[PATCH] D120394: [asan] Allow -fsanitize-address-globals-dead-stripping with -fno-data-sections for ELF

[Fangrui Song via Phabricator via cfe-commits]

MaskRay created this revision.
MaskRay added reviewers: Sanitizers, eugenis, kstoimenov, vitalybuka.
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-fdata-sections decides whether global variables go into different sections.
This is orthogonal to whether we place their metadata (`.data` or `asan_globals`) into different sections.

With -fno-data-sections, `-fsanitize-address-globals-dead-stripping` can still:

- deduplicate COMDAT `asan.module_ctor` and `asan.module_dtor`
- (with ld --gc-sections): discard `asan_globals` sections and associated unreferenced global variables

Similar to c7b90947bd0179d914fea56b52be545c8f60f20a for PE/COFF.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D120394

Files:
  clang/lib/CodeGen/BackendUtil.cpp
  clang/test/CodeGen/asan-globals-gc.cpp
  clang/test/CodeGen/asan-no-globals-no-comdat.cpp


Index: clang/test/CodeGen/asan-no-globals-no-comdat.cpp
===================================================================
--- clang/test/CodeGen/asan-no-globals-no-comdat.cpp
+++ clang/test/CodeGen/asan-no-globals-no-comdat.cpp
@@ -1,8 +1,7 @@
 // Test that on Linux asan constructor is placed in a comdat iff globals-gc is on.
 // Even if there are no globals in the module.
 
-// RUN: %clang_cc1 -fsanitize=address -fsanitize-address-globals-dead-stripping -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITHOUT-GC
-// RUN: %clang_cc1 -fsanitize=address -fsanitize-address-globals-dead-stripping -fdata-sections -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITH-GC
+// RUN: %clang_cc1 -fsanitize=address -fsanitize-address-globals-dead-stripping -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITH-GC
 // RUN: %clang_cc1 -fsanitize=address -fsanitize-address-globals-dead-stripping -fno-integrated-as -fdata-sections -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITHOUT-GC
 // RUN: %clang_cc1 -fsanitize=address -fsanitize-address-globals-dead-stripping -fno-integrated-as -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITHOUT-GC
 // RUN: %clang_cc1 -fsanitize=address -fdata-sections -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITHOUT-GC
Index: clang/test/CodeGen/asan-globals-gc.cpp
===================================================================
--- clang/test/CodeGen/asan-globals-gc.cpp
+++ clang/test/CodeGen/asan-globals-gc.cpp
@@ -1,5 +1,4 @@
-// RUN: %clang_cc1 -fsanitize=address -fsanitize-address-globals-dead-stripping -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITHOUT-GC
-// RUN: %clang_cc1 -fsanitize=address -fsanitize-address-globals-dead-stripping -fdata-sections -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITH-GC
+// RUN: %clang_cc1 -fsanitize=address -fsanitize-address-globals-dead-stripping -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITH-GC
 // RUN: %clang_cc1 -fsanitize=address -fsanitize-address-globals-dead-stripping -fno-integrated-as -fdata-sections -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITHOUT-GC
 // RUN: %clang_cc1 -fsanitize=address -fsanitize-address-globals-dead-stripping -fno-integrated-as -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITHOUT-GC
 // RUN: %clang_cc1 -fsanitize=address -fdata-sections -emit-llvm -o - -triple x86_64-linux %s | FileCheck %s --check-prefix=WITHOUT-GC
Index: clang/lib/CodeGen/BackendUtil.cpp
===================================================================
--- clang/lib/CodeGen/BackendUtil.cpp
+++ clang/lib/CodeGen/BackendUtil.cpp
@@ -281,7 +281,7 @@
   case Triple::COFF:
     return true;
   case Triple::ELF:
-    return CGOpts.DataSections && !CGOpts.DisableIntegratedAS;
+    return !CGOpts.DisableIntegratedAS;
   case Triple::GOFF:
     llvm::report_fatal_error("ASan not implemented for GOFF");
   case Triple::XCOFF:


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