[PATCH] C++: add type checking for static local vector variable in template

[wangpc via Gcc-patches]

This patch adds type checking for static local vector variable in
C++ template, both AArch64 SVE and RISCV RVV are of sizeless type
and they all have this issue.

2021-08-06  wangpc  <pc.w...@linux.alibaba.com>

gcc/cp/ChangeLog

        * pt.c (tsubst_decl): Add type checking.

gcc/testsuite/ChangeLog

        * g++.target/aarch64/sve/static-var-in-template.C: New test.

diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 90111e4c786..e3a06ea0858 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -7520,6 +7520,12 @@ cp_finish_decl (tree decl, tree init, bool 
init_const_expr_p,
       && DECL_INITIALIZED_IN_CLASS_P (decl))
     check_static_variable_definition (decl, type);
 
+  if (VAR_P (decl)
+      && DECL_FUNCTION_SCOPE_P (decl)
+      && TREE_STATIC (decl))
+    verify_type_context (DECL_SOURCE_LOCATION (decl),
+                             TCTX_STATIC_STORAGE, type);
+
   if (init && TREE_CODE (decl) == FUNCTION_DECL)
     {
       tree clone;
diff --git a/gcc/testsuite/g++.target/aarch64/sve/static-var-in-template.C 
b/gcc/testsuite/g++.target/aarch64/sve/static-var-in-template.C
new file mode 100644
index 00000000000..c2395d18d50
--- /dev/null
+++ b/gcc/testsuite/g++.target/aarch64/sve/static-var-in-template.C
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+
+#include <arm_sve.h>
+
+template <int N>
+void f()
+{
+    static svbool_t pg = svwhilelt_b64(0, N);
+}
+
+int main(int argc, char **argv)
+{
+    f<2>();
+    return 0;
+}
+
+/* { dg-error {SVE type 'svbool_t' does not have a fixed size} } */
-- 
2.33.0.windows.1