[Bug c++/111034] New: Precompiled headers still non-deterministic
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111034 Bug ID: 111034 Summary: Precompiled headers still non-deterministic Product: gcc Version: 13.2.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: skunk at iskunk dot org Target Milestone: --- This is a follow-on of bug #92717. In that bug, it was noted that .gch files are basically GCC memory dumps, and that because ASLR is typically enabled on modern Linux systems, this results in non-deterministic output every time such a file is generated. The solution given was to disable ASLR, e.g. by using "setarch -R". And I confirmed that if I generate the same .gch file multiple times in a tight loop with ASLR disabled, every file comes out identical. That was only a test, however. My production fix was to disable ASLR for the entire build process, with "setarch -R make bootstrap". And that yielded much spottier results. After multiple attempts, maybe 10% of the pairs of bootstraps that I ran came out with identical .gch files. And that was running on the same container host---if I tried the build in the same container architecture/environment but a different host, the files would end up different as a matter of course. I think, in the interests of reproducibility, the way .gch files are generated needs to be reworked in a way that does not depend on the runtime environment. The current approach may be fine for PCH purposes, but the security implications of any opaque non-determinism will only get worse with time.
[Bug c++/111033] New: libcody build does not use AR_FLAGS
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111033 Bug ID: 111033 Summary: libcody build does not use AR_FLAGS Product: gcc Version: 13.2.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: skunk at iskunk dot org Target Milestone: --- I am working on getting a reproducible GCC build. This includes passing the "D" option to ar(1) to avoid non-deterministic static library outputs. In bootstrapping 13.2.0, I noticed that libcody.a was not being generated consistently. The libcody makefile has the following: AR := @AR@ ... $(AR) -cr $@ $^ For comparison, in the rest of the GCC tree, you typically see AR = @AR@ AR_FLAGS = rc ... $(AR) $(AR_FLAGS) libfoo.a ... and AR_FLAGS is the natural place to add additional flags. An AR_FLAGS variable should thus likewise be added to the libcody makefile. (ARFLAGS is also used; I am not entirely sure which form is favored.) Beyond addressing this small inconsistency, it would be good to see the GCC build itself check whether ar(1) supports the "D" flag, and add it automatically if so.
[Bug tree-optimization/106247] GCC12 warning in Eigen: array subscript is partly outside array bounds
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106247 Daniel Richard G. changed: What|Removed |Added CC||skunk at iskunk dot org --- Comment #4 from Daniel Richard G. --- I am seeing what may be the same issue in a different context. This is occurring in a proprietary C source codebase newly being compiled with 12.1.0, and unfortunately the problem goes away if I attempt to cut it down to a minimal test case. Nevertheless, the actual issue is quite simple, and IMO clear-cut. (some names edited to protect the guilty) In file included from /usr/include/string.h:375, from foo.c:7: In function 'function3', inlined from 'function2' at foo.c:1206:5, inlined from 'function1' at foo.c:2840:7: foo.c:415:3: error: array subscript 'union [1]' is partly outside array bounds of 'unsigned char[5]' [-Werror=array-bounds] 415 | memset(constraints,0,sizeof(char)*NB_CONSTRAINTS); | ^~ foo.c: In function 'function1': foo.c:380:17: note: at offset 4 into object 'constraints' of size 5 380 | unsigned char constraints[NB_CONSTRAINTS]; | ^~~~ cc1: all warnings being treated as errors Curiously enough, I only see this issue in an i686 build. I don't get it on x86-64. (Dropping -march=i686 does not help.)
[Bug libstdc++/106501] New: libstdc++ is built without -fPIC despite --with-pic
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106501 Bug ID: 106501 Summary: libstdc++ is built without -fPIC despite --with-pic Product: gcc Version: 12.1.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: libstdc++ Assignee: unassigned at gcc dot gnu.org Reporter: skunk at iskunk dot org Target Milestone: --- Host: x86_64-pc-linux-gnu Target: x86_64-pc-linux-gnu Build: x86_64-pc-linux-gnu I bootstrapped GCC 12.1.0 with the following options: --disable-shared --disable-nls --enable-version-specific-runtime-libs --with-pic --disable-multilib --with-arch=opteron --disable-libsanitizer --disable-libcc1 --enable-languages=c,c++,lto Notable is the combination of "--disable-shared --with-pic", with the intention of having all the GCC support libraries be statically linkable when building executables, shared libraries, etc. Once the bootstrap was complete, I used the new GCC to build a current version of GDB. That build failed with CXXLD libinproctrace.so /usr/bin/ld: /opt/sfw/bin/../lib/gcc/x86_64-pc-linux-gnu/12.1.0/libstdc++.a(class_type_info.o): relocation R_X86_64_32S against `_ZTVN10__cxxabiv117__class_type_infoE' can not be used when making a shared object; recompile with -fPIC /opt/sfw/bin/../lib/gcc/x86_64-pc-linux-gnu/12.1.0/libstdc++.a: could not read symbols: Bad value collect2: error: ld returned 1 exit status gmake[2]: *** [Makefile:383: libinproctrace.so] Error 1 gmake[2]: Leaving directory '/tmp/gdb-12.1-build/gdbserver' gmake[1]: *** [Makefile:11743: all-gdbserver] Error 2 gmake[1]: Leaving directory '/tmp/gdb-12.1-build' gmake: *** [Makefile:1001: all] Error 2 I checked the build log for GCC. None of the compile lines for class_type_info.o include the -fPIC option (i.e. "fgrep class_type_info.o gcc12-build-log.txt | grep -c PIC" yields 0). The --with-pic option should cause all libraries to be built with -fPIC, even when they are built as static archives. It is possible that libstdc++ is not the only library that was built incorrectly; it is only the one I noticed. Related: bug #66955, bug #67128
[Bug bootstrap/106482] [12 Regression] bootstrap of 12.1.0 using 4.8.2 fails with C++ errors
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106482
--- Comment #2 from Daniel Richard G. ---
It would be good to have a specific minimum version of GCC in the documented
prerequisites, as the current text ("an existing GCC binary (version 4.8 or
later)", albeit referring to non-bootstrap builds) misses edge cases like this.
[Bug bootstrap/106482] New: [12 Regression] bootstrap of 12.1.0 using 4.8.2 fails with C++ errors
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106482 Bug ID: 106482 Summary: [12 Regression] bootstrap of 12.1.0 using 4.8.2 fails with C++ errors Product: gcc Version: 12.1.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: bootstrap Assignee: unassigned at gcc dot gnu.org Reporter: skunk at iskunk dot org Target Milestone: --- Host: x86_64-pc-linux-gnu Target: x86_64-pc-linux-gnu Build: x86_64-pc-linux-gnu I attempted to bootstrap 12.1.0 using GCC 4.8.2. The documented prerequisites include an "ISO C++11 compiler," so this appears to be a supported arrangement. GCC 12 was configured with --disable-shared --disable-nls --enable-version-specific-runtime-libs --with-pic --disable-multilib --with-arch=opteron --disable-libcc1 --enable-languages=c,c++,lto The bootstrap failed as shown below. I was able to bootstrap 10.2.0 using the original compiler, and then bootstrapped 12.1.0 with that intermediary. tg-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/home/src/gcc-12.1.0/gcc -I/home/src/gcc-12.1.0/gcc/. -I/home/src/gcc-12.1.0/gcc/../include -I/home/src/gcc-12.1.0/gcc/../libcpp/include -I/home/src/gcc-12.1.0/gcc/../libcody -I/home/sfw/arch/linux64/include -I/home/sfw/arch/linux64/include -I/home/sfw/arch/linux64/include -I/home/src/gcc-12.1.0/gcc/../libdecnumber -I/home/src/gcc-12.1.0/gcc/../libdecnumber/bid -I../libdecnumber -I/home/src/gcc-12.1.0/gcc/../libbacktrace -o fwprop.o -MT fwprop.o -MMD -MP -MF ./.deps/fwprop.TPo /home/src/gcc-12.1.0/gcc/fwprop.cc In file included from /home/src/gcc-12.1.0/gcc/splay-tree-utils.h:491:0, from /home/src/gcc-12.1.0/gcc/rtl-ssa.h:45, from /home/src/gcc-12.1.0/gcc/fwprop.cc:29: /home/src/gcc-12.1.0/gcc/splay-tree-utils.tcc:24:1: error: prototype for 'typename base_splay_tree::node_type base_splay_tree::get_child(typename Accessors::node_type, unsigned int)' does not match any in class 'base_splay_tree' base_splay_tree::get_child (node_type node, unsigned int index) ^ In file included from /home/src/gcc-12.1.0/gcc/rtl-ssa.h:45:0, from /home/src/gcc-12.1.0/gcc/fwprop.cc:29: /home/src/gcc-12.1.0/gcc/splay-tree-utils.h:125:20: error: candidate is: static typename Accessors::node_type base_splay_tree::get_child(typename Accessors::node_type, unsigned int) static node_type get_child (node_type, unsigned int); ^ In file included from /home/src/gcc-12.1.0/gcc/splay-tree-utils.h:491:0, from /home/src/gcc-12.1.0/gcc/rtl-ssa.h:45, from /home/src/gcc-12.1.0/gcc/fwprop.cc:29: /home/src/gcc-12.1.0/gcc/splay-tree-utils.tcc:49:1: error: prototype for 'typename base_splay_tree::node_type base_splay_tree::promote_child(typename Accessors::node_type, unsigned int)' does not match any in class 'base_splay_tree' base_splay_tree::promote_child (node_type node, unsigned int index) ^ In file included from /home/src/gcc-12.1.0/gcc/rtl-ssa.h:45:0, from /home/src/gcc-12.1.0/gcc/fwprop.cc:29: /home/src/gcc-12.1.0/gcc/splay-tree-utils.h:128:15: error: candidates are: static void base_splay_tree::promote_child(typename Accessors::node_type, unsigned int, typename Accessors::node_type) static void promote_child (node_type, unsigned int, node_type); ^ /home/src/gcc-12.1.0/gcc/splay-tree-utils.h:127:20: error: static typename Accessors::node_type base_splay_tree::promote_child(typename Accessors::node_type, unsigned int) static node_type promote_child (node_type, unsigned int); ^ In file included from /home/src/gcc-12.1.0/gcc/splay-tree-utils.h:491:0, from /home/src/gcc-12.1.0/gcc/rtl-ssa.h:45, from /home/src/gcc-12.1.0/gcc/fwprop.cc:29: /home/src/gcc-12.1.0/gcc/splay-tree-utils.tcc:187:1: error: prototype for 'typename base_splay_tree::node_type base_splay_tree::splay_limit(typename Accessors::node_type)' does not match any in class 'base_splay_tree' base_splay_tree::splay_limit (node_type start) ^ In file included from /home/src/gcc-12.1.0/gcc/rtl-ssa.h:45:0, from /home/src/gcc-12.1.0/gcc/fwprop.cc:29: /home/src/gcc-12.1.0/gcc/splay-tree-utils.h:131:20: error: candidate is: template template static typename Accessors::node_type base_splay_tree::splay_limit(typename Accessors::node_type) static node_type splay_limit (node_type); ^ In file included from /home/src/gcc-12.1.0/gcc/splay-tree-utils.h:491:0, from /home/src/gcc-12.1.0/gcc/rtl-ssa.h:45, from /home/sr
