This flags rich_locations associated with -Wbidi-chars= so that
non-ASCII bytes will be escaped when printing the source lines
(using the diagnostics support I added in
r12-4825-gbd5e882cf6e0def3dd1bc106075d59a303fe0d1e).
In particular, this ensures that the printed source lines will
be pure ASCII, and thus the visual ordering of the characters
will be the same as the logical ordering.
Before:
Wbidi-chars-1.c: In function ‘main’:
Wbidi-chars-1.c:6:43: warning: unpaired UTF-8 bidirectional control character detected [-Wbidi-chars=]
6 | /* } if (isAdmin) begin admins only */
| ^
Wbidi-chars-1.c:9:28: warning: unpaired UTF-8 bidirectional control character detected [-Wbidi-chars=]
9 | /* end admins only { */
| ^
Wbidi-chars-11.c:6:15: warning: UTF-8 vs UCN mismatch when closing a context by "U+202C (POP DIRECTIONAL FORMATTING)" [-Wbidi-chars=]
6 | int LRE__PDF_\u202c;
| ^
Wbidi-chars-11.c:8:19: warning: UTF-8 vs UCN mismatch when closing a context by "U+202C (POP DIRECTIONAL FORMATTING)" [-Wbidi-chars=]
8 | int LRE_\u202a_PDF__;
| ^
Wbidi-chars-11.c:10:28: warning: UTF-8 vs UCN mismatch when closing a context by "U+202C (POP DIRECTIONAL FORMATTING)" [-Wbidi-chars=]
10 | const char *s1 = "LRE__PDF_\u202c";
| ^
Wbidi-chars-11.c:12:33: warning: UTF-8 vs UCN mismatch when closing a context by "U+202C (POP DIRECTIONAL FORMATTING)" [-Wbidi-chars=]
12 | const char *s2 = "LRE_\u202a_PDF_";
| ^
After:
Wbidi-chars-1.c: In function ‘main’:
Wbidi-chars-1.c:6:43: warning: unpaired UTF-8 bidirectional control character detected [-Wbidi-chars=]
6 | /*<U+202E> } <U+2066>if (isAdmin)<U+2069> <U+2066> begin admins only */
| ^
Wbidi-chars-1.c:9:28: warning: unpaired UTF-8 bidirectional control character detected [-Wbidi-chars=]
9 | /* end admins only <U+202E> { <U+2066>*/
| ^
Wbidi-chars-11.c:6:15: warning: UTF-8 vs UCN mismatch when closing a context by "U+202C (POP DIRECTIONAL FORMATTING)" [-Wbidi-chars=]
6 | int LRE_<U+202A>_PDF_\u202c;
| ^
Wbidi-chars-11.c:8:19: warning: UTF-8 vs UCN mismatch when closing a context by "U+202C (POP DIRECTIONAL FORMATTING)" [-Wbidi-chars=]
8 | int LRE_\u202a_PDF_<U+202C>_;
| ^
Wbidi-chars-11.c:10:28: warning: UTF-8 vs UCN mismatch when closing a context by "U+202C (POP DIRECTIONAL FORMATTING)" [-Wbidi-chars=]
10 | const char *s1 = "LRE_<U+202A>_PDF_\u202c";
| ^
Wbidi-chars-11.c:12:33: warning: UTF-8 vs UCN mismatch when closing a context by "U+202C (POP DIRECTIONAL FORMATTING)" [-Wbidi-chars=]
12 | const char *s2 = "LRE_\u202a_PDF_<U+202C>";
| ^
libcpp/ChangeLog:
PR preprocessor/103026
* lex.c (maybe_warn_bidi_on_close): Use a rich_location
and call set_escape_on_output (true) on it.
(maybe_warn_bidi_on_char): Likewise.
Signed-off-by: David Malcolm <dmalcolm@redhat.com>
Normal preprocessing, -fdirectives-only preprocessing before the Nathan's
rewrite, and all other compilers I've tried on godbolt treat even \*/
as end of a block comment, but the new -fdirectives-only handling doesn't.
2021-11-17 Jakub Jelinek <jakub@redhat.com>
PR preprocessor/103130
* lex.c (cpp_directive_only_process): Treat even \*/ as end of block
comment.
* c-c++-common/cpp/dir-only-9.c: New test.
From a link below:
"An issue was discovered in the Bidirectional Algorithm in the Unicode
Specification through 14.0. It permits the visual reordering of
characters via control sequences, which can be used to craft source code
that renders different logic than the logical ordering of tokens
ingested by compilers and interpreters. Adversaries can leverage this to
encode source code for compilers accepting Unicode such that targeted
vulnerabilities are introduced invisibly to human reviewers."
More info:
https://nvd.nist.gov/vuln/detail/CVE-2021-42574https://trojansource.codes/
This is not a compiler bug. However, to mitigate the problem, this patch
implements -Wbidi-chars=[none|unpaired|any] to warn about possibly
misleading Unicode bidirectional control characters the preprocessor may
encounter.
The default is =unpaired, which warns about improperly terminated
bidirectional control characters; e.g. a LRE without its corresponding PDF.
The level =any warns about any use of bidirectional control characters.
This patch handles both UCNs and UTF-8 characters. UCNs designating
bidi characters in identifiers are accepted since r204886. Then r217144
enabled -fextended-identifiers by default. Extended characters in C/C++
identifiers have been accepted since r275979. However, this patch still
warns about mixing UTF-8 and UCN bidi characters; there seems to be no
good reason to allow mixing them.
We warn in different contexts: comments (both C and C++-style), string
literals, character constants, and identifiers. Expectedly, UCNs are ignored
in comments and raw string literals. The bidirectional control characters
can nest so this patch handles that as well.
I have not included nor tested this at all with Fortran (which also has
string literals and line comments).
Dave M. posted patches improving diagnostic involving Unicode characters.
This patch does not make use of this new infrastructure yet.
PR preprocessor/103026
gcc/c-family/ChangeLog:
* c.opt (Wbidi-chars, Wbidi-chars=): New option.
gcc/ChangeLog:
* doc/invoke.texi: Document -Wbidi-chars.
libcpp/ChangeLog:
* include/cpplib.h (enum cpp_bidirectional_level): New.
(struct cpp_options): Add cpp_warn_bidirectional.
(enum cpp_warning_reason): Add CPP_W_BIDIRECTIONAL.
* internal.h (struct cpp_reader): Add warn_bidi_p member
function.
* init.c (cpp_create_reader): Set cpp_warn_bidirectional.
* lex.c (bidi): New namespace.
(get_bidi_utf8): New function.
(get_bidi_ucn): Likewise.
(maybe_warn_bidi_on_close): Likewise.
(maybe_warn_bidi_on_char): Likewise.
(_cpp_skip_block_comment): Implement warning about bidirectional
control characters.
(skip_line_comment): Likewise.
(forms_identifier_p): Likewise.
(lex_identifier): Likewise.
(lex_string): Likewise.
(lex_raw_string): Likewise.
gcc/testsuite/ChangeLog:
* c-c++-common/Wbidi-chars-1.c: New test.
* c-c++-common/Wbidi-chars-2.c: New test.
* c-c++-common/Wbidi-chars-3.c: New test.
* c-c++-common/Wbidi-chars-4.c: New test.
* c-c++-common/Wbidi-chars-5.c: New test.
* c-c++-common/Wbidi-chars-6.c: New test.
* c-c++-common/Wbidi-chars-7.c: New test.
* c-c++-common/Wbidi-chars-8.c: New test.
* c-c++-common/Wbidi-chars-9.c: New test.
* c-c++-common/Wbidi-chars-10.c: New test.
* c-c++-common/Wbidi-chars-11.c: New test.
* c-c++-common/Wbidi-chars-12.c: New test.
* c-c++-common/Wbidi-chars-13.c: New test.
* c-c++-common/Wbidi-chars-14.c: New test.
* c-c++-common/Wbidi-chars-15.c: New test.
* c-c++-common/Wbidi-chars-16.c: New test.
* c-c++-common/Wbidi-chars-17.c: New test.
This patch adds support to GCC's diagnostic subsystem for escaping certain
bytes and Unicode characters when quoting source code.
Specifically, this patch adds a new flag rich_location::m_escape_on_output
which is a hint from a diagnostic that non-ASCII bytes in the pertinent
lines of the user's source code should be escaped when printed.
The patch sets this for the following diagnostics:
- when complaining about stray bytes in the program (when these
are non-printable)
- when complaining about "null character(s) ignored");
- for -Wnormalized= (and generate source ranges for such warnings)
The escaping is controlled by a new option:
-fdiagnostics-escape-format=[unicode|bytes]
For example, consider a diagnostic involing a source line containing the
string "before" followed by the Unicode character U+03C0 ("GREEK SMALL
LETTER PI", with UTF-8 encoding 0xCF 0x80) followed by the byte 0xBF
(a stray UTF-8 trailing byte), followed by the string "after", where the
diagnostic highlights the U+03C0 character.
By default, this line will be printed verbatim to the user when
reporting a diagnostic at it, as:
beforeπXafter
^
(using X for the stray byte to avoid putting invalid UTF-8 in this
commit message)
If the diagnostic sets the "escape" flag, it will be printed as:
before<U+03C0><BF>after
^~~~~~~~
with -fdiagnostics-escape-format=unicode (the default), or as:
before<CF><80><BF>after
^~~~~~~~
if the user supplies -fdiagnostics-escape-format=bytes.
This only affects how the source is printed; it does not affect
how column numbers that are printed (as per -fdiagnostics-column-unit=
and -fdiagnostics-column-origin=).
gcc/c-family/ChangeLog:
* c-lex.c (c_lex_with_flags): When complaining about non-printable
CPP_OTHER tokens, set the "escape on output" flag.
gcc/ChangeLog:
* common.opt (fdiagnostics-escape-format=): New.
(diagnostics_escape_format): New enum.
(DIAGNOSTICS_ESCAPE_FORMAT_UNICODE): New enum value.
(DIAGNOSTICS_ESCAPE_FORMAT_BYTES): Likewise.
* diagnostic-format-json.cc (json_end_diagnostic): Add
"escape-source" attribute.
* diagnostic-show-locus.c
(exploc_with_display_col::exploc_with_display_col): Replace
"tabstop" param with a cpp_char_column_policy and add an "aspect"
param. Use these to compute m_display_col accordingly.
(struct char_display_policy): New struct.
(layout::m_policy): New field.
(layout::m_escape_on_output): New field.
(def_policy): New function.
(make_range): Update for changes to exploc_with_display_col ctor.
(default_print_decoded_ch): New.
(width_per_escaped_byte): New.
(escape_as_bytes_width): New.
(escape_as_bytes_print): New.
(escape_as_unicode_width): New.
(escape_as_unicode_print): New.
(make_policy): New.
(layout::layout): Initialize new fields. Update m_exploc ctor
call for above change to ctor.
(layout::maybe_add_location_range): Update for changes to
exploc_with_display_col ctor.
(layout::calculate_x_offset_display): Update for change to
cpp_display_width.
(layout::print_source_line): Pass policy
to cpp_display_width_computation. Capture cpp_decoded_char when
calling process_next_codepoint. Move printing of source code to
m_policy.m_print_cb.
(line_label::line_label): Pass in policy rather than context.
(layout::print_any_labels): Update for change to line_label ctor.
(get_affected_range): Pass in policy rather than context, updating
calls to location_compute_display_column accordingly.
(get_printed_columns): Likewise, also for cpp_display_width.
(correction::correction): Pass in policy rather than tabstop.
(correction::compute_display_cols): Pass m_policy rather than
m_tabstop to cpp_display_width.
(correction::m_tabstop): Replace with...
(correction::m_policy): ...this.
(line_corrections::line_corrections): Pass in policy rather than
context.
(line_corrections::m_context): Replace with...
(line_corrections::m_policy): ...this.
(line_corrections::add_hint): Update to use m_policy rather than
m_context.
(line_corrections::add_hint): Likewise.
(layout::print_trailing_fixits): Likewise.
(selftest::test_display_widths): New.
(selftest::test_layout_x_offset_display_utf8): Update to use
policy rather than tabstop.
(selftest::test_one_liner_labels_utf8): Add test of escaping
source lines.
(selftest::test_diagnostic_show_locus_one_liner_utf8): Update to
use policy rather than tabstop.
(selftest::test_overlapped_fixit_printing): Likewise.
(selftest::test_overlapped_fixit_printing_utf8): Likewise.
(selftest::test_overlapped_fixit_printing_2): Likewise.
(selftest::test_tab_expansion): Likewise.
(selftest::test_escaping_bytes_1): New.
(selftest::test_escaping_bytes_2): New.
(selftest::diagnostic_show_locus_c_tests): Call the new tests.
* diagnostic.c (diagnostic_initialize): Initialize
context->escape_format.
(convert_column_unit): Update to use default character width policy.
(selftest::test_diagnostic_get_location_text): Likewise.
* diagnostic.h (enum diagnostics_escape_format): New enum.
(diagnostic_context::escape_format): New field.
* doc/invoke.texi (-fdiagnostics-escape-format=): New option.
(-fdiagnostics-format=): Add "escape-source" attribute to examples
of JSON output, and document it.
* input.c (location_compute_display_column): Pass in "policy"
rather than "tabstop", passing to
cpp_byte_column_to_display_column.
(selftest::test_cpp_utf8): Update to use cpp_char_column_policy.
* input.h (class cpp_char_column_policy): New forward decl.
(location_compute_display_column): Pass in "policy" rather than
"tabstop".
* opts.c (common_handle_option): Handle
OPT_fdiagnostics_escape_format_.
* selftest.c (temp_source_file::temp_source_file): New ctor
overload taking a size_t.
* selftest.h (temp_source_file::temp_source_file): Likewise.
gcc/testsuite/ChangeLog:
* c-c++-common/diagnostic-format-json-1.c: Add regexp to consume
"escape-source" attribute.
* c-c++-common/diagnostic-format-json-2.c: Likewise.
* c-c++-common/diagnostic-format-json-3.c: Likewise.
* c-c++-common/diagnostic-format-json-4.c: Likewise, twice.
* c-c++-common/diagnostic-format-json-5.c: Likewise.
* gcc.dg/cpp/warn-normalized-4-bytes.c: New test.
* gcc.dg/cpp/warn-normalized-4-unicode.c: New test.
* gcc.dg/encoding-issues-bytes.c: New test.
* gcc.dg/encoding-issues-unicode.c: New test.
* gfortran.dg/diagnostic-format-json-1.F90: Add regexp to consume
"escape-source" attribute.
* gfortran.dg/diagnostic-format-json-2.F90: Likewise.
* gfortran.dg/diagnostic-format-json-3.F90: Likewise.
libcpp/ChangeLog:
* charset.c (convert_escape): Use encoding_rich_location when
complaining about nonprintable unknown escape sequences.
(cpp_display_width_computation::::cpp_display_width_computation):
Pass in policy rather than tabstop.
(cpp_display_width_computation::process_next_codepoint): Add "out"
param and populate *out if non-NULL.
(cpp_display_width_computation::advance_display_cols): Pass NULL
to process_next_codepoint.
(cpp_byte_column_to_display_column): Pass in policy rather than
tabstop. Pass NULL to process_next_codepoint.
(cpp_display_column_to_byte_column): Pass in policy rather than
tabstop.
* errors.c (cpp_diagnostic_get_current_location): New function,
splitting out the logic from...
(cpp_diagnostic): ...here.
(cpp_warning_at): New function.
(cpp_pedwarning_at): New function.
* include/cpplib.h (cpp_warning_at): New decl for rich_location.
(cpp_pedwarning_at): Likewise.
(struct cpp_decoded_char): New.
(struct cpp_char_column_policy): New.
(cpp_display_width_computation::cpp_display_width_computation):
Replace "tabstop" param with "policy".
(cpp_display_width_computation::process_next_codepoint): Add "out"
param.
(cpp_display_width_computation::m_tabstop): Replace with...
(cpp_display_width_computation::m_policy): ...this.
(cpp_byte_column_to_display_column): Replace "tabstop" param with
"policy".
(cpp_display_width): Likewise.
(cpp_display_column_to_byte_column): Likewise.
* include/line-map.h (rich_location::escape_on_output_p): New.
(rich_location::set_escape_on_output): New.
(rich_location::m_escape_on_output): New.
* internal.h (cpp_diagnostic_get_current_location): New decl.
(class encoding_rich_location): New.
* lex.c (skip_whitespace): Use encoding_rich_location when
complaining about null characters.
(warn_about_normalization): Generate a source range when
complaining about improperly normalized tokens, rather than just a
point, and use encoding_rich_location so that the source code
is escaped on printing.
* line-map.c (rich_location::rich_location): Initialize
m_escape_on_output.
Signed-off-by: David Malcolm <dmalcolm@redhat.com>
Both #pragma and _Pragma ended up as CPP_PRAGMA. Presumably since
r131819 (2008, GCC 4.3) for PR34692, pragmas are not expanded in
macro arguments but are output as is before. From the old bug report,
that was to fix usage like
FOO (
#pragma GCC diagnostic
)
However, that change also affected _Pragma such that
BAR (
"1";
_Pragma("omp ..."); )
yielded
#pragma omp ...
followed by what BAR expanded too, possibly including '"1";'.
This commit adds a flag, PRAGMA_OP, to tokens to make the two
distinguishable - and include again _Pragma in the expanded arguments.
libcpp/ChangeLog:
PR c++/102409
* directives.c (destringize_and_run): Add PRAGMA_OP to the
CPP_PRAGMA token's flags to mark is as coming from _Pragma.
* include/cpplib.h (PRAGMA_OP): #define, to be used with token flags.
* macro.c (collect_args): Only handle CPP_PRAGMA special if PRAGMA_OP
is set.
gcc/testsuite/ChangeLog:
* c-c++-common/gomp/pragma-1.c: New test.
* c-c++-common/gomp/pragma-2.c: New test.
This patch implements C++23 P2334R1, which is easy because Joseph has done
all the hard work for C2X already.
Unlike the C N2645 paper, the C++ P2334R1 contains one important addition
(but not in the normative text):
"While this is a new preprocessor feature and cannot be treated as a defect
report, implementations that support older versions of the standard are
encouraged to implement this feature in the older language modes as well
as C++23."
so there are different variants how to implement it.
One is ignoring that sentence and only implementing it
for -std=c++23/-std=gnu++23 like it is only implemented for -std=c2x.
Another option would be to implement it also in the older GNU modes but
not in the C/CXX modes (but it would be strange if we did that just for
C++ and not for C).
Yet another option is to enable it unconditionally.
And yet another option would be to enable it unconditionally but emit
a warning (or pedwarn) when it is seen.
Note, when it is enabled for the older language modes, as Joseph wrote
in the c11-elifdef-1.c testcase, it can result e.g. in rejecting previously
valid code:
#define A
#undef B
#if 0
#elifdef A
#error "#elifdef A applied"
#endif
#if 0
#elifndef B
#error "#elifndef B applied"
#endif
Note, seems clang went the enable it unconditionally in all standard
versions of both C and C++, no warnings or anything whatsoever, so
essentially treated it as a DR that changed behavior of e.g. the above code.
After feedback, this option enables #elifdef/#elifndef for -std=c2x
and -std=c++2{b,3} and enables it also for -std=gnu*, but for GNU modes
older than C2X or C++23 if -pedantic it emits a pedwarn on the directives
that either would be rejected in the corresponding -std=c* modes, e.g.
#if 1
#elifdef A // pedwarn if -pedantic
#endif
or when the directives would be silently accepted, but when they are
recognized it changes behavior, so e.g.
#define A
#if 0
#elifdef A // pedwarn if -pedantic
#define M 1
#endif
It won't pedwarn if the directives would be silently ignored and wouldn't
change anything, like:
#define A
#if 0
#elifndef A
#define M 1
#endif
or
#undef B
#if 0
#elifdef B
#define M 1
#endif
2021-10-06 Jakub Jelinek <jakub@redhat.com>
libcpp/
* init.c (lang_defaults): Implement P2334R1, enable elifdef for
-std=c++23 and -std=gnu++23.
* directives.c (_cpp_handle_directive): Support elifdef/elifndef if
either CPP_OPTION (pfile, elifdef) or !CPP_OPTION (pfile, std).
(do_elif): For older non-std modes if pedantic pedwarn about
#elifdef/#elifndef directives that change behavior.
gcc/testsuite/
* gcc.dg/cpp/gnu11-elifdef-1.c: New test.
* gcc.dg/cpp/gnu11-elifdef-2.c: New test.
* gcc.dg/cpp/gnu11-elifdef-3.c: New test.
* gcc.dg/cpp/gnu11-elifdef-4.c: New test.
* g++.dg/cpp/elifdef-1.C: New test.
* g++.dg/cpp/elifdef-2.C: New test.
* g++.dg/cpp/elifdef-3.C: New test.
* g++.dg/cpp/elifdef-4.C: New test.
* g++.dg/cpp/elifdef-5.C: New test.
* g++.dg/cpp/elifdef-6.C: New test.
* g++.dg/cpp/elifdef-7.C: New test.
The following patch implements the
P1949R7 - C++ Identifier Syntax using Unicode Standard Annex 31
paper. We already allow UTF-8 characters in the source, so that part
is already implemented, so IMHO all we need to do is pedwarn instead of
just warn for the (default) -Wnormalize=nfc (or for -Wnormalize={id,nkfc})
if the character is not in NFC and to use the unicode XID_Start and
XID_Continue derived code properties to find out what characters are allowed
(the standard actually adds U+005F to XID_Start, but we are handling the
ASCII compatible characters differently already and they aren't allowed
in UCNs in identifiers). Instead of hardcoding the large tables
in ucnid.tab, this patch makes makeucnid.c read them from the Unicode
tables (13.0.0 version at this point).
For non-pedantic mode, we accept as 2nd+ char in identifiers a union
of valid characters in all supported modes, but for the 1st char it
was actually pedantically requiring that it is not any of the characters
that may not appear in the currently chosen standard as the first character.
This patch changes it such that also what is allowed at the start of an
identifier is a union of characters valid at the start of an identifier
in any of the pedantic modes.
2021-09-01 Jakub Jelinek <jakub@redhat.com>
PR c++/100977
libcpp/
* include/cpplib.h (struct cpp_options): Add cxx23_identifiers.
* charset.c (CXX23, NXX23): New enumerators.
(CID, NFC, NKC, CTX): Renumber.
(ucn_valid_in_identifier): Implement P1949R7 - use CXX23 and
NXX23 flags for cxx23_identifiers. For start character in
non-pedantic mode, allow characters that are allowed as start
characters in any of the supported language modes, rather than
disallowing characters allowed only as non-start characters in
current mode but for characters from other language modes allowing
them even if they are never allowed at start.
* init.c (struct lang_flags): Add cxx23_identifiers.
(lang_defaults): Add cxx23_identifiers column.
(cpp_set_lang): Initialize CPP_OPTION (pfile, cxx23_identifiers).
* lex.c (warn_about_normalization): If cxx23_identifiers, use
cpp_pedwarning_with_line instead of cpp_warning_with_line for
"is not in NFC" diagnostics.
* makeucnid.c: Adjust usage comment.
(CXX23, NXX23): New enumerators.
(all_languages): Add CXX23.
(not_NFC, not_NFKC, maybe_not_NFC): Renumber.
(read_derivedcore): New function.
(write_table): Print also CXX23 and NXX23 columns.
(main): Require 5 arguments instead of 4, call read_derivedcore.
* ucnid.h: Regenerated using Unicode 13.0.0 files.
gcc/testsuite/
* g++.dg/cpp23/normalize1.C: New test.
* g++.dg/cpp23/normalize2.C: New test.
* g++.dg/cpp23/normalize3.C: New test.
* g++.dg/cpp23/normalize4.C: New test.
* g++.dg/cpp23/normalize5.C: New test.
* g++.dg/cpp23/normalize6.C: New test.
* g++.dg/cpp23/normalize7.C: New test.
* g++.dg/cpp23/ucnid-1-utf8.C: New test.
* g++.dg/cpp23/ucnid-2-utf8.C: New test.
* gcc.dg/cpp/ucnid-4.c: Don't expect
"not valid at the start of an identifier" errors.
* gcc.dg/cpp/ucnid-4-utf8.c: Likewise.
* gcc.dg/cpp/ucnid-5-utf8.c: New test.
> We want to remove the latter <placemarker> but not the former one, and
> the patch adds the vaopt_padding_tokens counter for it to control
> how many placemarkers are removed on vaopt_state::END.
> As can be seen in #c1 and #c2 of the PR, I've tried various approaches,
> but neither worked out for all the cases except the posted one.
I notice that the second placemarker you mention is avoid_paste, which seems
relevant. This seems to also work, at least it doesn't seem to break any of
the va_opt tests.
2021-09-01 Jason Merrill <jason@redhat.com>
* macro.c (replace_args): When __VA_OPT__ is on the LHS of ##,
remove trailing avoid_paste tokens.
So, besides missing #__VA_OPT__ patch for which I've posted patch last week,
P1042R1 introduced some placemarker changes for __VA_OPT__, most notably
the addition of before "removal of placemarker tokens," rescanning ...
and the
#define H4(X, ...) __VA_OPT__(a X ## X) ## b
H4(, 1) // replaced by a b
example mentioned there where we replace it currently with ab
The following patch are the minimum changes (except for the
__builtin_expect) that achieve the same preprocessing between current
clang++ and patched gcc on all the testcases I've tried (i.e. gcc __VA_OPT__
testsuite in c-c++-common/cpp/va-opt* including the new test and the clang
clang/test/Preprocessor/macro_va_opt* testcases).
At one point I was trying to implement the __VA_OPT__(args) case as if
for non-empty __VA_ARGS__ it expanded as if __VA_OPT__( and ) were missing,
but from the tests it seems that is not how it should work, in particular
if after (or before) we have some macro argument and it is not followed
(or preceded) by ##, then it should be macro expanded even when __VA_OPT__
is after ## or ) is followed by ##. And it seems that not removing any
padding tokens isn't possible either, because the expansion of the arguments
typically has a padding token at the start and end and those at least
according to the testsuite need to go. It is unclear if it would be enough
to remove just one or if all padding tokens should be removed.
Anyway, e.g. the previous removal of all padding tokens at the end of
__VA_OPT__ is undesirable, as it e.g. eats also the padding tokens needed
for the H4 example from the paper.
2021-09-01 Jakub Jelinek <jakub@redhat.com>
PR preprocessor/101488
* macro.c (replace_args): Fix up handling of CPP_PADDING tokens at the
start or end of __VA_OPT__ arguments when preceeded or followed by ##.
* c-c++-common/cpp/va-opt-3.c: Adjust expected output.
* c-c++-common/cpp/va-opt-7.c: New test.
Adds the logic to handle -finput-charset in layout_get_source_line(), so that
source lines are converted from their input encodings prior to being output by
diagnostics machinery. Also adds the ability to strip a UTF-8 BOM similarly.
gcc/c-family/ChangeLog:
PR other/93067
* c-opts.c (c_common_input_charset_cb): New function.
(c_common_post_options): Call new function
diagnostic_initialize_input_context().
gcc/d/ChangeLog:
PR other/93067
* d-lang.cc (d_input_charset_callback): New function.
(d_init): Call new function
diagnostic_initialize_input_context().
gcc/fortran/ChangeLog:
PR other/93067
* cpp.c (gfc_cpp_post_options): Call new function
diagnostic_initialize_input_context().
gcc/ChangeLog:
PR other/93067
* coretypes.h (typedef diagnostic_input_charset_callback): Declare.
* diagnostic.c (diagnostic_initialize_input_context): New function.
* diagnostic.h (diagnostic_initialize_input_context): Declare.
* input.c (default_charset_callback): New function.
(file_cache::initialize_input_context): New function.
(file_cache_slot::create): Added ability to convert the input
according to the input context.
(file_cache::file_cache): Initialize the new input context.
(class file_cache_slot): Added new m_alloc_offset member.
(file_cache_slot::file_cache_slot): Initialize the new member.
(file_cache_slot::~file_cache_slot): Handle potentially offset buffer.
(file_cache_slot::maybe_grow): Likewise.
(file_cache_slot::needs_read_p): Handle NULL fp, which is now possible.
(file_cache_slot::get_next_line): Likewise.
* input.h (class file_cache): Added input context member.
libcpp/ChangeLog:
PR other/93067
* charset.c (init_iconv_desc): Adapt to permit PFILE argument to
be NULL.
(_cpp_convert_input): Likewise. Also move UTF-8 BOM logic to...
(cpp_check_utf8_bom): ...here. New function.
(cpp_input_conversion_is_trivial): New function.
* files.c (read_file_guts): Allow PFILE argument to be NULL. Add
INPUT_CHARSET argument as an alternate source of this information.
(read_file): Pass the new argument to read_file_guts.
(cpp_get_converted_source): New function.
* include/cpplib.h (struct cpp_converted_source): Declare.
(cpp_get_converted_source): Declare.
(cpp_input_conversion_is_trivial): Declare.
(cpp_check_utf8_bom): Declare.
gcc/testsuite/ChangeLog:
PR other/93067
* gcc.dg/diagnostic-input-charset-1.c: New test.
* gcc.dg/diagnostic-input-utf8-bom.c: New test.
The following patch implements C++20 # __VA_OPT__ (...) support.
Testcases cover what I came up with myself and what LLVM has for #__VA_OPT__
in its testsuite and the string literals are identical between the two
compilers on the va-opt-5.c testcase.
2021-08-17 Jakub Jelinek <jakub@redhat.com>
libcpp/
* macro.c (vaopt_state): Add m_stringify member.
(vaopt_state::vaopt_state): Initialize it.
(vaopt_state::update): Overwrite it.
(vaopt_state::stringify): New method.
(stringify_arg): Replace arg argument with first, count arguments
and add va_opt argument. Use first instead of arg->first and
count instead of arg->count, for va_opt add paste_tokens handling.
(paste_tokens): Fix up len calculation. Don't spell rhs twice,
instead use %.*s to supply lhs and rhs spelling lengths. Don't call
_cpp_backup_tokens here.
(paste_all_tokens): Call it here instead.
(replace_args): Adjust stringify_arg caller. For vaopt_state::END
if stringify is true handle __VA_OPT__ stringification.
(create_iso_definition): Handle # __VA_OPT__ similarly to # macro_arg.
gcc/testsuite/
* c-c++-common/cpp/va-opt-5.c: New test.
* c-c++-common/cpp/va-opt-6.c: New test.
The following testcase ICEs in cpp_sys_macro_p, because cpp_sys_macro_p
is called for a builtin macro which doesn't use node->value.macro union
member but a different one and so dereferencing it ICEs.
As the testcase is distilled from contemporary glibc headers, it means
basically -Wtraditional now ICEs on almost everything.
The fix can be either the patch below, return true for builtin macros,
or we could instead return false for builtin macros, or the fix could
be also (untested):
--- libcpp/expr.c 2021-05-07 10:34:46.345122608 +0200
+++ libcpp/expr.c 2021-08-12 09:54:01.837556365 +0200
@@ -783,13 +783,13 @@ cpp_classify_number (cpp_reader *pfile,
/* Traditional C only accepted the 'L' suffix.
Suppress warning about 'LL' with -Wno-long-long. */
- if (CPP_WTRADITIONAL (pfile) && ! cpp_sys_macro_p (pfile))
+ if (CPP_WTRADITIONAL (pfile))
{
int u_or_i = (result & (CPP_N_UNSIGNED|CPP_N_IMAGINARY));
int large = (result & CPP_N_WIDTH) == CPP_N_LARGE
&& CPP_OPTION (pfile, cpp_warn_long_long);
- if (u_or_i || large)
+ if ((u_or_i || large) && ! cpp_sys_macro_p (pfile))
cpp_warning_with_line (pfile, large ? CPP_W_LONG_LONG : CPP_W_TRADITIONAL,
virtual_location, 0,
"traditional C rejects the \"%.*s\" suffix",
The builtin macros at least currently don't add any suffixes
or numbers -Wtraditional would like to warn about. For floating
point suffixes, -Wtraditional calls cpp_sys_macro_p only right
away before emitting the warning, but in the above case the ICE
is because cpp_sys_macro_p is called even if the number doesn't
have any suffixes (that is I think always for builtin macros
right now).
2021-08-12 Jakub Jelinek <jakub@redhat.com>
PR preprocessor/101638
* macro.c (cpp_sys_macro_p): Return true instead of
crashing on builtin macros.
* gcc.dg/cpp/pr101638.c: New test.
The following patch (incremental to the makeucnid.c fix) regenerates
ucnid.h with https://www.unicode.org/Public/13.0.0/ucd/ files.
2021-08-05 Jakub Jelinek <jakub@redhat.com>
PR c++/100977
* ucnid.h: Regenerated using Unicode 13.0.0 files.
I've noticed in ucnid.h two adjacent lines that had all flags and combine
values identical and as such were supposed to be merged.
This is due to a bug in makeucnid.c, which records last_flag,
last_combine and really_safe of what has just been printed, but
because of a typo mishandles it for last_combine, always compares against
the combining_value[0] which is 0.
This has two effects on the table, one is that often the table is
unnecessarily large, as for non-zero .combine every character has its own
record instead of adjacent characters with the same flags and combine
being merged. This means larger tables.
The other is that sometimes the last char that has combine set doesn't
actually have it in the tables, because the code is printing entries only
upon seeing the next character and if that character does have
combining_value of 0 and flags are otherwise the same as previously printed,
it will not print anything.
The following patch fixes that, for clarity what exactly it affects
I've regenerated with the same Unicode files as last time it has
been regenerated.
2021-08-05 Jakub Jelinek <jakub@redhat.com>
PR c++/100977
* makeucnid.c (write_table): Fix computation of last_combine.
* ucnid.h: Regenerated using Unicode 6.3.0 files.
The patch for 96391 changed linemap_compare_locations to give up on
comparing locations from macro expansions if we don't have column
information. But in this testcase, the BOILERPLATE macro is multiple lines
long, so we do want to compare locations within the macro. So this patch
moves the LINE_MAP_MAX_LOCATION_WITH_COLS check inside the block, to use it
for failing gracefully.
PR c++/100796
PR preprocessor/96391
libcpp/ChangeLog:
* line-map.c (linemap_compare_locations): Only use comparison with
LINE_MAP_MAX_LOCATION_WITH_COLS to avoid abort.
gcc/testsuite/ChangeLog:
* g++.dg/plugin/location-overflow-test-pr100796.c: New test.
* g++.dg/plugin/plugin.exp: Run it.
The toolchain provided by ST for stm32 has had support for
__FILENAME__ for a while, but clang/llvm has recently implemented
support for __FILE_NAME__, so it seems better to use the same macro
name in GCC.
It happens that the ST patch is similar to the one proposed in PR
c/42579.
Given these input files:
::::::::::::::
mydir/myinc.h
::::::::::::::
char* mystringh_file = __FILE__;
char* mystringh_filename = __FILE_NAME__;
char* mystringh_base_file = __BASE_FILE__;
::::::::::::::
mydir/mysrc.c
::::::::::::::
char* mystring_file = __FILE__;
char* mystring_filename = __FILE_NAME__;
char* mystring_base_file = __BASE_FILE__;
we produce:
$ gcc mydir/mysrc.c -I . -E
char* mystringh_file = "./mydir/myinc.h";
char* mystringh_filename = "myinc.h";
char* mystringh_base_file = "mydir/mysrc.c";
char* mystring_file = "mydir/mysrc.c";
char* mystring_filename = "mysrc.c";
char* mystring_base_file = "mydir/mysrc.c";
2021-05-20 Christophe Lyon <christophe.lyon@linaro.org>
Torbjörn Svensson <torbjorn.svensson@st.com>
PR c/42579
libcpp/
* include/cpplib.h (cpp_builtin_type): Add BT_FILE_NAME entry.
* init.c (builtin_array): Likewise.
* macro.c (_cpp_builtin_macro_text): Add support for BT_FILE_NAME.
gcc/
* doc/cpp.texi (Common Predefined Macros): Document __FILE_NAME__.
gcc/testsuite/
* c-c++-common/spellcheck-reserved.c: Add tests for __FILE_NAME__.
* c-c++-common/cpp/file-name-1.c: New test.
As can be seen on the testcases, before the -fdirectives-only preprocessing
rewrite the preprocessor would assume // comments are terminated by the
end of file even when newline wasn't there, but now we error out.
The following patch restores the previous behavior.
2021-05-20 Jakub Jelinek <jakub@redhat.com>
PR preprocessor/100646
* lex.c (cpp_directive_only_process): Treat end of file as termination
for !is_block comments.
* gcc.dg/cpp/pr100646-1.c: New test.
* gcc.dg/cpp/pr100646-2.c: New test.
If a header doesn't end with a new-line, with -fdirectives-only we right now
preprocess it as
int i = 1;# 2 "pr100392.c" 2
i.e. the line directive isn't on the next line, which means we fail to parse
it when compiling.
GCC 10 and earlier libcpp/directives-only.c had for this:
if (!pfile->state.skipping && cur != base)
{
/* If the file was not newline terminated, add rlimit, which is
guaranteed to point to a newline, to the end of our range. */
if (cur[-1] != '\n')
{
cur++;
CPP_INCREMENT_LINE (pfile, 0);
lines++;
}
cb->print_lines (lines, base, cur - base);
}
and we have the assertion
/* Files always end in a newline or carriage return. We rely on this for
character peeking safety. */
gcc_assert (buffer->rlimit[0] == '\n' || buffer->rlimit[0] == '\r');
So, this patch just does readd the more less same thing, so that we emit
a newline after the inline even when it wasn't there before.
2021-05-12 Jakub Jelinek <jakub@redhat.com>
PR preprocessor/100392
* lex.c (cpp_directive_only_process): If buffer doesn't end with '\n',
add buffer->rlimit[0] character to the printed range and
CPP_INCREMENT_LINE and increment line_count.
* gcc.dg/cpp/pr100392.c: New test.
* gcc.dg/cpp/pr100392.h: New file.
C2X adds #elifdef and #elifndef preprocessor directives; these have
also been proposed for C++. Implement these directives in libcpp
accordingly.
In this implementation, #elifdef and #elifndef are treated as
non-directives for any language version other than c2x and gnu2x (if
the feature is accepted for C++, it can trivially be enabled for
relevant C++ versions). In strict conformance modes for prior
language versions, this is required, as illustrated by the
c11-elifdef-1.c test added.
Bootstrapped with no regressions for x86_64-pc-linux-gnu.
libcpp/
* include/cpplib.h (struct cpp_options): Add elifdef.
* init.c (struct lang_flags): Add elifdef.
(lang_defaults): Update to include elifdef initializers.
(cpp_set_lang): Set elifdef for pfile based on language.
* directives.c (STDC2X, ELIFDEF): New macros.
(EXTENSION): Increase value to 3.
(DIRECTIVE_TABLE): Add #elifdef and #elifndef.
(_cpp_handle_directive): Do not treat ELIFDEF directives as
directives for language versions without the #elifdef feature.
(do_elif): Handle #elifdef and #elifndef.
(do_elifdef, do_elifndef): New functions.
gcc/testsuite/
* gcc.dg/cpp/c11-elifdef-1.c, gcc.dg/cpp/c2x-elifdef-1.c,
gcc.dg/cpp/c2x-elifdef-2.c: New tests.
The libcpp function cpp_avoid_paste is used to insert whitespace in
preprocessed output where needed to avoid two consecutive
preprocessing tokens, that logically (e.g. when stringized) do not
have whitespace between them, from being incorrectly lexed as one when
the preprocessed input is reread by a compiler.
This fails to allow for digit separators, so meaning that invalid
code, that has a CPP_NUMBER (from a macro expansion) followed by a
character literal, can result in preprocessed output with a valid use
of digit separators, so that required syntax errors do not occur when
compiling with -save-temps. Fix this by handling that case in
cpp_avoid_paste (as with other cases in cpp_avoid_paste, this doesn't
try to check whether the language version in use supports digit
separators; it's always OK to have unnecessary whitespace in
preprocessed output).
Note: there are other cases, with various kinds of wide character or
string literal following a CPP_NUMBER, where spurious pasting of
preprocessing tokens can occur but the sequence of tokens remains
invalid both before and after that pasting. Maybe cpp_avoid_paste
should also handle those cases (and similar cases after a CPP_NAME),
to ensure the sequence of preprocessing tokens in preprocessed output
is exactly right, whether or not it affects whether syntax errors
occur. This patch only addresses the case with digit separators where
invalid code can fail to be diagnosed without the space inserted.
Bootstrapped with no regressions for x86_64-pc-linux-gnu.
libcpp/
* lex.c (cpp_avoid_paste): Do not allow pasting CPP_NUMBER with
CPP_CHAR.
gcc/testsuite/
* g++.dg/cpp1y/digit-sep-paste.C, gcc.dg/c2x-digit-separators-3.c:
New tests.
C2X adds digit separators, as in C++. Enable them accordingly in
libcpp and c-lex.c. Some basic tests are added that digit separators
behave as expected for C2X and are properly disabled for C11; further
test coverage is included in the existing g++.dg/cpp1y/digit-sep*.C
tests.
Bootstrapped with no regressions for x86_64-pc-linux-gnu.
gcc/c-family/
* c-lex.c (interpret_float): Handle digit separators for C2X.
libcpp/
* init.c (lang_defaults): Enable digit separators for GNUC2X and
STDC2X.
gcc/testsuite/
* gcc.dg/c11-digit-separators-1.c,
gcc.dg/c2x-digit-separators-1.c, gcc.dg/c2x-digit-separators-2.c:
New tests.
Since the r0-85991-ga25a8f3be322fe0f838947b679f73d6efc2a412c
https://gcc.gnu.org/legacy-ml/gcc-patches/2008-02/msg01329.html
changes, so that we handle macros inside of pragmas that should expand
macros, during preprocessing we print those pragmas token by token,
with CPP_PRAGMA printed as
fputs ("#pragma ", print.outf);
if (space)
fprintf (print.outf, "%s %s", space, name);
else
fprintf (print.outf, "%s", name);
where name is some identifier (so e.g. print
#pragma omp parallel
or
#pragma omp for
etc.). Because it ends in an identifier, we need to handle it like
an identifier (i.e. CPP_NAME) for the decision whether a space needs
to be emitted in between that #pragma whatever or #pragma whatever whatever
and following token, otherwise the attached testcase is preprocessed as
#pragma omp forreduction(+:red)
rather than
#pragma omp for reduction(+:red)
The cpp_avoid_paste function is only called for this purpose.
2021-05-07 Jakub Jelinek <jakub@redhat.com>
PR c/100450
* lex.c (cpp_avoid_paste): Handle token1 CPP_PRAGMA like CPP_NAME.
* c-c++-common/gomp/pr100450.c: New test.
When the preprocessor lexes preprocessing numbers in lex_number, it
accepts digit separators in more cases than actually permitted in
pp-numbers by the standard syntax.
One thing this accepts is adjacent digit separators; there is some
code to reject those later, but as noted in bug 83873 it fails to
cover the case of adjacent digit separators within a floating-point
exponent. Accepting adjacent digit separators only results in a
missing diagnostic, not in valid code being rejected or being accepted
with incorrect semantics, because the correct lexing in such a case
would have '' start the following preprocessing tokens, and no valid
preprocessing token starts '' while ' isn't valid on its own as a
preprocessing token either. So this patch fixes that case by moving
the error for adjacent digit separators to lex_number (allowing a more
specific diagnostic than if '' were excluded from the pp-number
completely).
Other cases inappropriately accepted involve digit separators before
'.', 'e+', 'e-', 'p+' or 'p-' (or corresponding uppercase variants).
In those cases, as shown by the test digit-sep-pp-number.C added, this
can result in valid code being wrongly rejected as a result of too
many characters being included in the pp-number. So this case is
fixed by terminating the pp-number at the correct character according
to the standard. That test also covers the case where a digit
separator was followed by an identifier-nondigit that is not a
nondigit (e.g. a UCN); that case was already handled correctly.
Bootstrapped with no regressions for x86_64-pc-linux-gnu.
libcpp/
PR c++/83873
PR preprocessor/97604
* lex.c (lex_number): Reject adjacent digit separators here. Do
not allow digit separators before '.' or an exponent with sign.
* expr.c (cpp_classify_number): Do not check for adjacent digit
separators here.
gcc/testsuite/
PR c++/83873
PR preprocessor/97604
* g++.dg/cpp1y/digit-sep-neg-2.C,
g++.dg/cpp1y/digit-sep-pp-number.C: New tests.
* g++.dg/cpp1y/digit-sep-line-neg.C, g++.dg/cpp1y/digit-sep-neg.C:
Adjust expected messages.
