-Werror,-Wunused-but-set-variable

...which was apparently meant as a "Possible debugger breakpoint" in
DBG_UTIL-only sw_DebugRedline.  The obvious fix is to mark nDummy as volatile,
but increment of a volatile variable is deprecated, so replace those with reads
of the variable, but which triggered false loplugin:casttovoid so fix that too.

Change-Id: I07376e665caa4fd9befaba06d261a50df7a63a10
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/132237
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

2 files changed, 8 insertions, 0 deletions

diff --git a/compilerplugins/clang/casttovoid.cxx b/compilerplugins/clang/casttovoid.cxx
index 63f1efdd85a5..bddfcb4da503 100644
--- a/compilerplugins/clang/casttovoid.cxx
+++ b/compilerplugins/clang/casttovoid.cxx
@@ -202,6 +202,9 @@ public:
         if (var == nullptr) {
             return true;
         }
+        if (var->getType().isVolatileQualified()) {
+            return true;
+        }
         auto & usage = vars_[var->getCanonicalDecl()];
         if (!castToVoid_.empty() && castToVoid_.top().sub == expr) {
             usage.castToVoid.push_back(castToVoid_.top().cast);
@@ -506,6 +509,9 @@ private:
         if (var == nullptr) {
             return;
         }
+        if (var->getType().isVolatileQualified()) {
+            return;
+        }
         auto & usage = vars_[var->getCanonicalDecl()];
         if (usage.firstConsumption != nullptr) {
             return;
diff --git a/compilerplugins/clang/test/casttovoid.cxx b/compilerplugins/clang/test/casttovoid.cxx
index c3b5eee17c96..3d8c22b49c7e 100644
--- a/compilerplugins/clang/test/casttovoid.cxx
+++ b/compilerplugins/clang/test/casttovoid.cxx
@@ -115,6 +115,8 @@ int main() {
     int n8 = 0;
     ASSERT(USE(USE(n8 == 0)));
     (void) n8;
+    int volatile n9 = 0;
+    (void) n9;
     return n1 // expected-note 8 {{first consumption is here [loplugin:casttovoid]}}
         + n2 // expected-note {{first consumption is here [loplugin:casttovoid]}}
         + n3;