diff options
| author | Teresa Johnson <tejohnson@google.com> | 2019-01-11 18:32:07 +0000 |
|---|---|---|
| committer | Teresa Johnson <tejohnson@google.com> | 2019-01-11 18:32:07 +0000 |
| commit | 84cecfcb3db7c3275ae2d64c419a752d9f5311d6 (patch) | |
| tree | 137b550e0763b8685551711c9a6829e232870ba6 /clang/include | |
| parent | 290a8398917a3d4ef521a0cfdb67e65238f0043a (diff) | |
[LTO] Add option to enable LTOUnit splitting, and disable unless needed
Summary:
Adds a new -f[no]split-lto-unit flag that is disabled by default to
control module splitting during ThinLTO. It is automatically enabled
for -fsanitize=cfi and -fwhole-program-vtables.
The new EnableSplitLTOUnit codegen flag is passed down to llvm
via a new module flag of the same name.
Depends on D53890.
Reviewers: pcc
Subscribers: ormris, mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, cfe-commits, llvm-commits
Differential Revision: https://reviews.llvm.org/D53891
llvm-svn: 350949
Diffstat (limited to 'clang/include')
| -rw-r--r-- | clang/include/clang/Basic/CodeGenOptions.def | 4 | ||||
| -rw-r--r-- | clang/include/clang/Driver/Options.td | 5 | ||||
| -rw-r--r-- | clang/include/clang/Driver/SanitizerArgs.h | 1 |
3 files changed, 10 insertions, 0 deletions
diff --git a/clang/include/clang/Basic/CodeGenOptions.def b/clang/include/clang/Basic/CodeGenOptions.def index 952aa588b607..ed2387b9a2e2 100644 --- a/clang/include/clang/Basic/CodeGenOptions.def +++ b/clang/include/clang/Basic/CodeGenOptions.def @@ -116,6 +116,10 @@ CODEGENOPT(PrepareForThinLTO , 1, 0) ///< Set when -flto=thin is enabled on the ///< compile step. CODEGENOPT(LTOUnit, 1, 0) ///< Emit IR to support LTO unit features (CFI, whole ///< program vtable opt). +CODEGENOPT(EnableSplitLTOUnit, 1, 0) ///< Enable LTO unit splitting to support + /// CFI and traditional whole program + /// devirtualization that require whole + /// program IR support. CODEGENOPT(IncrementalLinkerCompatible, 1, 0) ///< Emit an object file which can ///< be used with an incremental ///< linker. diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td index bb4436a6382c..72ded521bdec 100644 --- a/clang/include/clang/Driver/Options.td +++ b/clang/include/clang/Driver/Options.td @@ -1776,6 +1776,11 @@ def fwhole_program_vtables : Flag<["-"], "fwhole-program-vtables">, Group<f_Grou HelpText<"Enables whole-program vtable optimization. Requires -flto">; def fno_whole_program_vtables : Flag<["-"], "fno-whole-program-vtables">, Group<f_Group>, Flags<[CoreOption]>; +def fsplit_lto_unit : Flag<["-"], "fsplit-lto-unit">, Group<f_Group>, + Flags<[CoreOption, CC1Option]>, + HelpText<"Enables splitting of the LTO unit.">; +def fno_split_lto_unit : Flag<["-"], "fno-split-lto-unit">, Group<f_Group>, + Flags<[CoreOption]>; def fforce_emit_vtables : Flag<["-"], "fforce-emit-vtables">, Group<f_Group>, Flags<[CC1Option]>, HelpText<"Emits more virtual tables to improve devirtualization">; diff --git a/clang/include/clang/Driver/SanitizerArgs.h b/clang/include/clang/Driver/SanitizerArgs.h index 02338c22165b..e590a49deea3 100644 --- a/clang/include/clang/Driver/SanitizerArgs.h +++ b/clang/include/clang/Driver/SanitizerArgs.h @@ -81,6 +81,7 @@ class SanitizerArgs { bool requiresPIE() const; bool needsUnwindTables() const; + bool needsLTO() const; bool linkCXXRuntimes() const { return LinkCXXRuntimes; } bool hasCrossDsoCfi() const { return CfiCrossDso; } bool hasAnySanitizer() const { return !Sanitizers.empty(); } |