[cfe-commits] r82702 - in /cfe/trunk: include/clang/Analysis/CFG.h lib/Analysis/CFG.cpp
Ted Kremenek
kremenek at apple.com
Thu Sep 24 11:45:41 PDT 2009
Author: kremenek
Date: Thu Sep 24 13:45:41 2009
New Revision: 82702
URL: http://llvm.org/viewvc/llvm-project?rev=82702&view=rev
Log:
When building CFGs, no longer reverse the statements in the CFGBlock. Instead
have the iterators and operator[] handle the traversal of statements, as they
are stored in reverse order. Tests show this has no real performance impact, but
it does simply the CFG construction logic and will make it slightly easier to
change the allocation strategy for CFGBlocks (as we have fewer copies).
Modified:
cfe/trunk/include/clang/Analysis/CFG.h
cfe/trunk/lib/Analysis/CFG.cpp
Modified: cfe/trunk/include/clang/Analysis/CFG.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Analysis/CFG.h?rev=82702&r1=82701&r2=82702&view=diff
==============================================================================
--- cfe/trunk/include/clang/Analysis/CFG.h (original)
+++ cfe/trunk/include/clang/Analysis/CFG.h Thu Sep 24 13:45:41 2009
@@ -57,9 +57,39 @@
/// &&, || expression that uses result of && or ||, RHS
///
class CFGBlock {
- typedef std::vector<Stmt*> StatementListTy;
+ class StatementList {
+ typedef std::vector<Stmt*> ImplTy;
+ ImplTy Impl;
+ public:
+ typedef std::reverse_iterator<ImplTy::iterator> iterator;
+ typedef std::reverse_iterator<ImplTy::const_iterator> const_iterator;
+ typedef ImplTy::iterator reverse_iterator;
+ typedef ImplTy::const_iterator const_reverse_iterator;
+
+ void push_back(Stmt *s) { Impl.push_back(s); }
+ Stmt *front() const { return Impl.back(); }
+ Stmt *back() const { return Impl.front(); }
+
+ iterator begin() { return Impl.rbegin(); }
+ iterator end() { return Impl.rend(); }
+ const_iterator begin() const { return Impl.rbegin(); }
+ const_iterator end() const { return Impl.rend(); }
+ reverse_iterator rbegin() { return Impl.begin(); }
+ reverse_iterator rend() { return Impl.end(); }
+ const_reverse_iterator rbegin() const { return Impl.begin(); }
+ const_reverse_iterator rend() const { return Impl.end(); }
+
+ Stmt* operator[](size_t i) const {
+ assert(i < Impl.size());
+ return Impl[Impl.size() - 1 - i];
+ }
+
+ size_t size() const { return Impl.size(); }
+ bool empty() const { return Impl.empty(); }
+ };
+
/// Stmts - The set of statements in the basic block.
- StatementListTy Stmts;
+ StatementList Stmts;
/// Label - An (optional) label that prefixes the executable
/// statements in the block. When this variable is non-NULL, it is
@@ -92,10 +122,10 @@
~CFGBlock() {};
// Statement iterators
- typedef StatementListTy::iterator iterator;
- typedef StatementListTy::const_iterator const_iterator;
- typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
- typedef std::reverse_iterator<iterator> reverse_iterator;
+ typedef StatementList::iterator iterator;
+ typedef StatementList::const_iterator const_iterator;
+ typedef StatementList::reverse_iterator reverse_iterator;
+ typedef StatementList::const_reverse_iterator const_reverse_iterator;
Stmt* front() const { return Stmts.front(); }
Stmt* back() const { return Stmts.back(); }
@@ -113,7 +143,8 @@
unsigned size() const { return Stmts.size(); }
bool empty() const { return Stmts.empty(); }
- Stmt* operator[](size_t i) const { assert (i < size()); return Stmts[i]; }
+ Stmt* operator[](size_t i) const { return Stmts[i]; }
+
// CFG iterators
typedef AdjacentBlocks::iterator pred_iterator;
Modified: cfe/trunk/lib/Analysis/CFG.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Analysis/CFG.cpp?rev=82702&r1=82701&r2=82702&view=diff
==============================================================================
--- cfe/trunk/lib/Analysis/CFG.cpp (original)
+++ cfe/trunk/lib/Analysis/CFG.cpp Thu Sep 24 13:45:41 2009
@@ -270,14 +270,12 @@
return B;
}
-/// FinishBlock - When the last statement has been added to the block, we must
-/// reverse the statements because they have been inserted in reverse order.
+/// FinishBlock - "Finalize" the block by checking if we have a bad CFG.
bool CFGBuilder::FinishBlock(CFGBlock* B) {
if (badCFG)
return false;
assert(B);
- B->reverseStmts();
return true;
}
@@ -699,9 +697,8 @@
// first statement we are processing. In either case, we create a new basic
// block. First, we create the blocks for the then...else statements, and
// then we create the block containing the if statement. If we were in the
- // middle of a block, we stop processing that block and reverse its
- // statements. That block is then the implicit successor for the "then" and
- // "else" clauses.
+ // middle of a block, we stop processing that block. That block is then the
+ // implicit successor for the "then" and "else" clauses.
// The block we were proccessing is now finished. Make it the successor
// block.
@@ -772,14 +769,14 @@
CFGBlock* CFGBuilder::VisitReturnStmt(ReturnStmt* R) {
- // If we were in the middle of a block we stop processing that block and
- // reverse its statements.
+ // If we were in the middle of a block we stop processing that block.
//
// NOTE: If a "return" appears in the middle of a block, this means that the
// code afterwards is DEAD (unreachable). We still keep a basic block
// for that code; a simple "mark-and-sweep" from the entry block will be
// able to report such dead blocks.
- if (Block) FinishBlock(Block);
+ if (Block)
+ FinishBlock(Block);
// Create the new block.
Block = createBlock(false);
@@ -1183,8 +1180,7 @@
// FIXME: This isn't complete. We basically treat @throw like a return
// statement.
- // If we were in the middle of a block we stop processing that block and
- // reverse its statements.
+ // If we were in the middle of a block we stop processing that block.
if (Block && !FinishBlock(Block))
return 0;
@@ -1200,8 +1196,7 @@
}
CFGBlock* CFGBuilder::VisitCXXThrowExpr(CXXThrowExpr* T) {
- // If we were in the middle of a block we stop processing that block and
- // reverse its statements.
+ // If we were in the middle of a block we stop processing that block.
if (Block && !FinishBlock(Block))
return 0;
@@ -1518,9 +1513,6 @@
return Builder.buildCFG(Statement, C);
}
-/// reverseStmts - Reverses the orders of statements within a CFGBlock.
-void CFGBlock::reverseStmts() { std::reverse(Stmts.begin(),Stmts.end()); }
-
//===----------------------------------------------------------------------===//
// CFG: Queries for BlkExprs.
//===----------------------------------------------------------------------===//
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