[Bug gdb/27579] New: stap-probe.c : Invalid use of incomplete type ‘struct std::hash<exp_opcode>’

[Bug gdb/27579] New: stap-probe.c : Invalid use of incomplete type ‘struct std::hash<exp_opcode>’

[vvinayag at arm dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=27579

            Bug ID: 27579
           Summary: stap-probe.c : Invalid use of incomplete type ‘struct
                    std::hash<exp_opcode>’
           Product: gdb
           Version: HEAD
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: gdb
          Assignee: unassigned at sourceware dot org
          Reporter: vvinayag at arm dot com
  Target Milestone: ---

After this commit [1], I am seeing this error: invalid use of incomplete type
‘struct std::hash<exp_opcode>’.


In file included from /usr/include/c++/4.8.2/bits/hashtable.h:35:0,
                 from /usr/include/c++/4.8.2/unordered_map:47,
                 from src/binutils-gdb--gdb/gdb/stap-probe.c:40:
/usr/include/c++/4.8.2/bits/hashtable_policy.h: In instantiation of ‘struct
std::__detail::_Hash_code_base<exp_opcode, std::pair<const exp_opcode,
std::unique_ptr<expr::operation> (*)(std::unique_ptr<expr::operation>&&,
std::unique_ptr<expr::operation>&&)>, std::__detail::_Select1st,
std::hash<exp_opcode>, std::__detail::_Mod_range_hashing,
std::__detail::_Default_ranged_hash, true>’:
/usr/include/c++/4.8.2/bits/hashtable_policy.h:1402:10:   required from ‘struct
std::__detail::_Hashtable_base<exp_opcode, std::pair<const exp_opcode,
std::unique_ptr<expr::operation> (*)(std::unique_ptr<expr::operation>&&,
std::unique_ptr<expr::operation>&&)>, std::__detail::_Select1st,
std::equal_to<exp_opcode>, std::hash<exp_opcode>,
std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash,
std::__detail::_Hashtable_traits<true, false, true> >’
/usr/include/c++/4.8.2/bits/hashtable.h:174:11:   required from ‘class
std::_Hashtable<exp_opcode, std::pair<const exp_opcode,
std::unique_ptr<expr::operation> (*)(std::unique_ptr<expr::operation>&&,
std::unique_ptr<expr::operation>&&)>, std::allocator<std::pair<const
exp_opcode, std::unique_ptr<expr::operation>
(*)(std::unique_ptr<expr::operation>&&, std::unique_ptr<expr::operation>&&)> >,
std::__detail::_Select1st, std::equal_to<exp_opcode>, std::hash<exp_opcode>,
std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash,
std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true,
false, true> >’
/usr/include/c++/4.8.2/bits/unordered_map.h:100:18:   required from ‘class
std::unordered_map<exp_opcode, std::unique_ptr<expr::operation>
(*)(std::unique_ptr<expr::operation>&&, std::unique_ptr<expr::operation>&&)>’
/src/binutils-gdb--gdb/gdb/stap-probe.c:439:60:   required from here
/usr/include/c++/4.8.2/bits/hashtable_policy.h:1070:12: error: invalid use of
incomplete type ‘struct std::hash<exp_opcode>’
     struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2,
            ^
In file included from /usr/include/c++/4.8.2/bits/basic_string.h:3033:0,
                 from /usr/include/c++/4.8.2/string:52,
                 from /usr/include/c++/4.8.2/stdexcept:39,
                 from /usr/include/c++/4.8.2/array:38,
                 from /usr/include/c++/4.8.2/tuple:39,
                 from /usr/include/c++/4.8.2/functional:55,
                 from /src/binutils-gdb--gdb/gdb/../gdbsupport/ptid.h:35,
                 from
/src/binutils-gdb--gdb/gdb/../gdbsupport/common-defs.h:123,
                 from /src/binutils-gdb--gdb/gdb/defs.h:28,
                 from /src/binutils-gdb--gdb/gdb/stap-probe.c:20:
/usr/include/c++/4.8.2/bits/functional_hash.h:58:12: error: declaration of
‘struct std::hash<exp_opcode>’
     struct hash;
            ^

The build/host/target setup is:
Build: x86_64 (Linux)
Host: : x86_64 (Linux)
Target: arm-none-eabi / arm-none-linux-gnueabi  / aarch64-none-elf /
aarch64-none-linux-gnu


[1]
commit 4c5e7a930a46ddd6844eb7aede3ef60df535bc33
Author: Tom Tromey <tom@tromey.com>
Date:   Mon Mar 8 07:27:57 2021 -0700

    Convert stap probes to create operations

    This changes the stap probe code to create operations, rather than
    exp_elements.

    gdb/ChangeLog
    2021-03-08  Tom Tromey  <tom@tromey.com>

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[Bug build/27579] stap-probe.c : Invalid use of incomplete type ‘struct std::hash<exp_opcode>’

[tromey at sourceware dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=27579

Tom Tromey <tromey at sourceware dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|gdb                         |build
                 CC|                            |tromey at sourceware dot org

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[Bug build/27579] stap-probe.c : Invalid use of incomplete type ‘struct std::hash<exp_opcode>’

[tromey at sourceware dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=27579

--- Comment #1 from Tom Tromey <tromey at sourceware dot org> ---
Hi, thank you for the report.
I don't have GCC 4.8.2, but I did write a workaround patch.
Can you try this?  If it works for you, I will check it in.

diff --git a/gdb/stap-probe.c b/gdb/stap-probe.c
index 5995c2824dc..8baec03e5fc 100644
--- a/gdb/stap-probe.c
+++ b/gdb/stap-probe.c
@@ -435,8 +435,10 @@ stap_get_opcode (const char **s)
 typedef expr::operation_up binop_maker_ftype (expr::operation_up &&,
                                              expr::operation_up &&);
 /* Map from an expression opcode to a function that can create a
-   binary operation of that type.  */
-static std::unordered_map<exp_opcode, binop_maker_ftype *> stap_maker_map;
+   binary operation of that type.  We use 'int' as the key rather
+   than 'exp_opcode' due to a build problem with gcc 4.8.
+   See PR build/27579.  */
+static std::unordered_map<int, binop_maker_ftype *> stap_maker_map;

 /* Helper function to create a binary operation.  */
 static expr::operation_up

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[Bug build/27579] stap-probe.c : Invalid use of incomplete type ‘struct std::hash<exp_opcode>’

[vvinayag at arm dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=27579

--- Comment #2 from vvinayag at arm dot com ---
Similar problems were seen and fixed in:

https://sourceware.org/bugzilla/show_bug.cgi?id=25881 

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=f23f598e28ad39dac7ae87cdc400d2f6b27dc403

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[Bug build/27579] stap-probe.c : Invalid use of incomplete type ‘struct std::hash<exp_opcode>’

[tromey at sourceware dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=27579

--- Comment #3 from Tom Tromey <tromey at sourceware dot org> ---
That does seem like a better way.

diff --git a/gdb/stap-probe.c b/gdb/stap-probe.c
index 5995c2824dc..7f6d98a8ef2 100644
--- a/gdb/stap-probe.c
+++ b/gdb/stap-probe.c
@@ -38,6 +38,7 @@
 #include "elf-bfd.h"
 #include "expop.h"
 #include <unordered_map>
+#include "gdbsupport/hash_enum.h"

 #include <ctype.h>

@@ -436,7 +437,8 @@ typedef expr::operation_up binop_maker_ftype
(expr::operation_up &&,
                                              expr::operation_up &&);
 /* Map from an expression opcode to a function that can create a
    binary operation of that type.  */
-static std::unordered_map<exp_opcode, binop_maker_ftype *> stap_maker_map;
+static std::unordered_map<exp_opcode, binop_maker_ftype *,
+                         gdb::hash_enum<exp_opcode>> stap_maker_map;

 /* Helper function to create a binary operation.  */
 static expr::operation_up

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[Bug build/27579] stap-probe.c : Invalid use of incomplete type ‘struct std::hash<exp_opcode>’

[tromey at sourceware dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=27579

Tom Tromey <tromey at sourceware dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at sourceware dot org   |tromey at sourceware dot org

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[Bug build/27579] stap-probe.c : Invalid use of incomplete type ‘struct std::hash<exp_opcode>’

[vvinayag at arm dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=27579

--- Comment #4 from vvinayag at arm dot com ---
Hi Tom,

The previous patch fixes stap-probe.c and then the same issue happens in
gdb/rust-exp.y. I will try the new patch.

In file included from /usr/include/c++/4.8.2/bits/hashtable.h:35:0,
                 from /usr/include/c++/4.8.2/unordered_map:47,
                 from /src/binutils-gdb--gdb/gdb/rust-exp.y:45:
/usr/include/c++/4.8.2/bits/hashtable_policy.h: In instantiation of ‘struct
std::__detail::_Hash_code_base<exp_opcode, std::pair<const exp_opcode,
std::unique_ptr<expr::operation> (*)(std::unique_ptr<expr::operation>&&,
std::unique_ptr<expr::operation>&&)>, std::__detail::_Select1st,
std::hash<exp_opcode>, std::__detail::_Mod_range_hashing,
std::__detail::_Default_ranged_hash, true>’:

/usr/include/c++/4.8.2/bits/hashtable_policy.h:1402:10:   required from ‘struct
std::__detail::_Hashtable_base<exp_opcode, std::pair<const exp_opcode,
std::unique_ptr<expr::operation> (*)(std::unique_ptr<expr::operation>&&,
std::unique_ptr<expr::operation>&&)>, std::__detail::_Select1st,
std::equal_to<exp_opcode>, std::hash<exp_opcode>,
std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash,
std::__detail::_Hashtable_traits<true, false, true> >’

/usr/include/c++/4.8.2/bits/hashtable.h:174:11:   required from ‘class
std::_Hashtable<exp_opcode, std::pair<const exp_opcode,
std::unique_ptr<expr::operation> (*)(std::unique_ptr<expr::operation>&&,
std::unique_ptr<expr::operation>&&)>, std::allocator<std::pair<const
exp_opcode, std::unique_ptr<expr::operation>
(*)(std::unique_ptr<expr::operation>&&, std::unique_ptr<expr::operation>&&)> >,
std::__detail::_Select1st, std::equal_to<exp_opcode>, std::hash<exp_opcode>,
std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash,
std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true,
false, true> >’

/usr/include/c++/4.8.2/bits/unordered_map.h:100:18:   required from ‘class
std::unordered_map<exp_opcode, std::unique_ptr<expr::operation>
(*)(std::unique_ptr<expr::operation>&&, std::unique_ptr<expr::operation>&&)>’

/src/binutils-gdb--gdb/gdb/rust-exp.y:2205:60:   required from here
/usr/include/c++/4.8.2/bits/hashtable_policy.h:1070:12: error: invalid use of
incomplete type ‘struct std::hash<exp_opcode>’
     struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2,
            ^
In file included from /usr/include/c++/4.8.2/bits/basic_string.h:3033:0,
                 from /usr/include/c++/4.8.2/string:52,
                 from /usr/include/c++/4.8.2/stdexcept:39,
                 from /usr/include/c++/4.8.2/array:38,
                 from /usr/include/c++/4.8.2/tuple:39,
                 from /usr/include/c++/4.8.2/functional:55,
                 from /src/binutils-gdb--gdb/gdb/../gdbsupport/ptid.h:35,
                 from
/src/binutils-gdb--gdb/gdb/../gdbsupport/common-defs.h:123,
                 from /src/binutils-gdb--gdb/gdb/defs.h:28,
                 from /src/binutils-gdb--gdb/gdb/rust-exp.y:32:
/usr/include/c++/4.8.2/bits/functional_hash.h:58:12: error: declaration of
‘struct std::hash<exp_opcode>’
     struct hash;

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[Bug build/27579] stap-probe.c : Invalid use of incomplete type ‘struct std::hash<exp_opcode>’

[tromey at sourceware dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=27579

--- Comment #5 from Tom Tromey <tromey at sourceware dot org> ---
rust-exp.y will probably go away soon, but meanwhile here is a patch.
Try "make -k" to see if there are more errors, that way you can
report all the remaining ones at once.


diff --git a/gdb/rust-exp.y b/gdb/rust-exp.y
index 9a5bdd7a836..04003409887 100644
--- a/gdb/rust-exp.y
+++ b/gdb/rust-exp.y
@@ -43,6 +43,7 @@
 #include "gdbarch.h"
 #include "rust-exp.h"
 #include <unordered_map>
+#include "gdbsupport/hash_enum.h"

 #define GDB_YY_REMAP_PREFIX rust
 #include "yy-remap.h"
@@ -2202,7 +2203,8 @@ typedef expr::operation_up binop_maker_ftype
(expr::operation_up &&,
 /* Map from an expression opcode to a function that will create an
    instance of the appropriate operation subclass.  Only binary
    operations are handled this way.  */
-static std::unordered_map<exp_opcode, binop_maker_ftype *> maker_map;
+static std::unordered_map<exp_opcode, binop_maker_ftype *,
+                         gdb::hash_enum<exp_opcode>> maker_map;

 /* Lower a rust_op to a gdb expression.  STATE is the parser state.
    OPERATION is the operation to lower.  TOP is a pointer to the

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[Bug build/27579] stap-probe.c : Invalid use of incomplete type ‘struct std::hash<exp_opcode>’

[vvinayag at arm dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=27579

--- Comment #6 from vvinayag at arm dot com ---
Hi Tom,
It is just these 2 files with the error. The new patches work. Thank you.

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[Bug build/27579] stap-probe.c : Invalid use of incomplete type ‘struct std::hash<exp_opcode>’

[cvs-commit at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=27579

--- Comment #7 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Tom Tromey <tromey@sourceware.org>:

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=675da9a57e0ab1c384e0dfd20ddf715a83c18673

commit 675da9a57e0ab1c384e0dfd20ddf715a83c18673
Author: Tom Tromey <tromey@adacore.com>
Date:   Mon Mar 15 08:59:17 2021 -0600

    Fix GDB build with GCC 4.8.2

    PR build/27579 points out that the expression rewrite series
    introduced a build failure with GCC 4.8.2.  The bug is that there's no
    std::hash specialization for enum exp_opcode.  This patch fixes the
    problem by using gdb::hash_enum.

    2021-03-15  Tom Tromey  <tromey@adacore.com>

            PR build/27579:
            * rust-exp.y (maker_map): Use gdb::hash_enum.
            * stap-probe.c (stap_maker_map): Use gdb::hash_enum.

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[Bug build/27579] stap-probe.c : Invalid use of incomplete type ‘struct std::hash<exp_opcode>’

[tromey at sourceware dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=27579

Tom Tromey <tromey at sourceware dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #8 from Tom Tromey <tromey at sourceware dot org> ---
Ok, the fix is in.
Thanks again for the report, and I'm sorry for the breakage.

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[Bug build/27579] stap-probe.c : Invalid use of incomplete type ‘struct std::hash<exp_opcode>’

[tromey at sourceware dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=27579

Tom Tromey <tromey at sourceware dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |11.1

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