When cp_finish_decl calls cp_apply_type_quals_to_decl on a const auto or
constexpr auto variable, the type might not be complete the first time
(this happened when auto deduces to an initializer_list).
cp_apply_type_quals_to_decl removes the const qualifier if the type is
not complete, which is appropriate for grokdeclarator, on the assumption
that the type will be complete when called by cp_finish_decl.
Tested on x86_64 Ubuntu under WSL1 by bootstrapping and comparing results
from 24d51e749570dcb85bd43d3b528f58ad6141de26 with results from this
change. As far as I can tell, this fixes Wunused-var-38.C and
Wunused-var-39.C without regressions.
(Wunused-var-37.C passed before this change.)
gcc/cp/ChangeLog:
PR c++/80351
* decl.cc (cp_finish_decl): Call complete_type after performing
auto deduction.
gcc/testsuite/ChangeLog:
PR c++/80351
* g++.dg/warn/Wunused-var-37.C: New test.
* g++.dg/warn/Wunused-var-38.C: New test.
* g++.dg/warn/Wunused-var-39.C: New test.
---
gcc/cp/decl.cc | 2 +-
gcc/testsuite/g++.dg/warn/Wunused-var-37.C | 64 ++++++++++++++++++++++
gcc/testsuite/g++.dg/warn/Wunused-var-38.C | 16 ++++++
gcc/testsuite/g++.dg/warn/Wunused-var-39.C | 16 ++++++
4 files changed, 97 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/warn/Wunused-var-37.C
create mode 100644 gcc/testsuite/g++.dg/warn/Wunused-var-38.C
create mode 100644 gcc/testsuite/g++.dg/warn/Wunused-var-39.C
diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index 34d9dad9fb0..e382b8ad218 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -8098,7 +8098,7 @@ cp_finish_decl (tree decl, tree init, bool
init_const_expr_p,
TREE_TYPE (decl) = error_mark_node;
return;
}
- cp_apply_type_quals_to_decl (cp_type_quals (type), decl);
+ cp_apply_type_quals_to_decl (cp_type_quals (complete_type (type)), decl);
}
if (ensure_literal_type_for_constexpr_object (decl) == error_mark_node)
diff --git a/gcc/testsuite/g++.dg/warn/Wunused-var-37.C
b/gcc/testsuite/g++.dg/warn/Wunused-var-37.C
new file mode 100644
index 00000000000..54e76ac4e11
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wunused-var-37.C
@@ -0,0 +1,64 @@
+// Tangentially to PR c++/80351
+// { dg-do compile { target c++17 } }
+// { dg-options "-Wunused-variable" }
+#include <initializer_list>
+
+// Warnings:
+static int int_s1 = 0; // { dg-warning "defined but not used" }
+static int int_s2 = 0; // { dg-warning "defined but not used" }
+inline static int int_is1 = 0; // { dg-warning "defined but not used" }
+inline static int int_is2 = 0; // { dg-warning "defined but not used" }
+// No warnings:
+constexpr static int int_cs1 = 0; // { dg-bogus "defined but not used" }
+constexpr static int int_cs2 = 0; // { dg-bogus "defined but not used" }
+int int_1 = 0; // { dg-bogus "defined but not used" }
+int int_2 = 0; // { dg-bogus "defined but not used" }
+inline int int_i1 = 0; // { dg-bogus "defined but not used" }
+inline int int_i2 = 0; // { dg-bogus "defined but not used" }
+constexpr int int_c1 = 0; // { dg-bogus "defined but not used" }
+constexpr int int_c2 = 0; // { dg-bogus "defined but not used" }
+
+// Warnings:
+static auto int_as1 = 0; // { dg-warning "defined but not used" }
+static auto int_as2 = 0; // { dg-warning "defined but not used" }
+inline static auto int_ais1 = 0; // { dg-warning "defined but not used" }
+inline static auto int_ais2 = 0; // { dg-warning "defined but not used" }
+// No warnings:
+constexpr static auto int_acs1 = 0; // { dg-bogus "defined but not used" }
+constexpr static auto int_acs2 = 0; // { dg-bogus "defined but not used" }
+auto int_a1 = 0; // { dg-bogus "defined but not used" }
+auto int_a2 = 0; // { dg-bogus "defined but not used" }
+inline auto int_ai1 = 0; // { dg-bogus "defined but not used" }
+inline auto int_ai2 = 0; // { dg-bogus "defined but not used" }
+constexpr auto int_ac1 = 0; // { dg-bogus "defined but not used" }
+constexpr auto int_ac2 = 0; // { dg-bogus "defined but not used" }
+
+// Warnings:
+static std::initializer_list<int> il_s1 = {0, 1}; // {
dg-warning "defined but not used" }
+static std::initializer_list<int> il_s2 = {0, 1}; // {
dg-warning "defined but not used" }
+inline static std::initializer_list<int> il_is1 = {0, 1}; // {
dg-warning "defined but not used" }
+inline static std::initializer_list<int> il_is2 = {0, 1}; // {
dg-warning "defined but not used" }
+// No warnings:
+constexpr static std::initializer_list<int> il_cs1 = {0, 1}; // {
dg-bogus "defined but not used" }
+constexpr static std::initializer_list<int> il_cs2 = {0, 1}; // {
dg-bogus "defined but not used" }
+std::initializer_list<int> il_1 = {0, 1}; // {
dg-bogus "defined but not used" }
+std::initializer_list<int> il_2 = {0, 1}; // {
dg-bogus "defined but not used" }
+inline std::initializer_list<int> il_i1 = {0, 1}; // {
dg-bogus "defined but not used" }
+inline std::initializer_list<int> il_i2 = {0, 1}; // {
dg-bogus "defined but not used" }
+constexpr std::initializer_list<int> il_c1 = {0, 1}; // {
dg-bogus "defined but not used" }
+constexpr std::initializer_list<int> il_c2 = {0, 1}; // {
dg-bogus "defined but not used" }
+
+// Warnings:
+static auto il_as1 = {0, 1}; // { dg-warning "defined but
not used" }
+static auto il_as2 = {0, 1}; // { dg-warning "defined but
not used" }
+inline static auto il_ais1 = {0, 1}; // { dg-warning "defined but
not used" }
+inline static auto il_ais2 = {0, 1}; // { dg-warning "defined but
not used" }
+// No warnings:
+constexpr static auto il_acs1 = {0, 1}; // { dg-bogus "defined but not used" }
+constexpr static auto il_acs2 = {0, 1}; // { dg-bogus "defined but not used" }
+auto il_a1 = {0, 1}; // { dg-bogus "defined but not used" }
+auto il_a2 = {0, 1}; // { dg-bogus "defined but not used" }
+inline auto il_ai1 = {0, 1}; // { dg-bogus "defined but not used" }
+inline auto il_ai2 = {0, 1}; // { dg-bogus "defined but not used" }
+constexpr auto il_ac1 = {0, 1}; // { dg-bogus "defined but not used" }
+constexpr auto il_ac2 = {0, 1}; // { dg-bogus "defined but not used" }
diff --git a/gcc/testsuite/g++.dg/warn/Wunused-var-38.C
b/gcc/testsuite/g++.dg/warn/Wunused-var-38.C
new file mode 100644
index 00000000000..3d34bc8e8c1
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wunused-var-38.C
@@ -0,0 +1,16 @@
+// PR c++/80351
+// { dg-do compile { target c++11 } }
+// { dg-options "-Wunused-variable" }
+#include <initializer_list>
+
+constexpr auto int_1 = 1; // { dg-bogus "defined but not used" }
+constexpr auto int_2 = 2; // { dg-bogus "defined but not used" }
+
+constexpr auto il_int_1 = {3, 3}; // { dg-bogus "defined but not
used" "Triggered by PR80351" }
+constexpr auto il_int_2 = {4, 4}; // { dg-bogus "defined but not
used" "Not triggered by PR80351" }
+
+constexpr auto il_uint_1 = {5u, 5u}; // { dg-bogus "defined but not
used" "Triggered by PR80351" }
+constexpr auto il_uint_2 = {6u, 6u}; // { dg-bogus "defined but not
used" "Not triggered by PR80351" }
+
+constexpr auto uint_1 = 7u; // { dg-bogus "defined but not used" }
+constexpr auto uint_2 = 8u; // { dg-bogus "defined but not used" }
diff --git a/gcc/testsuite/g++.dg/warn/Wunused-var-39.C
b/gcc/testsuite/g++.dg/warn/Wunused-var-39.C
new file mode 100644
index 00000000000..d25a74c43c2
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wunused-var-39.C
@@ -0,0 +1,16 @@
+// PR c++/80351
+// { dg-do compile { target c++11 } }
+// { dg-options "-Wunused-variable" }
+#include <initializer_list>
+
+const auto int_1 = 1; // { dg-bogus "defined but not used" }
+const auto int_2 = 2; // { dg-bogus "defined but not used" }
+
+const auto il_int_1 = {3, 3}; // { dg-bogus "defined but not used"
"Triggered by PR80351" }
+const auto il_int_2 = {4, 4}; // { dg-bogus "defined but not used"
"Not triggered by PR80351" }
+
+const auto il_uint_1 = {5u, 5u}; // { dg-bogus "defined but not used"
"Triggered by PR80351" }
+const auto il_uint_2 = {6u, 6u}; // { dg-bogus "defined but not used"
"Not triggered by PR80351" }
+
+const auto uint_1 = 7u; // { dg-bogus "defined but not used" }
+const auto uint_2 = 8u; // { dg-bogus "defined but not used" }
--
2.25.1
