Add support for C++0x's range-based for loops, as specified by the C++11 draft standard (N3291).
llvm-svn: 129541
diff --git a/clang/lib/Analysis/CFG.cpp b/clang/lib/Analysis/CFG.cpp
index 3dcc763..1496074 100644
--- a/clang/lib/Analysis/CFG.cpp
+++ b/clang/lib/Analysis/CFG.cpp
@@ -312,6 +312,7 @@
AddStmtChoice asc);
CFGBlock *VisitCXXThrowExpr(CXXThrowExpr *T);
CFGBlock *VisitCXXTryStmt(CXXTryStmt *S);
+ CFGBlock *VisitCXXForRangeStmt(CXXForRangeStmt *S);
CFGBlock *VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E,
AddStmtChoice asc);
CFGBlock *VisitCXXConstructExpr(CXXConstructExpr *C, AddStmtChoice asc);
@@ -911,6 +912,9 @@
case Stmt::CXXTryStmtClass:
return VisitCXXTryStmt(cast<CXXTryStmt>(S));
+ case Stmt::CXXForRangeStmtClass:
+ return VisitCXXForRangeStmt(cast<CXXForRangeStmt>(S));
+
case Stmt::DeclStmtClass:
return VisitDeclStmt(cast<DeclStmt>(S));
@@ -2513,6 +2517,122 @@
return CatchBlock;
}
+CFGBlock* CFGBuilder::VisitCXXForRangeStmt(CXXForRangeStmt* S) {
+ // C++0x for-range statements are specified as [stmt.ranged]:
+ //
+ // {
+ // auto && __range = range-init;
+ // for ( auto __begin = begin-expr,
+ // __end = end-expr;
+ // __begin != __end;
+ // ++__begin ) {
+ // for-range-declaration = *__begin;
+ // statement
+ // }
+ // }
+
+ // Save local scope position before the addition of the implicit variables.
+ SaveAndRestore<LocalScope::const_iterator> save_scope_pos(ScopePos);
+
+ // Create local scopes and destructors for range, begin and end variables.
+ if (Stmt *Range = S->getRangeStmt())
+ addLocalScopeForStmt(Range);
+ if (Stmt *BeginEnd = S->getBeginEndStmt())
+ addLocalScopeForStmt(BeginEnd);
+ addAutomaticObjDtors(ScopePos, save_scope_pos.get(), S);
+
+ LocalScope::const_iterator ContinueScopePos = ScopePos;
+
+ // "for" is a control-flow statement. Thus we stop processing the current
+ // block.
+ CFGBlock* LoopSuccessor = NULL;
+ if (Block) {
+ if (badCFG)
+ return 0;
+ LoopSuccessor = Block;
+ } else
+ LoopSuccessor = Succ;
+
+ // Save the current value for the break targets.
+ // All breaks should go to the code following the loop.
+ SaveAndRestore<JumpTarget> save_break(BreakJumpTarget);
+ BreakJumpTarget = JumpTarget(LoopSuccessor, ScopePos);
+
+ // The block for the __begin != __end expression.
+ CFGBlock* ConditionBlock = createBlock(false);
+ ConditionBlock->setTerminator(S);
+
+ // Now add the actual condition to the condition block.
+ if (Expr *C = S->getCond()) {
+ Block = ConditionBlock;
+ CFGBlock *BeginConditionBlock = addStmt(C);
+ if (badCFG)
+ return 0;
+ assert(BeginConditionBlock == ConditionBlock &&
+ "condition block in for-range was unexpectedly complex");
+ (void)BeginConditionBlock;
+ }
+
+ // The condition block is the implicit successor for the loop body as well as
+ // any code above the loop.
+ Succ = ConditionBlock;
+
+ // See if this is a known constant.
+ TryResult KnownVal(true);
+
+ if (S->getCond())
+ KnownVal = tryEvaluateBool(S->getCond());
+
+ // Now create the loop body.
+ {
+ assert(S->getBody());
+
+ // Save the current values for Block, Succ, and continue targets.
+ SaveAndRestore<CFGBlock*> save_Block(Block), save_Succ(Succ);
+ SaveAndRestore<JumpTarget> save_continue(ContinueJumpTarget);
+
+ // Generate increment code in its own basic block. This is the target of
+ // continue statements.
+ Block = 0;
+ Succ = addStmt(S->getInc());
+ ContinueJumpTarget = JumpTarget(Succ, ContinueScopePos);
+
+ // The starting block for the loop increment is the block that should
+ // represent the 'loop target' for looping back to the start of the loop.
+ ContinueJumpTarget.block->setLoopTarget(S);
+
+ // Finish up the increment block and prepare to start the loop body.
+ assert(Block);
+ if (badCFG)
+ return 0;
+ Block = 0;
+
+
+ // Add implicit scope and dtors for loop variable.
+ addLocalScopeAndDtors(S->getLoopVarStmt());
+
+ // Populate a new block to contain the loop body and loop variable.
+ Block = addStmt(S->getBody());
+ if (badCFG)
+ return 0;
+ Block = addStmt(S->getLoopVarStmt());
+ if (badCFG)
+ return 0;
+
+ // This new body block is a successor to our condition block.
+ addSuccessor(ConditionBlock, KnownVal.isFalse() ? 0 : Block);
+ }
+
+ // Link up the condition block with the code that follows the loop (the
+ // false branch).
+ addSuccessor(ConditionBlock, KnownVal.isTrue() ? 0 : LoopSuccessor);
+
+ // Add the initialization statements.
+ Block = createBlock();
+ addStmt(S->getRangeStmt());
+ return addStmt(S->getBeginEndStmt());
+}
+
CFGBlock *CFGBuilder::VisitExprWithCleanups(ExprWithCleanups *E,
AddStmtChoice asc) {
if (BuildOpts.AddImplicitDtors) {