From: Manoj Gupta Date: Thu, 12 Sep 2019 22:36:13 +0000 (+0000) Subject: Add -Wpoison-system-directories warning X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e09b029c7f171157f06aa2d742a02a14d5b81cbd;p=clang Add -Wpoison-system-directories warning When using clang as a cross-compiler, we should not use system headers to do the compilation. This CL adds support of a new warning flag -Wpoison-system-directories which emits warnings if --sysroot is set and headers from common host system location are used. By default the warning is disabled. The intention of the warning is to catch bad includes which are usually generated by third party build system not targeting cross-compilation. Such cases happen in Chrome OS when someone imports a new package or upgrade one to a newer version from upstream. Patch by: denik (Denis Nikitin) git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@371785 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/include/clang/Basic/DiagnosticCommonKinds.td b/include/clang/Basic/DiagnosticCommonKinds.td index 8196a4601c..1cd62d1e13 100644 --- a/include/clang/Basic/DiagnosticCommonKinds.td +++ b/include/clang/Basic/DiagnosticCommonKinds.td @@ -315,4 +315,9 @@ def err_unknown_analyzer_checker_or_package : Error< "no analyzer checkers or packages are associated with '%0'">; def note_suggest_disabling_all_checkers : Note< "use -analyzer-disable-all-checks to disable all static analyzer checkers">; + +// Poison system directories. +def warn_poison_system_directories : Warning < + "include location '%0' is unsafe for cross-compilation">, + InGroup>, DefaultIgnore; } diff --git a/lib/Frontend/InitHeaderSearch.cpp b/lib/Frontend/InitHeaderSearch.cpp index ad0d232714..5d877ee9c0 100644 --- a/lib/Frontend/InitHeaderSearch.cpp +++ b/lib/Frontend/InitHeaderSearch.cpp @@ -137,6 +137,13 @@ bool InitHeaderSearch::AddUnmappedPath(const Twine &Path, IncludeDirGroup Group, SmallString<256> MappedPathStorage; StringRef MappedPathStr = Path.toStringRef(MappedPathStorage); + // If use system headers while cross-compiling, emit the warning. + if (HasSysroot && (MappedPathStr.startswith("/usr/include") || + MappedPathStr.startswith("/usr/local/include"))) { + Headers.getDiags().Report(diag::warn_poison_system_directories) + << MappedPathStr; + } + // Compute the DirectoryLookup type. SrcMgr::CharacteristicKind Type; if (Group == Quoted || Group == Angled || Group == IndexHeaderMap) { diff --git a/test/Frontend/Inputs/sysroot_x86_64_cross_linux_tree/lib/.keep b/test/Frontend/Inputs/sysroot_x86_64_cross_linux_tree/lib/.keep new file mode 100644 index 0000000000..e69de29bb2 diff --git a/test/Frontend/Inputs/sysroot_x86_64_cross_linux_tree/usr/include/c++/.keep b/test/Frontend/Inputs/sysroot_x86_64_cross_linux_tree/usr/include/c++/.keep new file mode 100644 index 0000000000..e69de29bb2 diff --git a/test/Frontend/Inputs/sysroot_x86_64_cross_linux_tree/usr/lib/gcc/.keep b/test/Frontend/Inputs/sysroot_x86_64_cross_linux_tree/usr/lib/gcc/.keep new file mode 100644 index 0000000000..e69de29bb2 diff --git a/test/Frontend/Inputs/sysroot_x86_64_cross_linux_tree/usr/local/include/.keep b/test/Frontend/Inputs/sysroot_x86_64_cross_linux_tree/usr/local/include/.keep new file mode 100644 index 0000000000..e69de29bb2 diff --git a/test/Frontend/Inputs/sysroot_x86_64_cross_linux_tree/usr/local/lib/.keep b/test/Frontend/Inputs/sysroot_x86_64_cross_linux_tree/usr/local/lib/.keep new file mode 100644 index 0000000000..e69de29bb2 diff --git a/test/Frontend/warning-poison-system-directories.c b/test/Frontend/warning-poison-system-directories.c new file mode 100644 index 0000000000..018f02db36 --- /dev/null +++ b/test/Frontend/warning-poison-system-directories.c @@ -0,0 +1,27 @@ +// System directory and sysroot option causes warning. +// RUN: %clang -Wpoison-system-directories -target x86_64 -I/usr/include --sysroot %S/Inputs/sysroot_x86_64_cross_linux_tree -c -o - %s 2> %t.1.stderr +// RUN: FileCheck -check-prefix=WARN < %t.1.stderr %s +// RUN: %clang -Wpoison-system-directories -target x86_64 -cxx-isystem/usr/include --sysroot %S/Inputs/sysroot_x86_64_cross_linux_tree -c -o - %s 2> %t.1.stderr +// RUN: FileCheck -check-prefix=WARN < %t.1.stderr %s +// RUN: %clang -Wpoison-system-directories -target x86_64 -iquote/usr/local/include --sysroot %S/Inputs/sysroot_x86_64_cross_linux_tree -c -o - %s 2> %t.1.stderr +// RUN: FileCheck -check-prefix=WARN < %t.1.stderr %s +// RUN: %clang -Wpoison-system-directories -target x86_64 -isystem/usr/local/include --sysroot %S/Inputs/sysroot_x86_64_cross_linux_tree -c -o - %s 2> %t.1.stderr +// RUN: FileCheck -check-prefix=WARN < %t.1.stderr %s + +// Missing target but included sysroot still causes the warning. +// RUN: %clang -Wpoison-system-directories -I/usr/include --sysroot %S/Inputs/sysroot_x86_64_cross_linux_tree -c -o - %s 2> %t.2.stderr +// RUN: FileCheck -check-prefix=WARN < %t.2.stderr %s + +// With -Werror the warning causes the failure. +// RUN: not %clang -Werror=poison-system-directories -target x86_64 -I/usr/include --sysroot %S/Inputs/sysroot_x86_64_cross_linux_tree -c -o - %s 2> %t.3.stderr +// RUN: FileCheck -check-prefix=ERROR < %t.3.stderr %s + +// Cros target without sysroot causes no warning. +// RUN: %clang -Wpoison-system-directories -Werror -target x86_64 -I/usr/include -c -o - %s + +// By default the warning is off. +// RUN: %clang -Werror -target x86_64 -I/usr/include --sysroot %S/Inputs/sysroot_x86_64_cross_linux_tree -c -o - %s + +// WARN: warning: include location {{[^ ]+}} is unsafe for cross-compilation [-Wpoison-system-directories] + +// ERROR: error: include location {{[^ ]+}} is unsafe for cross-compilation [-Werror,-Wpoison-system-directories]