Author: rsmith
Date: Fri Jan 13 16:16:41 2017
New Revision: 291964
URL: http://llvm.org/viewvc/llvm-project?rev=291964&view=rev
Log:
PR31631: fix bad CFG (and bogus warnings) when an if-statement has an
init-statement and has binary operator as its condition.
Modified:
cfe/trunk/lib/Analysis/CFG.cpp
cfe/trunk/test/SemaCXX/uninitialized.cpp
Modified: cfe/trunk/lib/Analysis/CFG.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Analysis/CFG.cpp?rev=291964&r1=291963&r2=291964&view=diff
==============================================================================
--- cfe/trunk/lib/Analysis/CFG.cpp (original)
+++ cfe/trunk/lib/Analysis/CFG.cpp Fri Jan 13 16:16:41 2017
@@ -2175,19 +2175,15 @@ CFGBlock *CFGBuilder::VisitIfStmt(IfStmt
SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos);
// Create local scope for C++17 if init-stmt if one exists.
- if (Stmt *Init = I->getInit()) {
- LocalScope::const_iterator BeginScopePos = ScopePos;
+ if (Stmt *Init = I->getInit())
addLocalScopeForStmt(Init);
- addAutomaticObjDtors(ScopePos, BeginScopePos, I);
- }
// Create local scope for possible condition variable.
// Store scope position. Add implicit destructor.
- if (VarDecl *VD = I->getConditionVariable()) {
- LocalScope::const_iterator BeginScopePos = ScopePos;
+ if (VarDecl *VD = I->getConditionVariable())
addLocalScopeForVarDecl(VD);
- addAutomaticObjDtors(ScopePos, BeginScopePos, I);
- }
+
+ addAutomaticObjDtors(ScopePos, save_scope_pos.get(), I);
// The block we were processing is now finished. Make it the successor
// block.
@@ -2256,36 +2252,39 @@ CFGBlock *CFGBuilder::VisitIfStmt(IfStmt
// removes infeasible paths from the control-flow graph by having the
// control-flow transfer of '&&' or '||' go directly into the then/else
// blocks directly.
- if (!I->getConditionVariable())
- if (BinaryOperator *Cond =
- dyn_cast<BinaryOperator>(I->getCond()->IgnoreParens()))
- if (Cond->isLogicalOp())
- return VisitLogicalOperator(Cond, I, ThenBlock, ElseBlock).first;
-
- // Now create a new block containing the if statement.
- Block = createBlock(false);
+ BinaryOperator *Cond =
+ I->getConditionVariable()
+ ? nullptr
+ : dyn_cast<BinaryOperator>(I->getCond()->IgnoreParens());
+ CFGBlock *LastBlock;
+ if (Cond && Cond->isLogicalOp())
+ LastBlock = VisitLogicalOperator(Cond, I, ThenBlock, ElseBlock).first;
+ else {
+ // Now create a new block containing the if statement.
+ Block = createBlock(false);
- // Set the terminator of the new block to the If statement.
- Block->setTerminator(I);
+ // Set the terminator of the new block to the If statement.
+ Block->setTerminator(I);
- // See if this is a known constant.
- const TryResult &KnownVal = tryEvaluateBool(I->getCond());
+ // See if this is a known constant.
+ const TryResult &KnownVal = tryEvaluateBool(I->getCond());
- // Add the successors. If we know that specific branches are
- // unreachable, inform addSuccessor() of that knowledge.
- addSuccessor(Block, ThenBlock, /* isReachable = */ !KnownVal.isFalse());
- addSuccessor(Block, ElseBlock, /* isReachable = */ !KnownVal.isTrue());
-
- // Add the condition as the last statement in the new block. This may create
- // new blocks as the condition may contain control-flow. Any newly created
- // blocks will be pointed to be "Block".
- CFGBlock *LastBlock = addStmt(I->getCond());
-
- // If the IfStmt contains a condition variable, add it and its
- // initializer to the CFG.
- if (const DeclStmt* DS = I->getConditionVariableDeclStmt()) {
- autoCreateBlock();
- LastBlock = addStmt(const_cast<DeclStmt *>(DS));
+ // Add the successors. If we know that specific branches are
+ // unreachable, inform addSuccessor() of that knowledge.
+ addSuccessor(Block, ThenBlock, /* isReachable = */ !KnownVal.isFalse());
+ addSuccessor(Block, ElseBlock, /* isReachable = */ !KnownVal.isTrue());
+
+ // Add the condition as the last statement in the new block. This may
+ // create new blocks as the condition may contain control-flow. Any newly
+ // created blocks will be pointed to be "Block".
+ LastBlock = addStmt(I->getCond());
+
+ // If the IfStmt contains a condition variable, add it and its
+ // initializer to the CFG.
+ if (const DeclStmt* DS = I->getConditionVariableDeclStmt()) {
+ autoCreateBlock();
+ LastBlock = addStmt(const_cast<DeclStmt *>(DS));
+ }
}
// Finally, if the IfStmt contains a C++17 init-stmt, add it to the CFG.
@@ -3078,19 +3077,15 @@ CFGBlock *CFGBuilder::VisitSwitchStmt(Sw
SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos);
// Create local scope for C++17 switch init-stmt if one exists.
- if (Stmt *Init = Terminator->getInit()) {
- LocalScope::const_iterator BeginScopePos = ScopePos;
+ if (Stmt *Init = Terminator->getInit())
addLocalScopeForStmt(Init);
- addAutomaticObjDtors(ScopePos, BeginScopePos, Terminator);
- }
// Create local scope for possible condition variable.
// Store scope position. Add implicit destructor.
- if (VarDecl *VD = Terminator->getConditionVariable()) {
- LocalScope::const_iterator SwitchBeginScopePos = ScopePos;
+ if (VarDecl *VD = Terminator->getConditionVariable())
addLocalScopeForVarDecl(VD);
- addAutomaticObjDtors(ScopePos, SwitchBeginScopePos, Terminator);
- }
+
+ addAutomaticObjDtors(ScopePos, save_scope_pos.get(), Terminator);
if (Block) {
if (badCFG)
Modified: cfe/trunk/test/SemaCXX/uninitialized.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/uninitialized.cpp?rev=291964&r1=291963&r2=291964&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/uninitialized.cpp (original)
+++ cfe/trunk/test/SemaCXX/uninitialized.cpp Fri Jan 13 16:16:41 2017
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -Wall -Wuninitialized -Wno-unused-value
-Wno-unused-lambda-capture -std=c++11 -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wall -Wuninitialized -Wno-unused-value
-Wno-unused-lambda-capture -std=c++1z -verify %s
// definitions for std::move
namespace std {
@@ -1437,3 +1437,13 @@ void array_capture(bool b) {
[fname]{};
}
}
+
+void if_switch_init_stmt(int k) {
+ if (int n = 0; (n == k || k > 5)) {}
+
+ if (int n; (n == k || k > 5)) {} // expected-warning {{uninitialized}}
expected-note {{initialize}}
+
+ switch (int n = 0; (n == k || k > 5)) {} // expected-warning {{boolean}}
+
+ switch (int n; (n == k || k > 5)) {} // expected-warning {{uninitialized}}
expected-note {{initialize}} expected-warning {{boolean}}
+}
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