[Committed] RISC-V: Fix ICE in non-canonical march parsing

[Patrick O'Neill]

Updated testcase names and committed.

Thanks,
Patrick

---

Passing in a base extension in non-canonical order (i, e, g) causes GCC
to ICE:
xgcc: error: '-march=rv64ge': ISA string is not in canonical order. 'e'
xgcc: internal compiler error: in add, at 
common/config/riscv/riscv-common.cc:671
...

This is fixed by skipping to the next extension when a non-canonical
order is detected.

gcc/ChangeLog:

        * common/config/riscv/riscv-common.cc
        (riscv_subset_list::parse_std_ext): Emit an error and skip to
        the next extension when a non-canonical ordering is detected.

gcc/testsuite/ChangeLog:

        * gcc.target/riscv/arch-27.c: New test.
        * gcc.target/riscv/arch-28.c: New test.

Signed-off-by: Patrick O'Neill <patr...@rivosinc.com>
---
Tested using rv64gc glibc on QEMU.
---
 gcc/common/config/riscv/riscv-common.cc  | 17 +++++++++++++----
 gcc/testsuite/gcc.target/riscv/arch-27.c |  7 +++++++
 gcc/testsuite/gcc.target/riscv/arch-28.c |  7 +++++++
 3 files changed, 27 insertions(+), 4 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/riscv/arch-27.c
 create mode 100644 gcc/testsuite/gcc.target/riscv/arch-28.c

diff --git a/gcc/common/config/riscv/riscv-common.cc 
b/gcc/common/config/riscv/riscv-common.cc
index 526dbb7603b..57fe856063e 100644
--- a/gcc/common/config/riscv/riscv-common.cc
+++ b/gcc/common/config/riscv/riscv-common.cc
@@ -1017,15 +1017,24 @@ riscv_subset_list::parse_std_ext (const char *p)
       std_ext = *p;
 
       /* Checking canonical order.  */
+      const char *prior_std_exts = std_exts;
+
       while (*std_exts && std_ext != *std_exts)
        std_exts++;
 
       subset[0] = std_ext;
       if (std_ext != *std_exts && standard_extensions_p (subset))
-       error_at (m_loc,
-                 "%<-march=%s%>: ISA string is not in canonical order. "
-                 "%<%c%>",
-                 m_arch, *p);
+       {
+         error_at (m_loc,
+                   "%<-march=%s%>: ISA string is not in canonical order. "
+                   "%<%c%>",
+                   m_arch, *p);
+         /* Extension ordering is invalid.  Ignore this extension and keep
+            searching for other issues with remaining extensions.  */
+         std_exts = prior_std_exts;
+         p++;
+         continue;
+       }
 
       std_exts++;
 
diff --git a/gcc/testsuite/gcc.target/riscv/arch-27.c 
b/gcc/testsuite/gcc.target/riscv/arch-27.c
new file mode 100644
index 00000000000..70143b2156f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/arch-27.c
@@ -0,0 +1,7 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64ge -mabi=lp64d" } */
+int foo()
+{
+}
+
+/* { dg-error "ISA string is not in canonical order. 'e'" "" { target *-*-* } 
0 } */
diff --git a/gcc/testsuite/gcc.target/riscv/arch-28.c 
b/gcc/testsuite/gcc.target/riscv/arch-28.c
new file mode 100644
index 00000000000..934399a7b3a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/arch-28.c
@@ -0,0 +1,7 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64imaefcv -mabi=lp64d" } */
+int foo()
+{
+}
+
+/* { dg-error "ISA string is not in canonical order. 'e'" "" { target *-*-* } 
0 } */
-- 
2.34.1