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authorLewis Hyatt <lhyatt@gmail.com>2022-10-06 18:05:02 -0400
committerLewis Hyatt <lhyatt@gmail.com>2022-10-12 18:08:31 -0400
commitddb7f0a0cac48762ba6408d69538f8115c4a2739 (patch)
tree0200cd9ddfa77a34ff96a816cd14f0bd74f2f9f0 /gcc/c-family
parentf77281b25ca6bb34ba271fa826e1e79a15df95fe (diff)
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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.cc17
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;
}
}