https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97820
Bug ID: 97820
Summary: VLAs in function declarations fail to compile
Product: gcc
Version: 10.2.0
Status: UNCONFIRMED
Keywords: rejects-valid
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: josephcsible at gmail dot com
Target Milestone: ---
Consider these 4 attempts at declaring a function:
void f1(int rows, int cols, int arr[rows][cols]);
void f2(int rows, int cols, int (*arr)[cols]);
void f3(int, int, int [*][*]);
void f4(int, int, int (*)[*]);
When I compile them with g++, they all have errors:
<source>:1:41: error: use of parameter outside function body before ']' token
1 | void f1(int rows, int cols, int arr[rows][cols]);
| ^
<source>:1:47: error: use of parameter outside function body before ']' token
1 | void f1(int rows, int cols, int arr[rows][cols]);
| ^
<source>:2:44: error: use of parameter outside function body before ']' token
2 | void f2(int rows, int cols, int (*arr)[cols]);
| ^
<source>:3:25: error: expected primary-expression before ']' token
3 | void f3(int, int, int [*][*]);
| ^
<source>:3:28: error: expected primary-expression before ']' token
3 | void f3(int, int, int [*][*]);
| ^
<source>:4:28: error: expected primary-expression before ']' token
4 | void f4(int, int, int (*)[*]);
| ^
Since we support VLAs in C++ as an extension, I expected that all of these
would work.
https://godbolt.org/z/Wca9ra
