This revision was automatically updated to reflect the committed changes.
Closed by commit rGf14642f2f185: Added support for "#pragma clang section
relro=<name>" (authored by dmikulin).
Herald added a project: clang.
Herald added a subscriber: cfe-commits.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D68806/new/
https://reviews.llvm.org/D68806
Files:
clang/docs/LanguageExtensions.rst
clang/include/clang/Basic/Attr.td
clang/include/clang/Basic/DiagnosticParseKinds.td
clang/include/clang/Sema/Sema.h
clang/lib/CodeGen/CGDecl.cpp
clang/lib/CodeGen/CodeGenModule.cpp
clang/lib/Parse/ParsePragma.cpp
clang/lib/Sema/SemaAttr.cpp
clang/lib/Sema/SemaDecl.cpp
clang/test/CodeGenCXX/clang-sections.cpp
clang/test/Sema/pragma-clang-section.c
llvm/include/llvm/IR/GlobalVariable.h
llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
llvm/lib/Target/TargetLoweringObjectFile.cpp
llvm/test/MC/ELF/section-relro.ll
Index: llvm/test/MC/ELF/section-relro.ll
===================================================================
--- /dev/null
+++ llvm/test/MC/ELF/section-relro.ll
@@ -0,0 +1,65 @@
+; Tests that data and relro are correctly placed in sections
+; specified by "#pragma clang section"
+; RUN: llc -filetype=obj -mtriple x86_64-unknown-linux %s -o - | llvm-readobj -S -t | FileCheck %s
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux"
+
+@funcs_relro = hidden constant [2 x i32 ()*] [i32 ()* bitcast (i32 (...)* @func1 to i32 ()*), i32 ()* bitcast (i32 (...)* @func2 to i32 ()*)], align 16 #0
+@var_data = hidden global i32 33, align 4 #0
+
+declare i32 @func1(...)
+declare i32 @func2(...)
+
+; Function Attrs: noinline nounwind optnone sspstrong uwtable
+define hidden i32 @foo(i32 %i) {
+entry:
+ %i.addr = alloca i32, align 4
+ store i32 %i, i32* %i.addr, align 4
+ %0 = load i32, i32* %i.addr, align 4
+ %idxprom = sext i32 %0 to i64
+ %arrayidx = getelementptr inbounds [2 x i32 ()*], [2 x i32 ()*]* @funcs_relro, i64 0, i64 %idxprom
+ %1 = load i32 ()*, i32 ()** %arrayidx, align 8
+ %call = call i32 %1()
+ %2 = load i32, i32* @var_data, align 4
+ %add = add nsw i32 %call, %2
+ ret i32 %add
+}
+
+attributes #0 = { "data-section"=".my_data" "relro-section"=".my_relro" "rodata-section"=".my_rodata" }
+
+; CHECK: Section {
+; CHECK: Index:
+; CHECK: Name: .my_rodata
+; CHECK: Type: SHT_PROGBITS (0x1)
+; CHECK: Flags [ (0x2)
+; CHECK: SHF_ALLOC (0x2)
+; CHECK: ]
+; CHECK: Size: 16
+; CHECK: }
+; CHECK: Section {
+; CHECK: Index:
+; CHECK: Name: .my_data
+; CHECK: Type: SHT_PROGBITS (0x1)
+; CHECK: Flags [ (0x3)
+; CHECK: SHF_ALLOC (0x2)
+; CHECK: SHF_WRITE (0x1)
+; CHECK: ]
+; CHECK: Size: 4
+; CHECK: }
+; CHECK: Symbol {
+; CHECK: Name: funcs_relro
+; CHECK: Value: 0x0
+; CHECK: Size: 16
+; CHECK: Binding: Global (0x1)
+; CHECK: Type: Object (0x1)
+; CHECK: Section: .my_rodata
+; CHECK: }
+; CHECK: Symbol {
+; CHECK: Name: var_data
+; CHECK: Value: 0x0
+; CHECK: Size: 4
+; CHECK: Binding: Global (0x1)
+; CHECK: Type: Object (0x1)
+; CHECK: Section: .my_data
+; CHECK: }
Index: llvm/lib/Target/TargetLoweringObjectFile.cpp
===================================================================
--- llvm/lib/Target/TargetLoweringObjectFile.cpp
+++ llvm/lib/Target/TargetLoweringObjectFile.cpp
@@ -253,6 +253,7 @@
auto Attrs = GVar->getAttributes();
if ((Attrs.hasAttribute("bss-section") && Kind.isBSS()) ||
(Attrs.hasAttribute("data-section") && Kind.isData()) ||
+ (Attrs.hasAttribute("relro-section") && Kind.isReadOnlyWithRel()) ||
(Attrs.hasAttribute("rodata-section") && Kind.isReadOnly())) {
return getExplicitSectionGlobal(GO, Kind, TM);
}
Index: llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
===================================================================
--- llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -568,6 +568,8 @@
SectionName = Attrs.getAttribute("bss-section").getValueAsString();
} else if (Attrs.hasAttribute("rodata-section") && Kind.isReadOnly()) {
SectionName = Attrs.getAttribute("rodata-section").getValueAsString();
+ } else if (Attrs.hasAttribute("relro-section") && Kind.isReadOnlyWithRel()) {
+ SectionName = Attrs.getAttribute("relro-section").getValueAsString();
} else if (Attrs.hasAttribute("data-section") && Kind.isData()) {
SectionName = Attrs.getAttribute("data-section").getValueAsString();
}
Index: llvm/include/llvm/IR/GlobalVariable.h
===================================================================
--- llvm/include/llvm/IR/GlobalVariable.h
+++ llvm/include/llvm/IR/GlobalVariable.h
@@ -243,6 +243,7 @@
bool hasImplicitSection() const {
return getAttributes().hasAttribute("bss-section") ||
getAttributes().hasAttribute("data-section") ||
+ getAttributes().hasAttribute("relro-section") ||
getAttributes().hasAttribute("rodata-section");
}
Index: clang/test/Sema/pragma-clang-section.c
===================================================================
--- clang/test/Sema/pragma-clang-section.c
+++ clang/test/Sema/pragma-clang-section.c
@@ -3,15 +3,17 @@
#pragma clang section bss="" data="" rodata="" text=""
#pragma clang section
-#pragma clang section dss="mybss.2" // expected-error {{expected one of [bss|data|rodata|text] section kind in '#pragma clang section'}}
-#pragma clang section deta="mydata.2" // expected-error {{expected one of [bss|data|rodata|text] section kind in '#pragma clang section'}}
-#pragma clang section rodeta="rodata.2" // expected-error {{expected one of [bss|data|rodata|text] section kind in '#pragma clang section'}}
-#pragma clang section taxt="text.2" // expected-error {{expected one of [bss|data|rodata|text] section kind in '#pragma clang section'}}
+#pragma clang section dss="mybss.2" // expected-error {{expected one of [bss|data|rodata|text|relro] section kind in '#pragma clang section'}}
+#pragma clang section deta="mydata.2" // expected-error {{expected one of [bss|data|rodata|text|relro] section kind in '#pragma clang section'}}
+#pragma clang section rodeta="rodata.2" // expected-error {{expected one of [bss|data|rodata|text|relro] section kind in '#pragma clang section'}}
+#pragma clang section taxt="text.2" // expected-error {{expected one of [bss|data|rodata|text|relro] section kind in '#pragma clang section'}}
-#pragma clang section section bss="mybss.2" // expected-error {{expected one of [bss|data|rodata|text] section kind in '#pragma clang section'}}
+#pragma clang section section bss="mybss.2" // expected-error {{expected one of [bss|data|rodata|text|relro] section kind in '#pragma clang section'}}
#pragma clang section bss "mybss.2" // expected-error {{expected '=' following '#pragma clang section bss'}}
#pragma clang section data "mydata.2" // expected-error {{expected '=' following '#pragma clang section data'}}
#pragma clang section rodata "myrodata.2" // expected-error {{expected '=' following '#pragma clang section rodata'}}
-#pragma clang section bss="" data="" rodata="" text="" more //expected-error {{expected one of [bss|data|rodata|text] section kind in '#pragma clang section'}}
+#pragma clang section text "text.2" // expected-error {{expected '=' following '#pragma clang section text'}}
+#pragma clang section relro "relro.2" // expected-error {{expected '=' following '#pragma clang section relro'}}
+#pragma clang section bss="" data="" rodata="" text="" more //expected-error {{expected one of [bss|data|rodata|text|relro] section kind in '#pragma clang section'}}
int a;
Index: clang/test/CodeGenCXX/clang-sections.cpp
===================================================================
--- clang/test/CodeGenCXX/clang-sections.cpp
+++ clang/test/CodeGenCXX/clang-sections.cpp
@@ -29,17 +29,20 @@
static int lstat_h; // my_bss.2
return zoo(g, &lstat_h);
}
-#pragma clang section rodata="my_rodata.2" data="my_data.2"
+#pragma clang section rodata="my_rodata.2" data="my_data.2" relro="my_relro.2"
int l = 5; // my_data.2
extern const int m;
const int m = 6; // my_rodata.2
+
+typedef int (*fptr_t)(void);
+const fptr_t fptrs[2] = {&foo, &goo};
#pragma clang section rodata="" data="" bss="" text=""
int n; // default
int o = 6; // default
extern const int p;
const int p = 7; // default
int hoo(void) {
- return b;
+ return b + fptrs[f]();
}
}
//CHECK: @a = global i32 0, align 4 #0
@@ -62,17 +65,19 @@
//CHECK: @n = global i32 0, align 4
//CHECK: @o = global i32 6, align 4
//CHECK: @p = constant i32 7, align 4
+//CHECK: @_ZL5fptrs = internal constant [2 x i32 ()*] [i32 ()* @foo, i32 ()* @goo], align 4 #3
-//CHECK: define i32 @foo() #4 {
-//CHECK: define i32 @goo() #5 {
-//CHECK: declare i32 @zoo(i32*, i32*) #6
-//CHECK: define i32 @hoo() #7 {
+//CHECK: define i32 @foo() #5 {
+//CHECK: define i32 @goo() #6 {
+//CHECK: declare i32 @zoo(i32*, i32*) #7
+//CHECK: define i32 @hoo() #8 {
//CHECK: attributes #0 = { "bss-section"="my_bss.1" "data-section"="my_data.1" "rodata-section"="my_rodata.1" }
//CHECK: attributes #1 = { "data-section"="my_data.1" "rodata-section"="my_rodata.1" }
//CHECK: attributes #2 = { "bss-section"="my_bss.2" "rodata-section"="my_rodata.1" }
-//CHECK: attributes #3 = { "bss-section"="my_bss.2" "data-section"="my_data.2" "rodata-section"="my_rodata.2" }
-//CHECK: attributes #4 = { {{.*"implicit-section-name"="my_text.1".*}} }
-//CHECK: attributes #5 = { {{.*"implicit-section-name"="my_text.2".*}} }
-//CHECK-NOT: attributes #6 = { {{.*"implicit-section-name".*}} }
+//CHECK: attributes #3 = { "bss-section"="my_bss.2" "data-section"="my_data.2" "relro-section"="my_relro.2" "rodata-section"="my_rodata.2" }
+//CHECK: attributes #4 = { "relro-section"="my_relro.2" }
+//CHECK: attributes #5 = { {{.*"implicit-section-name"="my_text.1".*}} }
+//CHECK: attributes #6 = { {{.*"implicit-section-name"="my_text.2".*}} }
//CHECK-NOT: attributes #7 = { {{.*"implicit-section-name".*}} }
+//CHECK-NOT: attributes #8 = { {{.*"implicit-section-name".*}} }
Index: clang/lib/Sema/SemaDecl.cpp
===================================================================
--- clang/lib/Sema/SemaDecl.cpp
+++ clang/lib/Sema/SemaDecl.cpp
@@ -12657,6 +12657,11 @@
Context, PragmaClangRodataSection.SectionName,
PragmaClangRodataSection.PragmaLocation,
AttributeCommonInfo::AS_Pragma));
+ if (PragmaClangRelroSection.Valid)
+ VD->addAttr(PragmaClangRelroSectionAttr::CreateImplicit(
+ Context, PragmaClangRelroSection.SectionName,
+ PragmaClangRelroSection.PragmaLocation,
+ AttributeCommonInfo::AS_Pragma));
}
if (auto *DD = dyn_cast<DecompositionDecl>(ThisDecl)) {
Index: clang/lib/Sema/SemaAttr.cpp
===================================================================
--- clang/lib/Sema/SemaAttr.cpp
+++ clang/lib/Sema/SemaAttr.cpp
@@ -266,6 +266,9 @@
case PragmaClangSectionKind::PCSK_Rodata:
CSec = &PragmaClangRodataSection;
break;
+ case PragmaClangSectionKind::PCSK_Relro:
+ CSec = &PragmaClangRelroSection;
+ break;
case PragmaClangSectionKind::PCSK_Text:
CSec = &PragmaClangTextSection;
break;
Index: clang/lib/Parse/ParsePragma.cpp
===================================================================
--- clang/lib/Parse/ParsePragma.cpp
+++ clang/lib/Parse/ParsePragma.cpp
@@ -1790,7 +1790,7 @@
/*IsReinject=*/false);
}
-// #pragma clang section bss="abc" data="" rodata="def" text=""
+// #pragma clang section bss="abc" data="" rodata="def" text="" relro=""
void PragmaClangSectionHandler::HandlePragma(Preprocessor &PP,
PragmaIntroducer Introducer,
Token &FirstToken) {
@@ -1812,6 +1812,8 @@
SecKind = Sema::PragmaClangSectionKind::PCSK_Data;
else if (SecType->isStr("rodata"))
SecKind = Sema::PragmaClangSectionKind::PCSK_Rodata;
+ else if (SecType->isStr("relro"))
+ SecKind = Sema::PragmaClangSectionKind::PCSK_Relro;
else if (SecType->isStr("text"))
SecKind = Sema::PragmaClangSectionKind::PCSK_Text;
else {
Index: clang/lib/CodeGen/CodeGenModule.cpp
===================================================================
--- clang/lib/CodeGen/CodeGenModule.cpp
+++ clang/lib/CodeGen/CodeGenModule.cpp
@@ -1717,6 +1717,8 @@
GV->addAttribute("data-section", SA->getName());
if (auto *SA = D->getAttr<PragmaClangRodataSectionAttr>())
GV->addAttribute("rodata-section", SA->getName());
+ if (auto *SA = D->getAttr<PragmaClangRelroSectionAttr>())
+ GV->addAttribute("relro-section", SA->getName());
}
if (auto *F = dyn_cast<llvm::Function>(GO)) {
@@ -4118,6 +4120,7 @@
// If no specialized section name is applicable, it will resort to default.
if (D->hasAttr<PragmaClangBSSSectionAttr>() ||
D->hasAttr<PragmaClangDataSectionAttr>() ||
+ D->hasAttr<PragmaClangRelroSectionAttr>() ||
D->hasAttr<PragmaClangRodataSectionAttr>())
return true;
Index: clang/lib/CodeGen/CGDecl.cpp
===================================================================
--- clang/lib/CodeGen/CGDecl.cpp
+++ clang/lib/CodeGen/CGDecl.cpp
@@ -419,6 +419,8 @@
var->addAttribute("data-section", SA->getName());
if (auto *SA = D.getAttr<PragmaClangRodataSectionAttr>())
var->addAttribute("rodata-section", SA->getName());
+ if (auto *SA = D.getAttr<PragmaClangRelroSectionAttr>())
+ var->addAttribute("relro-section", SA->getName());
if (const SectionAttr *SA = D.getAttr<SectionAttr>())
var->setSection(SA->getName());
Index: clang/include/clang/Sema/Sema.h
===================================================================
--- clang/include/clang/Sema/Sema.h
+++ clang/include/clang/Sema/Sema.h
@@ -418,7 +418,8 @@
PCSK_BSS = 1,
PCSK_Data = 2,
PCSK_Rodata = 3,
- PCSK_Text = 4
+ PCSK_Text = 4,
+ PCSK_Relro = 5
};
enum PragmaClangSectionAction {
@@ -439,6 +440,7 @@
PragmaClangSection PragmaClangBSSSection;
PragmaClangSection PragmaClangDataSection;
PragmaClangSection PragmaClangRodataSection;
+ PragmaClangSection PragmaClangRelroSection;
PragmaClangSection PragmaClangTextSection;
enum PragmaMsStackAction {
Index: clang/include/clang/Basic/DiagnosticParseKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticParseKinds.td
+++ clang/include/clang/Basic/DiagnosticParseKinds.td
@@ -976,9 +976,9 @@
// '#pragma clang section' related errors
def err_pragma_expected_clang_section_name : Error<
- "expected one of [bss|data|rodata|text] section kind in '#pragma %0'">;
+ "expected one of [bss|data|rodata|text|relro] section kind in '#pragma %0'">;
def err_pragma_clang_section_expected_equal : Error<
- "expected '=' following '#pragma clang section %select{invalid|bss|data|rodata|text}0'">;
+ "expected '=' following '#pragma clang section %select{invalid|bss|data|rodata|text|relro}0'">;
def warn_pragma_expected_section_name : Warning<
"expected a string literal for the section name in '#pragma %0' - ignored">,
InGroup<IgnoredPragmas>;
Index: clang/include/clang/Basic/Attr.td
===================================================================
--- clang/include/clang/Basic/Attr.td
+++ clang/include/clang/Basic/Attr.td
@@ -2020,6 +2020,14 @@
let Documentation = [Undocumented];
}
+def PragmaClangRelroSection : InheritableAttr {
+ // This attribute has no spellings as it is only ever created implicitly.
+ let Spellings = [];
+ let Args = [StringArgument<"Name">];
+ let Subjects = SubjectList<[GlobalVar], ErrorDiag>;
+ let Documentation = [Undocumented];
+}
+
def PragmaClangTextSection : InheritableAttr {
// This attribute has no spellings as it is only ever created implicitly.
let Spellings = [];
Index: clang/docs/LanguageExtensions.rst
===================================================================
--- clang/docs/LanguageExtensions.rst
+++ clang/docs/LanguageExtensions.rst
@@ -3445,14 +3445,14 @@
.. code-block:: c++
- #pragma clang section bss="myBSS" data="myData" rodata="myRodata" text="myText"
+ #pragma clang section bss="myBSS" data="myData" rodata="myRodata" relro="myRelro" text="myText"
The section names can be reverted back to default name by supplying an empty
string to the section kind, for example:
.. code-block:: c++
- #pragma clang section bss="" data="" text="" rodata=""
+ #pragma clang section bss="" data="" text="" rodata="" relro=""
The ``#pragma clang section`` directive obeys the following rules:
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