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* [RFA] Fix pascal behavior for class fields
@ 2015-01-08  8:53 Pierre Muller
  0 siblings, 0 replies; 30+ messages in thread
From: Pierre Muller @ 2015-01-08  8:53 UTC (permalink / raw)
  To: 'gdb-patches'

  This is the problem that triggered my previous RFA,
as I discovered it while debugging this problem.

  In the pascal parser, there is special code
that will try to emulate case-insensivity despite the
fact that pascal is not registered as a 'case-insensitive' language.

  This code does not work as expected for fields of a class,
for which exact casing is currently required.

See:
https://sourceware.org/bugzilla/show_bug.cgi?id=17815
for source code:

# Compile attached source code, using Free Pascal compiler

fpc -gs -Mobjfpc test-class-pascal.pas

# Debug it
gdb ./test-class-pascal
.......
(gdb) b TA__CHECK
Breakpoint 1 at 0x40154c: file test-class-pascal.pas, line 23.
(gdb) r
Starting program: E:\pas\test\test-class-pascal.exe
[New Thread 6700.0x1ae0]

Breakpoint 1, TA__CHECK (B=0x1572ee0, this=<error reading variable>)
    at test-class-pascal.pas:23
23        check:=(x < b.x);
(gdb) p this
$1 = (TA) 0x1572ed0
(gdb) p this^
warning: can't find linker symbol for virtual table for `TA' value
$2 = {<TOBJECT> = {_vptr$ = {0x408014, 0x43}}, X = 67, Y = 33}
(gdb) p X
warning: can't find linker symbol for virtual table for `TA' value
$3 = 67
(gdb) p B.X
warning: can't find linker symbol for virtual table for `TA' value
$4 = -1
(gdb) p b.x
warning: can't find linker symbol for virtual table for `TA' value
$5 = -1
(gdb) p x
Type TA has no component named x.
(gdb)


  The patch below fixes this odd behavior,
if there is no approval nor comments about it,
I will commit it in a few days (before 7.9 branching)
as pascal language maintainer.

  But, of course, don't hesitate to give feedback!
 
Pierre Muller

2015-01-07  Pierre Muller  <muller@sourceware.org>

       PR pascal/17815
       * p-exp.y (yylex): Remember the case pattern that allowed finding
       a field of this.


diff --git a/gdb/p-exp.y b/gdb/p-exp.y
index a1c78bf..3a4905a 100644
--- a/gdb/p-exp.y
+++ b/gdb/p-exp.y
@@ -1598,7 +1598,7 @@ yylex (void)
                              VAR_DOMAIN, &is_a_field_of_this);
       }

-    if (is_a_field)
+    if (is_a_field || (is_a_field_of_this.type != NULL))
       {
        tempbuf = (char *) realloc (tempbuf, namelen + 1);
        strncpy (tempbuf, tmp, namelen);
@@ -1606,7 +1606,11 @@ yylex (void)
        yylval.sval.ptr = tempbuf;
        yylval.sval.length = namelen;
        free (uptokstart);
-       return FIELDNAME;
+        yylval.ssym.is_a_field_of_this = is_a_field_of_this.type != NULL;
+       if (is_a_field)
+         return FIELDNAME;
+       else
+         return NAME;
       }
     /* Call lookup_symtab, not lookup_partial_symtab, in case there are
        no psymtabs (coff, xcoff, or some future change to blow away the
@@ -1739,7 +1743,6 @@ yylex (void)
     free(uptokstart);
     /* Any other kind of symbol.  */
     yylval.ssym.sym = sym;
-    yylval.ssym.is_a_field_of_this = is_a_field_of_this.type != NULL;
     return NAME;
   }
 }

^ permalink raw reply	[flat|nested] 30+ messages in thread

end of thread, other threads:[~2015-04-21 20:33 UTC | newest]

Thread overview: 30+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
     [not found] <54ae4586.01e3440a.7b06.fffff844SMTPIN_ADDED_BROKEN@mx.google.com>
2015-01-08 10:48 ` [RFA] Fix pascal behavior for class fields Pedro Alves
2015-01-08 13:01   ` Pierre Muller
     [not found]   ` <54ae7f9f.c323460a.36ed.ffffff30SMTPIN_ADDED_BROKEN@mx.google.com>
2015-01-08 13:41     ` Pedro Alves
2015-01-08 14:15       ` gdb-patches RFA: " Pierre Muller
     [not found]       ` <54ae911b.85e3440a.1d96.5ffdSMTPIN_ADDED_BROKEN@mx.google.com>
2015-01-09 10:52         ` Pedro Alves
2015-01-09 10:55           ` Pedro Alves
2015-01-09 16:16           ` [RFA PATCH 1/3] Remember the case pattern that allowed finding a field of this Pierre Muller
2015-01-23  7:30             ` [RFA PATCH 1/3 V3] " Pierre Muller
2015-02-04 23:37               ` [RFA PATCH 1/3 V4] " Pierre Muller
2015-01-09 16:16           ` [RFA 0/3] Fix pascal behavior for class fields with testcase Pierre Muller
2015-01-09 16:18             ` [RFA PATCH 2/3] Add debug-stabs debug-dwarf and class option for pascal compiler Pierre Muller
2015-02-04 23:37             ` [RFA 0/3 V4] Fix pascal behavior for class fields with testcase Pierre Muller
2015-02-15  6:59               ` PING " Pierre Muller
2015-04-07 20:06                 ` PING^2 " Pierre Muller
     [not found]               ` <54e043b2.626ec20a.0c59.ffffaeacSMTPIN_ADDED_BROKEN@mx.google.com>
2015-04-20  6:00                 ` PING " Doug Evans
2015-04-21 20:33                   ` Pierre Muller
2015-01-09 16:18           ` [RFA PATCH 3/3] Testcase for pascal/17815 Pierre Muller
     [not found]           ` <54afff61.6790420a.0fa7.4f63SMTPIN_ADDED_BROKEN@mx.google.com>
2015-01-10  0:45             ` [RFA PATCH 2/3] Add debug-stabs debug-dwarf and class option for pascal compiler Doug Evans
2015-01-10  0:55               ` Pierre Muller
     [not found]               ` <54b07891.01b3c20a.2a7b.ffff9f96SMTPIN_ADDED_BROKEN@mx.google.com>
2015-01-10 21:23                 ` Doug Evans
2015-01-14 15:04                   ` [RFA PATCH 2/3 V2] Add "class" " Pierre Muller
     [not found]                   ` <54b6858f.a287440a.5b61.ffff9ef0SMTPIN_ADDED_BROKEN@mx.google.com>
2015-01-22 12:49                     ` Pedro Alves
2015-01-23  5:21                       ` [RFA PATCH 2/3 V3] " Pierre Muller
2015-01-23 11:55                         ` Pedro Alves
2015-02-04 23:37                           ` [RFA PATCH 2/3 V4] " Pierre Muller
     [not found]           ` <54afff6b.ee8d440a.16ee.ffffb424SMTPIN_ADDED_BROKEN@mx.google.com>
2015-01-22 12:46             ` [RFA PATCH 3/3] Testcase for pascal/17815 Pedro Alves
2015-01-23  7:16               ` [RFA PATCH 3/3 V3] " Pierre Muller
2015-01-23 12:29                 ` Pedro Alves
2015-02-04 23:37                   ` [RFA PATCH 3/3 V4] " Pierre Muller
2015-01-08  8:53 [RFA] Fix pascal behavior for class fields Pierre Muller

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