st != end)
{ {
SgStatement* next = st->lexNext(); SgStatement* next = st->lexNext();
SgStatement* parent = NULL;
if (removable.find(st->variant()) != removable.end() && useful.find(st) == useful.end()) if (removable.find(st->variant()) != removable.end() && useful.find(st) == useful.end())
{ {
__spf_print(1, "[Useless statement '%s' on line %d]\n", st->unparse(), st->lineNumber()); __spf_print(PRINT_USELESS_STATEMENTS, "[Useless statement '%s' on line %d]\n", st->unparse(), st->lineNumber());
parent = st->controlParent(); st->deleteStmt();
st->extractStmt()->deleteStmt();
st = NULL;
} }
else else
{ {
if (st == encl_end) if (isSgControlEndStmt(st))
{ {
if (enclosing) SgStatement* parent = st->controlParent();
SgStatement* parent_end;
if (parent && (parent_end = parent->lastNodeOfStmt()) && parent_end == st)
{ {
bool empty_parent = false; bool empty_parent = false;
switch (enclosing->variant()) switch (parent->variant())
{ {
case IF_NODE: case IF_NODE:
empty_parent = empty_parent =
enclosing->lexNext() == encl_end || // IF THEN ENDIF parent->lexNext() == parent_end || // IF THEN ENDIF
enclosing->lexNext()->variant() == CONTROL_END && isSgControlEndStmt(parent->lexNext()) &&
enclosing->lexNext()->lexNext() == encl_end; // IF THEN ELSE ENDIF parent->lexNext()->lexNext() == parent_end; // IF THEN ELSE ENDIF
break; break;
default: default:
empty_parent = enclosing->lexNext() == encl_end; empty_parent = parent->lexNext() == parent_end; // DO, WHILE
break; break;
} }
if(empty_parent) if (empty_parent)
{ parent->deleteStmt();
parent = enclosing->controlParent(); else if(isSgIfStmt(parent) && isSgControlEndStmt(parent_end->lexPrev())) // IF with empty ELSE branch
enclosing->extractStmt()->deleteStmt(); parent_end->deleteStmt();
st->extractStmt()->deleteStmt();
st = NULL;
}
} }
} }
} }
if(!parent)
parent = st->controlParent();
if (parent != enclosing)
{
enclosing = parent;
encl_end = enclosing ? enclosing->lastNodeOfStmt() : NULL;
}
st = next; st = next;
} }
deleteCFG(cfg);
} }