The attached patch fixes bug 79548 - [5/6/7 Regression] missing
-Wunused-variable on a typedef'd variable in a function template,
most likely broken by the introduction of -Wunused-local-typedefs.
While testing the patch I came across a couple of other bugs:
79585 - spurious -Wunused-variable on a pointer with attribute
unused in function template
and
79586 - missing -Wdeprecated depending on position of attribute
The test I added for 79548 fails two assertions due to the first
of these two so I xfailed them. The second doesn't have an impact
on it. Neither of these is a regression so I didn't try to fix them.
Martin
PR c++/79548 - [5/6/7 Regression] missing -Wunused-variable on a typedef'd variable in a function template
gcc/cp/ChangeLog:
PR c++/79548
* decl.c (poplevel): Avoid diagnosing entities declared with
attribute unused.
(initialize_local_var): Do not consider the type of a variable
when determining whether or not it's used.
gcc/testsuite/ChangeLog:
PR c++/79548
* g++.dg/warn/Wunused-var-26.C: New test.
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 70c44fb..e315ad0 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -664,7 +664,8 @@ poplevel (int keep, int reverse, int functionbody)
&& (!CLASS_TYPE_P (type)
|| !TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)
|| lookup_attribute ("warn_unused",
- TYPE_ATTRIBUTES (TREE_TYPE (decl)))))
+ TYPE_ATTRIBUTES (TREE_TYPE (decl))))
+ && !lookup_attribute ("unused", TYPE_ATTRIBUTES (TREE_TYPE (decl))))
{
if (! TREE_USED (decl))
warning_at (DECL_SOURCE_LOCATION (decl),
@@ -6546,7 +6547,6 @@ initialize_local_var (tree decl, tree init)
{
tree type = TREE_TYPE (decl);
tree cleanup;
- int already_used;
gcc_assert (VAR_P (decl)
|| TREE_CODE (decl) == RESULT_DECL);
@@ -6564,7 +6564,7 @@ initialize_local_var (tree decl, tree init)
return;
/* Compute and store the initial value. */
- already_used = TREE_USED (decl) || TREE_USED (type);
+ bool already_used = TREE_USED (decl);
if (TREE_USED (type))
DECL_READ_P (decl) = 1;
diff --git a/gcc/testsuite/g++.dg/warn/Wunused-var-26.C b/gcc/testsuite/g++.dg/warn/Wunused-var-26.C
new file mode 100644
index 0000000..562f25b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wunused-var-26.C
@@ -0,0 +1,127 @@
+// PR c++/79548 - missing -Wunused-variable on a typedef'd variable
+// in a function template
+// { dg-do compile }
+// { dg-options "-Wunused" }
+
+
+#define UNUSED __attribute__ ((unused))
+
+template <class T>
+void f_int ()
+{
+ T t; // { dg-warning "unused variable" }
+
+ typedef T U;
+ U u; // { dg-warning "unused variable" }
+}
+
+template void f_int<int>();
+
+
+template <class T>
+void f_intptr ()
+{
+ T *t = 0; // { dg-warning "unused variable" }
+
+ typedef T U;
+ U *u = 0; // { dg-warning "unused variable" }
+}
+
+template void f_intptr<int>();
+
+
+template <class T>
+void f_var_unused ()
+{
+ // The variable is marked unused.
+ T t UNUSED;
+
+ typedef T U;
+ U u UNUSED;
+}
+
+template void f_var_unused<int>();
+
+
+template <class T>
+void f_var_type_unused ()
+{
+ // The variable's type is marked unused.
+ T* UNUSED t = new T; // { dg-bogus "unused variable" "bug 79585" { xfail *-*-* } }
+
+ typedef T U;
+ U* UNUSED u = new U; // { dg-bogus "unused variable" "bug 79585" { xfail *-*-* } }
+
+ typedef T UNUSED U;
+ U v = U (); // { dg-bogus "unused variable" "bug 79585" { xfail *-*-* } }
+}
+
+template void f_var_type_unused<int>();
+
+
+struct A { int i; };
+
+template <class T>
+void f_A ()
+{
+ T t; // { dg-warning "unused variable" }
+
+ typedef T U;
+ U u; // { dg-warning "unused variable" }
+}
+
+template void f_A<A>();
+
+
+template <class T>
+void f_A_unused ()
+{
+ T t UNUSED;
+
+ typedef T U;
+ U u UNUSED;
+}
+
+template void f_A_unused<A>();
+
+
+struct B { B (); };
+
+template <class T>
+void f_B ()
+{
+ T t;
+
+ typedef T U;
+ U u;
+}
+
+template void f_B<B>();
+
+
+struct C { ~C (); };
+
+template <class T>
+void f_C ()
+{
+ T t;
+
+ typedef T U;
+ U u;
+}
+
+template void f_C<C>();
+
+
+struct D { B b; };
+
+template <class T>
+void f_D ()
+{
+ T t;
+
+ typedef T U;
+ U u;
+}
+
+template void f_D<D>();
