[Bug c++/99072] [modules] Compiling header unit with partial preprocessing (-E -fdirectives-only) twice causes CRC mismatch
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99072 --- Comment #8 from Boris Kolpackov --- Can confirm works for me, thanks!
[Bug c++/99072] [modules] Compiling header unit with partial preprocessing (-E -fdirectives-only) twice causes CRC mismatch
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99072 Nathan Sidwell changed: What|Removed |Added Status|WAITING |RESOLVED Resolution|--- |FIXED --- Comment #7 from Nathan Sidwell --- a13be187cb2 2021-02-24 | c++: modules & -fpreprocessed [PR 99072]
[Bug c++/99072] [modules] Compiling header unit with partial preprocessing (-E -fdirectives-only) twice causes CRC mismatch
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99072 --- Comment #6 from CVS Commits --- The master branch has been updated by Nathan Sidwell : https://gcc.gnu.org/g:a13be187cb2987db851b3f096f5319d5fe3a7301 commit r11-7366-ga13be187cb2987db851b3f096f5319d5fe3a7301 Author: Nathan Sidwell Date: Wed Feb 24 05:50:12 2021 -0800 c++: modules & -fpreprocessed [PR 99072] When we read preprocessed source, we deal with a couple of special location lines at the start of the file. These provide information about the original filename of the source and the current directory, so we can process the source in the same manner. When updating that code, I had a somewhat philosophical question: Should the line table contain evidence of the filename the user provided to the compiler? I figured to leave it there, as it did no harm. But this defect shows an issue. It's in the line table and our (non optimizing) line table serializer emits that filename. Which means if one re-preprocesses the original source to a differently-named intermediate file, the resultant CMI is different. Boo. That's a difference that doesn't matter, except the CRC matching then fails. We should elide the filename, so that one can preprocess to mktemp intermediate filenames for whatever reason. This patch takes the approach of expunging it from the line table -- so the line table will end up with exactly the same form. That seems a better bet than trying to fix up mismatching line tables in CMI emission. PR c++/99072 libcpp/ * init.c (read_original_filename): Expunge all evidence of the original filename. gcc/testsuite/ * g++.dg/modules/pr99072.H: New.
[Bug c++/99072] [modules] Compiling header unit with partial preprocessing (-E -fdirectives-only) twice causes CRC mismatch
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99072 --- Comment #5 from Nathan Sidwell --- 99072_a.H: // Empty file 99072_b.C: export module Foo; import "99072_a.H"; 99072_c.C: import Foo; ./cc1plus -quiet -E -fdirectives-only -fmodule-header -E 99072_a.H > 99072_a.one ./cc1plus -quiet -fpreprocessed -fdirectives-only -fmodule-header 99072_a.one ./cc1plus -quiet -fmodules-ts 99072_b.C ./cc1plus -quiet -E -fdirectives-only -fmodule-header -E 99072_a.H > 99072_a.two ./cc1plus -quiet -fpreprocessed -fdirectives-only -fmodule-header 99072_a.two ./cc1plus -quiet -fmodules-ts 99072_c.C In module imported at 99072_b.C:2:1, of module Foo, imported at 99072_c.C:1: ./99072_a.H: error: module './99072_a.H' CRC mismatch ./99072_a.H: error: failed to read compiled module: Bad file data ./99072_a.H: note: compiled module file is 'gcm.cache/,/99072_a.H.gcm' In module imported at 99072_c.C:1:1: Foo: error: failed to read compiled module: Bad import dependency Foo: note: compiled module file is 'gcm.cache/Foo.gcm'
[Bug c++/99072] [modules] Compiling header unit with partial preprocessing (-E -fdirectives-only) twice causes CRC mismatch
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99072 --- Comment #4 from Boris Kolpackov --- You need to use different .ii file names on the first and second header unit builds. Using your original command lines as a reference: # first build of header-unit devvm1702:45>./xg++ [...] -o 99072_a.ii 99072_a.H devvm1702:46>./xg++ [...] -c 99072_a.ii # second build of string devvm1702:45>./xg++ [...] -o 99072_a.so.ii 99072_a.H devvm1702:46>./xg++ [...] -c 99072_a.so.ii
[Bug c++/99072] [modules] Compiling header unit with partial preprocessing (-E -fdirectives-only) twice causes CRC mismatch
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99072 --- Comment #3 from Nathan Sidwell --- Cannot reproduce: devvm1702:150>./xg++ -B./ -nostdinc++ -I../x86_64-pc-linux-gnu/libstdc++-v3/include/x86_64-pc-linux-gnu -I../x86_64-pc-linux-gnu/libstdc++-v3/include -I../../..//src/libstdc++-v3/libsupc++ -I../../../src/libstdc++-v3/include/backward -I../../../src/libstdc++-v3/testsuite/util -std=c++2a -fmodule-header -E -fdirectives-only -o 99072_a.so.ii 99072_a.H devvm1702:151>./xg++ -B./ -nostdinc++ -I../x86_64-pc-linux-gnu/libstdc++-v3/include/x86_64-pc-linux-gnu -I../x86_64-pc-linux-gnu/libstdc++-v3/include -I../../..//src/libstdc++-v3/libsupc++ -I../../../src/libstdc++-v3/include/backward -I../../../src/libstdc++-v3/testsuite/util -std=c++2a -fmodule-header -fpreprocessed -fdirectives-only -c 99072_a.so.ii devvm1702:152>./xg++ -B./ -nostdinc++ -I../x86_64-pc-linux-gnu/libstdc++-v3/include/x86_64-pc-linux-gnu -I../x86_64-pc-linux-gnu/libstdc++-v3/include -I../../..//src/libstdc++-v3/libsupc++ -I../../../src/libstdc++-v3/include/backward -I../../../src/libstdc++-v3/testsuite/util -std=c++2a -fmodules-ts -c 99072_b.C devvm1702:153>./xg++ -B./ -nostdinc++ -I../x86_64-pc-linux-gnu/libstdc++-v3/include/x86_64-pc-linux-gnu -I../x86_64-pc-linux-gnu/libstdc++-v3/include -I../../..//src/libstdc++-v3/libsupc++ -I../../../src/libstdc++-v3/include/backward -I../../../src/libstdc++-v3/testsuite/util -std=c++2a -fmodule-header -fpreprocessed -fdirectives-only -c 99072_a.so.ii devvm1702:154>./xg++ -B./ -nostdinc++ -I../x86_64-pc-linux-gnu/libstdc++-v3/include/x86_64-pc-linux-gnu -I../x86_64-pc-linux-gnu/libstdc++-v3/include -I../../..//src/libstdc++-v3/libsupc++ -I../../../src/libstdc++-v3/include/backward -I../../../src/libstdc++-v3/testsuite/util -std=c++2a -fmodules-ts -c 99072_c.C
[Bug c++/99072] [modules] Compiling header unit with partial preprocessing (-E -fdirectives-only) twice causes CRC mismatch
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99072 --- Comment #2 from Boris Kolpackov --- This has something to do with a different .ii file name the second time we compile the header. Try to make this change to your command lines (notice .so before .ii): # second build of string devvm1702:45>./xg++ [...] -o 99072_a.so.ii 99072_a.H devvm1702:46>./xg++ [...] -c 99072_a.so.ii
[Bug c++/99072] [modules] Compiling header unit with partial preprocessing (-E -fdirectives-only) twice causes CRC mismatch
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99072 Nathan Sidwell changed: What|Removed |Added Last reconfirmed||2021-02-16 Status|UNCONFIRMED |WAITING Ever confirmed|0 |1 --- Comment #1 from Nathan Sidwell --- cannot reproduce: 3 first build of header-unit devvm1702:41>./xg++ -B./ -nostdinc++ -I../x86_64-pc-linux-gnu/libstdc++-v3/include/x86_64-pc-linux-gnu -I../x86_64-pc-linux-gnu/libstdc++-v3/include -I../../..//src/libstdc++-v3/libsupc++ -I../../../src/libstdc++-v3/include/backward -I../../../src/libstdc++-v3/testsuite/util -std=c++2a -fmodule-header -E -fdirectives-only -o 99072_a.ii 99072_a.H devvm1702:42>./xg++ -B./ -nostdinc++ -I../x86_64-pc-linux-gnu/libstdc++-v3/include/x86_64-pc-linux-gnu -I../x86_64-pc-linux-gnu/libstdc++-v3/include -I../../..//src/libstdc++-v3/libsupc++ -I../../../src/libstdc++-v3/include/backward -I../../../src/libstdc++-v3/testsuite/util -std=c++2a -fmodule-header -fpreprocessed -fdirectives-only -c 99072_a.ii # build module 'hello' devvm1702:43>./xg++ -B./ -nostdinc++ -I../x86_64-pc-linux-gnu/libstdc++-v3/include/x86_64-pc-linux-gnu -I../x86_64-pc-linux-gnu/libstdc++-v3/include -I../../..//src/libstdc++-v3/libsupc++ -I../../../src/libstdc++-v3/include/backward -I../../../src/libstdc++-v3/testsuite/util -std=c++2a -fmodules-ts -c 99072_b.C # save header-unit cmi devvm1702:44>cp gcm.cache/,/99072_a.H.gcm . # second build of string devvm1702:45>./xg++ -B./ -nostdinc++ -I../x86_64-pc-linux-gnu/libstdc++-v3/include/x86_64-pc-linux-gnu -I../x86_64-pc-linux-gnu/libstdc++-v3/include -I../../..//src/libstdc++-v3/libsupc++ -I../../../src/libstdc++-v3/include/backward -I../../../src/libstdc++-v3/testsuite/util -std=c++2a -fmodule-header -E -fdirectives-only -o 99072_a.ii 99072_a.H devvm1702:46>./xg++ -B./ -nostdinc++ -I../x86_64-pc-linux-gnu/libstdc++-v3/include/x86_64-pc-linux-gnu -I../x86_64-pc-linux-gnu/libstdc++-v3/include -I../../..//src/libstdc++-v3/libsupc++ -I../../../src/libstdc++-v3/include/backward -I../../../src/libstdc++-v3/testsuite/util -std=c++2a -fmodule-header -fpreprocessed -fdirectives-only -c 99072_a.ii # build main devvm1702:47>./xg++ -B./ -nostdinc++ -I../x86_64-pc-linux-gnu/libstdc++-v3/include/x86_64-pc-linux-gnu -I../x86_64-pc-linux-gnu/libstdc++-v3/include -I../../..//src/libstdc++-v3/libsupc++ -I../../../src/libstdc++-v3/include/backward -I../../../src/libstdc++-v3/testsuite/util -std=c++2a -fmodules-ts -c 99072_c.C # no error
