[committed] RISC-V: Check multiletter extension has more than 1 letter

[Kito Cheng]

gcc/ChangeLog:

        * common/config/riscv/riscv-common.c
        (riscv_subset_list::parse_multiletter_ext): Checking multiletter
        extension has more than 1 letter.

gcc/testsuite/ChangeLog

        * gcc.target/riscv/arch-7.c: New.
        * gcc.target/riscv/attribute-10.c: Update test arch string.
---
 gcc/common/config/riscv/riscv-common.c        | 8 ++++++++
 gcc/testsuite/gcc.target/riscv/arch-7.c       | 6 ++++++
 gcc/testsuite/gcc.target/riscv/attribute-10.c | 2 +-
 3 files changed, 15 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.target/riscv/arch-7.c

diff --git a/gcc/common/config/riscv/riscv-common.c 
b/gcc/common/config/riscv/riscv-common.c
index b84503a7742..84695a6ed1b 100644
--- a/gcc/common/config/riscv/riscv-common.c
+++ b/gcc/common/config/riscv/riscv-common.c
@@ -524,6 +524,14 @@ riscv_subset_list::parse_multiletter_ext (const char *p,
 
       *q = '\0';
 
+      if (strlen (subset) == 1)
+       {
+         error_at (m_loc, "%<-march=%s%>: name of %s must be more than 1 
letter",
+                   m_arch, ext_type_str);
+         free (subset);
+         return NULL;
+       }
+
       add (subset, major_version, minor_version, explicit_version_p);
       free (subset);
       p += end_of_version - subset;
diff --git a/gcc/testsuite/gcc.target/riscv/arch-7.c 
b/gcc/testsuite/gcc.target/riscv/arch-7.c
new file mode 100644
index 00000000000..74ab248fa57
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/arch-7.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=rv32i -march=rv32im_s -mabi=ilp32" } */
+int foo()
+{
+}
+/* { dg-error ".'-march=rv32im_s': name of supervisor extension must be more 
than 1 letter" "" { target *-*-* } 0 } */
diff --git a/gcc/testsuite/gcc.target/riscv/attribute-10.c 
b/gcc/testsuite/gcc.target/riscv/attribute-10.c
index a874a6234dc..26fdd08b26d 100644
--- a/gcc/testsuite/gcc.target/riscv/attribute-10.c
+++ b/gcc/testsuite/gcc.target/riscv/attribute-10.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -march=rv32i -march=rv32im_s_sx_unexpectedstring 
-mabi=ilp32" } */
+/* { dg-options "-O2 -march=rv32i -march=rv32im_sx_unexpectedstring 
-mabi=ilp32" } */
 int foo()
 {
 }
-- 
2.28.0