Hello- The PR may be 20 years old, but by now it only needs a one-line fix :). Is it OK please? Bootstrapped + regtested all langauges on x86-64 Linux. Thanks!
-Lewis https://gcc.gnu.org/bugzilla/show_bug.cgi?id=9471 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47857 -- >8 -- libcpp will generate diagnostics when it encounters things in the main file that only belong in a header file, such as `#pragma once' or `#pragma GCC system_header'. But sometimes the main file is a header file that is just being compiled separately, e.g. to produce a C++ module or a PCH, in which case such diagnostics should be suppressed. libcpp already has an interface to request that, so make use of it in the C frontends to prevent libcpp from issuing unwanted diagnostics when compiling a PCH. gcc/c-family/ChangeLog: PR pch/9471 PR pch/47857 * c-opts.cc (c_common_post_options): Set cpp_opts->main_search so libcpp knows it is compiling a header file separately. gcc/testsuite/ChangeLog: PR pch/9471 PR pch/47857 * g++.dg/pch/main-file-warnings.C: New test. * g++.dg/pch/main-file-warnings.Hs: New test. * gcc.dg/pch/main-file-warnings.c: New test. * gcc.dg/pch/main-file-warnings.hs: New test. --- gcc/c-family/c-opts.cc | 3 +++ gcc/testsuite/g++.dg/pch/main-file-warnings.C | 7 +++++++ gcc/testsuite/g++.dg/pch/main-file-warnings.Hs | 3 +++ gcc/testsuite/gcc.dg/pch/main-file-warnings.c | 7 +++++++ gcc/testsuite/gcc.dg/pch/main-file-warnings.hs | 3 +++ 5 files changed, 23 insertions(+) create mode 100644 gcc/testsuite/g++.dg/pch/main-file-warnings.C create mode 100644 gcc/testsuite/g++.dg/pch/main-file-warnings.Hs create mode 100644 gcc/testsuite/gcc.dg/pch/main-file-warnings.c create mode 100644 gcc/testsuite/gcc.dg/pch/main-file-warnings.hs diff --git a/gcc/c-family/c-opts.cc b/gcc/c-family/c-opts.cc index fbabd1816c1..10403c03bd6 100644 --- a/gcc/c-family/c-opts.cc +++ b/gcc/c-family/c-opts.cc @@ -1174,6 +1174,9 @@ c_common_post_options (const char **pfilename) "the %qs debug info cannot be used with " "pre-compiled headers", debug_set_names (write_symbols & ~DWARF2_DEBUG)); + /* Let libcpp know that the main file is a header so it won't + complain about things like #include_next and #pragma once. */ + cpp_opts->main_search = CMS_header; } else if (write_symbols != NO_DEBUG && write_symbols != DWARF2_DEBUG) c_common_no_more_pch (); diff --git a/gcc/testsuite/g++.dg/pch/main-file-warnings.C b/gcc/testsuite/g++.dg/pch/main-file-warnings.C new file mode 100644 index 00000000000..a9e8b0ba9f2 --- /dev/null +++ b/gcc/testsuite/g++.dg/pch/main-file-warnings.C @@ -0,0 +1,7 @@ +/* PR pch/9471 */ +/* PR pch/47857 */ +/* Test will fail if any warnings get issued while compiling the header into a PCH. */ +#include "main-file-warnings.H" +#pragma once /* { dg-warning "in main file" } */ +#pragma GCC system_header /* { dg-warning "outside include file" } */ +#include_next <stdint.h> /* { dg-warning "in primary source file" } */ diff --git a/gcc/testsuite/g++.dg/pch/main-file-warnings.Hs b/gcc/testsuite/g++.dg/pch/main-file-warnings.Hs new file mode 100644 index 00000000000..d1582bb8290 --- /dev/null +++ b/gcc/testsuite/g++.dg/pch/main-file-warnings.Hs @@ -0,0 +1,3 @@ +#pragma once /* { dg-bogus "in main file" } */ +#pragma GCC system_header /* { dg-bogus "outside include file" } */ +#include_next <stdint.h> /* { dg-bogus "in primary source file" } */ diff --git a/gcc/testsuite/gcc.dg/pch/main-file-warnings.c b/gcc/testsuite/gcc.dg/pch/main-file-warnings.c new file mode 100644 index 00000000000..aedbc15f7ba --- /dev/null +++ b/gcc/testsuite/gcc.dg/pch/main-file-warnings.c @@ -0,0 +1,7 @@ +/* PR pch/9471 */ +/* PR pch/47857 */ +/* Test will fail if any warnings get issued while compiling the header into a PCH. */ +#include "main-file-warnings.h" +#pragma once /* { dg-warning "in main file" } */ +#pragma GCC system_header /* { dg-warning "outside include file" } */ +#include_next <stdint.h> /* { dg-warning "in primary source file" } */ diff --git a/gcc/testsuite/gcc.dg/pch/main-file-warnings.hs b/gcc/testsuite/gcc.dg/pch/main-file-warnings.hs new file mode 100644 index 00000000000..d1582bb8290 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pch/main-file-warnings.hs @@ -0,0 +1,3 @@ +#pragma once /* { dg-bogus "in main file" } */ +#pragma GCC system_header /* { dg-bogus "outside include file" } */ +#include_next <stdint.h> /* { dg-bogus "in primary source file" } */
