From 4ff3f205408ff8bb413d69151105d301858136ba Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E5=8D=9C=E9=83=A8=E6=98=8C=E5=B9=B3?= Date: Fri, 10 Apr 2020 14:11:40 +0900 Subject: add #include guard hack According to MSVC manual (*1), cl.exe can skip including a header file when that: - contains #pragma once, or - starts with #ifndef, or - starts with #if ! defined. GCC has a similar trick (*2), but it acts more stricter (e. g. there must be _no tokens_ outside of #ifndef...#endif). Sun C lacked #pragma once for a looong time. Oracle Developer Studio 12.5 finally implemented it, but we cannot assume such recent version. This changeset modifies header files so that each of them include strictly one #ifndef...#endif. I believe this is the most portable way to trigger compiler optimizations. [Bug #16770] *1: https://docs.microsoft.com/en-us/cpp/preprocessor/once *2: https://gcc.gnu.org/onlinedocs/cppinternals/Guard-Macros.html --- vm_opts.h | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) (limited to 'vm_opts.h') diff --git a/vm_opts.h b/vm_opts.h index 3df9ce837b..02d60e71fd 100644 --- a/vm_opts.h +++ b/vm_opts.h @@ -1,4 +1,5 @@ -/*-*-c-*-*/ +#ifndef RUBY_VM_OPTS_H/*-*-c-*-*/ +#define RUBY_VM_OPTS_H /********************************************************************** vm_opts.h - VM optimize option @@ -9,10 +10,6 @@ **********************************************************************/ - -#ifndef RUBY_VM_OPTS_H -#define RUBY_VM_OPTS_H - /* Compile options. * You can change these options at runtime by VM::CompileOption. * Following definitions are default values. -- cgit v1.2.3