| Message ID | 1457899426-7619-1-git-send-email-patrick@parcs.ath.cx |
|---|---|
| State | New |
| Headers | show |
On 13.03.2016 21:03, Patrick Palka wrote: > Here we are mishandling the deferred_access_stack by not coherently > pushing/popping from it. In cp_parser_lambda_expression we are calling > (in order): > > push_deferring_access_checks (dk_no_deferred); > cp_parser_start_tentative_firewall (parser); > ... > pop_deferring_access_checks (); > cp_parser_end_tentative_firewall (parser, start, lambda_expr); > > But the order of the last two popping calls does not correspond with the order > of the first two pushing calls. pop_deferring_access_checks should be > called last. This error may cause us to drop deferred access checks > instead of performing them. > > Bootstrap + regtest in progress, does this look OK to commit if testing > succeeds? when applying this patch to the gcc-5-branch I see regressions like /scratch/packages/gcc/5/gcc-5-5.3.1/src/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-70218.C: In function 'void foo()': /scratch/packages/gcc/5/gcc-5-5.3.1/src/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-70218.C:6:8: error: 'int X::i' is private /scratch/packages/gcc/5/gcc-5-5.3.1/src/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-70218.C:16:18: error: within this context Excess errors: /scratch/packages/gcc/5/gcc-5-5.3.1/src/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-70218.C:6:8: error: 'int X::i' is private /scratch/packages/gcc/5/gcc-5-5.3.1/src/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-70218.C:16:18: error: within this context haven't yet checked the trunk. I don't see any other regressions besides the usual noise in the ubsan tests. Matthias
OK. Jason
On Wed, Mar 16, 2016 at 5:20 PM, Matthias Klose <doko@ubuntu.com> wrote: > On 13.03.2016 21:03, Patrick Palka wrote: >> >> Here we are mishandling the deferred_access_stack by not coherently >> pushing/popping from it. In cp_parser_lambda_expression we are calling >> (in order): >> >> push_deferring_access_checks (dk_no_deferred); >> cp_parser_start_tentative_firewall (parser); >> ... >> pop_deferring_access_checks (); >> cp_parser_end_tentative_firewall (parser, start, lambda_expr); >> >> But the order of the last two popping calls does not correspond with the >> order >> of the first two pushing calls. pop_deferring_access_checks should be >> called last. This error may cause us to drop deferred access checks >> instead of performing them. >> >> Bootstrap + regtest in progress, does this look OK to commit if testing >> succeeds? > > > when applying this patch to the gcc-5-branch I see regressions like > > /scratch/packages/gcc/5/gcc-5-5.3.1/src/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-70218.C: > In function 'void foo()': > /scratch/packages/gcc/5/gcc-5-5.3.1/src/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-70218.C:6:8: > error: 'int X::i' is private > /scratch/packages/gcc/5/gcc-5-5.3.1/src/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-70218.C:16:18: > error: within this context > > Excess errors: > /scratch/packages/gcc/5/gcc-5-5.3.1/src/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-70218.C:6:8: > error: 'int X::i' is private > /scratch/packages/gcc/5/gcc-5-5.3.1/src/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-70218.C:16:18: > error: within this context > > > haven't yet checked the trunk. I don't see any other regressions besides the > usual noise in the ubsan tests. lambda-70218.C is the test case that this patch adds. It looks like GCC 5 and 6 report errors access errors that originate inside a lambda slightly differently. So I think the dg-error directives in lambda-70218.C would just have to be trivially adjusted for a GCC 5 backport.
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c index 6ae45b0..33f09b8 100644 --- a/gcc/cp/parser.c +++ b/gcc/cp/parser.c @@ -9781,8 +9781,6 @@ cp_parser_lambda_expression (cp_parser* parser) = auto_is_implicit_function_template_parm_p; } - pop_deferring_access_checks (); - /* This field is only used during parsing of the lambda. */ LAMBDA_EXPR_THIS_CAPTURE (lambda_expr) = NULL_TREE; @@ -9798,6 +9796,8 @@ cp_parser_lambda_expression (cp_parser* parser) cp_parser_end_tentative_firewall (parser, start, lambda_expr); + pop_deferring_access_checks (); + return lambda_expr; } diff --git a/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-70218.C b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-70218.C new file mode 100644 index 0000000..ae8cc2f --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-70218.C @@ -0,0 +1,17 @@ +// PR c++/70218 +// { dg-do compile { target c++11 } } + +struct X { +private: + int i; +}; + +struct Y { + Y (int) { } +}; + +void +foo () +{ + Y ([] { X x; x.i = 3; return 0; } ()); // { dg-error "private" } +}