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[MS] Improved implementation of MS stack pragmas (vtordisp, *_seg) 

Rework implementation of several MS pragmas that use internal stack:
vtordisp, {bss|code|const|data}_seg.
This patch:
  1. Makes #pragma vtordisp use PragmaStack class as *_seg pragmas do;
  2. Fixes "#pragma vtordisp()" behavior: it shouldn't affect stack;
  3. Saves/restores the stacks on enter/exit a C++ method body.

llvm-svn: 267866
This commit is contained in:
Denis Zobnin 2016-04-28 10:13:18 +00:00
parent 5b4faeec87
commit 2008dbb4ed
7 changed files with 133 additions and 86 deletions
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128
clang/include/clang/Sema/Sema.h
View File

@ -327,40 +327,21 @@ public:
LangOptions::PragmaMSPointersToMembersKind
MSPointerToMemberRepresentationMethod;
enum PragmaVtorDispKind {
PVDK_Push, ///< #pragma vtordisp(push, mode)
PVDK_Set, ///< #pragma vtordisp(mode)
PVDK_Pop, ///< #pragma vtordisp(pop)
PVDK_Reset ///< #pragma vtordisp()
};
enum PragmaMsStackAction {
PSK_Reset, // #pragma ()
PSK_Set, // #pragma ("name")
PSK_Push, // #pragma (push[, id])
PSK_Push_Set, // #pragma (push[, id], "name")
PSK_Pop, // #pragma (pop[, id])
PSK_Pop_Set, // #pragma (pop[, id], "name")
};
/// \brief Whether to insert vtordisps prior to virtual bases in the Microsoft
/// C++ ABI. Possible values are 0, 1, and 2, which mean:
///
/// 0: Suppress all vtordisps
/// 1: Insert vtordisps in the presence of vbase overrides and non-trivial
/// structors
/// 2: Always insert vtordisps to support RTTI on partially constructed
/// objects
///
/// The stack always has at least one element in it.
SmallVector<MSVtorDispAttr::Mode, 2> VtorDispModeStack;
/// Stack of active SEH __finally scopes. Can be empty.
SmallVector<Scope*, 2> CurrentSEHFinally;
/// \brief Source location for newly created implicit MSInheritanceAttrs
SourceLocation ImplicitMSInheritanceAttrLoc;
enum PragmaMsStackAction {
PSK_Reset = 0x0, // #pragma ()
PSK_Set = 0x1, // #pragma (value)
PSK_Push = 0x2, // #pragma (push[, id])
PSK_Pop = 0x4, // #pragma (pop[, id])
PSK_Push_Set = PSK_Push | PSK_Set, // #pragma (push[, id], value)
PSK_Pop_Set = PSK_Pop | PSK_Set, // #pragma (pop[, id], value)
};
template<typename ValueType>
struct PragmaStack {
struct Slot {
@ -377,18 +358,84 @@ public:
PragmaMsStackAction Action,
llvm::StringRef StackSlotLabel,
ValueType Value);
explicit PragmaStack(const ValueType &Value)
: CurrentValue(Value) {}
// MSVC seems to add artificial slots to #pragma stacks on entering a C++
// method body to restore the stacks on exit, so it works like this:
//
// struct S {
// #pragma <name>(push, InternalPragmaSlot, <current_pragma_value>)
// void Method {}
// #pragma <name>(pop, InternalPragmaSlot)
// };
//
// It works even with #pragma vtordisp, although MSVC doesn't support
// #pragma vtordisp(push [, id], n)
// syntax.
//
// Push / pop a named sentinel slot.
void SentinelAction(PragmaMsStackAction Action, StringRef Label) {
assert((Action == PSK_Push || Action == PSK_Pop) &&
"Can only push / pop #pragma stack sentinels!");
Act(CurrentPragmaLocation, Action, Label, CurrentValue);
}
// Constructors.
explicit PragmaStack(const ValueType &Default)
: DefaultValue(Default), CurrentValue(Default) {}
SmallVector<Slot, 2> Stack;
ValueType DefaultValue; // Value used for PSK_Reset action.
ValueType CurrentValue;
SourceLocation CurrentPragmaLocation;
};
// FIXME: We should serialize / deserialize these if they occur in a PCH (but
// we shouldn't do so if they're in a module).
/// \brief Whether to insert vtordisps prior to virtual bases in the Microsoft
/// C++ ABI. Possible values are 0, 1, and 2, which mean:
///
/// 0: Suppress all vtordisps
/// 1: Insert vtordisps in the presence of vbase overrides and non-trivial
/// structors
/// 2: Always insert vtordisps to support RTTI on partially constructed
/// objects
PragmaStack<MSVtorDispAttr::Mode> VtorDispStack;
PragmaStack<StringLiteral *> DataSegStack;
PragmaStack<StringLiteral *> BSSSegStack;
PragmaStack<StringLiteral *> ConstSegStack;
PragmaStack<StringLiteral *> CodeSegStack;
// TODO: Change implementation of #pragma pack to use PragmaStack<> approach.
// RAII object to psuh / pop sentinel slots for all MS #pragma stacks.
// Actions should be performed only if we enter / exit a C++ method body.
class PragmaStackSentinelRAII {
public:
PragmaStackSentinelRAII(Sema &S, StringRef SlotLabel, bool ShouldAct)
: S(S), SlotLabel(SlotLabel), ShouldAct(ShouldAct) {
if (ShouldAct) {
S.VtorDispStack.SentinelAction(PSK_Push, SlotLabel);
S.DataSegStack.SentinelAction(PSK_Push, SlotLabel);
S.BSSSegStack.SentinelAction(PSK_Push, SlotLabel);
S.ConstSegStack.SentinelAction(PSK_Push, SlotLabel);
S.CodeSegStack.SentinelAction(PSK_Push, SlotLabel);
}
}
~PragmaStackSentinelRAII() {
if (ShouldAct) {
S.VtorDispStack.SentinelAction(PSK_Pop, SlotLabel);
S.DataSegStack.SentinelAction(PSK_Pop, SlotLabel);
S.BSSSegStack.SentinelAction(PSK_Pop, SlotLabel);
S.ConstSegStack.SentinelAction(PSK_Pop, SlotLabel);
S.CodeSegStack.SentinelAction(PSK_Pop, SlotLabel);
}
}
private:
Sema &S;
StringRef SlotLabel;
bool ShouldAct;
};
/// A mapping that describes the nullability we've seen in each header file.
FileNullabilityMap NullabilityMap;
@ -1011,24 +1058,6 @@ public:
bool OldFPContractState : 1;
};
/// Records and restores the vtordisp state on entry/exit of C++ method body.
class VtorDispStackRAII {
public:
VtorDispStackRAII(Sema &S, bool ShouldSaveAndRestore)
: S(S), ShouldSaveAndRestore(ShouldSaveAndRestore), OldVtorDispStack() {
if (ShouldSaveAndRestore)
OldVtorDispStack = S.VtorDispModeStack;
}
~VtorDispStackRAII() {
if (ShouldSaveAndRestore)
S.VtorDispModeStack = OldVtorDispStack;
}
private:
Sema &S;
bool ShouldSaveAndRestore;
SmallVector<MSVtorDispAttr::Mode, 2> OldVtorDispStack;
};
void addImplicitTypedef(StringRef Name, QualType T);
public:
@ -7666,7 +7695,8 @@ public:
SourceLocation PragmaLoc);
/// \brief Called on well formed \#pragma vtordisp().
void ActOnPragmaMSVtorDisp(PragmaVtorDispKind Kind, SourceLocation PragmaLoc,
void ActOnPragmaMSVtorDisp(PragmaMsStackAction Action,
SourceLocation PragmaLoc,
MSVtorDispAttr::Mode Value);
enum PragmaSectionKind {

18
clang/lib/Parse/ParsePragma.cpp
View File

@ -497,11 +497,11 @@ void Parser::HandlePragmaMSPointersToMembers() {
void Parser::HandlePragmaMSVtorDisp() {
assert(Tok.is(tok::annot_pragma_ms_vtordisp));
uintptr_t Value = reinterpret_cast<uintptr_t>(Tok.getAnnotationValue());
Sema::PragmaVtorDispKind Kind =
static_cast<Sema::PragmaVtorDispKind>((Value >> 16) & 0xFFFF);
Sema::PragmaMsStackAction Action =
static_cast<Sema::PragmaMsStackAction>((Value >> 16) & 0xFFFF);
MSVtorDispAttr::Mode Mode = MSVtorDispAttr::Mode(Value & 0xFFFF);
SourceLocation PragmaLoc = ConsumeToken(); // The annotation token.
Actions.ActOnPragmaMSVtorDisp(Kind, PragmaLoc, Mode);
Actions.ActOnPragmaMSVtorDisp(Action, PragmaLoc, Mode);
}
void Parser::HandlePragmaMSPragma() {
@ -1606,7 +1606,7 @@ void PragmaMSVtorDisp::HandlePragma(Preprocessor &PP,
}
PP.Lex(Tok);
Sema::PragmaVtorDispKind Kind = Sema::PVDK_Set;
Sema::PragmaMsStackAction Action = Sema::PSK_Set;
const IdentifierInfo *II = Tok.getIdentifierInfo();
if (II) {
if (II->isStr("push")) {
@ -1617,24 +1617,24 @@ void PragmaMSVtorDisp::HandlePragma(Preprocessor &PP,
return;
}
PP.Lex(Tok);
Kind = Sema::PVDK_Push;
Action = Sema::PSK_Push_Set;
// not push, could be on/off
} else if (II->isStr("pop")) {
// #pragma vtordisp(pop)
PP.Lex(Tok);
Kind = Sema::PVDK_Pop;
Action = Sema::PSK_Pop;
}
// not push or pop, could be on/off
} else {
if (Tok.is(tok::r_paren)) {
// #pragma vtordisp()
Kind = Sema::PVDK_Reset;
Action = Sema::PSK_Reset;
}
}
uint64_t Value = 0;
if (Kind == Sema::PVDK_Push || Kind == Sema::PVDK_Set) {
if (Action & Sema::PSK_Push || Action & Sema::PSK_Set) {
const IdentifierInfo *II = Tok.getIdentifierInfo();
if (II && II->isStr("off")) {
PP.Lex(Tok);
@ -1676,7 +1676,7 @@ void PragmaMSVtorDisp::HandlePragma(Preprocessor &PP,
AnnotTok.setLocation(VtorDispLoc);
AnnotTok.setAnnotationEndLoc(EndLoc);
AnnotTok.setAnnotationValue(reinterpret_cast<void *>(
static_cast<uintptr_t>((Kind << 16) | (Value & 0xFFFF))));
static_cast<uintptr_t>((Action << 16) | (Value & 0xFFFF))));
PP.EnterToken(AnnotTok);
}

6
clang/lib/Parse/ParseStmt.cpp
View File

@ -1928,7 +1928,8 @@ Decl *Parser::ParseFunctionStatementBody(Decl *Decl, ParseScope &BodyScope) {
// Save and reset current vtordisp stack if we have entered a C++ method body.
bool IsCXXMethod =
getLangOpts().CPlusPlus && Decl && isa<CXXMethodDecl>(Decl);
Sema::VtorDispStackRAII SavedVtorDispStack(Actions, IsCXXMethod);
Sema::PragmaStackSentinelRAII
PragmaStackSentinel(Actions, "InternalPragmaState", IsCXXMethod);
// Do not enter a scope for the brace, as the arguments are in the same scope
// (the function body) as the body itself. Instead, just read the statement
@ -1972,7 +1973,8 @@ Decl *Parser::ParseFunctionTryBlock(Decl *Decl, ParseScope &BodyScope) {
// Save and reset current vtordisp stack if we have entered a C++ method body.
bool IsCXXMethod =
getLangOpts().CPlusPlus && Decl && isa<CXXMethodDecl>(Decl);
Sema::VtorDispStackRAII SavedVtorDispStack(Actions, IsCXXMethod);
Sema::PragmaStackSentinelRAII
PragmaStackSentinel(Actions, "InternalPragmaState", IsCXXMethod);
SourceLocation LBraceLoc = Tok.getLocation();
StmtResult FnBody(ParseCXXTryBlockCommon(TryLoc, /*FnTry*/true));

2
clang/lib/Sema/Sema.cpp
View File

@ -82,7 +82,7 @@ Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer,
PackContext(nullptr), MSStructPragmaOn(false),
MSPointerToMemberRepresentationMethod(
LangOpts.getMSPointerToMemberRepresentationMethod()),
VtorDispModeStack(1, MSVtorDispAttr::Mode(LangOpts.VtorDispMode)),
VtorDispStack(MSVtorDispAttr::Mode(LangOpts.VtorDispMode)),
DataSegStack(nullptr), BSSSegStack(nullptr), ConstSegStack(nullptr),
CodeSegStack(nullptr), CurInitSeg(nullptr), VisContext(nullptr),
IsBuildingRecoveryCallExpr(false),

32
clang/lib/Sema/SemaAttr.cpp
View File

@ -136,9 +136,9 @@ void Sema::AddMsStructLayoutForRecord(RecordDecl *RD) {
// FIXME: We should merge AddAlignmentAttributesForRecord with
// AddMsStructLayoutForRecord into AddPragmaAttributesForRecord, which takes
// all active pragmas and applies them as attributes to class definitions.
if (VtorDispModeStack.back() != getLangOpts().VtorDispMode)
if (VtorDispStack.CurrentValue != getLangOpts().VtorDispMode)
RD->addAttr(
MSVtorDispAttr::CreateImplicit(Context, VtorDispModeStack.back()));
MSVtorDispAttr::CreateImplicit(Context, VtorDispStack.CurrentValue));
}
void Sema::ActOnPragmaOptionsAlign(PragmaOptionsAlignKind Kind,
@ -292,29 +292,13 @@ void Sema::ActOnPragmaMSPointersToMembers(
ImplicitMSInheritanceAttrLoc = PragmaLoc;
}
void Sema::ActOnPragmaMSVtorDisp(PragmaVtorDispKind Kind,
void Sema::ActOnPragmaMSVtorDisp(PragmaMsStackAction Action,
SourceLocation PragmaLoc,
MSVtorDispAttr::Mode Mode) {
switch (Kind) {
case PVDK_Set:
VtorDispModeStack.back() = Mode;
break;
case PVDK_Push:
VtorDispModeStack.push_back(Mode);
break;
case PVDK_Reset:
VtorDispModeStack.clear();
VtorDispModeStack.push_back(MSVtorDispAttr::Mode(LangOpts.VtorDispMode));
break;
case PVDK_Pop:
VtorDispModeStack.pop_back();
if (VtorDispModeStack.empty()) {
Diag(PragmaLoc, diag::warn_pragma_pop_failed) << "vtordisp"
<< "stack empty";
VtorDispModeStack.push_back(MSVtorDispAttr::Mode(LangOpts.VtorDispMode));
}
break;
}
if (Action & PSK_Pop && VtorDispStack.Stack.empty())
Diag(PragmaLoc, diag::warn_pragma_pop_failed) << "vtordisp"
<< "stack empty";
VtorDispStack.Act(PragmaLoc, Action, StringRef(), Mode);
}
template<typename ValueType>
@ -323,7 +307,7 @@ void Sema::PragmaStack<ValueType>::Act(SourceLocation PragmaLocation,
llvm::StringRef StackSlotLabel,
ValueType Value) {
if (Action == PSK_Reset) {
CurrentValue = nullptr;
CurrentValue = DefaultValue;
return;
}
if (Action & PSK_Push)

29
clang/test/CodeGenCXX/sections.cpp
View File

@ -31,6 +31,31 @@ int TEST1;
#pragma bss_seg(pop)
int TEST2;
// Check "save-restore" of pragma stacks.
struct Outer {
void f() {
#pragma bss_seg(push, ".bss3")
#pragma code_seg(push, ".my_code1")
#pragma const_seg(push, ".my_const1")
#pragma data_seg(push, ".data3")
struct Inner {
void g() {
#pragma bss_seg(push, ".bss4")
#pragma code_seg(push, ".my_code2")
#pragma const_seg(push, ".my_const2")
#pragma data_seg(push, ".data4")
}
};
}
};
void h2(void) {} // should be in ".my_code"
int TEST3; // should be in ".bss1"
int d2 = 1; // should be in ".data"
extern const int b2; // should be in ".my_const"
const int b2 = 1;
#pragma section("read_flag_section", read)
// Even though they are not declared const, these become constant since they are
// in a read-only section.
@ -63,6 +88,9 @@ __declspec(allocate("short_section")) short short_var = 42;
//CHECK: @i = global i32 0
//CHECK: @TEST1 = global i32 0
//CHECK: @TEST2 = global i32 0, section ".bss1"
//CHECK: @TEST3 = global i32 0, section ".bss1"
//CHECK: @d2 = global i32 1, section ".data"
//CHECK: @b2 = constant i32 1, section ".my_const"
//CHECK: @unreferenced = constant i32 0, section "read_flag_section"
//CHECK: @referenced = constant i32 42, section "read_flag_section"
//CHECK: @implicitly_read_write = global i32 42, section "no_section_attributes"
@ -70,3 +98,4 @@ __declspec(allocate("short_section")) short short_var = 42;
//CHECK: @short_var = global i16 42, section "short_section"
//CHECK: define void @g()
//CHECK: define void @h() {{.*}} section ".my_code"
//CHECK: define void @h2() {{.*}} section ".my_code"

4
clang/test/SemaCXX/pragma-vtordisp.cpp
View File

@ -22,7 +22,8 @@ struct B : virtual A { int b; };
// Test a reset.
#pragma vtordisp()
#pragma vtordisp(pop) // expected-warning {{#pragma vtordisp(pop, ...) failed: stack empty}}
#pragma vtordisp(pop) // stack should NOT be affected by reset.
// Now stack contains '1'.
#pragma vtordisp( // expected-warning {{unknown action for '#pragma vtordisp' - ignored}}
#pragma vtordisp(asdf) // expected-warning {{unknown action for '#pragma vtordisp' - ignored}}
@ -42,6 +43,7 @@ struct E {
virtual void f();
};
#pragma vtordisp(pop) // After this stack should be empty.
#pragma vtordisp(pop) // expected-warning {{#pragma vtordisp(pop, ...) failed: stack empty}}
void g() {