PING: https://gcc.gnu.org/ml/gcc-patches/2014-08/msg01709.html
On 18 August 2014 00:03, Manuel López-Ibáñez <lopeziba...@gmail.com> wrote: > Following a suggestion in PR16564, this patch makes excessive template > instantiation depth a fatal error. In fact, this allows simplifying > the code a lot, just by printing first the context (like we do for > every other diagnostic) instead of printing it after (which is not > possible for a fatal error). > > This changes the output of quite a few testcases, so before modifying > those I would like to know whether the idea is OK. > > Examples of changed output are: > > [Before] > g++.dg/cpp0x/decltype26.C:6:15: error: template instantiation depth > exceeds maximum of 900 (use -ftemplate-depth= to increase the maximum) > substituting 'template<class T> decltype (f(T())) f(T) [with T = > <missing>]' > g++.dg/cpp0x/decltype26.C:6:15: recursively required by substitution > of 'template<class T> decltype (f(T())) f(T) [with T = A]' > g++.dg/cpp0x/decltype26.C:6:15: required by substitution of > 'template<class T> decltype (f(T())) f(T) [with T = A]' > g++.dg/cpp0x/decltype26.C:13:8: required from here > > g++.dg/cpp0x/decltype26.C: In function 'int main()': > g++.dg/cpp0x/decltype26.C:13:8: error: no matching function for call to 'f(A)' > g++.dg/cpp0x/decltype26.C:6:18: note: candidate: template<class T> > decltype (f(T())) f(T) > g++.dg/cpp0x/decltype26.C:6:18: note: substitution of deduced > template arguments resulted in errors seen above > > [After] > > g++.dg/cpp0x/decltype26.C: In substitution of 'template<class T> > decltype (f(T())) f(T) [with T = A]': > g++.dg/cpp0x/decltype26.C:6:15: recursively required by substitution > of 'template<class T> decltype (f(T())) f(T) [with T = A]' > g++.dg/cpp0x/decltype26.C:6:15: required by substitution of > 'template<class T> decltype (f(T())) f(T) [with T = A]' > g++.dg/cpp0x/decltype26.C:13:8: required from here > g++.dg/cpp0x/decltype26.C:6:15: fatal error: template instantiation > depth exceeds maximum of 900 (use -ftemplate-depth= to increase the > maximum) > > > One interesting case is for operator->(). Here we have to adjust > the location of the template instantiations so we can point the > user to the point of recursion: > > [Before] > > g++.dg/template/arrow1.C:12:11: error: template instantiation depth > exceeds maximum of 900 (use -ftemplate-depth= to increase the maximum) > instantiating 'a<(n + 1)> a<n>::operator->() [with int n = 900]' > g++.dg/template/arrow1.C:12:11: recursively required from 'a<(n + > 1)> a<n>::operator->() [with int n = 0]' > g++.dg/template/arrow1.C:12:11: required from here > > g++.dg/template/arrow1.C:12:11: error: template instantiation depth > exceeds maximum of 900 (use -ftemplate-depth= to increase the maximum) > instantiating 'struct a<901>' > g++.dg/template/arrow1.C:12:11: recursively required from 'a<(n + > 1)> a<n>::operator->() [with int n = 0]' > g++.dg/template/arrow1.C:12:11: required from here > > g++.dg/template/arrow1.C:12:11: error: invalid use of incomplete type > 'struct a<901>' > g++.dg/template/arrow1.C:5:8: note: declaration of 'struct a<901>' > > [After] > > g++.dg/template/arrow1.C: In instantiation of 'a<(n + 1)> > a<n>::operator->() [with int n = 899]': > g++.dg/template/arrow1.C:7:2: recursively required from 'a<(n + 1)> > a<n>::operator->() [with int n = 1]' > g++.dg/template/arrow1.C:7:2: required from 'a<(n + 1)> > a<n>::operator->() [with int n = 0]' > g++.dg/template/arrow1.C:12:11: required from here > g++.dg/template/arrow1.C:12:11: fatal error: template instantiation > depth exceeds maximum of 900 (use -ftemplate-depth= to increase the > maximum) > > The rest of testcases follow the pattern: > > [Before] > > g++.dg/template/pr23510.C:9:1: error: expected ';' after struct definition > g++.dg/template/pr23510.C:6:27: error: template instantiation depth > exceeds maximum of 15 (use -ftemplate-depth= to increase the maximum) > instantiating 'struct Factorial<5u>' > g++.dg/template/pr23510.C:6:27: recursively required from 'struct > Factorial<19u>' > g++.dg/template/pr23510.C:6:27: required from 'struct Factorial<20u>' > g++.dg/template/pr23510.C:21:20: required from here > > [After] > > g++.dg/template/pr23510.C:9:1: error: expected ';' after struct definition > g++.dg/template/pr23510.C: In instantiation of 'struct Factorial<6u>': > g++.dg/template/pr23510.C:6:27: recursively required from 'struct > Factorial<19u>' > g++.dg/template/pr23510.C:6:27: required from 'struct Factorial<20u>' > g++.dg/template/pr23510.C:21:20: required from here > g++.dg/template/pr23510.C:6:27: fatal error: template instantiation > depth exceeds maximum of 15 (use -ftemplate-depth= to increase the > maximum) > > Apart from these changes, the patch bootstraps and passes the > regression suite on x86_64-linux. > > OK with the updated testcases? > > gcc/cp/ChangeLog: > > 2014-08-17 Manuel López-Ibáñez <m...@gcc.gnu.org> > > * error.c (print_instantiation_context): Delete. > * typeck2.c (build_x_arrow): Record location when pushing > template instantiation. > * pt.c (push_tinst_level): Make it a wrapper around ... > (push_tinst_level_loc): ... this. New function. Make excessive > template instantiation depth a fatal error. Record location. Use > bool as return type. > (instantiate_pending_templates): Make excessive > template instantiation depth a fatal error. > (problematic_instantiation_changed): Use bool as return type. > * cp-tree.h (print_instantiation_context): Delete. > (push_tinst_level): Update declaration. > (problematic_instantiation_changed): Likewise. > (push_tinst_level_loc): New. > > gcc/testsuite/ChangeLog: > > 2014-08-17 Manuel López-Ibáñez <m...@gcc.gnu.org> > > * lib/gcc.exp: Accept "fatal error:" as error prefix. > * lib/g++.exp: Likewise. > * lib/obj-c++.exp: Likewise. > * lib/objc.exp: Likewise. > * g++.dg/template/pr16564.C: New test.
