https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95742
Bug ID: 95742
Summary: Bad error message in parsing a function with
"decltype()"
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Keywords: diagnostic
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: haoxintu at gmail dot com
CC: redi at gcc dot gnu.org
Target Milestone: ---
This code test.cc, I think it's not a garbage input for GCC, but it parses
badly and emits some confusing error messages.
$cat test.cc
int foo( decltype(),int) { }
$g++-trunk -c -w test.cc
test.cc:1:19: error: expected primary-expression before ‘)’ token
1 | int foo( decltype(),int) { }
| ^
test.cc:1:10: error: expected primary-expression before ‘decltype’
1 | int foo( decltype(),int) { }
| ^~~~~~~~~~
test.cc:1:21: error: expected primary-expression before ‘int’
1 | int foo( decltype(),int) { }
| ^~~
test.cc:1:24: error: expression list treated as compound expression in
initializer [-fpermissive]
1 | int foo( decltype(),int) { }
| ^
While in Clang
$clang++ -c -w test.cc
test.cc:1:19: error: expected expression
int foo( decltype(),int) { }
^
1 error generated.
When I change the code into test1.cc, GCC get following results:
$cat test1.cc
void foo( decltype(),int) { }
$g++-trunk -c -w test1.cc
test1.cc:1:6: error: variable or field ‘foo’ declared void
1 | void foo( decltype(),int) { }
| ^~~
test1.cc:1:20: error: expected primary-expression before ‘)’ token
1 | void foo( decltype(),int) { }
| ^
test1.cc:1:11: error: expected primary-expression before ‘decltype’
1 | void foo( decltype(),int) { }
| ^~~~~~~~~~
test1.cc:1:22: error: expected primary-expression before ‘int’
1 | void foo( decltype(),int) { }
This time GCC emits "error: variable or field ‘foo’ declared void"?
Also in Clang
$clang++ -c -w test1.cc
test1.cc:1:20: error: expected expression
void foo( decltype(),int) { }
^
1 error generated.
I guess GCC might can not recognize the function definition correctly?
