This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
[PATCH] C++: avoid most reserved words as misspelling suggestions (PR c++/81610 and PR c++/80567)
- From: David Malcolm <dmalcolm at redhat dot com>
- To: gcc-patches at gcc dot gnu dot org
- Cc: David Malcolm <dmalcolm at redhat dot com>
- Date: Wed, 22 Nov 2017 10:36:47 -0500
- Subject: [PATCH] C++: avoid most reserved words as misspelling suggestions (PR c++/81610 and PR c++/80567)
- Authentication-results: sourceware.org; auth=none
lookup_name_fuzzy can offer some reserved words as suggestions for
misspelled words, helping with "singed"/"signed" typos.
PR c++/81610 and PR c++/80567 report problems where the C++ frontend
suggested "if", "for" and "else" as corrections for misspelled variable
names.
The root cause is that in r247233
("Fix spelling suggestions for reserved words (PR c++/80177)")
I loosened the conditions on these reserved words, adding this condition:
if (kind == FUZZY_LOOKUP_TYPENAME)
to the logic for rejecting words that don't start decl-specifiers, to
allow for "static_assert" to be offered.
This is too loose a condition: we don't want to suggest *any* reserved word
when we're in a context where we don't know we expect a typename.
For the kinds of error-recover situations where we're suggesting
spelling corrections we don't have much contextual information, so it
seems prudent to be stricter about which reserved words we offer
as spelling suggestions; I don't think it makes sense for us to
suggest e.g. "for".
This patch implements that by effectively reinstating the old logic,
but special-casing RID_STATIC_ASSERT, moving the logic to a new
subroutine (in case we want to allow for other special-cases).
I attempted to add suggestions for the various RID_*CAST, to cope
with e.g. "reinterptet_cast" (I can never type that correctly on the
first try), but the following '<' token confuses the error-recovery
enough that the suggestion code isn't triggered.
Hence this more minimal fix.
Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu.
OK for trunk?
gcc/cp/ChangeLog:
PR c++/81610
PR c++/80567
* name-lookup.c (suggest_rid_p): New function.
(lookup_name_fuzzy): Replace enum-rid-filtering logic with call to
suggest_rid_p.
gcc/testsuite/ChangeLog:
PR c++/81610
PR c++/80567
* g++.dg/spellcheck-reswords.C: New test case.
* g++.dg/spellcheck-stdlib.C: Remove xfail from dg-bogus
suggestion of "if".
---
gcc/cp/name-lookup.c | 31 +++++++++++++++++++++++++++---
gcc/testsuite/g++.dg/spellcheck-reswords.C | 11 +++++++++++
gcc/testsuite/g++.dg/spellcheck-stdlib.C | 2 +-
3 files changed, 40 insertions(+), 4 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/spellcheck-reswords.C
diff --git a/gcc/cp/name-lookup.c b/gcc/cp/name-lookup.c
index 7c363b0..a96be46 100644
--- a/gcc/cp/name-lookup.c
+++ b/gcc/cp/name-lookup.c
@@ -5671,6 +5671,32 @@ class macro_use_before_def : public deferred_diagnostic
cpp_hashnode *m_macro;
};
+/* Determine if it can ever make sense to offer RID as a suggestion for
+ a misspelling.
+
+ Subroutine of lookup_name_fuzzy. */
+
+static bool
+suggest_rid_p (enum rid rid)
+{
+ switch (rid)
+ {
+ /* Support suggesting function-like keywords. */
+ case RID_STATIC_ASSERT:
+ return true;
+
+ default:
+ /* Support suggesting the various decl-specifier words, to handle
+ e.g. "singed" vs "signed" typos. */
+ if (cp_keyword_starts_decl_specifier_p (rid))
+ return true;
+
+ /* Otherwise, don't offer it. This avoids suggesting e.g. "if"
+ and "do" for short misspellings, which are likely to lead to
+ nonsensical results. */
+ return false;
+ }
+}
/* Search for near-matches for NAME within the current bindings, and within
macro names, returning the best match as a const char *, or NULL if
@@ -5735,9 +5761,8 @@ lookup_name_fuzzy (tree name, enum lookup_name_fuzzy_kind kind, location_t loc)
{
const c_common_resword *resword = &c_common_reswords[i];
- if (kind == FUZZY_LOOKUP_TYPENAME)
- if (!cp_keyword_starts_decl_specifier_p (resword->rid))
- continue;
+ if (!suggest_rid_p (resword->rid))
+ continue;
tree resword_identifier = ridpointers [resword->rid];
if (!resword_identifier)
diff --git a/gcc/testsuite/g++.dg/spellcheck-reswords.C b/gcc/testsuite/g++.dg/spellcheck-reswords.C
new file mode 100644
index 0000000..db6104b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/spellcheck-reswords.C
@@ -0,0 +1,11 @@
+void pr81610 (void *p)
+{
+ forget (p); // { dg-error "not declared" }
+ // { dg-bogus "'for'" "" { target *-*-*} .-1 }
+}
+
+void pr80567 (void *p)
+{
+ memset (p, 0, 4); // { dg-error "not declared" }
+ // { dg-bogus "'else'" "" { target *-*-*} .-1 }
+}
diff --git a/gcc/testsuite/g++.dg/spellcheck-stdlib.C b/gcc/testsuite/g++.dg/spellcheck-stdlib.C
index 6e6ab1d..c7a6626 100644
--- a/gcc/testsuite/g++.dg/spellcheck-stdlib.C
+++ b/gcc/testsuite/g++.dg/spellcheck-stdlib.C
@@ -16,7 +16,7 @@ void test_cstdio (void)
FILE *f; // { dg-error "'FILE' was not declared in this scope" }
// { dg-message "'FILE' is defined in header '<cstdio>'; did you forget to '#include <cstdio>'?" "" { target *-*-* } .-1 }
// { dg-error "'f' was not declared in this scope" "" { target *-*-* } .-2 }
- // { dg-bogus "suggested alternative: 'if'" "PR c++/80567" { xfail *-*-* } .-3 }
+ // { dg-bogus "suggested alternative: 'if'" "PR c++/80567" { target *-*-* } .-3 }
char buf[BUFSIZ]; // { dg-error "'BUFSIZ' was not declared" }
// { dg-message "'BUFSIZ' is defined in header '<cstdio>'; did you forget to '#include <cstdio>'?" "" { target *-*-* } .-1 }
--
1.8.5.3