Fix hex floating point lexing

PR gdb/18318 notes that gdb will sometimes incorrectly handle hex
floating point input.  This turns out to be a bug in the C lexer; the
'p' was not being correctly recognized, and so the exponent was not
always passed to the floating point "from_string" method.

Tested by the buildbot "Fedora-x86_64-m64" builder.

gdb/ChangeLog
2020-06-11  Tom Tromey  <tom@tromey.com>

	PR gdb/18318:
	* c-exp.y (lex_one_token): Handle 'p' like 'e'.

gdb/testsuite/ChangeLog
2020-06-11  Tom Tromey  <tom@tromey.com>

	PR gdb/18318:
	* gdb.base/printcmds.exp (test_float_accepted): Add more hex
	floating point tests.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index e5008f668709a3a1af2c4a7de5973319a86d83d6..5ef6ee6aca4616d77268f680ebadbc70ffd187fb 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2020-06-11  Tom Tromey  <tom@tromey.com>
+
+       PR gdb/18318:
+       * c-exp.y (lex_one_token): Handle 'p' like 'e'.
+
 2020-06-09  Jonny Grant  <jg@jguk.org>
 2020-06-09  Simon Marchi  <simon.marchi@polymtl.ca>
 

diff --git a/gdb/c-exp.y b/gdb/c-exp.y
index e7d0a0dc4ad398f514ccb866b1cd6eb27324c3dc..5ec84eb8ed7abcd09287c2aaab10a53f5095a44e 100644 (file)
--- a/gdb/c-exp.y
+++ b/gdb/c-exp.y
@@ -2748,7 +2748,7 @@ lex_one_token (struct parser_state *par_state, bool *is_quoted_name)
     case '9':
       {
        /* It's a number.  */
-       int got_dot = 0, got_e = 0, toktype;
+       int got_dot = 0, got_e = 0, got_p = 0, toktype;
        const char *p = tokstart;
        int hex = input_radix > 10;
 
@@ -2768,13 +2768,16 @@ lex_one_token (struct parser_state *par_state, bool *is_quoted_name)
            /* This test includes !hex because 'e' is a valid hex digit
               and thus does not indicate a floating point number when
               the radix is hex.  */
-           if (!hex && !got_e && (*p == 'e' || *p == 'E'))
+           if (!hex && !got_e && !got_p && (*p == 'e' || *p == 'E'))
              got_dot = got_e = 1;
+           else if (!got_e && !got_p && (*p == 'p' || *p == 'P'))
+             got_dot = got_p = 1;
            /* This test does not include !hex, because a '.' always indicates
               a decimal floating point number regardless of the radix.  */
            else if (!got_dot && *p == '.')
              got_dot = 1;
-           else if (got_e && (p[-1] == 'e' || p[-1] == 'E')
+           else if (((got_e && (p[-1] == 'e' || p[-1] == 'E'))
+                     || (got_p && (p[-1] == 'p' || p[-1] == 'P')))
                     && (*p == '-' || *p == '+'))
              /* This is the sign of the exponent, not the end of the
                 number.  */
@@ -2787,7 +2790,7 @@ lex_one_token (struct parser_state *par_state, bool *is_quoted_name)
              break;
          }
        toktype = parse_number (par_state, tokstart, p - tokstart,
-                               got_dot|got_e, &yylval);
+                               got_dot | got_e | got_p, &yylval);
         if (toktype == ERROR)
          {
            char *err_copy = (char *) alloca (p - tokstart + 1);

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 7ff7de2b52614065fefd50ea6b557707ac2e4723..0523f7cb8813b47bca9d4b4483ec0fb416ed6b1e 100644 (file)
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2020-06-11  Tom Tromey  <tom@tromey.com>
+
+       PR gdb/18318:
+       * gdb.base/printcmds.exp (test_float_accepted): Add more hex
+       floating point tests.
+
 2020-06-11  Keith Seitz  <keiths@redhat.com>
 
        PR gdb/21356

diff --git a/gdb/testsuite/gdb.base/printcmds.exp b/gdb/testsuite/gdb.base/printcmds.exp
index 066e7fce87b6fb6919e9ea9f07891cc30ebbccc9..0a96b228b89d0656df1fe5d6b16ff7186fcd20c0 100644 (file)
--- a/gdb/testsuite/gdb.base/printcmds.exp
+++ b/gdb/testsuite/gdb.base/printcmds.exp
@@ -127,15 +127,15 @@ proc test_float_accepted {} {
     gdb_test "p 1.5l" " = 1.5"
 
     # Test hexadecimal floating point.
-    set test "p 0x1.1"
-    gdb_test_multiple $test $test {
-       -re " = 1\\.0625\r\n$gdb_prompt $" {
-           pass $test
-       }
-       -re "Invalid number \"0x1\\.1\"\\.\r\n$gdb_prompt $" {
-           # Older glibc does not support hex float, newer does.
-           xfail $test
-       }
+    foreach {num result} {
+       0x1.1 1.0625
+       0x1.8480000000000p+6 97.125
+       0x1.8480000000000p6 97.125
+       0x00.1p0 0.0625
+       0x00.1p1 0.125
+       0x00.1p-1 0.03125
+    } {
+       gdb_test "p $num" " = [string_to_regexp $result]"
     }
 }