replica
/
hanchenye-llvm-project
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Fixed bug where the CFG would fail to build when an 'if' statement had 

an empty then or else block (or contained only ';' statements).

For example, we now handle the following:

int empty_else() { if (0) { int a; } else ; }
int empty_then() { if (0) ; else { int a; } }

Thanks to Nico Weber for spotting this problem.

llvm-svn: 41617
This commit is contained in:
Ted Kremenek 2007-08-30 18:13:31 +00:00
parent 90dfdd5774
commit bbad8ce2e7
1 changed files with 14 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
clang/AST/CFG.cpp
View File

@ -34,6 +34,7 @@ template<typename T>
struct SaveAndRestore {
SaveAndRestore(T& x) : X(x), old_value(x) {}
~SaveAndRestore() { X = old_value; }
T get() { return old_value; }
T& X;
T old_value;
@ -397,8 +398,11 @@ CFGBlock* CFGBuilder::VisitIfStmt(IfStmt* I) {
// create a new basic block.
Block = NULL;
ElseBlock = Visit(Else);
if (!ElseBlock) return NULL;
if (Block) FinishBlock(ElseBlock);
if (!ElseBlock) // Can occur when the Else body has all NullStmts.
ElseBlock = sv.get();
else if (Block)
FinishBlock(ElseBlock);
}
// Process the true branch. NULL out Block so that the recursive
@ -411,8 +415,11 @@ CFGBlock* CFGBuilder::VisitIfStmt(IfStmt* I) {
SaveAndRestore<CFGBlock*> sv(Succ);
Block = NULL;
ThenBlock = Visit(Then);
if (!ThenBlock) return NULL;
if (Block) FinishBlock(ThenBlock);
if (!ThenBlock) // Can occur when the Then body has all NullStmts.
ThenBlock = sv.get();
else if (Block)
FinishBlock(ThenBlock);
}
// Now create a new block containing the if statement.