Bug 98624 - UBSAN: gcc/cp/module.cc:5895:29: runtime error: member call on null pointer of type 'struct module_state'
Summary: UBSAN: gcc/cp/module.cc:5895:29: runtime error: member call on null pointer o...
Status: RESOLVED FIXED
Alias: None
Product: gcc
Classification: Unclassified
Component: c++ (show other bugs)
Version: 11.0
: P3 normal
Target Milestone: ---
Assignee: Nathan Sidwell
URL:
Keywords:
Depends on:
Blocks: ubsan
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Reported: 2021-01-11 16:55 UTC by Martin Liška
Modified: 2021-01-21 18:42 UTC (History)
2 users (show)

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Target:
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Known to work:
Known to fail:
Last reconfirmed: 2021-01-11 00:00:00

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Description Martin Liška 2021-01-11 16:55:00 UTC 
Seen with UBSAN compiler:

$ ./xg++ -B. /home/marxin/Programming/gcc/gcc/testsuite/g++.dg/modules/align-type-1_a.C -c -fmodules-ts
/home/marxin/Programming/gcc2/gcc/cp/module.cc:5895:29: runtime error: member call on null pointer of type 'struct module_state'
    #0 0xf56fc4 in trees_out::core_vals(tree_node*) /home/marxin/Programming/gcc2/gcc/cp/module.cc:5895
    #1 0xf67347 in trees_out::tree_node_vals(tree_node*) /home/marxin/Programming/gcc2/gcc/cp/module.cc:7141
    #2 0xf6cd92 in trees_out::decl_value(tree_node*, depset*) /home/marxin/Programming/gcc2/gcc/cp/module.cc:7753
    #3 0xfb2a97 in depset::hash::find_dependencies() /home/marxin/Programming/gcc2/gcc/cp/module.cc:13199
    #4 0xfd1f35 in module_state::write(elf_out*, cpp_reader*) /home/marxin/Programming/gcc2/gcc/cp/module.cc:17568
    #5 0xfe1ab8 in finish_module_processing(cpp_reader*) /home/marxin/Programming/gcc2/gcc/cp/module.cc:19747
    #6 0xdcc2d1 in c_parse_final_cleanups() /home/marxin/Programming/gcc2/gcc/cp/decl2.c:5178
    #7 0x15ae87f in c_common_parse_file() /home/marxin/Programming/gcc2/gcc/c-family/c-opts.c:1233
    #8 0x2ccb435 in compile_file /home/marxin/Programming/gcc2/gcc/toplev.c:457
    #9 0x2cd3e17 in do_compile /home/marxin/Programming/gcc2/gcc/toplev.c:2193
    #10 0x2cd441a in toplev::main(int, char**) /home/marxin/Programming/gcc2/gcc/toplev.c:2332
    #11 0x59b3bff in main /home/marxin/Programming/gcc2/gcc/main.c:39
    #12 0x7ffff6ce5151 in __libc_start_main (/lib64/libc.so.6+0x28151)
    #13 0xa82bdd in _start (/home/marxin/Programming/gcc2/objdir/gcc/cc1plus+0xa82bdd)
Comment 1 GCC Commits 2021-01-19 19:37:59 UTC 
The master branch has been updated by Nathan Sidwell <nathan@gcc.gnu.org>:

https://gcc.gnu.org/g:6e6f3ed47e5cb575819f8253e42313664b89b042

commit r11-6797-g6e6f3ed47e5cb575819f8253e42313664b89b042
Author: Nathan Sidwell <nathan@acm.org>
Date:   Tue Jan 19 11:31:57 2021 -0800

    c++: Fix null this pointer [PR 98624]
    
    There's no need for this function to have an object, so make it
    static and avoid UB.
    
            PR c++/98624
            gcc/cp/
            * module.cc (trees_out::write_location): Make static.
Comment 2 Nathan Sidwell 2021-01-19 19:38:42 UTC 
fixed  6e6f3ed47e5 2021-01-19 | c++: Fix null this pointer [PR 98624]
Comment 3 Nathan Sidwell 2021-01-21 13:07:23 UTC 
I flubbed testing
Comment 4 GCC Commits 2021-01-21 18:41:44 UTC 
The master branch has been updated by Nathan Sidwell <nathan@gcc.gnu.org>:

https://gcc.gnu.org/g:7944753fad501194eb8a828d6b74270e79d14a4d

commit r11-6841-g7944753fad501194eb8a828d6b74270e79d14a4d
Author: Nathan Sidwell <nathan@acm.org>
Date:   Thu Jan 21 10:37:23 2021 -0800

    c++: Fix null this pointer [PR 98624]
    
    One may not use a null this pointer to invoke a static member
    function.  This fixes the remaining ubsan errors found with an
    ubsan bootstrap.
    
            PR c++/98624
            gcc/cp/
            * module.cc (depset::hash::find_dependencies): Add
            module arg.
            (trees_out::core_vals): Check state before calling
            write_location.
            (sort_cluster, module_state::write): Adjust
            find_dependencies call.
Comment 5 Nathan Sidwell 2021-01-21 18:42:21 UTC 
7944753fad5 2021-01-21 | c++: Fix null this pointer [PR 98624]