[PATCH] RISC-V: Properly parse the letter 'p' in '-march'.

[Geng Qi via Gcc-patches]

gcc/ChangeLog:
        * common/config/riscv/riscv-common.c
        (riscv_subset_list::parsing_subset_version): Properly parse the letter
        'p' in '-march'.
        (riscv_subset_list::parse_std_ext,
         riscv_subset_list::parse_multiletter_ext): To handle errors generated
        in riscv_subset_list::parsing_subset_version.

gcc/testsuite/ChangeLog:
        * gcc.target/riscv/arch-12.c: New.
        * gcc.target/riscv/attribute-19.c: New.
---
 gcc/common/config/riscv/riscv-common.c        | 67 ++++++++++++++-------------
 gcc/testsuite/gcc.target/riscv/arch-12.c      |  4 ++
 gcc/testsuite/gcc.target/riscv/attribute-19.c |  4 ++
 3 files changed, 42 insertions(+), 33 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/riscv/arch-12.c
 create mode 100644 gcc/testsuite/gcc.target/riscv/attribute-19.c

diff --git a/gcc/common/config/riscv/riscv-common.c 
b/gcc/common/config/riscv/riscv-common.c
index 34b74e5..65e5641 100644
--- a/gcc/common/config/riscv/riscv-common.c
+++ b/gcc/common/config/riscv/riscv-common.c
@@ -518,40 +518,38 @@ riscv_subset_list::parsing_subset_version (const char 
*ext,
   unsigned version = 0;
   unsigned major = 0;
   unsigned minor = 0;
-  char np;
   *explicit_version_p = false;
 
-  for (; *p; ++p)
-    {
-      if (*p == 'p')
-       {
-         np = *(p + 1);
-
-         if (!ISDIGIT (np))
-           {
-             /* Might be beginning of `p` extension.  */
-             if (std_ext_p)
-               {
-                 get_default_version (ext, major_version, minor_version);
-                 return p;
-               }
-             else
-               {
-                 error_at (m_loc, "%<-march=%s%>: Expect number "
-                           "after %<%dp%>.", m_arch, version);
-                 return NULL;
-               }
-           }
-
-         major = version;
-         major_p = false;
-         version = 0;
-       }
-      else if (ISDIGIT (*p))
-       version = (version * 10) + (*p - '0');
-      else
-       break;
-    }
+  if (*p == 'p')
+    gcc_assert (std_ext_p);
+  else {
+    for (; *p; ++p)
+      {
+       if (*p == 'p')
+         {
+           if (!ISDIGIT (*(p+1)))
+             {
+               error_at (m_loc, "%<-march=%s%>: Expect number "
+                         "after %<%dp%>.", m_arch, version);
+               return NULL;
+             }
+           if (!major_p)
+             {
+               error_at (m_loc, "%<-march=%s%>: For %<%s%dp%dp?%>, version "
+                         "number with more than 2 level is not supported.",
+                         m_arch, ext, major, version);
+               return NULL;
+             }
+           major = version;
+           major_p = false;
+           version = 0;
+         }
+       else if (ISDIGIT (*p))
+         version = (version * 10) + (*p - '0');
+       else
+         break;
+      }
+  }
 
   if (major_p)
     major = version;
@@ -643,7 +641,7 @@ riscv_subset_list::parse_std_ext (const char *p)
       return NULL;
     }
 
-  while (*p)
+  while (p != NULL && *p)
     {
       char subset[2] = {0, 0};
 
@@ -771,6 +769,9 @@ riscv_subset_list::parse_multiletter_ext (const char *p,
                                  /* std_ext_p= */ false, &explicit_version_p);
       free (ext);
 
+      if (end_of_version == NULL)
+       return NULL;
+
       *q = '\0';
 
       if (strlen (subset) == 1)
diff --git a/gcc/testsuite/gcc.target/riscv/arch-12.c 
b/gcc/testsuite/gcc.target/riscv/arch-12.c
new file mode 100644
index 0000000..29e16c3
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/arch-12.c
@@ -0,0 +1,4 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=rv64im1p2p3 -mabi=lp64" } */
+int foo() {}
+/* { dg-error "'-march=rv64im1p2p3': For 'm1p2p\\?', version number with more 
than 2 level is not supported." "" { target *-*-* } 0 } */
diff --git a/gcc/testsuite/gcc.target/riscv/attribute-19.c 
b/gcc/testsuite/gcc.target/riscv/attribute-19.c
new file mode 100644
index 0000000..18f68d9
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/attribute-19.c
@@ -0,0 +1,4 @@
+/* { dg-do compile } */
+/* { dg-options "-mriscv-attribute -march=rv64imp0p9 -mabi=lp64" } */
+int foo() {}
+/* { dg-final { scan-assembler ".attribute arch, \"rv64i2p0_m2p0_p0p9\"" } } */
-- 
2.7.4