commit 71ac240620c4fedb6e49c302c490e99bb2d37eb4
author Weiming Zhao <weimingz@codeaurora.org> Tue Feb 03 22:35:58 2015 +0000
committer Weiming Zhao <weimingz@codeaurora.org> Tue Feb 03 22:35:58 2015 +0000
tree 7e77100160781705607098aa9d51d08dfffc1970
parent ab1dc2d54db5fc2ad4ee748745420eac844a5ea3

Diagnose CXX 'this' pointer reference in funcs with naked attr

Clang asserts for this pointer reference in asms of naked functions.
This patch diagnoses if this pointer reference is used.

Differential Revision: http://reviews.llvm.org/D7329

llvm-svn: 228052

clang/include/clang/Basic/DiagnosticSemaKinds.td

diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 1283baf..9bbdab4 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -7211,6 +7211,8 @@
 
 def err_non_asm_stmt_in_naked_function : Error<
   "non-ASM statement in naked function is not supported">;
+def err_asm_naked_this_ref : Error<
+  "'this' pointer references not allowed in naked functions">;
 def err_asm_naked_parm_ref : Error<
   "parameter references not allowed in naked functions">;
 

clang/lib/Sema/SemaStmtAsm.cpp

diff --git a/clang/lib/Sema/SemaStmtAsm.cpp b/clang/lib/Sema/SemaStmtAsm.cpp
index 0d32581..1beac36 100644
--- a/clang/lib/Sema/SemaStmtAsm.cpp
+++ b/clang/lib/Sema/SemaStmtAsm.cpp
@@ -12,6 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/Sema/SemaInternal.h"
+#include "clang/AST/ExprCXX.h"
 #include "clang/AST/RecordLayout.h"
 #include "clang/AST/TypeLoc.h"
 #include "clang/Basic/TargetInfo.h"
@@ -86,6 +87,11 @@
   WorkList.push_back(E);
   while (WorkList.size()) {
     Expr *E = WorkList.pop_back_val();
+    if (isa<CXXThisExpr>(E)) {
+      S.Diag(E->getLocStart(), diag::err_asm_naked_this_ref);
+      S.Diag(Func->getAttr<NakedAttr>()->getLocation(), diag::note_attribute);
+      return true;
+    }
     if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
       if (isa<ParmVarDecl>(DRE->getDecl())) {
         S.Diag(DRE->getLocStart(), diag::err_asm_naked_parm_ref);

clang/test/Sema/attr-naked.cpp

diff --git a/clang/test/Sema/attr-naked.cpp b/clang/test/Sema/attr-naked.cpp
new file mode 100644
index 0000000..eaa8e22
--- /dev/null
+++ b/clang/test/Sema/attr-naked.cpp
@@ -0,0 +1,15 @@
+// RUN: %clang_cc1 %s -verify -fsyntax-only -triple arm-none-linux
+class Foo {
+  void bar();
+  static void bar2();
+  unsigned v;
+  static unsigned s;
+};
+
+void __attribute__((naked)) Foo::bar() { // expected-note{{attribute is here}}
+  asm("mov r2, %0" : : "r"(v)); // expected-error{{'this' pointer references not allowed in naked functions}}
+}
+
+void __attribute__((naked)) Foo::bar2() {
+  asm("mov r2, %0" : : "r"(s)); // static member reference is OK
+}