The P2843R3 Preprocessing is never undefined paper contains comments that various compilers handle comma operators in preprocessor expressions incorrectly and I think they are right. In both C and C++ the grammar uses constant-expression non-terminal for #if/#elif and in both C and C++ that NT is conditional-expression, so #if 1, 2 is IMHO clearly wrong in both languages. C89 then says for constant-expression "Constant expressions shall not contain assignment, increment, decrement, function-call, or comma operators, except when they are contained within the operand of a sizeof operator." Because all the remaining identifiers in the #if/#elif expression are replaced with 0 I think assignments, increment, decrement and function-call aren't that big deal because (0 = 1) or ++4 etc. are all invalid, but for comma expressions I think it matters. In r0-56429 PR456 Joseph has added !CPP_OPTION (pfile, c99) to handle that correctly. Then C99 changed that to: "Constant expressions shall not contain assignment, increment, decrement, function-call, or comma operators, except when they are contained within a subexpression that is not evaluated." That made for C99+ #if 1 || (1, 2) etc. valid but #if (1, 2) is still invalid, ditto #if 1 ? 1, 2 : 3 In C++ I can't find anything like that though, and as can be seen on say int a[(1, 2)]; int b[1 ? 1, 2 : 3]; being accepted by C++ and rejected by C while int c[1, 2]; int d[1 ? 2 : 3, 4]; being rejected in both C and C++, so I think for C++ it is indeed just the grammar that prevents #if 1, 2. When it is the second operand of ?: or inside of () the grammar just uses expression and that allows comma operator. So, the following patch uses different decisions for C++ when to diagnose comma operator in preprocessor expressions, for C++ tracks if it is inside of () (obviously () around #embed clauses don't count unless one uses limit ((1, 2)) etc.) or inside of the second ?: operand and allows comma operator there and disallows elsewhere. BTW, I wonder if anything in the standard disallows <=> in the preprocessor expressions. Say #if (0 <=> 1) < 0 etc. #include <compare> constexpr int a = (0 <=> 1) < 0; is valid (but not valid without #include <compare>) and the expressions don't use any identifiers. 2025-07-30 Jakub Jelinek <jakub@redhat.com> PR c++/120778 * internal.h (struct lexer_state): Add comma_ok member. * expr.cc (_cpp_parse_expr): Initialize it to 0, increment on CPP_OPEN_PAREN and CPP_QUERY, decrement on CPP_CLOSE_PAREN and CPP_COLON. (num_binary_op): For C++ pedwarn on comma operator if pfile->state.comma_ok is 0 instead of !c99 or skip_eval. * g++.dg/cpp/if-comma-1.C: New test.
No functional change intended. gcc/ChangeLog: * Makefile.in: Replace diagnostic.def with diagnostics/kinds.def. * config/aarch64/aarch64.cc: Update for diagnostic_t becoming enum class diagnostics::kind. * config/i386/i386-options.cc: Likewise. * config/s390/s390.cc: Likewise. * diagnostic-core.h: Replace typedef diagnostic_t with enum class diagnostics::kind in diagnostics/kinds.h and include it. * diagnostic-global-context.cc: Update for diagnostic_t becoming enum class diagnostics::kind. * diagnostic.cc: Likewise. * diagnostic.h: Likewise. * diagnostics/buffering.cc: Likewise. * diagnostics/buffering.h: Likewise. * diagnostics/context.h: Likewise. * diagnostics/diagnostic-info.h: Likewise. * diagnostics/html-sink.cc: Likewise. * diagnostic.def: Move to... * diagnostics/kinds.def: ...here and update for diagnostic_t becoming enum class diagnostics::kind. * diagnostics/kinds.h: New file, based on material in diagnostic-core.h. * diagnostics/lazy-paths.cc: Update for diagnostic_t becoming enum class diagnostics::kind. * diagnostics/option-classifier.cc: Likewise. * diagnostics/option-classifier.h: Likewise. * diagnostics/output-spec.h: Likewise. * diagnostics/paths-output.cc: Likewise. * diagnostics/sarif-sink.cc: Likewise. * diagnostics/selftest-context.cc: Likewise. * diagnostics/selftest-context.h: Likewise. * diagnostics/sink.h: Likewise. * diagnostics/source-printing.cc: Likewise. * diagnostics/text-sink.cc: Likewise. * diagnostics/text-sink.h: Likewise. * gcc.cc: Likewise. * libgdiagnostics.cc: Likewise. * lto-wrapper.cc: Likewise. * opts-common.cc: Likewise. * opts-diagnostic.h: Likewise. * opts.cc: Likewise. * rtl-error.cc: Likewise. * substring-locations.cc: Likewise. * toplev.cc: Likewise. gcc/ada/ChangeLog: * gcc-interface/trans.cc: Update for diagnostic_t becoming enum class diagnostics::kind. gcc/analyzer/ChangeLog: * pending-diagnostic.cc: Update for diagnostic_t becoming enum class diagnostics::kind. * program-point.cc: Likewise. gcc/c-family/ChangeLog: * c-common.cc: Update for diagnostic_t becoming enum class diagnostics::kind. * c-format.cc: Likewise. * c-lex.cc: Likewise. * c-opts.cc: Likewise. * c-pragma.cc: Likewise. * c-warn.cc: Likewise. gcc/c/ChangeLog: * c-errors.cc: Update for diagnostic_t becoming enum class diagnostics::kind. * c-parser.cc: Likewise. * c-typeck.cc: Likewise. gcc/cobol/ChangeLog: * util.cc: Update for diagnostic_t becoming enum class diagnostics::kind. gcc/cp/ChangeLog: * call.cc: Update for diagnostic_t becoming enum class diagnostics::kind. * constexpr.cc: Likewise. * cp-tree.h: Likewise. * decl.cc: Likewise. * error.cc: Likewise. * init.cc: Likewise. * method.cc: Likewise. * module.cc: Likewise. * parser.cc: Likewise. * pt.cc: Likewise. * semantics.cc: Likewise. * typeck.cc: Likewise. * typeck2.cc: Likewise. gcc/d/ChangeLog: * d-diagnostic.cc: Update for diagnostic_t becoming enum class diagnostics::kind. gcc/fortran/ChangeLog: * cpp.cc: Update for diagnostic_t becoming enum class diagnostics::kind. * error.cc: Likewise. * options.cc: Likewise. gcc/jit/ChangeLog: * dummy-frontend.cc: Update for diagnostic_t becoming enum class diagnostics::kind. gcc/m2/ChangeLog: * gm2-gcc/m2linemap.cc: Update for diagnostic_t becoming enum class diagnostics::kind. * gm2-gcc/rtegraph.cc: Likewise. gcc/rust/ChangeLog: * backend/rust-tree.cc: Update for diagnostic_t becoming enum class diagnostics::kind. * backend/rust-tree.h: Likewise. * resolve/rust-ast-resolve-expr.cc: Likewise. * resolve/rust-ice-finalizer.cc: Likewise. * resolve/rust-ice-finalizer.h: Likewise. * resolve/rust-late-name-resolver-2.0.cc: Likewise. gcc/testsuite/ChangeLog: * gcc.dg/plugin/diagnostic_plugin_test_show_locus.cc: Update for diagnostic_t becoming enum class diagnostics::kind. * gcc.dg/plugin/expensive_selftests_plugin.cc: Likewise. * gcc.dg/plugin/location_overflow_plugin.cc: Likewise. * lib/gcc-dg.exp: Likewise. libcpp/ChangeLog: * internal.h: Update comment for diagnostic_t becoming enum class diagnostics::kind. Signed-off-by: David Malcolm <dmalcolm@redhat.com>
libcpp makes use of the cpp_buffer pfile->a_buff to store things while it is handling macros. It uses it to store pointers (cpp_hashnode*, for macro arguments) and cpp_macro objects. This works fine because a cpp_hashnode* and a cpp_macro have the same alignment requirement on either 32-bit or 64-bit systems (namely, the same alignment as a pointer.) When 64-bit location_t is enabled on a 32-bit sytem, the alignment requirement may cease to be the same, because the alignment requirement of a cpp_macro object changes to that of a uint64_t, which be larger than that of a pointer. It's not the case for x86 32-bit, but for example, on sparc, a pointer has 4-byte alignment while a uint64_t has 8. In that case, intermixing the two within the same cpp_buffer leads to a misaligned access. The code path that triggers this is the one in _cpp_commit_buff in which a hash table with its own allocator (i.e. ggc) is not being used, so it doesn't happen within the compiler itself, but it happens in the other libcpp clients, such as genmatch. Fix that up by ensuring _cpp_commit_buff commits a fully aligned chunk of the buffer, so it's ready for anything it may be used for next. Also modify CPP_ALIGN so that it guarantees to return an alignment at least the size of location_t. Currently it returns the max of a pointer and a double. I am not aware of any platform where a double may have smaller alignment than a uint64_t, but it does not hurt to add location_t here to be sure. libcpp/ChangeLog: * lex.cc (_cpp_commit_buff): Make sure that the buffer is properly aligned for the next allocation. * internal.h (struct dummy): Make sure alignment is large enough for a location_t, just in case.
The dependency output for header unit modules is based on the absolute pathname of the header file, but that's not something that a makefile can portably refer to. This patch adds a .c++-header-unit target based on the header name relative to an element of the include path. libcpp/ChangeLog: * internal.h (_cpp_get_file_dir): Declare. * files.cc (_cpp_get_file_dir): New fn. * mkdeps.cc (make_write): Use it. gcc/testsuite/ChangeLog: * g++.dg/modules/dep-4.H: New test.
The C++ modules code has a -fmodule-header (or -x c++-{user,system}-header)
option to specify looking up headers to compile to header units on the usual
include paths. I'd like to have the same functionality for full C++20
modules such as module std, which I proposed to live on the include path at
bits/std.cc. But this behavior doesn't seem necessarily connected to
modules, so I'm proposing a general C/C++ option to specify the behavior of
looking in the include path for the input files specified on the command
line.
Other ideas for the name of the option are very welcome.
The libcpp change is to allow -fsearch-include-path{,=user} to find files in
the current working directory, like -include. This can be handy for a quick
compile of both std.cc and a file that imports it, e.g.
g++ -std=c++20 -fmodules -fsearch-include-path bits/std.cc importer.cc
gcc/ChangeLog:
* doc/cppopts.texi: Document -fsearch-include-path.
* doc/invoke.texi: Mention it for modules.
gcc/c-family/ChangeLog:
* c.opt: Add -fsearch-include-path.
* c-opts.cc (c_common_post_options): Handle it.
gcc/cp/ChangeLog:
* module.cc (module_preprocess_options): Don't override it.
libcpp/ChangeLog:
* internal.h (search_path_head): Declare.
* files.cc (search_path_head): No longer static.
* init.cc (cpp_read_main_file): Use it.
This is an attempt to implement the https://wg21.link/p3034r1 paper, but I'm afraid the wording in the paper is bad for multiple reasons. I think I understand the intent, that the module name and partition if any shouldn't come from macros so that they can be scanned for without preprocessing, but on the other side doesn't want to disable macro expansion in pp-module altogether, because e.g. the optional attribute in module-declaration would be nice to come from macros as which exact attribute is needed might need to be decided based on preprocessor checks. The paper added https://eel.is/c++draft/cpp.module#2 which uses partly the wording from https://eel.is/c++draft/cpp.module#1 The first issue I see is that using that "defined as an object-like macro" from there means IMHO something very different in those 2 paragraphs. As per https://eel.is/c++draft/cpp.pre#7.sentence-1 preprocessing tokens in preprocessing directives aren't subject to macro expansion unless otherwise stated, and so the export and module tokens aren't expanded and so the requirement that they aren't defined as an object-like macro makes perfect sense. The problem with the new paragraph is that https://eel.is/c++draft/cpp.module#3.sentence-1 says that the rest of the tokens are macro expanded and after macro expansion none of the tokens can be defined as an object-like macro, if they would be, they'd be expanded to that. So, I think either the wording needs to change such that not all preprocessing tokens after module are macro expanded, only those which are after the pp-module-name and if any pp-module-partition tokens, or all tokens after module are macro expanded but none of the tokens in pp-module-name and pp-module-partition if any must come from macro expansion. The patch below implements it as if the former would be specified (but see later), so essentially scans the preprocessing tokens after module without expansion, if the first one is an identifier, it disables expansion for it and then if followed by . or : expects another such identifier (again with disabled expansion), but stops after second : is seen. Second issue is that while the global-module-fragment start is fine, matches the syntax of the new paragraph where the pp-tokens[opt] aren't present, there is also private-module-fragment in the syntax where module is followed by : private ; and in that case the colon doesn't match the pp-module-name grammar and appears now to be invalid. I think the https://eel.is/c++draft/cpp.module#2 paragraph needs to change so that it allows also that pp-tokens of a pp-module may also be : pp-tokens[opt] (and in that case, I think the colon shouldn't come from a macro and private and/or ; can). Third issue is that there are too many pp-tokens in https://eel.is/c++draft/cpp.module , one is all the tokens between module keyword and the semicolon and one is the optional extra tokens after pp-module-partition (if any, if missing, after pp-module). Perhaps introducing some other non-terminal would help talking about it? So in "where the pp-tokens (if any) shall not begin with a ( preprocessing token" it isn't obvious which pp-tokens it is talking about (my assumption is the latter) and also whether ( can't appear there just before macro expansion or also after expansion. The patch expects only before expansion, so #define F (); export module foo F would be valid during preprocessing but obviously invalid during compilation, but #define foo(n) n; export module foo (3) would be invalid already during preprocessing. The last issue applies only if the first issue is resolved to allow expansion of tokens after : if first token, or after pp-module-partition if present or after pp-module-name if present. When non-preprocessing scanner sees export module foo.bar:baz.qux; it knows nothing can come from preprocessing macros and is ok, but if it sees export module foo.bar:baz qux then it can't know whether it will be export module foo.bar:baz; or export module foo.bar:baz [[]]; or export module foo.bar:baz.freddy.garply; because qux could be validly a macro, which expands to ; or [[]]; or .freddy.garply; etc. So, either the non-preprocessing scanner would need to note it as possible export of foo.bar:baz* module partitions and preprocess if it needs to know the details or just compile, or if that is not ok, the wording would need to rule out that the expansion of (the second) pp-tokens if any can't start with . or : (colon would be only problematic if it isn't present in the tokens before it already). So, if e.g. defining qux above to . whatever is invalid, then the scanner can rely it sees the whole module name and partition. The patch below implements what is above described as the first variant of the first issue resolution, i.e. disables expansion of as many tokens as could be in the valid module name and module partition syntax, but as soon as it e.g. sees two adjacent identifiers, the second one can be macro expanded. If it is macro expanded though, the expansion can't start with . or :, and if it expands to nothing, tokens after it (whether they come from macro expansion or not) can't start with . or :. So, effectively: #define SEMI ; export module SEMI used to be valid and isn't anymore, #define FOO bar export module FOO; isn't valid, #define COLON : export module COLON private; isn't valid, #define BAR baz export module foo.bar:baz.qux.BAR; isn't valid, #define BAZ .qux export module foo BAZ; isn't valid, #define FREDDY :garply export module foo FREDDY; isn't valid, while #define QUX [[]] export module foo QUX; or #define GARPLY private module : GARPLY; etc. is. 2024-11-01 Jakub Jelinek <jakub@redhat.com> PR c++/114461 libcpp/ * include/cpplib.h: Implement C++26 P3034R1 - Module Declarations Shouldn’t be Macros (or more precisely its expected intent). (NO_DOT_COLON): Define. * internal.h (struct cpp_reader): Add diagnose_dot_colon_from_macro_p member. * lex.cc (cpp_maybe_module_directive): For pp-module, if module keyword is followed by CPP_NAME, ensure all CPP_NAME tokens possibly matching module name and module partition syntax aren't expanded and aren't defined as object-like macros. Verify first token after that doesn't start with open paren. If the next token after module name/partition is CPP_NAME defined as macro, set NO_DOT_COLON flag on it. * macro.cc (cpp_get_token_1): Set pfile->diagnose_dot_colon_from_macro_p if token to be expanded has NO_DOT_COLON bit set in flags. Before returning, if pfile->diagnose_dot_colon_from_macro_p is true and not returning CPP_PADDING or CPP_COMMENT and not during macro expansion preparation, set pfile->diagnose_dot_colon_from_macro_p to false and diagnose if returning CPP_DOT or CPP_COLON. gcc/testsuite/ * g++.dg/modules/cpp-7.C: New test. * g++.dg/modules/cpp-8.C: New test. * g++.dg/modules/cpp-9.C: New test. * g++.dg/modules/cpp-10.C: New test. * g++.dg/modules/cpp-11.C: New test. * g++.dg/modules/cpp-12.C: New test. * g++.dg/modules/cpp-13.C: New test. * g++.dg/modules/cpp-14.C: New test. * g++.dg/modules/cpp-15.C: New test. * g++.dg/modules/cpp-16.C: New test. * g++.dg/modules/cpp-17.C: New test. * g++.dg/modules/cpp-18.C: New test. * g++.dg/modules/cpp-19.C: New test. * g++.dg/modules/cpp-20.C: New test. * g++.dg/modules/pmp-4.C: New test. * g++.dg/modules/pmp-5.C: New test. * g++.dg/modules/pmp-6.C: New test. * g++.dg/modules/token-6.C: New test. * g++.dg/modules/token-7.C: New test. * g++.dg/modules/token-8.C: New test. * g++.dg/modules/token-9.C: New test. * g++.dg/modules/token-10.C: New test. * g++.dg/modules/token-11.C: New test. * g++.dg/modules/token-12.C: New test. * g++.dg/modules/token-13.C: New test. * g++.dg/modules/token-14.C: New test. * g++.dg/modules/token-15.C: New test. * g++.dg/modules/token-16.C: New test. * g++.dg/modules/dir-only-3.C: Expect an error. * g++.dg/modules/dir-only-4.C: Expect an error. * g++.dg/modules/dir-only-5.C: New test. * g++.dg/modules/atom-preamble-2_a.C: In export module malcolm; replace malcolm with kevin. Don't define malcolm macro. * g++.dg/modules/atom-preamble-4.C: Expect an error. * g++.dg/modules/atom-preamble-5.C: New test.
I've tried to build stage3 with -Wleading-whitespace=blanks -Wtrailing-whitespace=blank -Wno-error=leading-whitespace=blanks -Wno-error=trailing-whitespace=blank added to STRICT_WARN and that expectably resulted in about 2744 unique trailing whitespace warnings and 124837 leading whitespace warnings when excluding *.md files (which obviously is in big part a generator issue). Others from that are generator related, I think those need to be solved later. The following patch just fixes up the easy case (trailing whitespace), which could be easily automated: for i in `find . -name \*.h -o -name \*.cc -o -name \*.c | xargs grep -l '[ ]$' | grep -v testsuite/`; do sed -i -e 's/[ ]*$//' $i; done I've excluded files which I knew are obviously generated or go FE. Is there anything else we'd want to avoid the changes? Due to patch size, I've split it between gcc/ part and rest (include/, libiberty/, libgcc/, libcpp/, libstdc++-v3/; this part). 2024-10-24 Jakub Jelinek <jakub@redhat.com> include/ * dyn-string.h: Remove trailing whitespace. * libiberty.h: Likewise. * xregex.h: Likewise. * splay-tree.h: Likewise. * partition.h: Likewise. * plugin-api.h: Likewise. * demangle.h: Likewise. * vtv-change-permission.h: Likewise. * fibheap.h: Likewise. * hsa_ext_image.h: Likewise. * hashtab.h: Likewise. * libcollector.h: Likewise. * sort.h: Likewise. * symcat.h: Likewise. * hsa_ext_amd.h: Likewise. libcpp/ * directives.cc: Remove trailing whitespace. * mkdeps.cc: Likewise. * line-map.cc: Likewise. * internal.h: Likewise. * files.cc: Likewise. * init.cc: Likewise. * makeucnid.cc: Likewise. * system.h: Likewise. * include/line-map.h: Likewise. * include/symtab.h: Likewise. * include/cpplib.h: Likewise. * expr.cc: Likewise. * charset.cc: Likewise. * macro.cc: Likewise. * errors.cc: Likewise. * lex.cc: Likewise. * traditional.cc: Likewise. libgcc/ * crtstuff.c: Remove trailing whitespace. * libgcov.h: Likewise. * config/alpha/crtfastmath.c: Likewise. * config/alpha/vms-gcc_shell_handler.c: Likewise. * config/alpha/vms-unwind.h: Likewise. * config/pa/linux-atomic.c: Likewise. * config/pa/linux-unwind.h: Likewise. * config/pa/quadlib.c: Likewise. * config/pa/fptr.c: Likewise. * config/s390/32/_fixsfdi.c: Likewise. * config/s390/32/_fixunssfdi.c: Likewise. * config/s390/32/_fixunsdfdi.c: Likewise. * config/c6x/pr-support.c: Likewise. * config/lm32/_udivsi3.c: Likewise. * config/lm32/libgcc_lm32.h: Likewise. * config/lm32/_udivmodsi4.c: Likewise. * config/lm32/_mulsi3.c: Likewise. * config/lm32/_modsi3.c: Likewise. * config/lm32/_umodsi3.c: Likewise. * config/lm32/_divsi3.c: Likewise. * config/darwin-crt3.c: Likewise. * config/msp430/mpy.c: Likewise. * config/ia64/tf-signs.c: Likewise. * config/ia64/fde-vms.c: Likewise. * config/ia64/unwind-ia64.c: Likewise. * config/ia64/vms-unwind.h: Likewise. * config/ia64/sfp-exceptions.c: Likewise. * config/ia64/quadlib.c: Likewise. * config/ia64/unwind-ia64.h: Likewise. * config/rl78/vregs.h: Likewise. * config/arm/bpabi.c: Likewise. * config/arm/unwind-arm.c: Likewise. * config/arm/pr-support.c: Likewise. * config/arm/linux-atomic.c: Likewise. * config/arm/bpabi-lib.h: Likewise. * config/frv/frvend.c: Likewise. * config/frv/cmovw.c: Likewise. * config/frv/frvbegin.c: Likewise. * config/frv/cmovd.c: Likewise. * config/frv/cmovh.c: Likewise. * config/aarch64/cpuinfo.c: Likewise. * config/i386/crtfastmath.c: Likewise. * config/i386/cygming-crtend.c: Likewise. * config/i386/32/tf-signs.c: Likewise. * config/i386/crtprec.c: Likewise. * config/i386/sfp-exceptions.c: Likewise. * config/i386/w32-unwind.h: Likewise. * config/m32r/initfini.c: Likewise. * config/sparc/crtfastmath.c: Likewise. * config/gcn/amdgcn_veclib.h: Likewise. * config/nios2/linux-atomic.c: Likewise. * config/nios2/linux-unwind.h: Likewise. * config/nios2/lib2-mul.c: Likewise. * config/nios2/lib2-nios2.h: Likewise. * config/xtensa/unwind-dw2-xtensa.c: Likewise. * config/rs6000/darwin-fallback.c: Likewise. * config/rs6000/ibm-ldouble.c: Likewise. * config/rs6000/sfp-machine.h: Likewise. * config/rs6000/darwin-asm.h: Likewise. * config/rs6000/darwin-crt2.c: Likewise. * config/rs6000/aix-unwind.h: Likewise. * config/rs6000/sfp-exceptions.c: Likewise. * config/gthr-vxworks.c: Likewise. * config/riscv/atomic.c: Likewise. * config/visium/memcpy.c: Likewise. * config/darwin-crt-tm.c: Likewise. * config/stormy16/lib2funcs.c: Likewise. * config/arc/ieee-754/divtab-arc-sf.c: Likewise. * config/arc/ieee-754/divtab-arc-df.c: Likewise. * config/arc/initfini.c: Likewise. * config/sol2/gmon.c: Likewise. * config/microblaze/divsi3_table.c: Likewise. * config/m68k/fpgnulib.c: Likewise. * libgcov-driver.c: Likewise. * unwind-dw2.c: Likewise. * fp-bit.c: Likewise. * dfp-bit.h: Likewise. * dfp-bit.c: Likewise. * libgcov-driver-system.c: Likewise. libgcc/config/libbid/ * _le_td.c: Remove trailing whitespace. * bid128_compare.c: Likewise. * bid_div_macros.h: Likewise. * bid64_to_bid128.c: Likewise. * bid64_to_uint32.c: Likewise. * bid128_to_uint64.c: Likewise. * bid64_div.c: Likewise. * bid128_round_integral.c: Likewise. * bid_binarydecimal.c: Likewise. * bid128_string.c: Likewise. * bid_flag_operations.c: Likewise. * bid128_to_int64.c: Likewise. * _mul_sd.c: Likewise. * bid64_mul.c: Likewise. * bid128_noncomp.c: Likewise. * _gt_dd.c: Likewise. * bid64_add.c: Likewise. * bid64_string.c: Likewise. * bid_from_int.c: Likewise. * bid128.c: Likewise. * _ge_dd.c: Likewise. * _ne_sd.c: Likewise. * _dd_to_td.c: Likewise. * _unord_sd.c: Likewise. * bid64_to_uint64.c: Likewise. * _gt_sd.c: Likewise. * _sd_to_td.c: Likewise. * _addsub_td.c: Likewise. * _ne_td.c: Likewise. * bid_dpd.c: Likewise. * bid128_add.c: Likewise. * bid128_next.c: Likewise. * _lt_sd.c: Likewise. * bid64_next.c: Likewise. * bid128_mul.c: Likewise. * _lt_dd.c: Likewise. * _ge_td.c: Likewise. * _unord_dd.c: Likewise. * bid64_sqrt.c: Likewise. * bid_sqrt_macros.h: Likewise. * bid64_fma.c: Likewise. * _sd_to_dd.c: Likewise. * bid_conf.h: Likewise. * bid64_noncomp.c: Likewise. * bid_gcc_intrinsics.h: Likewise. * _gt_td.c: Likewise. * _ge_sd.c: Likewise. * bid128_minmax.c: Likewise. * bid128_quantize.c: Likewise. * bid32_to_bid64.c: Likewise. * bid_round.c: Likewise. * _td_to_sd.c: Likewise. * bid_inline_add.h: Likewise. * bid128_fma.c: Likewise. * _eq_td.c: Likewise. * bid32_to_bid128.c: Likewise. * bid64_rem.c: Likewise. * bid128_2_str_tables.c: Likewise. * _mul_dd.c: Likewise. * _dd_to_sd.c: Likewise. * bid128_div.c: Likewise. * _lt_td.c: Likewise. * bid64_compare.c: Likewise. * bid64_to_int32.c: Likewise. * _unord_td.c: Likewise. * bid128_rem.c: Likewise. * bid_internal.h: Likewise. * bid64_to_int64.c: Likewise. * _eq_dd.c: Likewise. * _td_to_dd.c: Likewise. * bid128_to_int32.c: Likewise. * bid128_to_uint32.c: Likewise. * _ne_dd.c: Likewise. * bid64_quantize.c: Likewise. * _le_dd.c: Likewise. * bid64_round_integral.c: Likewise. * _le_sd.c: Likewise. * bid64_minmax.c: Likewise. libgcc/config/avr/libf7/ * f7-renames.h: Remove trailing whitespace. libstdc++-v3/ * include/debug/debug.h: Remove trailing whitespace. * include/parallel/base.h: Likewise. * include/parallel/types.h: Likewise. * include/parallel/settings.h: Likewise. * include/parallel/multiseq_selection.h: Likewise. * include/parallel/partition.h: Likewise. * include/parallel/random_number.h: Likewise. * include/parallel/find_selectors.h: Likewise. * include/parallel/partial_sum.h: Likewise. * include/parallel/list_partition.h: Likewise. * include/parallel/search.h: Likewise. * include/parallel/algorithmfwd.h: Likewise. * include/parallel/random_shuffle.h: Likewise. * include/parallel/multiway_mergesort.h: Likewise. * include/parallel/sort.h: Likewise. * include/parallel/algobase.h: Likewise. * include/parallel/numericfwd.h: Likewise. * include/parallel/multiway_merge.h: Likewise. * include/parallel/losertree.h: Likewise. * include/bits/basic_ios.h: Likewise. * include/bits/stringfwd.h: Likewise. * include/bits/ostream_insert.h: Likewise. * include/bits/stl_heap.h: Likewise. * include/bits/unordered_map.h: Likewise. * include/bits/hashtable_policy.h: Likewise. * include/bits/stl_iterator_base_funcs.h: Likewise. * include/bits/valarray_before.h: Likewise. * include/bits/regex.h: Likewise. * include/bits/postypes.h: Likewise. * include/bits/stl_iterator.h: Likewise. * include/bits/localefwd.h: Likewise. * include/bits/stl_algo.h: Likewise. * include/bits/ios_base.h: Likewise. * include/bits/stl_function.h: Likewise. * include/bits/basic_string.h: Likewise. * include/bits/hashtable.h: Likewise. * include/bits/valarray_after.h: Likewise. * include/bits/char_traits.h: Likewise. * include/bits/gslice.h: Likewise. * include/bits/locale_facets_nonio.h: Likewise. * include/bits/mask_array.h: Likewise. * include/bits/specfun.h: Likewise. * include/bits/random.h: Likewise. * include/bits/slice_array.h: Likewise. * include/bits/valarray_array.h: Likewise. * include/tr1/float.h: Likewise. * include/tr1/functional_hash.h: Likewise. * include/tr1/math.h: Likewise. * include/tr1/hashtable_policy.h: Likewise. * include/tr1/stdio.h: Likewise. * include/tr1/complex.h: Likewise. * include/tr1/stdbool.h: Likewise. * include/tr1/stdarg.h: Likewise. * include/tr1/inttypes.h: Likewise. * include/tr1/fenv.h: Likewise. * include/tr1/stdlib.h: Likewise. * include/tr1/wchar.h: Likewise. * include/tr1/tgmath.h: Likewise. * include/tr1/limits.h: Likewise. * include/tr1/wctype.h: Likewise. * include/tr1/stdint.h: Likewise. * include/tr1/ctype.h: Likewise. * include/tr1/random.h: Likewise. * include/tr1/shared_ptr.h: Likewise. * include/ext/mt_allocator.h: Likewise. * include/ext/sso_string_base.h: Likewise. * include/ext/debug_allocator.h: Likewise. * include/ext/vstring_fwd.h: Likewise. * include/ext/pointer.h: Likewise. * include/ext/pod_char_traits.h: Likewise. * include/ext/malloc_allocator.h: Likewise. * include/ext/vstring.h: Likewise. * include/ext/bitmap_allocator.h: Likewise. * include/ext/pool_allocator.h: Likewise. * include/ext/type_traits.h: Likewise. * include/ext/ropeimpl.h: Likewise. * include/ext/codecvt_specializations.h: Likewise. * include/ext/throw_allocator.h: Likewise. * include/ext/extptr_allocator.h: Likewise. * include/ext/atomicity.h: Likewise. * include/ext/concurrence.h: Likewise. * include/c_compatibility/wchar.h: Likewise. * include/c_compatibility/stdint.h: Likewise. * include/backward/hash_fun.h: Likewise. * include/backward/binders.h: Likewise. * include/backward/hashtable.h: Likewise. * include/backward/auto_ptr.h: Likewise. * libsupc++/eh_arm.cc: Likewise. * libsupc++/unwind-cxx.h: Likewise. * libsupc++/si_class_type_info.cc: Likewise. * libsupc++/vec.cc: Likewise. * libsupc++/class_type_info.cc: Likewise. * libsupc++/vmi_class_type_info.cc: Likewise. * libsupc++/guard_error.cc: Likewise. * libsupc++/bad_typeid.cc: Likewise. * libsupc++/eh_personality.cc: Likewise. * libsupc++/atexit_arm.cc: Likewise. * libsupc++/pmem_type_info.cc: Likewise. * libsupc++/vterminate.cc: Likewise. * libsupc++/eh_terminate.cc: Likewise. * libsupc++/bad_cast.cc: Likewise. * libsupc++/exception_ptr.h: Likewise. * libsupc++/eh_throw.cc: Likewise. * libsupc++/bad_alloc.cc: Likewise. * libsupc++/nested_exception.cc: Likewise. * libsupc++/pointer_type_info.cc: Likewise. * libsupc++/pbase_type_info.cc: Likewise. * libsupc++/bad_array_new.cc: Likewise. * libsupc++/pure.cc: Likewise. * libsupc++/eh_exception.cc: Likewise. * libsupc++/bad_array_length.cc: Likewise. * libsupc++/cxxabi.h: Likewise. * libsupc++/guard.cc: Likewise. * libsupc++/eh_catch.cc: Likewise. * libsupc++/cxxabi_forced.h: Likewise. * libsupc++/tinfo.h: Likewise.
The following patch on top of the r15-4346 patch adds -Wleading-whitespace= warning option. This warning doesn't care how much one actually indents which line in the source (that is something that can't be easily done in the preprocessor without doing syntactic analysis), but just simple checks on what kind of whitespace is used in the indentation. I think it is still useful to get warnings about such issues early, while git diagnoses some of it in patches (e.g. the tab after space case), getting the warnings earlier might help avoiding such issues sooner. There are projects which ban use of tabs and require just spaces, others which require indentation just with horizontal tabs, and finally projects which want indentation with tabs for multiples of tabstop size followed by spaces (fewer than tabstop size), like GCC. For all 3 kinds the warning diagnoses indentation with '\v' or '\f' characters (unless line contains just whitespace), and for the last one also cases where a space in the indentation is followed by horizontal tab or where there are N or more consecutive spaces in the indentation (for -ftabstop=N). BTW, for additional testing I've enabled the warnings (without -Werror for them) in stage3. There are many warnings (both trailing and leading whitespace), some of them something that can be easily fixed in the headers or source files, but others with whitespace issues in generated sources, so if we enable the warnings, either we'd need to adjust the generators or disable the warnings in (some of the) generated files. 2024-10-23 Jakub Jelinek <jakub@redhat.com> libcpp/ * include/cpplib.h (struct cpp_options): Add cpp_warn_leading_whitespace and cpp_tabstop members. (enum cpp_warning_reason): Add CPP_W_LEADING_WHITESPACE. * internal.h (struct _cpp_line_note): Document new line note kinds. * init.cc (cpp_create_reader): Set cpp_tabstop to 8. * lex.cc (find_leading_whitespace_issues): New function. (_cpp_clean_line): Use it. (_cpp_process_line_notes): Handle 'L', 'S' and 'T' line notes. (lex_raw_string): Clear type on 'L', 'S' and 'T' line notes inside of raw string literals. gcc/ * doc/invoke.texi (Wleading-whitespace=): Document. gcc/c-family/ * c.opt (Wleading-whitespace=): New option. * c-opts.cc (c_common_post_options): Set cpp_opts->cpp_tabstop to global_dc->m_tabstop. gcc/testsuite/ * c-c++-common/cpp/Wleading-whitespace-1.c: New test. * c-c++-common/cpp/Wleading-whitespace-2.c: New test. * c-c++-common/cpp/Wleading-whitespace-3.c: New test. * c-c++-common/cpp/Wleading-whitespace-4.c: New test.
libcpp is not currently set up to be able to generate valid
locations for tokens lexed from a _Pragma string. Instead, after obtaining
the tokens, it sets their locations all to the location of the _Pragma
operator itself. This makes things like _Pragma("GCC diagnostic") work well
enough, but if any diagnostics are issued during lexing, prior to resetting
the token locations, those diagnostics get issued at the invalid
locations. Fix that up by adding a new field pfile->diagnostic_override_loc
that instructs libcpp to issue diagnostics at the alternate location.
libcpp/ChangeLog:
PR preprocessor/114423
* internal.h (struct cpp_reader): Add DIAGNOSTIC_OVERRIDE_LOC
field.
* directives.cc (destringize_and_run): Set the new field to the
location of the _Pragma operator.
* errors.cc (cpp_diagnostic_at): Support DIAGNOSTIC_OVERRIDE_LOC to
temporarily issue diagnostics at a different location.
(cpp_diagnostic_with_line): Likewise.
gcc/testsuite/ChangeLog:
PR preprocessor/114423
* c-c++-common/cpp/pragma-diagnostic-loc.c: New test.
* c-c++-common/cpp/diagnostic-pragma-1.c: Adjust expected output.
* g++.dg/pch/operator-1.C: Likewise.