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Revert "Revert "[clang, llvm] Add __declspec(safebuffers), support it in CodeView"" 

This reverts commit cd20a18286 and adds a
"let Heading" to NoStackProtectorDocs.
This commit is contained in:
David Majnemer 2022-09-16 18:59:15 +00:00
parent e0bc76eb23
commit 8a868d8859
12 changed files with 106 additions and 43 deletions
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9
clang/include/clang/Basic/Attr.td
View File

@ -2080,12 +2080,19 @@ def NotTailCalled : InheritableAttr {
def : MutualExclusions<[AlwaysInline, NotTailCalled]>;
def NoStackProtector : InheritableAttr {
let Spellings = [Clang<"no_stack_protector">];
let Spellings = [Clang<"no_stack_protector">, Declspec<"safebuffers">];
let Subjects = SubjectList<[Function]>;
let Documentation = [NoStackProtectorDocs];
let SimpleHandler = 1;
}
def StrictGuardStackCheck : InheritableAttr {
let Spellings = [Declspec<"strict_gs_check">];
let Subjects = SubjectList<[Function]>;
let Documentation = [StrictGuardStackCheckDocs];
let SimpleHandler = 1;
}
def NoThrow : InheritableAttr {
let Spellings = [GCC<"nothrow">, Declspec<"nothrow">];
let Subjects = SubjectList<[FunctionLike]>;

25
clang/include/clang/Basic/AttrDocs.td
View File

@ -4452,8 +4452,10 @@ spelled "XYZ" in the `OpenMP 5.1 Standard`_).
def NoStackProtectorDocs : Documentation {
let Category = DocCatFunction;
let Heading = "no_stack_protector, safebuffers";
let Content = [{
Clang supports the ``__attribute__((no_stack_protector))`` attribute which disables
Clang supports the ``__attribute__((no_stack_protector))`` and Microsoft style
``__declspec(safebuffers)`` attribute which disables
the stack protector on the specified function. This attribute is useful for
selectively disabling the stack protector on some functions when building with
``-fstack-protector`` compiler option.
@ -4472,6 +4474,27 @@ option.
}];
}
def StrictGuardStackCheckDocs : Documentation {
let Category = DocCatFunction;
let Content = [{
Clang supports the Microsoft style ``__declspec((strict_gs_check))`` attribute
which upgrades the stack protector check from ``-fstack-protector`` to
``-fstack-protector-strong``.
For example, it upgrades the stack protector for the function ``foo`` to
``-fstack-protector-strong`` but function ``bar`` will still be built with the
stack protector with the ``-fstack-protector`` option.
.. code-block:: c
__declspec((strict_gs_check))
int foo(int x); // stack protection will be upgraded for foo.
int bar(int y); // bar can be built with the standard stack protector checks.
}];
}
def NotTailCalledDocs : Documentation {
let Category = DocCatFunction;
let Content = [{

19
clang/lib/CodeGen/CodeGenModule.cpp
View File

@ -1970,14 +1970,17 @@ void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
if (!hasUnwindExceptions(LangOpts))
B.addAttribute(llvm::Attribute::NoUnwind);
if (!D || !D->hasAttr<NoStackProtectorAttr>()) {
if (LangOpts.getStackProtector() == LangOptions::SSPOn)
B.addAttribute(llvm::Attribute::StackProtect);
else if (LangOpts.getStackProtector() == LangOptions::SSPStrong)
B.addAttribute(llvm::Attribute::StackProtectStrong);
else if (LangOpts.getStackProtector() == LangOptions::SSPReq)
B.addAttribute(llvm::Attribute::StackProtectReq);
}
if (D && D->hasAttr<NoStackProtectorAttr>())
; // Do nothing.
else if (D && D->hasAttr<StrictGuardStackCheckAttr>() &&
LangOpts.getStackProtector() == LangOptions::SSPOn)
B.addAttribute(llvm::Attribute::StackProtectStrong);
else if (LangOpts.getStackProtector() == LangOptions::SSPOn)
B.addAttribute(llvm::Attribute::StackProtect);
else if (LangOpts.getStackProtector() == LangOptions::SSPStrong)
B.addAttribute(llvm::Attribute::StackProtectStrong);
else if (LangOpts.getStackProtector() == LangOptions::SSPReq)
B.addAttribute(llvm::Attribute::StackProtectReq);
if (!D) {
// If we don't have a declaration to control inlining, the function isn't

2
clang/test/Parser/MicrosoftExtensions.c
View File

@ -5,7 +5,7 @@ typedef int (__cdecl *tptr)(void);
void (*__fastcall fastpfunc)(void);
extern __declspec(dllimport) void __stdcall VarR4FromDec(void);
__declspec(deprecated) __declspec(deprecated) char * __cdecl ltoa( long _Val, char * _DstBuf, int _Radix);
__declspec(safebuffers) __declspec(noalias) __declspec(restrict) void * __cdecl xxx(void *_Memory); /* expected-warning{{__declspec attribute 'safebuffers' is not supported}} */
__declspec(safebuffers) __declspec(noalias) __declspec(restrict) void * __cdecl xxx(void *_Memory);
typedef __w64 unsigned long ULONG_PTR, *PULONG_PTR;
void * __ptr64 PtrToPtr64(const void *p) {

17
llvm/include/llvm/BinaryFormat/COFF.h
View File

@ -772,6 +772,23 @@ enum CodeViewIdentifiers {
DEBUG_HASHES_SECTION_MAGIC = 0x133C9C5
};
// These flags show up in the @feat.00 symbol. They appear to be some kind of
// compiler features bitfield read by link.exe.
enum Feat00Flags : uint32_t {
// Object is compatible with /safeseh.
SafeSEH = 0x1,
// Object was compiled with /GS.
GuardStack = 0x100,
// Object was compiled with /sdl.
SDL = 0x200,
// Object was compiled with /guard:cf.
GuardCF = 0x800,
// Object was compiled with /guard:ehcont.
GuardEHCont = 0x4000,
// Object was compiled with /kernel.
Kernel = 0x40000000,
};
inline bool isReservedSectionNumber(int32_t SectionNumber) {
return SectionNumber <= 0;
}

10
llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
View File

@ -1498,8 +1498,16 @@ void CodeViewDebug::beginFunctionImpl(const MachineFunction *MF) {
FPO |= FrameProcedureOptions::MarkedInline;
if (GV.hasFnAttribute(Attribute::Naked))
FPO |= FrameProcedureOptions::Naked;
if (MFI.hasStackProtectorIndex())
if (MFI.hasStackProtectorIndex()) {
FPO |= FrameProcedureOptions::SecurityChecks;
if (GV.hasFnAttribute(Attribute::StackProtectStrong) ||
GV.hasFnAttribute(Attribute::StackProtectReq)) {
FPO |= FrameProcedureOptions::StrictSecurityChecks;
}
} else if (!GV.hasStackProtectorFnAttr()) {
// __declspec(safebuffers) disables stack guards.
FPO |= FrameProcedureOptions::SafeBuffers;
}
FPO |= FrameProcedureOptions(uint32_t(CurFn->EncodedLocalFramePtrReg) << 14U);
FPO |= FrameProcedureOptions(uint32_t(CurFn->EncodedParamFramePtrReg) << 16U);
if (Asm->TM.getOptLevel() != CodeGenOpt::None &&

16
llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
View File

@ -201,30 +201,32 @@ void AArch64AsmPrinter::emitStartOfAsmFile(Module &M) {
const Triple &TT = TM.getTargetTriple();
if (TT.isOSBinFormatCOFF()) {
// Emit an absolute @feat.00 symbol. This appears to be some kind of
// compiler features bitfield read by link.exe.
// Emit an absolute @feat.00 symbol
MCSymbol *S = MMI->getContext().getOrCreateSymbol(StringRef("@feat.00"));
OutStreamer->beginCOFFSymbolDef(S);
OutStreamer->emitCOFFSymbolStorageClass(COFF::IMAGE_SYM_CLASS_STATIC);
OutStreamer->emitCOFFSymbolType(COFF::IMAGE_SYM_DTYPE_NULL);
OutStreamer->endCOFFSymbolDef();
int64_t Feat00Flags = 0;
int64_t Feat00Value = 0;
if (M.getModuleFlag("cfguard")) {
Feat00Flags |= 0x800; // Object is CFG-aware.
// Object is CFG-aware.
Feat00Value |= COFF::Feat00Flags::GuardCF;
}
if (M.getModuleFlag("ehcontguard")) {
Feat00Flags |= 0x4000; // Object also has EHCont.
// Object also has EHCont.
Feat00Value |= COFF::Feat00Flags::GuardEHCont;
}
if (M.getModuleFlag("ms-kernel")) {
Feat00Flags |= 0x40000000; // Object is compiled with /kernel.
// Object is compiled with /kernel.
Feat00Value |= COFF::Feat00Flags::Kernel;
}
OutStreamer->emitSymbolAttribute(S, MCSA_Global);
OutStreamer->emitAssignment(
S, MCConstantExpr::create(Feat00Flags, MMI->getContext()));
S, MCConstantExpr::create(Feat00Value, MMI->getContext()));
}
if (!TT.isOSBinFormatELF())

18
llvm/lib/Target/X86/X86AsmPrinter.cpp
View File

@ -792,14 +792,13 @@ void X86AsmPrinter::emitStartOfAsmFile(Module &M) {
OutStreamer->switchSection(getObjFileLowering().getTextSection());
if (TT.isOSBinFormatCOFF()) {
// Emit an absolute @feat.00 symbol. This appears to be some kind of
// compiler features bitfield read by link.exe.
// Emit an absolute @feat.00 symbol.
MCSymbol *S = MMI->getContext().getOrCreateSymbol(StringRef("@feat.00"));
OutStreamer->beginCOFFSymbolDef(S);
OutStreamer->emitCOFFSymbolStorageClass(COFF::IMAGE_SYM_CLASS_STATIC);
OutStreamer->emitCOFFSymbolType(COFF::IMAGE_SYM_DTYPE_NULL);
OutStreamer->endCOFFSymbolDef();
int64_t Feat00Flags = 0;
int64_t Feat00Value = 0;
if (TT.getArch() == Triple::x86) {
// According to the PE-COFF spec, the LSB of this value marks the object
@ -807,24 +806,27 @@ void X86AsmPrinter::emitStartOfAsmFile(Module &M) {
// must be registered in .sxdata. Use of any unregistered handlers will
// cause the process to terminate immediately. LLVM does not know how to
// register any SEH handlers, so its object files should be safe.
Feat00Flags |= 1;
Feat00Value |= COFF::Feat00Flags::SafeSEH;
}
if (M.getModuleFlag("cfguard")) {
Feat00Flags |= 0x800; // Object is CFG-aware.
// Object is CFG-aware.
Feat00Value |= COFF::Feat00Flags::GuardCF;
}
if (M.getModuleFlag("ehcontguard")) {
Feat00Flags |= 0x4000; // Object also has EHCont.
// Object also has EHCont.
Feat00Value |= COFF::Feat00Flags::GuardEHCont;
}
if (M.getModuleFlag("ms-kernel")) {
Feat00Flags |= 0x40000000; // Object is compiled with /kernel.
// Object is compiled with /kernel.
Feat00Value |= COFF::Feat00Flags::Kernel;
}
OutStreamer->emitSymbolAttribute(S, MCSA_Global);
OutStreamer->emitAssignment(
S, MCConstantExpr::create(Feat00Flags, MMI->getContext()));
S, MCConstantExpr::create(Feat00Value, MMI->getContext()));
}
OutStreamer->emitSyntaxDirective();

14
llvm/test/DebugInfo/COFF/frameproc-flags.ll
View File

@ -65,7 +65,7 @@
; CHECK-LABEL: S_GPROC32_ID [size = 52] `use_alloca`
; CHECK: S_FRAMEPROC [size = 32]
; CHECK: local fp reg = VFRAME, param fp reg = EBP
; CHECK: flags = has alloca | secure checks | opt speed
; CHECK: flags = has alloca | secure checks | strict secure checks | opt speed
; CHECK-LABEL: S_GPROC32_ID [size = 52] `call_setjmp`
; CHECK: S_FRAMEPROC [size = 32]
; CHECK: local fp reg = NONE, param fp reg = NONE
@ -73,7 +73,7 @@
; CHECK-LABEL: S_GPROC32_ID [size = 56] `use_inlineasm`
; CHECK: S_FRAMEPROC [size = 32]
; CHECK: local fp reg = NONE, param fp reg = NONE
; CHECK: flags = has inline asm | opt speed
; CHECK: flags = has inline asm | safe buffers | opt speed
; CHECK-LABEL: S_GPROC32_ID [size = 48] `cpp_eh`
; CHECK: S_FRAMEPROC [size = 32]
; CHECK: local fp reg = EBP, param fp reg = EBP
@ -81,11 +81,11 @@
; CHECK-LABEL: S_GPROC32_ID [size = 52] `use_inline`
; CHECK: S_FRAMEPROC [size = 32]
; CHECK: local fp reg = NONE, param fp reg = NONE
; CHECK: flags = opt speed
; CHECK: flags = safe buffers | opt speed
; CHECK-LABEL: S_LPROC32_ID [size = 56] `is_marked_inline`
; CHECK: S_FRAMEPROC [size = 32]
; CHECK: local fp reg = NONE, param fp reg = NONE
; CHECK: flags = marked inline | opt speed
; CHECK: flags = marked inline | safe buffers | opt speed
; CHECK-LABEL: S_GPROC32_ID [size = 44] `seh`
; CHECK: S_FRAMEPROC [size = 32]
; CHECK: local fp reg = EBP, param fp reg = EBP
@ -93,15 +93,15 @@
; CHECK-LABEL: S_LPROC32_ID [size = 56] `?filt$0@0@seh@@`
; CHECK: S_FRAMEPROC [size = 32]
; CHECK: local fp reg = EBP, param fp reg = EBP
; CHECK: flags = opt speed
; CHECK: flags = safe buffers | opt speed
; CHECK-LABEL: S_GPROC32_ID [size = 52] `use_naked`
; CHECK: S_FRAMEPROC [size = 32]
; CHECK: local fp reg = NONE, param fp reg = NONE
; CHECK: flags = has inline asm | naked | opt speed
; CHECK: flags = has inline asm | naked | safe buffers | opt speed
; CHECK-LABEL: S_GPROC32_ID [size = 52] `stack_guard`
; CHECK: S_FRAMEPROC [size = 32]
; CHECK: local fp reg = VFRAME, param fp reg = EBP
; CHECK: flags = secure checks | opt speed
; CHECK: flags = secure checks | strict secure checks | opt speed
; ModuleID = 'frameproc-flags.cpp'
source_filename = "frameproc-flags.cpp"

12
llvm/test/DebugInfo/COFF/multifunction.ll
View File

@ -91,7 +91,7 @@
; X86-NEXT: .long 0 # Bytes of callee saved registers
; X86-NEXT: .long 0 # Exception handler offset
; X86-NEXT: .short 0 # Exception handler section
; X86-NEXT: .long 0 # Flags (defines frame register)
; X86-NEXT: .long 8192 # Flags (defines frame register)
; X86-NEXT: .p2align 2
; X86-NEXT: [[FPROC_END]]:
; X86-NEXT: .short 2
@ -130,7 +130,7 @@
; X86-NEXT: .long 0 # Bytes of callee saved registers
; X86-NEXT: .long 0 # Exception handler offset
; X86-NEXT: .short 0 # Exception handler section
; X86-NEXT: .long 0 # Flags (defines frame register)
; X86-NEXT: .long 8192 # Flags (defines frame register)
; X86-NEXT: .p2align 2
; X86-NEXT: [[FPROC_END]]:
; X86-NEXT: .short 2
@ -169,7 +169,7 @@
; X86-NEXT: .long 0 # Bytes of callee saved registers
; X86-NEXT: .long 0 # Exception handler offset
; X86-NEXT: .short 0 # Exception handler section
; X86-NEXT: .long 0 # Flags (defines frame register)
; X86-NEXT: .long 8192 # Flags (defines frame register)
; X86-NEXT: .p2align 2
; X86-NEXT: [[FPROC_END]]:
; X86-NEXT: .short 2
@ -403,7 +403,7 @@
; X64-NEXT: .long 0 # Bytes of callee saved registers
; X64-NEXT: .long 0 # Exception handler offset
; X64-NEXT: .short 0 # Exception handler section
; X64-NEXT: .long 81920 # Flags (defines frame register)
; X64-NEXT: .long 90112 # Flags (defines frame register)
; X64-NEXT: .p2align 2
; X64-NEXT: [[FPROC_END]]:
; X64-NEXT: .short 2
@ -441,7 +441,7 @@
; X64-NEXT: .long 0 # Bytes of callee saved registers
; X64-NEXT: .long 0 # Exception handler offset
; X64-NEXT: .short 0 # Exception handler section
; X64-NEXT: .long 81920 # Flags (defines frame register)
; X64-NEXT: .long 90112 # Flags (defines frame register)
; X64-NEXT: .p2align 2
; X64-NEXT: [[FPROC_END]]:
; X64-NEXT: .short 2
@ -479,7 +479,7 @@
; X64-NEXT: .long 0 # Bytes of callee saved registers
; X64-NEXT: .long 0 # Exception handler offset
; X64-NEXT: .short 0 # Exception handler section
; X64-NEXT: .long 81920 # Flags (defines frame register)
; X64-NEXT: .long 90112 # Flags (defines frame register)
; X64-NEXT: .p2align 2
; X64-NEXT: [[FPROC_END]]:
; X64-NEXT: .short 2

4
llvm/test/DebugInfo/COFF/simple.ll
View File

@ -71,7 +71,7 @@
; X86-NEXT: .long 0 # Bytes of callee saved registers
; X86-NEXT: .long 0 # Exception handler offset
; X86-NEXT: .short 0 # Exception handler section
; X86-NEXT: .long 0 # Flags (defines frame register)
; X86-NEXT: .long 8192 # Flags (defines frame register)
; X86-NEXT: .p2align 2
; X86-NEXT: [[FPROC_END]]:
; X86-NEXT: .short 2
@ -201,7 +201,7 @@
; X64-NEXT: .long 0 # Bytes of callee saved registers
; X64-NEXT: .long 0 # Exception handler offset
; X64-NEXT: .short 0 # Exception handler section
; X64-NEXT: .long 81920 # Flags (defines frame register)
; X64-NEXT: .long 90112 # Flags (defines frame register)
; X64-NEXT: .p2align 2
; X64-NEXT: [[FPROC_END]]:
; X64-NEXT: .short 2

3
llvm/test/DebugInfo/COFF/vframe-fpo.ll
View File

@ -125,7 +125,8 @@
; CODEVIEW-NEXT: BytesOfCalleeSavedRegisters: 0xC
; CODEVIEW-NEXT: OffsetOfExceptionHandler: 0x0
; CODEVIEW-NEXT: SectionIdOfExceptionHandler: 0x0
; CODEVIEW-NEXT: Flags [ (0x14000)
; CODEVIEW-NEXT: Flags [ (0x16000)
; CODEVIEW-NEXT: SafeBuffers (0x2000)
; CODEVIEW-NEXT: ]
; CODEVIEW-NEXT: LocalFramePtrReg: VFRAME (0x7536)
; CODEVIEW-NEXT: ParamFramePtrReg: VFRAME (0x7536)