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author | Lewis Hyatt <lhyatt@gmail.com> | 2022-10-06 18:05:02 -0400 |
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committer | Lewis Hyatt <lhyatt@gmail.com> | 2022-10-12 18:08:31 -0400 |
commit | ddb7f0a0cac48762ba6408d69538f8115c4a2739 (patch) | |
tree | 0200cd9ddfa77a34ff96a816cd14f0bd74f2f9f0 /gcc/c-family | |
parent | f77281b25ca6bb34ba271fa826e1e79a15df95fe (diff) | |
download | gcc-ddb7f0a0cac48762ba6408d69538f8115c4a2739.zip gcc-ddb7f0a0cac48762ba6408d69538f8115c4a2739.tar.gz gcc-ddb7f0a0cac48762ba6408d69538f8115c4a2739.tar.bz2 |
preprocessor: Fix tracking of system header state [PR60014,PR60723]
The token_streamer class (which implements gcc mode -E and
-save-temps/-no-integrated-cpp) needs to keep track whether the last tokens
output were in a system header, so that it can generate line marker
annotations as necessary for a downstream consumer to reconstruct the
state. The logic for tracking it, which was added by r5-1863 to resolve
PR60723, has some edge case issues as revealed by the three new test
cases. The first, coming from the original PR60014, was incidentally fixed by
r9-1926 for unrelated reasons. The other two were still failing on master
prior to this commit. Such code paths were not realizable prior to r13-1544,
which made it possible for the token streamer to see CPP_PRAGMA tokens in more
contexts.
The two main issues being corrected here are:
1) print.prev_was_system_token needs to indicate whether the previous token
output was in a system location. However, it was not being set on every token,
only on those that triggered the main code path; specifically it was not
triggered on a CPP_PRAGMA token. Testcase 2 covers this case.
2) The token_streamer uses a variable "line_marker_emitted" to remember
whether a line marker has been emitted while processing a given token, so that
it wouldn't be done more than once in case multiple conditions requiring a
line marker are true. There was no reason for this to be a member variable
that retains its value from token to token, since it is just needed for
tracking the state locally while processing a single given token. The fact
that it could retain its value for a subsequent token is rather difficult to
observe, but testcase 3 demonstrates incorrect behavior resulting from
that. Moving this to a local variable also simplifies understanding the
control flow going forward.
gcc/c-family/ChangeLog:
PR preprocessor/60014
PR preprocessor/60723
* c-ppoutput.cc (class token_streamer): Remove member
line_marker_emitted to...
(token_streamer::stream): ...a local variable here. Set
print.prev_was_system_token on all code paths.
gcc/testsuite/ChangeLog:
PR preprocessor/60014
PR preprocessor/60723
* gcc.dg/cpp/pr60014-1.c: New test.
* gcc.dg/cpp/pr60014-1.h: New test.
* gcc.dg/cpp/pr60014-2.c: New test.
* gcc.dg/cpp/pr60014-2.h: New test.
* gcc.dg/cpp/pr60014-3.c: New test.
* gcc.dg/cpp/pr60014-3.h: New test.
Diffstat (limited to 'gcc/c-family')
-rw-r--r-- | gcc/c-family/c-ppoutput.cc | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/gcc/c-family/c-ppoutput.cc b/gcc/c-family/c-ppoutput.cc index 98081cc..a99d9e9 100644 --- a/gcc/c-family/c-ppoutput.cc +++ b/gcc/c-family/c-ppoutput.cc @@ -184,15 +184,13 @@ class token_streamer bool avoid_paste; bool do_line_adjustments; bool in_pragma; - bool line_marker_emitted; public: token_streamer (cpp_reader *pfile) :avoid_paste (false), do_line_adjustments (cpp_get_options (pfile)->lang != CLK_ASM && !flag_no_line_commands), - in_pragma (false), - line_marker_emitted (false) + in_pragma (false) { gcc_assert (!print.streamer); print.streamer = this; @@ -227,7 +225,14 @@ token_streamer::stream (cpp_reader *pfile, const cpp_token *token, if (token->type == CPP_EOF) return; + /* Keep track when we move into and out of system locations. */ + const bool is_system_token = in_system_header_at (loc); + const bool system_state_changed + = (is_system_token != print.prev_was_system_token); + print.prev_was_system_token = is_system_token; + /* Subtle logic to output a space if and only if necessary. */ + bool line_marker_emitted = false; if (avoid_paste) { unsigned src_line = LOCATION_LINE (loc); @@ -301,19 +306,17 @@ token_streamer::stream (cpp_reader *pfile, const cpp_token *token, if (do_line_adjustments && !in_pragma && !line_marker_emitted - && print.prev_was_system_token != !!in_system_header_at (loc) + && system_state_changed && !is_location_from_builtin_token (loc)) /* The system-ness of this token is different from the one of the previous token. Let's emit a line change to mark the new system-ness before we emit the token. */ { - do_line_change (pfile, token, loc, false); - print.prev_was_system_token = !!in_system_header_at (loc); + line_marker_emitted = do_line_change (pfile, token, loc, false); } if (!in_pragma || should_output_pragmas ()) { cpp_output_token (token, print.outf); - line_marker_emitted = false; print.printed = true; } } |