maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[Driver] Prioritize SYSROOT/usr/include over RESOURCE_DIR/include on linux-musl 

On a musl-based Linux distribution, stdalign.h stdarg.h stdbool.h stddef.h stdint.h stdnoreturn.h are expected to be provided by musl (/usr/include), instead of RESOURCE_DIR/include.
Reorder RESOURCE_DIR/include to fix the search order problem.
(Currently musl doesn't provide stdatomic.h. stdatomic.h is still found in RESOURCE_DIR/include.)

gcc on musl has a similar search order:

```
 /usr/lib/gcc/x86_64-alpine-linux-musl/8.3.0/../../../../include/c++/8.3.0
 /usr/lib/gcc/x86_64-alpine-linux-musl/8.3.0/../../../../include/c++/8.3.0/x86_64-alpine-linux-musl
 /usr/lib/gcc/x86_64-alpine-linux-musl/8.3.0/../../../../include/c++/8.3.0/backward
 /usr/local/include
 /usr/include/fortify
 /usr/include
 /usr/lib/gcc/x86_64-alpine-linux-musl/8.3.0/include
```

This is different from a glibc-based distribution where RESOURCE_DIR/include is placed before SYSROOT/usr/include.

According to the maintainer of musl:

> musl does not support use/mixing of compiler-provided std headers with its headers, and intentionally has no mechanism for communicating with such headers as to which types have already been defined or still need to be defined. If the current include order, with clang's headers before the libc ones, works in some situations, it's only by accident.

Reviewed by: phosek

Differential Revision: https://reviews.llvm.org/D65699

llvm-svn: 367981
This commit is contained in:
Fangrui Song 2019-08-06 06:25:32 +00:00
parent ec818d7fb3
commit c37022b22a
2 changed files with 47 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
clang/lib/Driver/ToolChains/Linux.cpp
View File

@ -658,11 +658,11 @@ void Linux::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
if (!DriverArgs.hasArg(options::OPT_nostdlibinc))
addSystemInclude(DriverArgs, CC1Args, SysRoot + "/usr/local/include");
if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {
SmallString<128> P(D.ResourceDir);
llvm::sys::path::append(P, "include");
addSystemInclude(DriverArgs, CC1Args, P);
}
SmallString<128> ResourceDirInclude(D.ResourceDir);
llvm::sys::path::append(ResourceDirInclude, "include");
if (!DriverArgs.hasArg(options::OPT_nobuiltininc) &&
(!getTriple().isMusl() || DriverArgs.hasArg(options::OPT_nostdlibinc)))
addSystemInclude(DriverArgs, CC1Args, ResourceDirInclude);
if (DriverArgs.hasArg(options::OPT_nostdlibinc))
return;
@ -860,6 +860,9 @@ void Linux::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
addExternCSystemInclude(DriverArgs, CC1Args, SysRoot + "/include");
addExternCSystemInclude(DriverArgs, CC1Args, SysRoot + "/usr/include");
if (!DriverArgs.hasArg(options::OPT_nobuiltininc) && getTriple().isMusl())
addSystemInclude(DriverArgs, CC1Args, ResourceDirInclude);
}
static std::string DetectLibcxxIncludePath(llvm::vfs::FileSystem &vfs,

39
clang/test/Driver/linux-musl-header-search.cpp Normal file
View File

@ -0,0 +1,39 @@
// RUN: %clang -no-canonical-prefixes %s -### -fsyntax-only 2>&1 \
// RUN: -target x86_64-linux-musl -stdlib=libc++ \
// RUN: -ccc-install-dir %S/Inputs/basic_linux_tree/usr/bin \
// RUN: -resource-dir=%S/Inputs/resource_dir \
// RUN: --sysroot=%S/Inputs/basic_linux_libcxx_tree --gcc-toolchain= \
// RUN: | FileCheck --check-prefix=CHECK-X86-64-LIBCXX %s
// RESOURCE_DIR/include comes after /usr/include on linux-musl.
// This is different from a glibc-based distribution.
// CHECK-X86-64-LIBCXX: "-resource-dir" "[[RESOURCE_DIR:[^"]+]]"
// CHECK-X86-64-LIBCXX: "-isysroot" "[[SYSROOT:[^"]+]]"
// CHECK-X86-64-LIBCXX: "-internal-isystem" "[[SYSROOT]]/usr/include/c++/v1"
// CHECK-X86-64-LIBCXX: "-internal-isystem" "[[SYSROOT]]/usr/local/include"
// CHECK-X86-64-LIBCXX: "-internal-externc-isystem" "[[SYSROOT]]/usr/include"
// CHECK-X86-64-LIBCXX: "-internal-isystem" "[[RESOURCE_DIR]]{{/|\\\\}}include"
// RUN: %clang -no-canonical-prefixes %s -### -fsyntax-only -nobuiltininc 2>&1 \
// RUN: -target x86_64-linux-musl \
// RUN: -ccc-install-dir %S/Inputs/basic_linux_tree/usr/bin \
// RUN: -resource-dir=%S/Inputs/resource_dir \
// RUN: --sysroot=%S/Inputs/basic_linux_libcxx_tree --gcc-toolchain= \
// RUN: | FileCheck --check-prefix=CHECK-NOBUILTININC %s
// CHECK-NOBUILTININC: "-resource-dir" "[[RESOURCE_DIR:[^"]+]]"
// CHECK-NOBUILTININC-NOT: "-internal-isystem" "[[RESOURCE_DIR]]{{/|\\\\}}include"
// RUN: %clang -no-canonical-prefixes %s -### -fsyntax-only -nostdlibinc 2>&1 \
// RUN: -target x86_64-linux-musl \
// RUN: -ccc-install-dir %S/Inputs/basic_linux_tree/usr/bin \
// RUN: -resource-dir=%S/Inputs/resource_dir \
// RUN: --sysroot=%S/Inputs/basic_linux_libcxx_tree --gcc-toolchain= \
// RUN: | FileCheck --check-prefix=CHECK-NOSTDLIBINC %s
// CHECK-NOSTDLIBINC: "-resource-dir" "[[RESOURCE_DIR:[^"]+]]"
// CHECK-NOSTDLIBINC-NOT: "-internal-externc-isystem"
// CHECK-NOSTDLIBINC-NOT: "-internal-isystem"
// CHECK-NOSTDLIBINC: "-internal-isystem" "[[RESOURCE_DIR]]{{/|\\\\}}include"
// CHECK-NOSTDLIBINC-NOT: "-internal-externc-isystem"
// CHECK-NOSTDLIBINC-NOT: "-internal-isystem"