Unused ivar checker: ivars referenced by lexically nested functions should not be flagged as unused. Fixes <rdar://problem/7254495>.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@89448 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/CheckObjCUnusedIVars.cpp b/lib/Analysis/CheckObjCUnusedIVars.cpp
index 2d9b531..3ee5cb1 100644
--- a/lib/Analysis/CheckObjCUnusedIVars.cpp
+++ b/lib/Analysis/CheckObjCUnusedIVars.cpp
@@ -85,6 +85,17 @@
}
}
+static void Scan(IvarUsageMap &M, const DeclContext *C, const FileID FID,
+ SourceManager &SM) {
+ for (DeclContext::decl_iterator I=C->decls_begin(), E=C->decls_end();
+ I!=E; ++I)
+ if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) {
+ SourceLocation L = FD->getLocStart();
+ if (SM.getFileID(L) == FID)
+ Scan(M, FD->getBody());
+ }
+}
+
void clang::CheckObjCUnusedIvar(const ObjCImplementationDecl *D,
BugReporter &BR) {
@@ -110,10 +121,30 @@
if (M.empty())
return;
-
+
// Now scan the implementation declaration.
Scan(M, D);
+
+ // Any potentially unused ivars?
+ bool hasUnused = false;
+ for (IvarUsageMap::iterator I = M.begin(), E = M.end(); I!=E; ++I)
+ if (I->second == Unused) {
+ hasUnused = true;
+ break;
+ }
+
+ if (!hasUnused)
+ return;
+
+ // We found some potentially unused ivars. Scan the entire translation unit
+ // for functions inside the @implementation that reference these ivars.
+ // FIXME: In the future hopefully we can just use the lexical DeclContext
+ // to go from the ObjCImplementationDecl to the lexically "nested"
+ // C functions.
+ SourceManager &SM = BR.getSourceManager();
+ Scan(M, D->getDeclContext(), SM.getFileID(D->getLocation()), SM);
+
// Find ivars that are unused.
for (IvarUsageMap::iterator I = M.begin(), E = M.end(); I!=E; ++I)
if (I->second == Unused) {
diff --git a/test/Analysis/unused-ivars.m b/test/Analysis/unused-ivars.m
index 754799b..bbbf6ae 100644
--- a/test/Analysis/unused-ivars.m
+++ b/test/Analysis/unused-ivars.m
@@ -65,3 +65,19 @@
}
@end
+//===----------------------------------------------------------------------===//
+// <rdar://problem/7254495> - ivars referenced by lexically nested functions
+// should not be flagged as unused
+//===----------------------------------------------------------------------===//
+
+@interface RDar7254495 {
+@private
+ int x; // no-warning
+}
+@end
+
+@implementation RDar7254495
+int radar_7254495(RDar7254495 *a) {
+ return a->x;
+}
+@end