[PATCH 3/6] Add 128-bit integer support to the Rust parser

[Tom Tromey <tromey@adacore.com>]

This adds support for 128-bit integers to the Rust parser.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=21185
---
 gdb/rust-lang.c                         |  2 ++
 gdb/rust-parse.c                        | 37 ++++++++++++++++++++-------------
 gdb/testsuite/gdb.base/parse_number.exp |  7 ++++---
 gdb/testsuite/gdb.rust/onetwoeight.exp  |  4 ++++
 4 files changed, 33 insertions(+), 17 deletions(-)

diff --git a/gdb/rust-lang.c b/gdb/rust-lang.c
index cb128f13f0e..3ef8fcaa329 100644
--- a/gdb/rust-lang.c
+++ b/gdb/rust-lang.c
@@ -1607,6 +1607,8 @@ rust_language::language_arch_info (struct gdbarch *gdbarch,
   add (init_integer_type (alloc, 32, 1, "u32"));
   add (init_integer_type (alloc, 64, 0, "i64"));
   add (init_integer_type (alloc, 64, 1, "u64"));
+  add (init_integer_type (alloc, 128, 0, "i128"));
+  add (init_integer_type (alloc, 128, 1, "u128"));
 
   unsigned int length = 8 * builtin->builtin_data_ptr->length ();
   add (init_integer_type (alloc, length, 0, "isize"));
diff --git a/gdb/rust-parse.c b/gdb/rust-parse.c
index eca98aa286f..6c7922de9c7 100644
--- a/gdb/rust-parse.c
+++ b/gdb/rust-parse.c
@@ -69,7 +69,7 @@ static const char number_regex_text[] =
 #define INT_TEXT 5
 #define INT_TYPE 6
   "(0x[a-fA-F0-9_]+|0o[0-7_]+|0b[01_]+|[0-9][0-9_]*)"
-  "([iu](size|8|16|32|64))?"
+  "([iu](size|8|16|32|64|128))?"
   ")";
 /* The number of subexpressions to allocate space for, including the
    "0th" whole match subexpression.  */
@@ -126,7 +126,7 @@ enum token_type : int
 
 struct typed_val_int
 {
-  ULONGEST val;
+  gdb_mpz val;
   struct type *type;
 };
 
@@ -1007,7 +1007,6 @@ rust_parser::lex_number ()
   /* Parse the number.  */
   if (is_integer)
     {
-      uint64_t value;
       int radix = 10;
       int offset = 0;
 
@@ -1026,14 +1025,22 @@ rust_parser::lex_number ()
 	    }
 	}
 
-      const char *trailer;
-      value = strtoulst (number.c_str () + offset, &trailer, radix);
-      if (*trailer != '\0')
-	error (_("Integer literal is too large"));
-      if (implicit_i32 && value >= ((uint64_t) 1) << 31)
-	type = get_type ("i64");
+      if (!current_int_val.val.set (number.c_str () + offset, radix))
+	{
+	  /* Shouldn't be possible.  */
+	  error (_("Invalid integer"));
+	}
+      if (implicit_i32)
+	{
+	  static gdb_mpz sixty_three_bit = gdb_mpz::pow (2, 63);
+	  static gdb_mpz thirty_one_bit = gdb_mpz::pow (2, 31);
+
+	  if (current_int_val.val >= sixty_three_bit)
+	    type = get_type ("i128");
+	  else if (current_int_val.val >= thirty_one_bit)
+	    type = get_type ("i64");
+	}
 
-      current_int_val.val = value;
       current_int_val.type = type;
     }
   else
@@ -1556,9 +1563,11 @@ rust_parser::parse_field (operation_up &&lhs)
       break;
 
     case DECIMAL_INTEGER:
-      result = make_operation<rust_struct_anon> (current_int_val.val,
-						 std::move (lhs));
-      lex ();
+      {
+	int idx = current_int_val.val.as_integer<int> ();
+	result = make_operation<rust_struct_anon> (idx, std::move (lhs));
+	lex ();
+      }
       break;
 
     case INTEGER:
@@ -1659,7 +1668,7 @@ rust_parser::parse_array_type ()
 
   if (current_token != INTEGER && current_token != DECIMAL_INTEGER)
     error (_("integer expected"));
-  ULONGEST val = current_int_val.val;
+  ULONGEST val = current_int_val.val.as_integer<ULONGEST> ();
   lex ();
   require (']');
 
diff --git a/gdb/testsuite/gdb.base/parse_number.exp b/gdb/testsuite/gdb.base/parse_number.exp
index 07104433a16..5dd4fa705e9 100644
--- a/gdb/testsuite/gdb.base/parse_number.exp
+++ b/gdb/testsuite/gdb.base/parse_number.exp
@@ -108,9 +108,10 @@ proc parse_number { lang n } {
 	    return [list "i32" $n]
 	} elseif { [fits_in_type $n 64 s] } {
 	    return [list "i64" $n]
-	} elseif { [fits_in_type $n 64 u] } {
-	    # Note: Interprets MAX_U64 as -1.
-	    return [list "i64" $n]
+	} elseif { [fits_in_type $n 128 u] } {
+	    return [list "i128" $n]
+	} elseif { [fits_in_type $n 128 u] } {
+	    return [list "i128" $n]
 	} else {
 	    # Overflow.
 	    return [list $re_overflow $re_overflow]
diff --git a/gdb/testsuite/gdb.rust/onetwoeight.exp b/gdb/testsuite/gdb.rust/onetwoeight.exp
index ef56bcafda2..5ca30712830 100644
--- a/gdb/testsuite/gdb.rust/onetwoeight.exp
+++ b/gdb/testsuite/gdb.rust/onetwoeight.exp
@@ -64,3 +64,7 @@ gdb_test "print x >> 2" "= 85070591730234615865843651857942052863"
 gdb_test "print/x x & mask" " = 0xf0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0"
 gdb_test "print/x x ^ mask" " = 0xf0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f"
 gdb_test "print/x mask | (mask >> 4)" " = 0xffffffffffffffffffffffffffffffff"
+
+gdb_test "print 170141183460469231731687303715884105727" \
+    " = 170141183460469231731687303715884105727"
+gdb_test "ptype 23i128" "type = i128"

-- 
2.39.1