[cfe-commits] r76133 - in /cfe/trunk: lib/Analysis/CFG.cpp test/Analysis/dead-stores.c
Mike Stump
mrs at apple.com
Thu Jul 16 18:04:40 PDT 2009
Author: mrs
Date: Thu Jul 16 20:04:31 2009
New Revision: 76133
URL: http://llvm.org/viewvc/llvm-project?rev=76133&view=rev
Log:
Make noreturn functions alter the CFG.
Modified:
cfe/trunk/lib/Analysis/CFG.cpp
cfe/trunk/test/Analysis/dead-stores.c
Modified: cfe/trunk/lib/Analysis/CFG.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Analysis/CFG.cpp?rev=76133&r1=76132&r2=76133&view=diff
==============================================================================
--- cfe/trunk/lib/Analysis/CFG.cpp (original)
+++ cfe/trunk/lib/Analysis/CFG.cpp Thu Jul 16 20:04:31 2009
@@ -117,9 +117,9 @@
CFGBlock* VisitStmt(Stmt* Statement);
CFGBlock* VisitSwitchStmt(SwitchStmt* Terminator);
CFGBlock* VisitWhileStmt(WhileStmt* W);
-
+
// FIXME: Add support for ObjC-specific control-flow structures.
-
+
// NYS == Not Yet Supported
CFGBlock* NYS() {
badCFG = true;
@@ -280,7 +280,7 @@
/// WalkAST - Used by addStmt to walk the subtree of a statement and
/// add extra blocks for ternary operators, &&, and ||. We also
/// process "," and DeclStmts (which may contain nested control-flow).
-CFGBlock* CFGBuilder::WalkAST(Stmt* Terminator, bool AlwaysAddStmt = false) {
+CFGBlock* CFGBuilder::WalkAST(Stmt* Terminator, bool AlwaysAddStmt = false) {
switch (Terminator->getStmtClass()) {
case Stmt::ConditionalOperatorClass: {
ConditionalOperator* C = cast<ConditionalOperator>(Terminator);
@@ -478,6 +478,36 @@
case Stmt::ParenExprClass:
return WalkAST(cast<ParenExpr>(Terminator)->getSubExpr(), AlwaysAddStmt);
+ case Stmt::CallExprClass: {
+ bool NoReturn = false;
+ CallExpr *C = cast<CallExpr>(Terminator);
+ Expr *CEE = C->getCallee()->IgnoreParenCasts();
+ if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CEE)) {
+ // FIXME: We can follow objective-c methods and C++ member functions...
+ if (FunctionDecl *FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
+ if (FD->hasAttr<NoReturnAttr>())
+ NoReturn = true;
+ }
+ }
+
+ if (!NoReturn)
+ break;
+
+ if (Block) {
+ if (!FinishBlock(Block))
+ return 0;
+ }
+
+ // Create new block with no successor for the remaining pieces.
+ Block = createBlock(false);
+ Block->appendStmt(Terminator);
+
+ // Wire this to the exit block directly.
+ Block->addSuccessor(&cfg->getExit());
+
+ return WalkAST_VisitChildren(Terminator);
+ }
+
default:
break;
};
@@ -1190,7 +1220,7 @@
return 0;
}
- // Now create a new block that ends with the continue statement.
+ // Now create a new block that ends with the break statement.
Block = createBlock(false);
Block->setTerminator(B);
Modified: cfe/trunk/test/Analysis/dead-stores.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/dead-stores.c?rev=76133&r1=76132&r2=76133&view=diff
==============================================================================
--- cfe/trunk/test/Analysis/dead-stores.c (original)
+++ cfe/trunk/test/Analysis/dead-stores.c Thu Jul 16 20:04:31 2009
@@ -138,7 +138,8 @@
// <rdar://problem/6506065>
// The values of dead stores are only "consumed" in an enclosing expression
-// what that value is actually used. In other words, don't say "Although the value stored to 'x' is used...".
+// what that value is actually used. In other words, don't say "Although the
+// value stored to 'x' is used...".
int f18() {
int x = 0; // no-warning
if (1)
@@ -173,3 +174,14 @@
#pragma unused(x)
}
+void halt() __attribute__((noreturn));
+int f21() {
+ int x = 4;
+
+ ++x; // expected-warning{{never read}}
+ if (1) {
+ halt();
+ (void)x;
+ }
+ return 1;
+}
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