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hanchenye-llvm-project/clang/test/SemaTemplate/instantiation-depth.cpp

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Introduce a limit on the depth of the template instantiation backtrace we will print with each error that occurs during template instantiation. When the backtrace is longer than that, we will print N/2 of the innermost backtrace entries and N/2 of the outermost backtrace entries, then skip the middle entries with a note such as: note: suppressed 2 template instantiation contexts; use -ftemplate-backtrace-limit=N to change the number of template instantiation entries shown This should eliminate some excessively long backtraces that aren't providing any value. llvm-svn: 101882
2010-04-20 15:18:24 +08:00
// RUN: %clang_cc1 -fsyntax-only -verify -ftemplate-depth 5 -ftemplate-backtrace-limit 4 %s
Add driver arguments -ftemplate-depth=N and -fconstexpr-depth=N, with the same semantics and defaults as the corresponding g++ arguments. The historical g++ argument -ftemplate-depth-N is kept for compatibility, but modern g++ versions no longer document that option. Add -cc1 argument -fconstexpr-depth N to implement the corresponding functionality. The -ftemplate-depth=N part of this fixes PR9890. llvm-svn: 145045
2011-11-22 03:36:32 +08:00
// RUN: %clang -fsyntax-only -Xclang -verify -ftemplate-depth-5 -ftemplate-backtrace-limit=4 %s
// RUN: %clang -fsyntax-only -Xclang -verify -ftemplate-depth=5 -ftemplate-backtrace-limit=4 %s
Limit the template instantiation depth to some user-configurable value (default: 99). Beyond this limit, produce an error and consider the current template instantiation a failure. The stack we're building to track the instantiations will, eventually, be used to produce instantiation backtraces from diagnostics within template instantiation. However, we're not quite there yet. This adds a new Clang driver option -ftemplate-depth=NNN, which should eventually be generated from the GCC command-line operation -ftemplate-depth-NNN (note the '-' rather than the '='!). I did not make the driver changes to do this mapping. llvm-svn: 66513
2009-03-10 08:06:19 +08:00
Final piece of core issue 1330: delay computing the exception specification of a defaulted special member function until the exception specification is needed (using the same criteria used for the delayed instantiation of exception specifications for function temploids). EST_Delayed is now EST_Unevaluated (using 1330's terminology), and, like EST_Uninstantiated, carries a pointer to the FunctionDecl which will be used to resolve the exception specification. This is enabled for all C++ modes: it's a little faster in the case where the exception specification isn't used, allows our C++11-in-C++98 extensions to work, and is still correct for C++98, since in that mode the computation of the exception specification can't fail. The diagnostics here aren't great (in particular, we should include implicit evaluation of exception specifications for defaulted special members in the template instantiation backtraces), but they're not much worse than before. Our approach to the problem of cycles between in-class initializers and the exception specification for a defaulted default constructor is modified a little by this change -- we now reject any odr-use of a defaulted default constructor if that constructor uses an in-class initializer and the use is in an in-class initialzer which is declared lexically earlier. This is a closer approximation to the current draft solution in core issue 1351, but isn't an exact match (but the current draft wording isn't reasonable, so that's to be expected). llvm-svn: 160847
2012-07-27 12:22:15 +08:00
#ifndef NOEXCEPT
Introduce a limit on the depth of the template instantiation backtrace we will print with each error that occurs during template instantiation. When the backtrace is longer than that, we will print N/2 of the innermost backtrace entries and N/2 of the outermost backtrace entries, then skip the middle entries with a note such as: note: suppressed 2 template instantiation contexts; use -ftemplate-backtrace-limit=N to change the number of template instantiation entries shown This should eliminate some excessively long backtraces that aren't providing any value. llvm-svn: 101882
2010-04-20 15:18:24 +08:00
template<typename T> struct X : X<T*> { }; \
// expected-error{{recursive template instantiation exceeded maximum depth of 5}} \
// expected-note 3 {{instantiation of template class}} \
Reword the note we emit when suppressing template instantiation contexts, per John's advice llvm-svn: 101988
2010-04-21 13:40:43 +08:00
// expected-note {{skipping 2 contexts in backtrace}} \
Add driver arguments -ftemplate-depth=N and -fconstexpr-depth=N, with the same semantics and defaults as the corresponding g++ arguments. The historical g++ argument -ftemplate-depth-N is kept for compatibility, but modern g++ versions no longer document that option. Add -cc1 argument -fconstexpr-depth N to implement the corresponding functionality. The -ftemplate-depth=N part of this fixes PR9890. llvm-svn: 145045
2011-11-22 03:36:32 +08:00
// expected-note {{use -ftemplate-depth=N to increase recursive template instantiation depth}}
Limit the template instantiation depth to some user-configurable value (default: 99). Beyond this limit, produce an error and consider the current template instantiation a failure. The stack we're building to track the instantiations will, eventually, be used to produce instantiation backtraces from diagnostics within template instantiation. However, we're not quite there yet. This adds a new Clang driver option -ftemplate-depth=NNN, which should eventually be generated from the GCC command-line operation -ftemplate-depth-NNN (note the '-' rather than the '='!). I did not make the driver changes to do this mapping. llvm-svn: 66513
2009-03-10 08:06:19 +08:00
Final piece of core issue 1330: delay computing the exception specification of a defaulted special member function until the exception specification is needed (using the same criteria used for the delayed instantiation of exception specifications for function temploids). EST_Delayed is now EST_Unevaluated (using 1330's terminology), and, like EST_Uninstantiated, carries a pointer to the FunctionDecl which will be used to resolve the exception specification. This is enabled for all C++ modes: it's a little faster in the case where the exception specification isn't used, allows our C++11-in-C++98 extensions to work, and is still correct for C++98, since in that mode the computation of the exception specification can't fail. The diagnostics here aren't great (in particular, we should include implicit evaluation of exception specifications for defaulted special members in the template instantiation backtraces), but they're not much worse than before. Our approach to the problem of cycles between in-class initializers and the exception specification for a defaulted default constructor is modified a little by this change -- we now reject any odr-use of a defaulted default constructor if that constructor uses an in-class initializer and the use is in an in-class initialzer which is declared lexically earlier. This is a closer approximation to the current draft solution in core issue 1351, but isn't an exact match (but the current draft wording isn't reasonable, so that's to be expected). llvm-svn: 160847
2012-07-27 12:22:15 +08:00
void test() {
Add a notion of "post-diagnostic hooks", which are callbacks attached to a diagnostic that will be invoked after the diagnostic (if it is not suppressed). The hooks are allowed to produce additional diagnostics (typically notes) that provide more information. We should be able to use this to help diagnostic clients link notes back to the diagnostic they clarify. Comments welcome; I'll write up documentation and convert other clients (e.g., overload resolution failures) if there are no screams of protest. As the first client of post-diagnostic hooks, we now produce a template instantiation backtrace when a failure occurs during template instantiation. There's still more work to do to make this output pretty, if that's even possible. llvm-svn: 66557
2009-03-11 02:03:33 +08:00
(void)sizeof(X<int>); // expected-note {{instantiation of template class}}
Limit the template instantiation depth to some user-configurable value (default: 99). Beyond this limit, produce an error and consider the current template instantiation a failure. The stack we're building to track the instantiations will, eventually, be used to produce instantiation backtraces from diagnostics within template instantiation. However, we're not quite there yet. This adds a new Clang driver option -ftemplate-depth=NNN, which should eventually be generated from the GCC command-line operation -ftemplate-depth-NNN (note the '-' rather than the '='!). I did not make the driver changes to do this mapping. llvm-svn: 66513
2009-03-10 08:06:19 +08:00
}
Final piece of core issue 1330: delay computing the exception specification of a defaulted special member function until the exception specification is needed (using the same criteria used for the delayed instantiation of exception specifications for function temploids). EST_Delayed is now EST_Unevaluated (using 1330's terminology), and, like EST_Uninstantiated, carries a pointer to the FunctionDecl which will be used to resolve the exception specification. This is enabled for all C++ modes: it's a little faster in the case where the exception specification isn't used, allows our C++11-in-C++98 extensions to work, and is still correct for C++98, since in that mode the computation of the exception specification can't fail. The diagnostics here aren't great (in particular, we should include implicit evaluation of exception specifications for defaulted special members in the template instantiation backtraces), but they're not much worse than before. Our approach to the problem of cycles between in-class initializers and the exception specification for a defaulted default constructor is modified a little by this change -- we now reject any odr-use of a defaulted default constructor if that constructor uses an in-class initializer and the use is in an in-class initialzer which is declared lexically earlier. This is a closer approximation to the current draft solution in core issue 1351, but isn't an exact match (but the current draft wording isn't reasonable, so that's to be expected). llvm-svn: 160847
2012-07-27 12:22:15 +08:00
#else
// RUN: %clang_cc1 -fsyntax-only -verify -ftemplate-depth 5 -ftemplate-backtrace-limit 4 -std=c++11 -DNOEXCEPT %s
template<typename T> struct S {
S() noexcept(noexcept(T()));
};
struct T : S<T> {}; \
// expected-error{{recursive template instantiation exceeded maximum depth of 5}} \
// expected-note 4 {{in instantiation of exception spec}} \
// expected-note {{skipping 2 contexts in backtrace}} \
// expected-note {{use -ftemplate-depth=N to increase recursive template instantiation depth}}
T t; // expected-note {{implicit default constructor for 'T' first required here}}
#endif