==== THEIR file#m
(text from their file)
==== YOURS file
(text from your file)
<<<<
From what I can tell, Perforce is the outlier here.
> > +static bool
> > +c_parser_peek_conflict_marker (c_parser *parser, enum cpp_ttype tok1_kind)
> > +{
> > + c_token *token2 = c_parser_peek_2nd_token (parser);
> > + if (token2->type != tok1_kind)
> > + return false;
> > + c_token *token3 = c_parser_peek_nth_token (parser, 3);
> > + if (token3->type != tok1_kind)
> > + return false;
> > + c_token *token4 = c_parser_peek_nth_token (parser, 4);
> > + if (token4->type != conflict_marker_get_final_tok_kind (tok1_kind))
> > + return false;
> > + return true;
> > +}
>
> Just thinking out loud - I guess it would be too much to hope for to
> share lexers between frontends so that we need only one copy of this?
Probably :(
> > +extern short some_var; /* this line would lead to a warning */
>
> Would or does? I don't see anything suppressing it?
It's skipped in error-handling.
c_parser_declaration_or_fndef has:
1794 declarator = c_parser_declarator (parser,
1795 specs->typespec_kind != ctsk_none,
1796 C_DTR_NORMAL, &dummy);
1797 if (declarator == NULL)
1798 {
[...snip...]
1807 c_parser_skip_to_end_of_block_or_statement (parser);
The call to c_parser_declarator fails, and when issuing:
3465 c_parser_error (parser, "expected identifier or %<(%>");
we emit the "conflict marker" wording error for the error.
Then at line 1807 we skip, discarding everything up to the ";" in that
decl.
Would a better wording be:
extern short some_var; /* This line would lead to a warning due to the
duplicate name, but it is skipped when handling
the conflict marker. */
> There seems to be no testcase verifying what happens if the marker is
> not at the start of the line (IMO it should not be interpreted as a marker).
The v3 patch actually reported them as markers regardless of
location.
The v4 patch now verifies that they are at the start of the line;
I've added test coverage for this (patch-conflict-markers-11.c).
That said, it's not clear they're always at the beginning of a line;
this bazaar bug indicates that CVS (and bazaar) can emit them
mid-line:
https://bugs.launchpad.net/bzr/+bug/36399
I noticed a visual glitch with the v3 patch now that we have range
information for tokens: with caret-printing, we get just the first
token within the marker underlined:
<<<<<<< HEAD
^~
which looks strange (especially with the underlined chars colorized).
Hence in the v4 patch I've added a location tweak so that it
underline/colorizes *all* of the marker:
<<<<<<< HEAD
^~~~~~~
Wording-wise, should it be "merge conflict marker", rather
than "patch conflict marker"?
Clang spells it:
"error: version control conflict marker in file"
http://blog.llvm.org/2010/04/amazing-feats-of-clang-error-recovery.html#merge_conflicts
Maybe I should simply use that wording?
> It would be good to have buy-in from the frontend maintainers (Joseph
> commented on v1 and as far as I can see you've addressed his feedback).
> If you do not hear back from them by the end of the week, I'll approve
> it if the start-of-line thing is sorted.
(clearly over a week by now; I got bogged down in the C++ FE
expression ranges; sorry).
> Bernd
Rebased on top of r231445 (from yesterday).
Successfully bootstrapped®rtested on x86_64-pc-linux-gnu.
Adds 82 new PASSes to g++.sum and 27 new PASSes to gcc.sum.
OK for trunk?
gcc/c-family/ChangeLog:
* c-common.h (conflict_marker_get_final_tok_kind): New prototype.
* c-lex.c (conflict_marker_get_final_tok_kind): New function.
gcc/c/ChangeLog:
* c-parser.c (struct c_parser): Expand array "tokens_buf" from 2
to 4.
(c_parser_peek_nth_token): New function.
(c_parser_peek_conflict_marker): New function.
(c_parser_error): Detect patch conflict markers and report them as
such.
gcc/cp/ChangeLog:
* parser.c (cp_lexer_peek_conflict_marker): New function.
(cp_parser_error): Detect patch conflict markers and report them
as such.
gcc/testsuite/ChangeLog:
* c-c++-common/patch-conflict-markers-1.c: New testcase.
* c-c++-common/patch-conflict-markers-2.c: Likewise.
* c-c++-common/patch-conflict-markers-3.c: Likewise.
* c-c++-common/patch-conflict-markers-4.c: Likewise.
* c-c++-common/patch-conflict-markers-5.c: Likewise.
* c-c++-common/patch-conflict-markers-6.c: Likewise.
* c-c++-common/patch-conflict-markers-7.c: Likewise.
* c-c++-common/patch-conflict-markers-8.c: Likewise.
* c-c++-common/patch-conflict-markers-9.c: Likewise.
* c-c++-common/patch-conflict-markers-10.c: Likewise.
* c-c++-common/patch-conflict-markers-11.c: Likewise.
* g++.dg/patch-conflict-markers-1.C: Likewise.
---
gcc/c-family/c-common.h | 4 ++
gcc/c-family/c-lex.c | 26 ++++++++
gcc/c/c-parser.c | 72 +++++++++++++++++++++-
gcc/cp/parser.c | 53 ++++++++++++++++
.../c-c++-common/patch-conflict-markers-1.c | 9 +++
.../c-c++-common/patch-conflict-markers-10.c | 23 +++++++
.../c-c++-common/patch-conflict-markers-11.c | 14 +++++
.../c-c++-common/patch-conflict-markers-2.c | 2 +
.../c-c++-common/patch-conflict-markers-3.c | 11 ++++
.../c-c++-common/patch-conflict-markers-4.c | 11 ++++
.../c-c++-common/patch-conflict-markers-5.c | 11 ++++
.../c-c++-common/patch-conflict-markers-6.c | 38 ++++++++++++
.../c-c++-common/patch-conflict-markers-7.c | 6 ++
.../c-c++-common/patch-conflict-markers-8.c | 4 ++
.../c-c++-common/patch-conflict-markers-9.c | 8 +++
gcc/testsuite/g++.dg/patch-conflict-markers-1.C | 13 ++++
16 files changed, 303 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/c-c++-common/patch-conflict-markers-1.c
create mode 100644 gcc/testsuite/c-c++-common/patch-conflict-markers-10.c
create mode 100644 gcc/testsuite/c-c++-common/patch-conflict-markers-11.c
create mode 100644 gcc/testsuite/c-c++-common/patch-conflict-markers-2.c
create mode 100644 gcc/testsuite/c-c++-common/patch-conflict-markers-3.c
create mode 100644 gcc/testsuite/c-c++-common/patch-conflict-markers-4.c
create mode 100644 gcc/testsuite/c-c++-common/patch-conflict-markers-5.c
create mode 100644 gcc/testsuite/c-c++-common/patch-conflict-markers-6.c
create mode 100644 gcc/testsuite/c-c++-common/patch-conflict-markers-7.c
create mode 100644 gcc/testsuite/c-c++-common/patch-conflict-markers-8.c
create mode 100644 gcc/testsuite/c-c++-common/patch-conflict-markers-9.c
create mode 100644 gcc/testsuite/g++.dg/patch-conflict-markers-1.C
@@ -1089,6 +1089,10 @@ extern void c_genericize (tree);
extern int c_gimplify_expr (tree *, gimple_seq *, gimple_seq *);
extern tree c_build_bind_expr (location_t, tree, tree);
+/* In c-lex.c. */
+extern enum cpp_ttype
+conflict_marker_get_final_tok_kind (enum cpp_ttype tok1_kind);
+
/* In c-pch.c */
extern void pch_init (void);
extern void pch_cpp_save_state (void);
@@ -1263,3 +1263,29 @@ lex_charconst (const cpp_token *token)
return value;
}
+
+/* Helper function for c_parser_peek_conflict_marker
+ and cp_lexer_peek_conflict_marker.
+ Given a possible patch conflict marker token of kind TOK1_KIND
+ consisting of a pair of characters, get the token kind for the
+ standalone final character. */
+
+enum cpp_ttype
+conflict_marker_get_final_tok_kind (enum cpp_ttype tok1_kind)
+{
+ switch (tok1_kind)
+ {
+ default: gcc_unreachable ();
+ case CPP_LSHIFT:
+ /* "<<" and '<' */
+ return CPP_LESS;
+
+ case CPP_EQ_EQ:
+ /* "==" and '=' */
+ return CPP_EQ;
+
+ case CPP_RSHIFT:
+ /* ">>" and '>' */
+ return CPP_GREATER;
+ }
+}
@@ -202,8 +202,8 @@ struct GTY(()) c_parser {
/* The look-ahead tokens. */
c_token * GTY((skip)) tokens;
/* Buffer for look-ahead tokens. */
- c_token tokens_buf[2];
- /* How many look-ahead tokens are available (0, 1 or 2, or
+ c_token tokens_buf[4];
+ /* How many look-ahead tokens are available (0 - 4, or
more if parsing from pre-lexed tokens). */
unsigned int tokens_avail;
/* True if a syntax error is being recovered from; false otherwise.
@@ -492,6 +492,20 @@ c_parser_peek_2nd_token (c_parser *parser)
return &parser->tokens[1];
}
+/* Return a pointer to the Nth token from PARSER, reading it
+ in if necessary. The N-1th token is already read in. */
+
+static c_token *
+c_parser_peek_nth_token (c_parser *parser, unsigned int n)
+{
+ if (parser->tokens_avail >= n)
+ return &parser->tokens[n - 1];
+ gcc_assert (parser->tokens_avail == n - 1);
+ c_lex_one_token (parser, &parser->tokens[n - 1]);
+ parser->tokens_avail = n;
+ return &parser->tokens[n - 1];
+}
+
/* Return true if TOKEN can start a type name,
false otherwise. */
static bool
@@ -829,6 +843,46 @@ c_parser_set_source_position_from_token (c_token *token)
}
}
+/* Helper function for c_parser_error.
+ Having peeked a token of kind TOK1_KIND that might signify
+ a patch conflict marker, peek successor tokens to determine
+ if we actually do have a patch conflict marker.
+ Specifically, we consider a run of 7 '<', '=' or '>' characters
+ at the start of a line as a patch conflict marker.
+ These come through the lexer as three pairs and a single,
+ e.g. three CPP_LSHIFT ("<<") and a CPP_LESS ('<').
+ If it returns true, *OUT_LOC is written to with the location/range
+ of the marker. */
+
+static bool
+c_parser_peek_conflict_marker (c_parser *parser, enum cpp_ttype tok1_kind,
+ location_t *out_loc)
+{
+ c_token *token2 = c_parser_peek_2nd_token (parser);
+ if (token2->type != tok1_kind)
+ return false;
+ c_token *token3 = c_parser_peek_nth_token (parser, 3);
+ if (token3->type != tok1_kind)
+ return false;
+ c_token *token4 = c_parser_peek_nth_token (parser, 4);
+ if (token4->type != conflict_marker_get_final_tok_kind (tok1_kind))
+ return false;
+
+ /* It must be at the start of the line. */
+ location_t start_loc = c_parser_peek_token (parser)->location;
+ if (LOCATION_COLUMN (start_loc) != 1)
+ return false;
+
+ /* We have a conflict marker. Construct a location of the form:
+ <<<<<<<
+ ^~~~~~~
+ with start == caret, finishing at the end of the marker. */
+ location_t finish_loc = get_finish (token4->location);
+ *out_loc = make_location (start_loc, start_loc, finish_loc);
+
+ return true;
+}
+
/* Issue a diagnostic of the form
FILE:LINE: MESSAGE before TOKEN
where TOKEN is the next token in the input stream of PARSER.
@@ -850,6 +904,20 @@ c_parser_error (c_parser *parser, const char *gmsgid)
parser->error = true;
if (!gmsgid)
return;
+
+ /* If this is actually a patch conflict marker, report it as such. */
+ if (token->type == CPP_LSHIFT
+ || token->type == CPP_RSHIFT
+ || token->type == CPP_EQ_EQ)
+ {
+ location_t loc;
+ if (c_parser_peek_conflict_marker (parser, token->type, &loc))
+ {
+ error_at (loc, "source file contains patch conflict marker");
+ return;
+ }
+ }
+
/* This diagnostic makes more sense if it is tagged to the line of
the token we just peeked at. */
c_parser_set_source_position_from_token (token);
@@ -2689,6 +2689,46 @@ cp_parser_is_keyword (cp_token* token, enum rid keyword)
return token->keyword == keyword;
}
+/* Helper function for cp_parser_error.
+ Having peeked a token of kind TOK1_KIND that might signify
+ a patch conflict marker, peek successor tokens to determine
+ if we actually do have a patch conflict marker.
+ Specifically, we consider a run of 7 '<', '=' or '>' characters
+ at the start of a line as a patch conflict marker.
+ These come through the lexer as three pairs and a single,
+ e.g. three CPP_LSHIFT tokens ("<<") and a CPP_LESS token ('<').
+ If it returns true, *OUT_LOC is written to with the location/range
+ of the marker. */
+
+static bool
+cp_lexer_peek_conflict_marker (cp_lexer *lexer, enum cpp_ttype tok1_kind,
+ location_t *out_loc)
+{
+ cp_token *token2 = cp_lexer_peek_nth_token (lexer, 2);
+ if (token2->type != tok1_kind)
+ return false;
+ cp_token *token3 = cp_lexer_peek_nth_token (lexer, 3);
+ if (token3->type != tok1_kind)
+ return false;
+ cp_token *token4 = cp_lexer_peek_nth_token (lexer, 4);
+ if (token4->type != conflict_marker_get_final_tok_kind (tok1_kind))
+ return false;
+
+ /* It must be at the start of the line. */
+ location_t start_loc = cp_lexer_peek_token (lexer)->location;
+ if (LOCATION_COLUMN (start_loc) != 1)
+ return false;
+
+ /* We have a conflict marker. Construct a location of the form:
+ <<<<<<<
+ ^~~~~~~
+ with start == caret, finishing at the end of the marker. */
+ location_t finish_loc = get_finish (token4->location);
+ *out_loc = make_location (start_loc, start_loc, finish_loc);
+
+ return true;
+}
+
/* If not parsing tentatively, issue a diagnostic of the form
FILE:LINE: MESSAGE before TOKEN
where TOKEN is the next token in the input stream. MESSAGE
@@ -2713,6 +2753,19 @@ cp_parser_error (cp_parser* parser, const char* gmsgid)
return;
}
+ /* If this is actually a patch conflict marker, report it as such. */
+ if (token->type == CPP_LSHIFT
+ || token->type == CPP_RSHIFT
+ || token->type == CPP_EQ_EQ)
+ {
+ location_t loc;
+ if (cp_lexer_peek_conflict_marker (parser->lexer, token->type, &loc))
+ {
+ error_at (loc, "source file contains patch conflict marker");
+ return;
+ }
+ }
+
c_parse_error (gmsgid,
/* Because c_parser_error does not understand
CPP_KEYWORD, keywords are treated like
new file mode 100644
@@ -0,0 +1,9 @@
+int p;
+
+<<<<<<< HEAD /* { dg-error "patch conflict marker" } */
+extern int some_var;
+======= /* { dg-error "patch conflict marker" } */
+extern short some_var; /* this line would lead to a warning */
+>>>>>>> Some commit message /* { dg-error "patch conflict marker" } */
+
+int q;
new file mode 100644
@@ -0,0 +1,23 @@
+/* { dg-options "-fdiagnostics-show-caret" } */
+
+<<<<<<< HEAD /* { dg-error "patch conflict marker" } */
+/* { dg-begin-multiline-output "" }
+ <<<<<<< HEAD
+ ^~~~~~~
+ { dg-end-multiline-output "" } */
+
+extern int some_var;
+
+======= /* { dg-error "patch conflict marker" } */
+/* { dg-begin-multiline-output "" }
+ =======
+ ^~~~~~~
+ { dg-end-multiline-output "" } */
+
+extern short some_var; /* this line would lead to a warning */
+
+>>>>>>> Some commit message /* { dg-error "patch conflict marker" } */
+/* { dg-begin-multiline-output "" }
+ >>>>>>>
+ ^~~~~~~
+ { dg-end-multiline-output "" } */
new file mode 100644
@@ -0,0 +1,14 @@
+/* Verify that we only report conflict markers at the start of lines. */
+int p;
+
+ <<<<<<< HEAD /* { dg-error "expected identifier|expected unqualified-id" } */
+
+int q;
+
+ ======= /* { dg-error "expected identifier|expected unqualified-id" } */
+
+int r;
+
+ >>>>>>> Some commit message /* { dg-error "expected identifier|expected unqualified-id" } */
+
+int s;
new file mode 100644
@@ -0,0 +1,2 @@
+/* This should not be flagged as a patch conflict marker. */
+const char *msg = "<<<<<<< ";
new file mode 100644
@@ -0,0 +1,11 @@
+/* Ensure we can handle unterminated conflict markers. */
+
+int p;
+
+<<<<<<< HEAD /* { dg-error "patch conflict marker" } */
+
+int q;
+
+<<<<<<< HEAD /* { dg-error "patch conflict marker" } */
+
+int r;
new file mode 100644
@@ -0,0 +1,11 @@
+/* Ensure we can handle mismatched conflict markers. */
+
+int p;
+
+>>>>>>> Some commit message /* { dg-error "patch conflict marker" } */
+
+int q;
+
+>>>>>>> Some other commit message /* { dg-error "patch conflict marker" } */
+
+int r;
new file mode 100644
@@ -0,0 +1,11 @@
+/* Ensure we can handle mismatched conflict markers. */
+
+int p;
+
+======= /* { dg-error "patch conflict marker" } */
+
+int q;
+
+======= /* { dg-error "patch conflict marker" } */
+
+int r;
new file mode 100644
@@ -0,0 +1,38 @@
+/* Branch coverage of patch conflict marker detection:
+ none of these should be reported as patch conflict markers. */
+
+int a0;
+
+<< HEAD /* { dg-error "expected" } */
+
+int a1;
+
+<<<< HEAD /* { dg-error "expected" } */
+
+int a2;
+
+<<<<<< HEAD /* { dg-error "expected" } */
+
+int b0;
+
+== HEAD /* { dg-error "expected" } */
+
+int b1;
+
+==== HEAD /* { dg-error "expected" } */
+
+int b2;
+
+====== HEAD /* { dg-error "expected" } */
+
+int c0;
+
+>> HEAD /* { dg-error "expected" } */
+
+int c1;
+
+>>>> HEAD /* { dg-error "expected" } */
+
+int c2;
+
+>>>>>> HEAD /* { dg-error "expected" } */
new file mode 100644
@@ -0,0 +1,6 @@
+/* It's valid to stringize the "<<<<<<<"; don't
+ report it as a patch conflict marker. */
+#define str(s) #s
+const char *s = str(
+<<<<<<<
+);
new file mode 100644
@@ -0,0 +1,4 @@
+/* A macro that's never expanded shouldn't be reported as a patch
+ conflict marker. */
+#define foo \
+<<<<<<<
new file mode 100644
@@ -0,0 +1,8 @@
+/* It's valid to have
+<<<<<<<
+ inside both
+ comments (as above), and within string literals. */
+const char *s = "\
+<<<<<<<";
+
+/* The above shouldn't be reported as errors. */
new file mode 100644
@@ -0,0 +1,13 @@
+/* Ensure that we don't complain about patch conflict markers on
+ valid template argument lists, valid in C++11 onwards. */
+// { dg-options "-std=c++11" }
+
+template <typename T>
+struct foo
+{
+ T t;
+};
+
+foo <foo <foo <foo <foo <foo <foo <int
+>>>>>>> f;
+// The above line is valid C++11, and isn't a patch conflict marker