[llvm] f565444 - [libLTO] Set data-sections by default in libLTO.
Quinn Pham via llvm-commits
llvm-commits at lists.llvm.org
Wed Jul 27 06:34:46 PDT 2022
Author: Quinn Pham
Date: 2022-07-27T08:34:40-05:00
New Revision: f565444b486d49f84297c3a279ca24d785961ea8
URL: https://github.com/llvm/llvm-project/commit/f565444b486d49f84297c3a279ca24d785961ea8
DIFF: https://github.com/llvm/llvm-project/commit/f565444b486d49f84297c3a279ca24d785961ea8.diff
LOG: [libLTO] Set data-sections by default in libLTO.
This patch changes legacy LTO to set data-sections by default. The user can
explicitly unset data-sections. The reason for this patch is to match the
behaviour of lld and gold plugin. Both lld and gold plugin have data-sections on
by default.
This patch also fixes the forwarding of the clang options -fno-data-sections and
-fno-function-sections to libLTO. Now, when -fno-data/function-sections are
specified in clang, -data/function-sections=0 will be passed to libLTO to
explicitly unset data/function-sections.
Reviewed By: w2yehia, MaskRay
Differential Revision: https://reviews.llvm.org/D129401
Added:
llvm/test/LTO/PowerPC/data-sections-aix.ll
llvm/test/LTO/PowerPC/data-sections-linux.ll
Modified:
clang/lib/Driver/ToolChains/CommonArgs.cpp
clang/test/Driver/function-sections.c
llvm/lib/LTO/LTOCodeGenerator.cpp
Removed:
clang/test/Driver/gold-lto-sections.c
################################################################################
diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index 1d2c085d683e1..05afa712a809c 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -567,14 +567,16 @@ void tools::addLTOOptions(const ToolChain &ToolChain, const ArgList &Args,
isUseSeparateSections(ToolChain.getEffectiveTriple());
if (Args.hasFlag(options::OPT_ffunction_sections,
- options::OPT_fno_function_sections, UseSeparateSections)) {
- CmdArgs.push_back("-plugin-opt=-function-sections");
- }
+ options::OPT_fno_function_sections, UseSeparateSections))
+ CmdArgs.push_back("-plugin-opt=-function-sections=1");
+ else if (Args.hasArg(options::OPT_fno_function_sections))
+ CmdArgs.push_back("-plugin-opt=-function-sections=0");
if (Args.hasFlag(options::OPT_fdata_sections, options::OPT_fno_data_sections,
- UseSeparateSections)) {
- CmdArgs.push_back("-plugin-opt=-data-sections");
- }
+ UseSeparateSections))
+ CmdArgs.push_back("-plugin-opt=-data-sections=1");
+ else if (Args.hasArg(options::OPT_fno_data_sections))
+ CmdArgs.push_back("-plugin-opt=-data-sections=0");
// Pass an option to enable split machine functions.
if (auto *A = Args.getLastArg(options::OPT_fsplit_machine_functions,
diff --git a/clang/test/Driver/function-sections.c b/clang/test/Driver/function-sections.c
index bfb6cc6920bd4..4d206ad150291 100644
--- a/clang/test/Driver/function-sections.c
+++ b/clang/test/Driver/function-sections.c
@@ -6,6 +6,12 @@
// CHECK-NODS-NOT: -fdata-sections
// CHECK-US-NOT: -fno-unique-section-names
// CHECK-NOUS: -fno-unique-section-names
+// CHECK-PLUGIN-DEFAULT-NOT: "-plugin-opt=-function-sections
+// CHECK-PLUGIN-DEFAULT-NOT: "-plugin-opt=-data-sections
+// CHECK-PLUGIN-SECTIONS: "-plugin-opt=-function-sections=1"
+// CHECK-PLUGIN-SECTIONS: "-plugin-opt=-data-sections=1"
+// CHECK-PLUGIN-NO-SECTIONS: "-plugin-opt=-function-sections=0"
+// CHECK-PLUGIN-NO-SECTIONS: "-plugin-opt=-data-sections=0"
// RUN: %clang -### %s -fsyntax-only 2>&1 \
// RUN: --target=i386-unknown-linux \
@@ -72,3 +78,18 @@
// RUN: --target=i386-unknown-linux \
// RUN: -fno-unique-section-names \
// RUN: | FileCheck --check-prefix=CHECK-NOUS %s
+
+
+// RUN: %clang -### %s -flto 2>&1 \
+// RUN: --target=x86_64-unknown-linux \
+// RUN: | FileCheck --check-prefix=CHECK-PLUGIN-DEFAULT %s
+
+// RUN: %clang -### %s -flto 2>&1 \
+// RUN: --target=x86_64-unknown-linux \
+// RUN: -ffunction-sections -fdata-sections \
+// RUN: | FileCheck --check-prefix=CHECK-PLUGIN-SECTIONS %s
+
+// RUN: %clang -### %s -flto 2>&1 \
+// RUN: --target=x86_64-unknown-linux \
+// RUN: -fno-function-sections -fno-data-sections \
+// RUN: | FileCheck --check-prefix=CHECK-PLUGIN-NO-SECTIONS %s
diff --git a/clang/test/Driver/gold-lto-sections.c b/clang/test/Driver/gold-lto-sections.c
deleted file mode 100644
index 83d72cf7f97b8..0000000000000
--- a/clang/test/Driver/gold-lto-sections.c
+++ /dev/null
@@ -1,8 +0,0 @@
-// RUN: touch %t.o
-//
-// RUN: %clang -target x86_64-unknown-linux -### %t.o -flto 2>&1 \
-// RUN: -Wl,-plugin-opt=foo -O3 \
-// RUN: -ffunction-sections -fdata-sections \
-// RUN: | FileCheck %s
-// CHECK: "-plugin-opt=-function-sections"
-// CHECK: "-plugin-opt=-data-sections"
diff --git a/llvm/lib/LTO/LTOCodeGenerator.cpp b/llvm/lib/LTO/LTOCodeGenerator.cpp
index 2f7c485b9fc8f..8c374e0f2f858 100644
--- a/llvm/lib/LTO/LTOCodeGenerator.cpp
+++ b/llvm/lib/LTO/LTOCodeGenerator.cpp
@@ -19,6 +19,7 @@
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/Bitcode/BitcodeWriter.h"
+#include "llvm/CodeGen/CommandFlags.h"
#include "llvm/CodeGen/ParallelCG.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/Config/config.h"
@@ -344,6 +345,11 @@ bool LTOCodeGenerator::determineTarget() {
Config.CPU = "cyclone";
}
+ // If data-sections is not explicitly set or unset, set data-sections by
+ // default to match the behaviour of lld and gold plugin.
+ if (!codegen::getExplicitDataSections())
+ Config.Options.DataSections = true;
+
TargetMach = createTargetMachine();
assert(TargetMach && "Unable to create target machine");
diff --git a/llvm/test/LTO/PowerPC/data-sections-aix.ll b/llvm/test/LTO/PowerPC/data-sections-aix.ll
new file mode 100644
index 0000000000000..98d7e094dd4a2
--- /dev/null
+++ b/llvm/test/LTO/PowerPC/data-sections-aix.ll
@@ -0,0 +1,20 @@
+; RUN: rm -rf %t
+; RUN: mkdir %t
+; RUN: llvm-as %s -o %t/bc.bc
+; RUN: llvm-lto -exported-symbol var -O0 %t/bc.bc -o %t/default.o
+; RUN: llvm-lto -exported-symbol var -O0 --data-sections=1 %t/bc.bc -o \
+; RUN: %t/data-sections.o
+; RUN: llvm-lto -exported-symbol var -O0 --data-sections=0 %t/bc.bc -o \
+; RUN: %t/no-data-sections.o
+; RUN: llvm-objdump -t %t/default.o | FileCheck %s
+; RUN: llvm-objdump -t %t/data-sections.o | FileCheck %s
+; RUN: llvm-objdump -t %t/no-data-sections.o | FileCheck --check-prefix \
+; RUN: CHECK-NO-DATA-SECTIONS %s
+
+target triple = "powerpc-ibm-aix7.2.0.0"
+
+ at var = global i32 0
+
+; CHECK-NOT: 00000000 g O .data (csect: .data) [[#%x,]] var
+
+; CHECK-NO-DATA-SECTIONS: 00000000 g O .data (csect: .data) [[#%x,]] var
diff --git a/llvm/test/LTO/PowerPC/data-sections-linux.ll b/llvm/test/LTO/PowerPC/data-sections-linux.ll
new file mode 100644
index 0000000000000..2ece3c3c90fae
--- /dev/null
+++ b/llvm/test/LTO/PowerPC/data-sections-linux.ll
@@ -0,0 +1,20 @@
+; RUN: rm -rf %t
+; RUN: mkdir %t
+; RUN: llvm-as %s -o %t/bc.bc
+; RUN: llvm-lto -exported-symbol var -O0 %t/bc.bc -o %t/default.o
+; RUN: llvm-lto -exported-symbol var -O0 --data-sections=1 %t/bc.bc -o \
+; RUN: %t/data-sections.o
+; RUN: llvm-lto -exported-symbol var -O0 --data-sections=0 %t/bc.bc -o \
+; RUN: %t/no-data-sections.o
+; RUN: llvm-objdump -t %t/default.o | FileCheck %s
+; RUN: llvm-objdump -t %t/data-sections.o | FileCheck %s
+; RUN: llvm-objdump -t %t/no-data-sections.o | FileCheck --check-prefix \
+; RUN: CHECK-NO-DATA-SECTIONS %s
+
+target triple = "powerpc64le-unknown-linux-gnu"
+
+ at var = global i32 0
+
+; CHECK: 0000000000000000 g O .bss.var [[#%x,]] var
+
+; CHECK-NO-DATA-SECTIONS: 0000000000000000 g O .bss [[#%x,]] var
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