| Message ID | 1524787750-31142-1-git-send-email-dmalcolm@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | v2: Don't offer suggestions for compiler-generated variables (PR c++/85515) | expand |
On Thu, Apr 26, 2018 at 8:09 PM, David Malcolm <dmalcolm@redhat.com> wrote: > On Thu, 2018-04-26 at 15:53 -0400, Jason Merrill wrote: >> On Thu, Apr 26, 2018 at 3:45 AM, Richard Biener >> <richard.guenther@gmail.com> wrote: >> > On Wed, Apr 25, 2018 at 7:10 PM, Nathan Sidwell <nathan@acm.org> >> > wrote: >> > > On 04/25/2018 11:41 AM, David Malcolm wrote: >> > > > >> > > > Jason Turner's video C++ Weekly - Ep 112 - GCC's Leaky >> > > > Abstractions shows >> > > > two issues where g++ offers suggestions about implementation >> > > > details: >> > > >> > > >> > > > For the lambda capture case, there are multiple members: >> > > > >> > > > $9 = <function_decl 0x7ffff1a1dd00 __ct > >> > > >> > > >> > > These names have a space at the end, so the user cannot name >> > > them. We could >> > > move the space to the beginning, if that helps? >> > >> > I think compiler-generated entities that are not supposed to be >> > user-visible should be DECL_ARTIFICIAL. >> >> Agreed, add_capture should set that flag on the FIELD_DECLs. > > I had tried flagging the lambda-captured vars as DECL_ARTIFICIAL, > but it lead to a "too many initializers" error from reshape_init, > so (before I saw your email), I tried the following approach: rather > than looking at underscores, it uses is_lambda_ignored_entity (similar > to qualify_lookup without LOOKUP_HIDDEN). > > Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu. > > Do you want me to do the DECL_ARTIFICAL approach, or is this OK? This is OK.
diff --git a/gcc/cp/name-lookup.c b/gcc/cp/name-lookup.c index d2e5acb..a51cf1b 100644 --- a/gcc/cp/name-lookup.c +++ b/gcc/cp/name-lookup.c @@ -5860,6 +5860,12 @@ consider_binding_level (tree name, best_match <tree, const char *> &bm, && DECL_ANTICIPATED (d)) continue; + /* Skip compiler-generated variables (e.g. __for_begin/__for_end + within range for). */ + if (TREE_CODE (d) == VAR_DECL + && DECL_ARTIFICIAL (d)) + continue; + tree suggestion = DECL_NAME (d); if (!suggestion) continue; diff --git a/gcc/cp/search.c b/gcc/cp/search.c index bfeaf2c..22c0492 100644 --- a/gcc/cp/search.c +++ b/gcc/cp/search.c @@ -1224,9 +1224,16 @@ lookup_field_fuzzy_info::fuzzy_lookup_field (tree type) for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) { - if (!m_want_type_p || DECL_DECLARES_TYPE_P (field)) - if (DECL_NAME (field)) - m_candidates.safe_push (DECL_NAME (field)); + if (m_want_type_p && !DECL_DECLARES_TYPE_P (field)) + continue; + + if (!DECL_NAME (field)) + continue; + + if (is_lambda_ignored_entity (field)) + continue; + + m_candidates.safe_push (DECL_NAME (field)); } } diff --git a/gcc/testsuite/g++.dg/pr85515-1.C b/gcc/testsuite/g++.dg/pr85515-1.C new file mode 100644 index 0000000..96f767d --- /dev/null +++ b/gcc/testsuite/g++.dg/pr85515-1.C @@ -0,0 +1,18 @@ +// { dg-require-effective-target c++14 } + +void test_1 () +{ + auto lambda = [val = 2](){}; + lambda.val; // { dg-bogus "did you mean" } + // { dg-error "has no member named 'val'" "" { target *-*-* } .-1 } +} + +int test_2 () +{ + auto lambda = [val = 2](){ return val; }; + + // TODO: should we issue an error for the following assignment? + lambda.__val = 4; + + return lambda(); +} diff --git a/gcc/testsuite/g++.dg/pr85515-2.C b/gcc/testsuite/g++.dg/pr85515-2.C new file mode 100644 index 0000000..621ddb8 --- /dev/null +++ b/gcc/testsuite/g++.dg/pr85515-2.C @@ -0,0 +1,22 @@ +// { dg-require-effective-target c++11 } + +void test_1 () +{ + int arr[] = {1, 2, 3, 4, 5}; + for (const auto v: arr) { + _forbegin; // { dg-bogus "suggested alternative" } + // { dg-error "'_forbegin' was not declared in this scope" "" { target *-*-*} .-1 } + } +} + +int test_2 () +{ + int arr[] = {1, 2, 3, 4, 5}; + int sum = 0; + for (const auto v: arr) { + sum += v; + // TODO: should we issue an error for the following assignment? + __for_begin = __for_end; + } + return sum; +}