diff options
Diffstat (limited to 'clang')
| -rw-r--r-- | clang/docs/ControlFlowIntegrity.rst | 5 | ||||
| -rw-r--r-- | clang/docs/UsersManual.rst | 10 | ||||
| -rw-r--r-- | clang/include/clang/Basic/CodeGenOptions.def | 2 | ||||
| -rw-r--r-- | clang/include/clang/Driver/Options.td | 7 | ||||
| -rw-r--r-- | clang/lib/CodeGen/CodeGenModule.cpp | 4 | ||||
| -rw-r--r-- | clang/lib/Driver/ToolChains/Clang.cpp | 3 | ||||
| -rw-r--r-- | clang/test/CodeGen/unique-source-file-names.c | 2 | ||||
| -rw-r--r-- | clang/test/Driver/unique-source-file-names.c | 5 |
8 files changed, 38 insertions, 0 deletions
diff --git a/clang/docs/ControlFlowIntegrity.rst b/clang/docs/ControlFlowIntegrity.rst index 2f2f8ccf..baff9ab 100644 --- a/clang/docs/ControlFlowIntegrity.rst +++ b/clang/docs/ControlFlowIntegrity.rst @@ -42,6 +42,11 @@ default visibility setting is ``-fvisibility=default``, which would disable CFI checks for classes without visibility attributes. Most users will want to specify ``-fvisibility=hidden``, which enables CFI checks for such classes. +When using ``-fsanitize=cfi*`` with ``-flto=thin``, it is recommended +to reduce link times by passing `-funique-source-file-names +<UsersManual.html#cmdoption-f-no-unique-source-file-names>`_, provided +that your program is compatible with it. + Experimental support for :ref:`cross-DSO control flow integrity <cfi-cross-dso>` exists that does not require classes to have hidden LTO visibility. This cross-DSO support has unstable ABI at this time. diff --git a/clang/docs/UsersManual.rst b/clang/docs/UsersManual.rst index 2a93c25..d4656a7 100644 --- a/clang/docs/UsersManual.rst +++ b/clang/docs/UsersManual.rst @@ -2297,6 +2297,16 @@ are listed below. pure ThinLTO, as all split regular LTO modules are merged and LTO linked with regular LTO. +.. option:: -f[no-]unique-source-file-names + + When enabled, allows the compiler to assume that each object file + passed to the linker has been compiled using a unique source file + name. This is useful for reducing link times when doing ThinLTO + in combination with whole-program devirtualization or CFI. + + A misuse of this flag will generally result in a duplicate symbol + error at link time. + .. option:: -fforce-emit-vtables In order to improve devirtualization, forces emitting of vtables even in diff --git a/clang/include/clang/Basic/CodeGenOptions.def b/clang/include/clang/Basic/CodeGenOptions.def index a436c0e..c5990fb 100644 --- a/clang/include/clang/Basic/CodeGenOptions.def +++ b/clang/include/clang/Basic/CodeGenOptions.def @@ -278,6 +278,8 @@ CODEGENOPT(SanitizeCfiICallNormalizeIntegers, 1, 0) ///< Normalize integer types ///< CFI icall function signatures CODEGENOPT(SanitizeCfiCanonicalJumpTables, 1, 0) ///< Make jump table symbols canonical ///< instead of creating a local jump table. +CODEGENOPT(UniqueSourceFileNames, 1, 0) ///< Allow the compiler to assume that TUs + ///< have unique source file names at link time CODEGENOPT(SanitizeKcfiArity, 1, 0) ///< Embed arity in KCFI patchable function prefix CODEGENOPT(SanitizeCoverageType, 2, 0) ///< Type of sanitizer coverage ///< instrumentation. diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td index c9d2bc5..e9acb20 100644 --- a/clang/include/clang/Driver/Options.td +++ b/clang/include/clang/Driver/Options.td @@ -4140,6 +4140,13 @@ def ftrigraphs : Flag<["-"], "ftrigraphs">, Group<f_Group>, def fno_trigraphs : Flag<["-"], "fno-trigraphs">, Group<f_Group>, HelpText<"Do not process trigraph sequences">, Visibility<[ClangOption, CC1Option]>; +defm unique_source_file_names: BoolOption<"f", "unique-source-file-names", + CodeGenOpts<"UniqueSourceFileNames">, DefaultFalse, + PosFlag<SetTrue, [], [CC1Option], "Allow">, + NegFlag<SetFalse, [], [], "Do not allow">, + BothFlags<[], [ClangOption], " the compiler to assume that each translation unit has a unique " + "source file name at link time">>, + Group<f_clang_Group>; def funsigned_bitfields : Flag<["-"], "funsigned-bitfields">, Group<f_Group>; def funsigned_char : Flag<["-"], "funsigned-char">, Group<f_Group>; def fno_unsigned_char : Flag<["-"], "fno-unsigned-char">; diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp index 4a48c2f..26e09fe 100644 --- a/clang/lib/CodeGen/CodeGenModule.cpp +++ b/clang/lib/CodeGen/CodeGenModule.cpp @@ -1144,6 +1144,10 @@ void CodeGenModule::Release() { 1); } + if (CodeGenOpts.UniqueSourceFileNames) { + getModule().addModuleFlag(llvm::Module::Max, "Unique Source File Names", 1); + } + if (LangOpts.Sanitize.has(SanitizerKind::KCFI)) { getModule().addModuleFlag(llvm::Module::Override, "kcfi", 1); // KCFI assumes patchable-function-prefix is the same for all indirectly diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp index 65910e7..8506a5c 100644 --- a/clang/lib/Driver/ToolChains/Clang.cpp +++ b/clang/lib/Driver/ToolChains/Clang.cpp @@ -7744,6 +7744,9 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA, Args.addOptInFlag(CmdArgs, options::OPT_fexperimental_late_parse_attributes, options::OPT_fno_experimental_late_parse_attributes); + Args.addOptInFlag(CmdArgs, options::OPT_funique_source_file_names, + options::OPT_fno_unique_source_file_names); + // Setup statistics file output. SmallString<128> StatsFile = getStatsFileName(Args, Output, Input, D); if (!StatsFile.empty()) { diff --git a/clang/test/CodeGen/unique-source-file-names.c b/clang/test/CodeGen/unique-source-file-names.c new file mode 100644 index 0000000..1d5a4a5 --- /dev/null +++ b/clang/test/CodeGen/unique-source-file-names.c @@ -0,0 +1,2 @@ +// RUN: %clang_cc1 -funique-source-file-names -triple x86_64-linux-gnu -emit-llvm %s -o - | FileCheck %s +// CHECK: !{i32 7, !"Unique Source File Names", i32 1} diff --git a/clang/test/Driver/unique-source-file-names.c b/clang/test/Driver/unique-source-file-names.c new file mode 100644 index 0000000..8322f0e --- /dev/null +++ b/clang/test/Driver/unique-source-file-names.c @@ -0,0 +1,5 @@ +// RUN: %clang -funique-source-file-names -### %s 2> %t +// RUN: FileCheck < %t %s + +// CHECK: "-cc1" +// CHECK: "-funique-source-file-names" |