Teach loplugin:stringconstant about RTL_CONSTASCII_STRINGPARAM

Change-Id: I8ff0e104aad045f3835dc8facc760a8339b1d088

3 files changed, 26 insertions, 0 deletions

diff --git a/compilerplugins/clang/stringconstant.cxx b/compilerplugins/clang/stringconstant.cxx
index 456413c6eb99..c68d58f9b6b0 100644
--- a/compilerplugins/clang/stringconstant.cxx
+++ b/compilerplugins/clang/stringconstant.cxx
@@ -821,6 +821,20 @@ bool StringConstant::isStringConstant(
     assert(embeddedNuls != nullptr);
     assert(terminatingNul != nullptr);
     QualType t = expr->getType();
+    // Look inside RTL_CONSTASCII_STRINGPARAM:
+    if (loplugin::TypeCheck(t).Pointer().Const().Char()) {
+        auto e2 = dyn_cast<UnaryOperator>(expr);
+        if (e2 == nullptr || e2->getOpcode() != UO_AddrOf) {
+            return false;
+        }
+        auto e3 = dyn_cast<ArraySubscriptExpr>(
+            e2->getSubExpr()->IgnoreParenImpCasts());
+        if (e3 == nullptr || !isZero(e3->getIdx()->IgnoreParenImpCasts())) {
+            return false;
+        }
+        expr = e3->getBase()->IgnoreParenImpCasts();
+        t = expr->getType();
+    }
     if (!(t->isConstantArrayType() && t.isConstQualified()
           && (loplugin::TypeCheck(t->getAsArrayTypeUnsafe()->getElementType())
               .Char())))
diff --git a/compilerplugins/clang/typecheck.cxx b/compilerplugins/clang/typecheck.cxx
index e185643ec32e..800a2d295bc7 100644
--- a/compilerplugins/clang/typecheck.cxx
+++ b/compilerplugins/clang/typecheck.cxx
@@ -39,6 +39,16 @@ TypeCheck TypeCheck::LvalueReference() const {
     return TypeCheck();
 }
 
+TypeCheck TypeCheck::Pointer() const {
+    if (!type_.isNull()) {
+        auto const t = type_->getAs<clang::PointerType>();
+        if (t != nullptr) {
+            return TypeCheck(t->getPointeeType());
+        }
+    }
+    return TypeCheck();
+}
+
 TypeCheck TypeCheck::NotSubstTemplateTypeParmType() const {
     return
         (!type_.isNull()
diff --git a/compilerplugins/clang/typecheck.hxx b/compilerplugins/clang/typecheck.hxx
index 70e3d8c9c265..c49adccae3c3 100644
--- a/compilerplugins/clang/typecheck.hxx
+++ b/compilerplugins/clang/typecheck.hxx
@@ -31,6 +31,8 @@ public:
 
     TerminalCheck Char() const;
 
+    TypeCheck Pointer() const;
+
     TypeCheck LvalueReference() const;
 
     template<std::size_t N> inline NamespaceCheck Class(char const (& id)[N])