[cfe-commits] r97497 - in /cfe/trunk: include/clang/Basic/DiagnosticSemaKinds.td lib/Sema/JumpDiagnostics.cpp lib/Sema/Sema.cpp lib/Sema/Sema.h lib/Sema/SemaDecl.cpp lib/Sema/SemaDeclObjC.cpp lib/Sema/SemaExpr.cpp test/SemaCXX/statements.cpp
Chris Lattner
sabre at nondot.org
Mon Mar 1 12:59:53 PST 2010
Author: lattner
Date: Mon Mar 1 14:59:53 2010
New Revision: 97497
URL: http://llvm.org/viewvc/llvm-project?rev=97497&view=rev
Log:
Implement jump checking for initialized c++ variables, implementing
a fixme and PR6451.
Only perform jump checking if the containing function has no errors,
and add the infrastructure needed to do this.
On the testcase in the PR, we produce:
t.cc:6:3: error: illegal goto into protected scope
goto later;
^
t.cc:7:5: note: jump bypasses variable initialization
X x;
^
Modified:
cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
cfe/trunk/lib/Sema/JumpDiagnostics.cpp
cfe/trunk/lib/Sema/Sema.cpp
cfe/trunk/lib/Sema/Sema.h
cfe/trunk/lib/Sema/SemaDecl.cpp
cfe/trunk/lib/Sema/SemaDeclObjC.cpp
cfe/trunk/lib/Sema/SemaExpr.cpp
cfe/trunk/test/SemaCXX/statements.cpp
Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=97497&r1=97496&r2=97497&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Mon Mar 1 14:59:53 2010
@@ -1592,6 +1592,8 @@
def err_addr_of_label_in_protected_scope : Error<
"address taken of label in protected scope, jump to it would have "
"unknown effect on scope">;
+def note_protected_by_variable_init : Note<
+ "jump bypasses variable initialization">;
def note_protected_by_vla_typedef : Note<
"jump bypasses initialization of VLA typedef">;
def note_protected_by_vla : Note<
Modified: cfe/trunk/lib/Sema/JumpDiagnostics.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/JumpDiagnostics.cpp?rev=97497&r1=97496&r2=97497&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/JumpDiagnostics.cpp (original)
+++ cfe/trunk/lib/Sema/JumpDiagnostics.cpp Mon Mar 1 14:59:53 2010
@@ -77,7 +77,7 @@
/// GetDiagForGotoScopeDecl - If this decl induces a new goto scope, return a
/// diagnostic that should be emitted if control goes over it. If not, return 0.
-static unsigned GetDiagForGotoScopeDecl(const Decl *D) {
+static unsigned GetDiagForGotoScopeDecl(const Decl *D, bool isCPlusPlus) {
if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
if (VD->getType()->isVariablyModifiedType())
return diag::note_protected_by_vla;
@@ -85,6 +85,9 @@
return diag::note_protected_by_cleanup;
if (VD->hasAttr<BlocksAttr>())
return diag::note_protected_by___block;
+ if (isCPlusPlus && VD->hasLocalStorage() && VD->hasInit())
+ return diag::note_protected_by_variable_init;
+
} else if (const TypedefDecl *TD = dyn_cast<TypedefDecl>(D)) {
if (TD->getUnderlyingType()->isVariablyModifiedType())
return diag::note_protected_by_vla_typedef;
@@ -116,18 +119,17 @@
Stmt *SubStmt = *CI;
if (SubStmt == 0) continue;
- // FIXME: diagnose jumps past initialization: required in C++, warning in C.
- // goto L; int X = 4; L: ;
+ bool isCPlusPlus = this->S.getLangOptions().CPlusPlus;
// If this is a declstmt with a VLA definition, it defines a scope from here
// to the end of the containing context.
if (DeclStmt *DS = dyn_cast<DeclStmt>(SubStmt)) {
- // The decl statement creates a scope if any of the decls in it are VLAs or
- // have the cleanup attribute.
+ // The decl statement creates a scope if any of the decls in it are VLAs
+ // or have the cleanup attribute.
for (DeclStmt::decl_iterator I = DS->decl_begin(), E = DS->decl_end();
I != E; ++I) {
// If this decl causes a new scope, push and switch to it.
- if (unsigned Diag = GetDiagForGotoScopeDecl(*I)) {
+ if (unsigned Diag = GetDiagForGotoScopeDecl(*I, isCPlusPlus)) {
Scopes.push_back(GotoScope(ParentScope, Diag, (*I)->getLocation()));
ParentScope = Scopes.size()-1;
}
Modified: cfe/trunk/lib/Sema/Sema.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/Sema.cpp?rev=97497&r1=97496&r2=97497&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/Sema.cpp (original)
+++ cfe/trunk/lib/Sema/Sema.cpp Mon Mar 1 14:59:53 2010
@@ -127,6 +127,8 @@
if (getLangOptions().CPlusPlus)
FieldCollector.reset(new CXXFieldCollector());
+ NumErrorsAtStartOfFunction = 0;
+
// Tell diagnostics how to render things from the AST library.
PP.getDiagnostics().SetArgToStringFn(&FormatASTNodeDiagnosticArgument,
&Context);
Modified: cfe/trunk/lib/Sema/Sema.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/Sema.h?rev=97497&r1=97496&r2=97497&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/Sema.h (original)
+++ cfe/trunk/lib/Sema/Sema.h Mon Mar 1 14:59:53 2010
@@ -147,6 +147,10 @@
/// return types, if any, in the block body.
QualType ReturnType;
+ /// SavedNumErrorsAtStartOfFunction - This is the value of the
+ /// NumErrorsAtStartOfFunction variable at the point when the block started.
+ unsigned SavedNumErrorsAtStartOfFunction;
+
/// SavedFunctionNeedsScopeChecking - This is the value of
/// CurFunctionNeedsScopeChecking at the point when the block started.
bool SavedFunctionNeedsScopeChecking;
@@ -241,6 +245,13 @@
/// the current full expression.
llvm::SmallVector<CXXTemporary*, 8> ExprTemporaries;
+ /// NumErrorsAtStartOfFunction - This is the number of errors that were
+ /// emitted to the diagnostics object at the start of the current
+ /// function/method definition. If no additional errors are emitted by the
+ /// end of the function, we assume the AST is well formed enough to be
+ /// worthwhile to emit control flow diagnostics.
+ unsigned NumErrorsAtStartOfFunction;
+
/// CurFunctionNeedsScopeChecking - This is set to true when a function or
/// ObjC method body contains a VLA or an ObjC try block, which introduce
/// scopes that need to be checked for goto conditions. If a function does
Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=97497&r1=97496&r2=97497&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDecl.cpp Mon Mar 1 14:59:53 2010
@@ -850,7 +850,7 @@
// is normally mapped to an error, but can be controlled with
// -Wtypedef-redefinition. If either the original or the redefinition is
// in a system header, don't emit this for compatibility with GCC.
- if (PP.getDiagnostics().getSuppressSystemWarnings() &&
+ if (getDiagnostics().getSuppressSystemWarnings() &&
(Context.getSourceManager().isInSystemHeader(Old->getLocation()) ||
Context.getSourceManager().isInSystemHeader(New->getLocation())))
return;
@@ -2500,7 +2500,12 @@
bool isVM = T->isVariablyModifiedType();
if (isVM || NewVD->hasAttr<CleanupAttr>() ||
- NewVD->hasAttr<BlocksAttr>())
+ NewVD->hasAttr<BlocksAttr>() ||
+ // FIXME: We need to diagnose jumps passed initialized variables in C++.
+ // However, this turns on the scope checker for everything with a variable
+ // which may impact compile time. See if we can find a better solution
+ // to this, perhaps only checking functions that contain gotos in C++?
+ (LangOpts.CPlusPlus && NewVD->hasLocalStorage()))
CurFunctionNeedsScopeChecking = true;
if ((isVM && NewVD->hasLinkage()) ||
@@ -4079,6 +4084,7 @@
FD = cast<FunctionDecl>(D.getAs<Decl>());
CurFunctionNeedsScopeChecking = false;
+ NumErrorsAtStartOfFunction = getDiagnostics().getNumErrors();
// See if this is a redefinition.
// But don't complain if we're in GNU89 mode and the previous definition
@@ -4257,7 +4263,8 @@
CheckUnreachable(AC);
// Verify that that gotos and switch cases don't jump into scopes illegally.
- if (CurFunctionNeedsScopeChecking)
+ if (CurFunctionNeedsScopeChecking &&
+ NumErrorsAtStartOfFunction == getDiagnostics().getNumErrors())
DiagnoseInvalidJumps(Body);
// C++ constructors that have function-try-blocks can't have return
@@ -4272,7 +4279,7 @@
// If any errors have occurred, clear out any temporaries that may have
// been leftover. This ensures that these temporaries won't be picked up for
// deletion in some later function.
- if (PP.getDiagnostics().hasErrorOccurred())
+ if (getDiagnostics().hasErrorOccurred())
ExprTemporaries.clear();
assert(ExprTemporaries.empty() && "Leftover temporaries in function");
Modified: cfe/trunk/lib/Sema/SemaDeclObjC.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclObjC.cpp?rev=97497&r1=97496&r2=97497&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDeclObjC.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDeclObjC.cpp Mon Mar 1 14:59:53 2010
@@ -50,6 +50,7 @@
return;
CurFunctionNeedsScopeChecking = false;
+ NumErrorsAtStartOfFunction = getDiagnostics().getNumErrors();
// Allow the rest of sema to find private method decl implementations.
if (MDecl->isInstanceMethod())
Modified: cfe/trunk/lib/Sema/SemaExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=97497&r1=97496&r2=97497&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExpr.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExpr.cpp Mon Mar 1 14:59:53 2010
@@ -6734,8 +6734,10 @@
BSI->hasBlockDeclRefExprs = false;
BSI->hasPrototype = false;
BSI->SavedFunctionNeedsScopeChecking = CurFunctionNeedsScopeChecking;
+ BSI->SavedNumErrorsAtStartOfFunction = NumErrorsAtStartOfFunction;
CurFunctionNeedsScopeChecking = false;
-
+ NumErrorsAtStartOfFunction = getDiagnostics().getNumErrors();
+
BSI->TheDecl = BlockDecl::Create(Context, CurContext, CaretLoc);
CurContext->addDecl(BSI->TheDecl);
PushDeclContext(BlockScope, BSI->TheDecl);
@@ -6849,6 +6851,7 @@
llvm::OwningPtr<BlockScopeInfo> CC(CurBlock);
CurFunctionNeedsScopeChecking = CurBlock->SavedFunctionNeedsScopeChecking;
+ NumErrorsAtStartOfFunction = CurBlock->SavedNumErrorsAtStartOfFunction;
// Pop off CurBlock, handle nested blocks.
PopDeclContext();
@@ -6895,9 +6898,12 @@
BlockTy = Context.getBlockPointerType(BlockTy);
// If needed, diagnose invalid gotos and switches in the block.
- if (CurFunctionNeedsScopeChecking)
+ if (CurFunctionNeedsScopeChecking &&
+ NumErrorsAtStartOfFunction == getDiagnostics().getNumErrors())
DiagnoseInvalidJumps(static_cast<CompoundStmt*>(body.get()));
+
CurFunctionNeedsScopeChecking = BSI->SavedFunctionNeedsScopeChecking;
+ NumErrorsAtStartOfFunction = BSI->SavedNumErrorsAtStartOfFunction;
BSI->TheDecl->setBody(body.takeAs<CompoundStmt>());
Modified: cfe/trunk/test/SemaCXX/statements.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/statements.cpp?rev=97497&r1=97496&r2=97497&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/statements.cpp (original)
+++ cfe/trunk/test/SemaCXX/statements.cpp Mon Mar 1 14:59:53 2010
@@ -1,5 +1,17 @@
-// RUN: %clang_cc1 %s -fsyntax-only -pedantic
+// RUN: %clang_cc1 %s -fsyntax-only -pedantic -verify
void foo() {
return foo();
}
+
+// PR6451 - C++ Jump checking
+struct X {
+ X();
+};
+
+void test2() {
+ goto later; // expected-error {{illegal goto into protected scope}}
+ X x; // expected-note {{jump bypasses variable initialization}}
+later:
+ ;
+}
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