Bug 96734 - gcc 10.2.0 fails to compile on mips64 due to crash in IPA SRA pass
Summary: gcc 10.2.0 fails to compile on mips64 due to crash in IPA SRA pass
Status: RESOLVED FIXED
Alias: None
Product: gcc
Classification: Unclassified
Component: ipa (show other bugs)
Version: 10.2.0
: P3 normal
Target Milestone: ---
Assignee: Not yet assigned to anyone
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2020-08-21 11:18 UTC by Ariadne Conill
Modified: 2020-11-24 12:25 UTC (History)
2 users (show)

See Also:
Host:
Target: mips64
Build:
Known to work:
Known to fail:
Last reconfirmed: 2020-08-24 00:00:00


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Description Ariadne Conill 2020-08-21 11:18:22 UTC
When building gcc 10.2.0 using previous gcc 9.3.0 on a mips64 host, gcc 10.2.0 crashes while building stage3:

during IPA pass: sra
In file included from /home/buildozer/aports/main/gcc/src/gcc-10.2.0/gcc/cp/method.c:3199:
./gt-cp-method.h:36:2: internal compiler error: Segmentation fault
   36 | };
      |  ^
0x1208017a3 crash_signal
	/home/buildozer/aports/main/gcc/src/gcc-10.2.0/gcc/toplev.c:328
0x12041ef55 cgraph_edge::redirect_callee(cgraph_node*)
	/home/buildozer/aports/main/gcc/src/gcc-10.2.0/gcc/cgraph.c:1374
0x120431cd3 cgraph_edge::redirect_callee_duplicating_thunks(cgraph_node*)
	/home/buildozer/aports/main/gcc/src/gcc-10.2.0/gcc/cgraphclones.c:262
0x120432167 cgraph_node::create_clone(tree_node*, profile_count, bool, vec<cgraph_edge*, va_heap, vl_ptr>, bool, cgraph_node*, ipa_param_adjustments*, char const*)
	/home/buildozer/aports/main/gcc/src/gcc-10.2.0/gcc/cgraphclones.c:427
0x12043258b cgraph_node::create_virtual_clone(vec<cgraph_edge*, va_heap, vl_ptr>, vec<ipa_replace_map*, va_gc, vl_embed>*, ipa_param_adjustments*, char const*, unsigned int)
	/home/buildozer/aports/main/gcc/src/gcc-10.2.0/gcc/cgraphclones.c:613
0x1205eba27 process_isra_node_results
	/home/buildozer/aports/main/gcc/src/gcc-10.2.0/gcc/ipa-sra.c:3811
0x1205eba27 ipa_sra_analysis
	/home/buildozer/aports/main/gcc/src/gcc-10.2.0/gcc/ipa-sra.c:4047
0x1205eba27 execute
	/home/buildozer/aports/main/gcc/src/gcc-10.2.0/gcc/ipa-sra.c:4099
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.

Full log of building cp/method.o:
https://distfiles.dereferenced.org/method.log

method.ii:
https://distfiles.dereferenced.org/method.ii

Unfortunately I wouldn't know where to begin creating a reduced test case for this.  Sorry.

I suspect the issue is because `caller` is null, which means to->check_calls_comdat_local_p() does a null dereference when trying to fetch the vtable.  But I could be wrong entirely.  :)
Comment 1 Ariadne Conill 2020-08-21 11:37:45 UTC
Manually compiling cp/method.o using:

g++ -c -o cp/method.o -O2 method.ii

works fine.

I wonder if this is somehow related to pre-compiled headers, actually.
Comment 2 Martin Liška 2020-08-24 07:21:32 UTC
(In reply to Ariadne Conill from comment #1)
> Manually compiling cp/method.o using:
> 
> g++ -c -o cp/method.o -O2 method.ii

Can you please try it will all the original arguments:

-march=mips3 -mtune=mips64 -mabi=64 -msoft-float -mllsc -mips3 -mno-shared -auxbase-strip cp/method.o -Os -Wextra -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wno-error=format-diag -Wsuggest-attribute=format -Woverloaded-virtual -Wpedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -version -fno-PIE -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -fomit-frame-pointer

> 
> works fine.
> 
> I wonder if this is somehow related to pre-compiled headers, actually.

If I see correctly, pre-compiled headers are not used in your case.
Comment 3 Ariadne Conill 2020-08-24 09:58:30 UTC
When that method.ii is compiled against g++ 9.3.0 with the provided options, it compiles successfully.

When built using a cross-compiled g++ 10.2.0, it crashes.  So, the issue is specific to 10.2.0 it seems.
Comment 4 Martin Liška 2020-08-24 10:08:56 UTC
(In reply to Ariadne Conill from comment #3)
> When that method.ii is compiled against g++ 9.3.0 with the provided options,
> it compiles successfully.
> 
> When built using a cross-compiled g++ 10.2.0, it crashes.  So, the issue is
> specific to 10.2.0 it seems.

I've just tried building 10.2.0 cross compiler (x86_64-linux-gnu as host) and I can't reproduce it.
Which options do you use?
Comment 5 Ariadne Conill 2020-08-24 10:19:31 UTC
I should clarify.

I cross-compiled g++ 10.2.0 to run on mips64 *host*.  That part worked fine.

Afterwards, the *host* mips64 g++ cannot compile itself.

The *host* mips64 g++ (which was cross-compiled from an aarch64 machine), is built with:

Configured with: /home/buildozer/aports/main/gcc/src/gcc-10.2.0/configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --build=mips64-alpine-linux-musl --host=mips64-alpine-linux-musl --target=mips64-alpine-linux-musl --with-pkgversion='Alpine 10.2.0' --enable-checking=release --disable-fixed-point --disable-libstdcxx-pch --disable-multilib --disable-nls --disable-werror --disable-symvers --enable-__cxa_atexit --enable-default-pie --enable-default-ssp --enable-cloog-backend --enable-languages=c,c++,d,objc,fortran,ada --with-arch=mips3 --with-tune=mips64 --with-mips-plt --with-float=soft --with-abi=64 --disable-bootstrap --disable-libquadmath --disable-libssp --disable-libmpx --disable-libmudflap --disable-libsanitizer --enable-shared --enable-threads --enable-tls --disable-libitm --with-system-zlib --with-linker-hash-style=sysv

So we have this crashing whenever we try to build gcc with 10.2.0 on a mips64 host, either rebuilding from gcc 9.3.0 or from cross-compiled 10.2.0.
Comment 6 Ariadne Conill 2020-08-24 10:20:59 UTC
(In reply to Ariadne Conill from comment #5)
> I should clarify.
> 
> I cross-compiled g++ 10.2.0 to run on mips64 *host*.  That part worked fine.
> 
> Afterwards, the *host* mips64 g++ cannot compile itself.
> 
> The *host* mips64 g++ (which was cross-compiled from an aarch64 machine), is
> built with:
> 
> Configured with: /home/buildozer/aports/main/gcc/src/gcc-10.2.0/configure
> --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info
> --build=mips64-alpine-linux-musl --host=mips64-alpine-linux-musl
> --target=mips64-alpine-linux-musl --with-pkgversion='Alpine 10.2.0'
> --enable-checking=release --disable-fixed-point --disable-libstdcxx-pch
> --disable-multilib --disable-nls --disable-werror --disable-symvers
> --enable-__cxa_atexit --enable-default-pie --enable-default-ssp
> --enable-cloog-backend --enable-languages=c,c++,d,objc,fortran,ada
> --with-arch=mips3 --with-tune=mips64 --with-mips-plt --with-float=soft
> --with-abi=64 --disable-bootstrap --disable-libquadmath --disable-libssp
> --disable-libmpx --disable-libmudflap --disable-libsanitizer --enable-shared
> --enable-threads --enable-tls --disable-libitm --with-system-zlib
> --with-linker-hash-style=sysv
> 
> So we have this crashing whenever we try to build gcc with 10.2.0 on a
> mips64 host, either rebuilding from gcc 9.3.0 or from cross-compiled 10.2.0.

An easy way to observe the behavior for yourself would be to use an Alpine chroot on a mips64 host (I think the GCC build farm has one, if not, I can facilitate access to a mips64 container).
Comment 7 Natanael Copa 2020-11-13 14:20:55 UTC
I was able to reproduce using latest commit from gcc 10 branch:

/home/ncopa/aports/main/gcc/src/build/./prev-gcc/xg++ -B/home/ncopa/aports/main/gcc/src/build/./prev-gcc/ -B/usr/mips64-alpine-linux-musl/bin/ -nostdinc++ -B/home/ncopa/aports/main/gcc/src/build/prev-mips64-alpine-linux-musl/libstdc++-v3/src/.libs -B/home/ncopa/aports/main/gcc/src/build/prev-mips64-alpine-linux-musl/libstdc++-v3/libsupc++/.libs  -I/home/ncopa/aports/main/gcc/src/build/prev-mips64-alpine-linux-musl/libstdc++-v3/include/mips64-alpine-linux-musl  -I/home/ncopa/aports/main/gcc/src/build/prev-mips64-alpine-linux-musl/libstdc++-v3/include  -I/home/ncopa/aports/main/gcc/src/gcc-10.2.1/libstdc++-v3/libsupc++ -L/home/ncopa/aports/main/gcc/src/build/prev-mips64-alpine-linux-musl/libstdc++-v3/src/.libs -L/home/ncopa/aports/main/gcc/src/build/prev-mips64-alpine-linux-musl/libstdc++-v3/libsupc++/.libs -fno-PIE -c  -DIN_GCC_FRONTEND -g -O2 -fno-checking -gtoggle  -DIN_GCC     -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wno-error=format-diag -Wmissing-format-attribute -Woverloaded-virtual -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings   -DHAVE_CONFIG_H -I. -Icp -I/home/ncopa/aports/main/gcc/src/gcc-10.2.1/gcc -I/home/ncopa/aports/main/gcc/src/gcc-10.2.1/gcc/cp -I/home/ncopa/aports/main/gcc/src/gcc-10.2.1/gcc/../include -I/home/ncopa/aports/main/gcc/src/gcc-10.2.1/gcc/../libcpp/include  -I/home/ncopa/aports/main/gcc/src/gcc-10.2.1/gcc/../libdecnumber -I/home/ncopa/aports/main/gcc/src/gcc-10.2.1/gcc/../libdecnumber/dpd -I../libdecnumber -I/home/ncopa/aports/main/gcc/src/gcc-10.2.1/gcc/../libbacktrace  -Os -fomit-frame-pointer -o cp/method.o -MT cp/method.o -MMD -MP -MF cp/.deps/method.TPo /home/ncopa/aports/main/gcc/src/gcc-10.2.1/gcc/cp/method.c
during IPA pass: sra
In file included from /home/ncopa/aports/main/gcc/src/gcc-10.2.1/gcc/cp/method.c:3199:
./gt-cp-method.h:36:2: internal compiler error: Segmentation fault
   36 | };
      |  ^
0x120807513 crash_signal
        /home/ncopa/aports/main/gcc/src/gcc-10.2.1/gcc/toplev.c:328
0x1204210f5 cgraph_edge::redirect_callee(cgraph_node*)
        /home/ncopa/aports/main/gcc/src/gcc-10.2.1/gcc/cgraph.c:1374
0x1204340c3 cgraph_edge::redirect_callee_duplicating_thunks(cgraph_node*)
        /home/ncopa/aports/main/gcc/src/gcc-10.2.1/gcc/cgraphclones.c:262
0x120434557 cgraph_node::create_clone(tree_node*, profile_count, bool, vec<cgraph_edge*, va_heap, vl_ptr>, bool, cgraph_node*, ipa_param_adjustments*, char const*)
        /home/ncopa/aports/main/gcc/src/gcc-10.2.1/gcc/cgraphclones.c:427
0x12043497b cgraph_node::create_virtual_clone(vec<cgraph_edge*, va_heap, vl_ptr>, vec<ipa_replace_map*, va_gc, vl_embed>*, ipa_param_adjustments*, char const*, unsigned int)
        /home/ncopa/aports/main/gcc/src/gcc-10.2.1/gcc/cgraphclones.c:613
0x1205ee357 process_isra_node_results
        /home/ncopa/aports/main/gcc/src/gcc-10.2.1/gcc/ipa-sra.c:3811
0x1205ee357 ipa_sra_analysis
        /home/ncopa/aports/main/gcc/src/gcc-10.2.1/gcc/ipa-sra.c:4047
0x1205ee357 execute
        /home/ncopa/aports/main/gcc/src/gcc-10.2.1/gcc/ipa-sra.c:4099
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
make: *** [Makefile:1117: cp/method.o] Error 1

Withs some help from Ariadne we figured out that

 it passes with -O1
 it fails with -O2 (or -Os)
 it fails with -O1 -fipa-sra -fpartial-inlining
 it fails with -Og -fipa-sra -fpartial-inlining
 it passes with -Og -fipa-sra
 it passes with -Og -fpartial-inlining
 it passes with -O2  and either -fnoipa-sra or -fnopartial-inlining
 it passes with -fipa-sra -fpartial-inlining
 

So it seems that it is some -Og optimization in combination with -fipa-sra -fpartial-inlining triggers it. I have not been able to pinpoint any of the documented -O1 or -Og optimization flags.

It fails with:
-Og -fipa-sra -fpartial-inlining  -fno-combine-stack-adjustments -fno-compare-elim -fno-cprop-registers -fno-defer-pop -fno-ipa-profile -fno-ipa-pure-const -fno-ipa-reference -fno-ipa-reference-addressable -fno-merge-constants -fno-omit-frame-pointer -fno-reorder-blocks -fno-shrink-wrap -fno-split-wide-types -fno-tree-builtin-call-dce -fno-tree-ccp -fno-tree-ch -fno-tree-coalesce-vars -fno-tree-copy-prop -fno-tree-dce -fno-tree-dominator-opts -fno-tree-fre -fno-tree-sink -fno-tree-slsr -fno-tree-ter
Comment 8 Martin Liška 2020-11-16 10:38:13 UTC
All right, there's a compile farm mips64 machine gcc24 so I'll try it there..
Comment 9 Martin Liška 2020-11-16 12:33:14 UTC
g++ -std=c++11  -fno-PIE -c   -g -DIN_GCC     -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wno-format -Wmissing-format-attribute -Woverloaded-virtual -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -fno-common  -DHAVE_CONFIG_H -I. -I. -I../../gcc -I../../gcc/. -I../../gcc/../include -I../../gcc/../libcpp/include  -I../../gcc/../libdecnumber -I../../gcc/../libdecnumber/dpd -I../libdecnumber -I../../gcc/../libbacktrace   -o calls.o -MT calls.o -MMD -MP -MF ./.deps/calls.TPo ../../gcc/calls.c
/bin/bash: line 1:  7006 Killed                  build/genautomata ../../gcc/common.md ../../gcc/config/mips/mips.md insn-conditions.md > tmp-automata.c
make[3]: *** [Makefile:2399: s-automata] Error 137


So I won't be able to help you :/
Comment 10 Martin Liška 2020-11-23 12:42:24 UTC
All right, I have a reduced test-case (with the failing stage1 compiler):

$ cat method.ii

typedef union tree_node *tree;
struct tree_typed {
  tree type;
};
struct tree_type_non_common {
  tree lang_1;
};
union tree_node {
  tree_typed typed;
  tree_type_non_common type_non_common;
};
;
struct comp_info {
  bool noex;
  comp_info(tree fndecl, int ) {
    if (noex) {
      if ((((((fndecl)->typed.type)))->type_non_common.lang_1) )
        noex = false;
    }
  }
};
tree build_comparison_op_fndecl;
int build_comparison_op_complain;
void synthesize_method() {
  {
    {
      comp_info (build_comparison_op_fndecl, build_comparison_op_complain);
    }
  }
}
Comment 11 Martin Liška 2020-11-24 12:25:56 UTC
Apparently, it's gone.