From 90f454aeb9807c038c7d05dbf1a7482f425c7c7b Mon Sep 17 00:00:00 2001 From: Richard Smith Date: Mon, 31 Oct 2016 20:25:52 +0000 Subject: [PATCH] Add comment explaining this mysterious macro name. llvm-svn: 285631 --- clang/lib/Frontend/InitPreprocessor.cpp | 3 +++ 1 file changed, 3 insertions(+) diff --git a/clang/lib/Frontend/InitPreprocessor.cpp b/clang/lib/Frontend/InitPreprocessor.cpp index 5da547e..613248a 100644 --- a/clang/lib/Frontend/InitPreprocessor.cpp +++ b/clang/lib/Frontend/InitPreprocessor.cpp @@ -992,6 +992,9 @@ static void InitializePredefinedMacros(const TargetInfo &TI, } if (TI.hasInt128Type() && LangOpts.CPlusPlus && LangOpts.GNUMode) { + // For each extended integer type, g++ defines a macro mapping the + // index of the type (0 in this case) in some list of extended types + // to the type. Builder.defineMacro("__GLIBCXX_TYPE_INT_N_0", "__int128"); Builder.defineMacro("__GLIBCXX_BITSIZE_INT_N_0", "128"); } -- 2.7.4