From 273b25e491a98a58481085a7fb3766c5116ffd4c Mon Sep 17 00:00:00 2001 From: Matthias Braun Date: Fri, 19 May 2017 22:37:15 +0000 Subject: [PATCH] CodeGenModule: Always output wchar_size, check LLVM assumptions. llvm::TargetLibraryInfo needs to know the size of wchar_t to work on functions like `wcslen`. This patch changes clang to always emit the wchar_size module flag (it would only do so for ARM previously). This also adds an `assert()` to ensure the LLVM defaults based on the target triple are in sync with clang. Differential Revision: https://reviews.llvm.org/D32982 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@303463 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/CodeGenModule.cpp | 19 +++++++++++++------ test/CodeGen/wchar-size.c | 8 ++++++++ 2 files changed, 21 insertions(+), 6 deletions(-) create mode 100644 test/CodeGen/wchar-size.c diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp index dee4351a51..9d0f802ece 100644 --- a/lib/CodeGen/CodeGenModule.cpp +++ b/lib/CodeGen/CodeGenModule.cpp @@ -45,6 +45,7 @@ #include "clang/Frontend/CodeGenOptions.h" #include "clang/Sema/SemaDiagnostic.h" #include "llvm/ADT/Triple.h" +#include "llvm/Analysis/TargetLibraryInfo.h" #include "llvm/IR/CallSite.h" #include "llvm/IR/CallingConv.h" #include "llvm/IR/DataLayout.h" @@ -465,18 +466,24 @@ void CodeGenModule::Release() { getModule().addModuleFlag(llvm::Module::Warning, "Debug Info Version", llvm::DEBUG_METADATA_VERSION); + // Width of wchar_t in bytes + uint64_t WCharWidth = + Context.getTypeSizeInChars(Context.getWideCharType()).getQuantity(); + assert(LangOpts.ShortWChar || + llvm::TargetLibraryInfoImpl::getTargetWCharSize(Target.getTriple()) == + Target.getWCharWidth() / 8 && + "LLVM wchar_t size out of sync"); + // We need to record the widths of enums and wchar_t, so that we can generate - // the correct build attributes in the ARM backend. + // the correct build attributes in the ARM backend. wchar_size is also used by + // TargetLibraryInfo. + getModule().addModuleFlag(llvm::Module::Error, "wchar_size", WCharWidth); + llvm::Triple::ArchType Arch = Context.getTargetInfo().getTriple().getArch(); if ( Arch == llvm::Triple::arm || Arch == llvm::Triple::armeb || Arch == llvm::Triple::thumb || Arch == llvm::Triple::thumbeb) { - // Width of wchar_t in bytes - uint64_t WCharWidth = - Context.getTypeSizeInChars(Context.getWideCharType()).getQuantity(); - getModule().addModuleFlag(llvm::Module::Error, "wchar_size", WCharWidth); - // The minimum width of an enum in bytes uint64_t EnumWidth = Context.getLangOpts().ShortEnums ? 1 : 4; getModule().addModuleFlag(llvm::Module::Error, "min_enum_size", EnumWidth); diff --git a/test/CodeGen/wchar-size.c b/test/CodeGen/wchar-size.c new file mode 100644 index 0000000000..38da462d98 --- /dev/null +++ b/test/CodeGen/wchar-size.c @@ -0,0 +1,8 @@ +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm -o - %s | FileCheck %s -check-prefix=LONG-WCHAR +// RUN: %clang_cc1 -triple x86_64-unknown-windows-msvc -emit-llvm -o - %s | FileCheck %s -check-prefix=SHORT-WCHAR +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm -o - -fshort-wchar %s | FileCheck %s -check-prefix=SHORT-WCHAR +// Note: -fno-short-wchar implies the target default is used; so there is no +// need to test this separately here. + +// LONG-WCHAR: !{{[0-9]+}} = !{i32 {{[0-9]+}}, !"wchar_size", i32 4} +// SHORT-WCHAR: !{{[0-9]+}} = !{i32 {{[0-9]+}}, !"wchar_size", i32 2} -- 2.40.0