Add -Wimplicit-fallthrough warning flag, which warns on fallthrough between
cases in switch statements. Also add a [[clang::fallthrough]] attribute, which
can be used to suppress the warning in the case of intentional fallthrough.
Patch by Alexander Kornienko!
The handling of C++11 attribute namespaces in this patch is temporary, and will
be replaced with a cleaner mechanism in a subsequent patch.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@156086 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaStmtAttr.cpp b/lib/Sema/SemaStmtAttr.cpp
index 21c3297..912d7c6 100644
--- a/lib/Sema/SemaStmtAttr.cpp
+++ b/lib/Sema/SemaStmtAttr.cpp
@@ -15,20 +15,46 @@
#include "TargetAttributesSema.h"
#include "clang/AST/ASTContext.h"
#include "clang/Basic/SourceManager.h"
+#include "clang/Lex/Lexer.h"
#include "clang/Sema/DelayedDiagnostic.h"
#include "clang/Sema/Lookup.h"
+#include "clang/Sema/ScopeInfo.h"
#include "llvm/ADT/StringExtras.h"
+
using namespace clang;
using namespace sema;
+static Attr *handleFallThroughAttr(Sema &S, Stmt *St, const AttributeList &A,
+ SourceRange Range) {
+ if (!isa<NullStmt>(St)) {
+ S.Diag(A.getRange().getBegin(), diag::err_fallthrough_attr_wrong_target)
+ << St->getLocStart();
+ if (isa<SwitchCase>(St)) {
+ SourceLocation L = Lexer::getLocForEndOfToken(Range.getEnd(), 0,
+ S.getSourceManager(), S.getLangOpts());
+ S.Diag(L, diag::note_fallthrough_insert_semi_fixit)
+ << FixItHint::CreateInsertion(L, ";");
+ }
+ return 0;
+ }
+ if (S.getCurFunction()->SwitchStack.empty()) {
+ S.Diag(A.getRange().getBegin(), diag::err_fallthrough_attr_outside_switch);
+ return 0;
+ }
+ return ::new (S.Context) FallThroughAttr(A.getRange(), S.Context);
+}
-static Attr *ProcessStmtAttribute(Sema &S, Stmt *St, const AttributeList &A) {
+
+static Attr *ProcessStmtAttribute(Sema &S, Stmt *St, const AttributeList &A,
+ SourceRange Range) {
switch (A.getKind()) {
+ case AttributeList::AT_clang___fallthrough:
+ return handleFallThroughAttr(S, St, A, Range);
default:
// if we're here, then we parsed an attribute, but didn't recognize it as a
// statement attribute => it is declaration attribute
- S.Diag(A.getRange().getBegin(), diag::warn_attribute_invalid_on_stmt) <<
- A.getName()->getName();
+ S.Diag(A.getRange().getBegin(), diag::warn_attribute_invalid_on_stmt)
+ << A.getName()->getName() << St->getLocStart();
return 0;
}
}
@@ -37,7 +63,7 @@
SourceRange Range) {
AttrVec Attrs;
for (const AttributeList* l = AttrList; l; l = l->getNext()) {
- if (Attr *a = ProcessStmtAttribute(*this, S, *l))
+ if (Attr *a = ProcessStmtAttribute(*this, S, *l, Range))
Attrs.push_back(a);
}