IR: Don't allow non-default visibility on local linkage

Visibilities of `hidden` and `protected` are meaningless for symbols
with local linkage.

  - Change the assembler to reject non-default visibility on symbols
    with local linkage.

  - Change the bitcode reader to auto-upgrade `hidden` and `protected`
    to `default` when the linkage is local.

  - Update LangRef.

<rdar://problem/16141113>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208263 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Duncan P. N. Exon Smith 2014-05-07 22:57:20 +00:00
parent c7e175a743
commit 76c17d324c
23 changed files with 199 additions and 25 deletions

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@ -440,6 +440,9 @@ styles:
defining module will bind to the local symbol. That is, the symbol
cannot be overridden by another module.
A symbol with ``internal`` or ``private`` linkage must have ``default``
visibility.
.. _namedtypes:
DLL Storage Classes

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@ -622,6 +622,11 @@ bool LLParser::ParseStandaloneMetadata() {
return false;
}
static bool isValidVisibilityForLinkage(unsigned V, unsigned L) {
return !GlobalValue::isLocalLinkage((GlobalValue::LinkageTypes)L) ||
(GlobalValue::VisibilityTypes)V == GlobalValue::DefaultVisibility;
}
/// ParseAlias:
/// ::= GlobalVar '=' OptionalVisibility OptionalDLLStorageClass 'alias'
/// OptionalLinkage Aliasee
@ -646,6 +651,10 @@ bool LLParser::ParseAlias(const std::string &Name, LocTy NameLoc,
if(!GlobalAlias::isValidLinkage(Linkage))
return Error(LinkageLoc, "invalid linkage type for alias");
if (!isValidVisibilityForLinkage(Visibility, L))
return Error(LinkageLoc,
"symbol with local linkage must have default visibility");
Constant *Aliasee;
LocTy AliaseeLoc = Lex.getLoc();
if (Lex.getKind() != lltok::kw_bitcast &&
@ -714,6 +723,10 @@ bool LLParser::ParseAlias(const std::string &Name, LocTy NameLoc,
bool LLParser::ParseGlobal(const std::string &Name, LocTy NameLoc,
unsigned Linkage, bool HasLinkage,
unsigned Visibility, unsigned DLLStorageClass) {
if (!isValidVisibilityForLinkage(Visibility, Linkage))
return Error(NameLoc,
"symbol with local linkage must have default visibility");
unsigned AddrSpace;
bool IsConstant, UnnamedAddr, IsExternallyInitialized;
GlobalVariable::ThreadLocalMode TLM;
@ -3014,6 +3027,10 @@ bool LLParser::ParseFunctionHeader(Function *&Fn, bool isDefine) {
return Error(LinkageLoc, "invalid function linkage type");
}
if (!isValidVisibilityForLinkage(Visibility, Linkage))
return Error(LinkageLoc,
"symbol with local linkage must have default visibility");
if (!FunctionType::isValidReturnType(RetType))
return Error(RetTypeLoc, "invalid function return type");

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@ -1856,7 +1856,9 @@ error_code BitcodeReader::ParseModule(bool Resume) {
Section = SectionTable[Record[5]-1];
}
GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
if (Record.size() > 6)
// Local linkage must have default visibility.
if (Record.size() > 6 && !GlobalValue::isLocalLinkage(Linkage))
// FIXME: Change to an error if non-default in 4.0.
Visibility = GetDecodedVisibility(Record[6]);
GlobalVariable::ThreadLocalMode TLM = GlobalVariable::NotThreadLocal;
@ -1922,7 +1924,10 @@ error_code BitcodeReader::ParseModule(bool Resume) {
return Error(InvalidID);
Func->setSection(SectionTable[Record[6]-1]);
}
Func->setVisibility(GetDecodedVisibility(Record[7]));
// Local linkage must have default visibility.
if (!Func->hasLocalLinkage())
// FIXME: Change to an error if non-default in 4.0.
Func->setVisibility(GetDecodedVisibility(Record[7]));
if (Record.size() > 8 && Record[8]) {
if (Record[8]-1 > GCTable.size())
return Error(InvalidID);
@ -1964,7 +1969,9 @@ error_code BitcodeReader::ParseModule(bool Resume) {
GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
"", nullptr, TheModule);
// Old bitcode files didn't have visibility field.
if (Record.size() > 3)
// Local linkage must have default visibility.
if (Record.size() > 3 && !NewGA->hasLocalLinkage())
// FIXME: Change to an error if non-default in 4.0.
NewGA->setVisibility(GetDecodedVisibility(Record[3]));
if (Record.size() > 4)
NewGA->setDLLStorageClass(GetDecodedDLLStorageClass(Record[4]));

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@ -0,0 +1,6 @@
; RUN: not llvm-as < %s -o /dev/null 2>&1 | FileCheck %s
@global = global i32 0
@alias = hidden alias internal i32* @global
; CHECK: symbol with local linkage must have default visibility

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@ -0,0 +1,7 @@
; RUN: not llvm-as < %s -o /dev/null 2>&1 | FileCheck %s
define internal hidden void @function() {
; CHECK: symbol with local linkage must have default visibility
entry:
ret void
}

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@ -0,0 +1,4 @@
; RUN: not llvm-as < %s -o /dev/null 2>&1 | FileCheck %s
@var = internal hidden global i32 0
; CHECK: symbol with local linkage must have default visibility

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@ -0,0 +1,6 @@
; RUN: not llvm-as < %s -o /dev/null 2>&1 | FileCheck %s
@global = global i32 0
@alias = protected alias internal i32* @global
; CHECK: symbol with local linkage must have default visibility

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@ -0,0 +1,7 @@
; RUN: not llvm-as < %s -o /dev/null 2>&1 | FileCheck %s
define internal protected void @function() {
; CHECK: symbol with local linkage must have default visibility
entry:
ret void
}

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@ -0,0 +1,4 @@
; RUN: not llvm-as < %s -o /dev/null 2>&1 | FileCheck %s
@var = internal protected global i32 0
; CHECK: symbol with local linkage must have default visibility

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@ -0,0 +1,6 @@
; RUN: not llvm-as < %s -o /dev/null 2>&1 | FileCheck %s
@global = global i32 0
@alias = hidden alias private i32* @global
; CHECK: symbol with local linkage must have default visibility

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@ -0,0 +1,7 @@
; RUN: not llvm-as < %s -o /dev/null 2>&1 | FileCheck %s
define private hidden void @function() {
; CHECK: symbol with local linkage must have default visibility
entry:
ret void
}

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@ -0,0 +1,4 @@
; RUN: not llvm-as < %s -o /dev/null 2>&1 | FileCheck %s
@var = private hidden global i32 0
; CHECK: symbol with local linkage must have default visibility

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@ -0,0 +1,6 @@
; RUN: not llvm-as < %s -o /dev/null 2>&1 | FileCheck %s
@global = global i32 0
@alias = protected alias private i32* @global
; CHECK: symbol with local linkage must have default visibility

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@ -0,0 +1,7 @@
; RUN: not llvm-as < %s -o /dev/null 2>&1 | FileCheck %s
define private protected void @function() {
; CHECK: symbol with local linkage must have default visibility
entry:
ret void
}

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@ -0,0 +1,4 @@
; RUN: not llvm-as < %s -o /dev/null 2>&1 | FileCheck %s
@var = private protected global i32 0
; CHECK: symbol with local linkage must have default visibility

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@ -0,0 +1,79 @@
; RUN: llvm-dis < %s.bc | FileCheck %s
; local-linkage-default-visibility.3.4.ll.bc was generated by passing this file
; to llvm-as-3.4. The test checks that LLVM upgrades visibility of symbols
; with local linkage to default visibility.
@default.internal.var = internal global i32 0
; CHECK: @default.internal.var = internal global i32 0
@hidden.internal.var = internal hidden global i32 0
; CHECK: @hidden.internal.var = internal global i32 0
@protected.internal.var = internal protected global i32 0
; CHECK: @protected.internal.var = internal global i32 0
@default.private.var = private global i32 0
; CHECK: @default.private.var = private global i32 0
@hidden.private.var = private hidden global i32 0
; CHECK: @hidden.private.var = private global i32 0
@protected.private.var = private protected global i32 0
; CHECK: @protected.private.var = private global i32 0
@global = global i32 0
@default.internal.alias = alias internal i32* @global
; CHECK: @default.internal.alias = alias internal i32* @global
@hidden.internal.alias = hidden alias internal i32* @global
; CHECK: @hidden.internal.alias = alias internal i32* @global
@protected.internal.alias = protected alias internal i32* @global
; CHECK: @protected.internal.alias = alias internal i32* @global
@default.private.alias = alias private i32* @global
; CHECK: @default.private.alias = alias private i32* @global
@hidden.private.alias = hidden alias private i32* @global
; CHECK: @hidden.private.alias = alias private i32* @global
@protected.private.alias = protected alias private i32* @global
; CHECK: @protected.private.alias = alias private i32* @global
define internal void @default.internal() {
; CHECK: define internal void @default.internal
entry:
ret void
}
define internal hidden void @hidden.internal() {
; CHECK: define internal void @hidden.internal
entry:
ret void
}
define internal protected void @protected.internal() {
; CHECK: define internal void @protected.internal
entry:
ret void
}
define private void @default.private() {
; CHECK: define private void @default.private
entry:
ret void
}
define private hidden void @hidden.private() {
; CHECK: define private void @hidden.private
entry:
ret void
}
define private protected void @protected.private() {
; CHECK: define private void @protected.private
entry:
ret void
}

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@ -20,14 +20,14 @@ entry:
ret i32 0
}
define internal hidden i32 @printf(i8* readonly nocapture %fmt, ...) {
define internal i32 @printf(i8* readonly nocapture %fmt, ...) {
entry:
%ret = call i32 @bar(i8* %fmt)
ret i32 %ret
}
; CHECK: define {{.*}} @puts(
define internal hidden i32 @puts(i8* %s) {
define internal i32 @puts(i8* %s) {
entry:
%ret = call i32 @bar(i8* %s)
ret i32 %ret

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@ -1,8 +1,8 @@
; RUN: opt -S -globalopt < %s | FileCheck %s
@_Z17in_custom_section = internal global i8 42, section "CUSTOM"
@in_custom_section = protected dllexport alias internal i8* @_Z17in_custom_section
@in_custom_section = dllexport alias internal i8* @_Z17in_custom_section
; CHECK: @in_custom_section = internal protected dllexport global i8 42, section "CUSTOM"
; CHECK: @in_custom_section = internal dllexport global i8 42, section "CUSTOM"
@llvm.used = appending global [1 x i8*] [i8* @in_custom_section], section "llvm.metadata"

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@ -1,6 +1,6 @@
; RUN: opt < %s -globalopt -S | FileCheck %s
; CHECK: ModuleID
define internal hidden i32 @__cxa_atexit(void (i8*)* nocapture %func, i8* nocapture %arg, i8* nocapture %dso_handle) nounwind readnone optsize noimplicitfloat {
define internal i32 @__cxa_atexit(void (i8*)* nocapture %func, i8* nocapture %arg, i8* nocapture %dso_handle) nounwind readnone optsize noimplicitfloat {
unreachable
}

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@ -8,9 +8,9 @@ target triple = "i386-pc-linux-gnu"
%.qux.2585 = type { i32, i32, i8* }
@g2 = external unnamed_addr constant [9 x i8], align 1
@g3 = internal hidden unnamed_addr constant [1 x i8*] [i8* bitcast (i8* (%.qux.2585*)* @func35 to i8*)]
@g3 = internal unnamed_addr constant [1 x i8*] [i8* bitcast (i8* (%.qux.2585*)* @func35 to i8*)]
define internal hidden i32 @func1(i32* %ptr, { i32, i32 }* nocapture %method) align 2 {
define internal i32 @func1(i32* %ptr, { i32, i32 }* nocapture %method) align 2 {
br label %1
; <label>:1
@ -20,26 +20,26 @@ define internal hidden i32 @func1(i32* %ptr, { i32, i32 }* nocapture %method) al
ret i32 undef
}
define internal hidden i32 @func10(%.qux.2496* nocapture %this) align 2 {
define internal i32 @func10(%.qux.2496* nocapture %this) align 2 {
%1 = getelementptr inbounds %.qux.2496* %this, i32 0, i32 1, i32 1
%2 = load i32* %1, align 4
ret i32 %2
}
define internal hidden i8* @func29(i32* nocapture %this) align 2 {
define internal i8* @func29(i32* nocapture %this) align 2 {
ret i8* getelementptr inbounds ([9 x i8]* @g2, i32 0, i32 0)
}
define internal hidden i32* @func33(%.qux.2585* nocapture %this) align 2 {
define internal i32* @func33(%.qux.2585* nocapture %this) align 2 {
ret i32* undef
}
define internal hidden i32* @func34(%.qux.2585* nocapture %this) align 2 {
define internal i32* @func34(%.qux.2585* nocapture %this) align 2 {
%1 = getelementptr inbounds %.qux.2585* %this, i32 0
ret i32* undef
}
define internal hidden i8* @func35(%.qux.2585* nocapture %this) align 2 {
define internal i8* @func35(%.qux.2585* nocapture %this) align 2 {
%1 = getelementptr inbounds %.qux.2585* %this, i32 0, i32 2
%2 = load i8** %1, align 4
ret i8* %2

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@ -6,10 +6,10 @@ target datalayout = "e-p:32:32:32-p1:16:16:16-i1:8:8-i8:8:8-i16:16:16-i32:32:32-
%.qux.2585 = type { i32, i32, i8* }
@g2 = external addrspace(1) constant [9 x i8], align 1
@g3 = internal hidden unnamed_addr constant [1 x i8*] [i8* bitcast (i8* (%.qux.2585 addrspace(1)*)* @func35 to i8*)]
@g3 = internal unnamed_addr constant [1 x i8*] [i8* bitcast (i8* (%.qux.2585 addrspace(1)*)* @func35 to i8*)]
define internal hidden i32 @func10(%.qux.2496 addrspace(1)* nocapture %this) align 2 {
define internal i32 @func10(%.qux.2496 addrspace(1)* nocapture %this) align 2 {
bb:
%tmp = getelementptr inbounds %.qux.2496 addrspace(1)* %this, i32 0, i32 1, i32 1
%tmp1 = load i32 addrspace(1)* %tmp, align 4
@ -17,7 +17,7 @@ bb:
}
; Check for pointer bitwidth equal assertion failure
define internal hidden i8* @func35(%.qux.2585 addrspace(1)* nocapture %this) align 2 {
define internal i8* @func35(%.qux.2585 addrspace(1)* nocapture %this) align 2 {
bb:
; CHECK-LABEL: @func35(
; CHECK: %[[V2:.+]] = bitcast %.qux.2585 addrspace(1)* %{{.*}} to %.qux.2496 addrspace(1)*

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@ -8,9 +8,9 @@ target triple = "i386-pc-linux-gnu"
%.qux.2585 = type { i32, i32, i8* }
@g2 = external unnamed_addr constant [9 x i8], align 1
@g3 = internal hidden unnamed_addr constant [1 x i8*] [i8* bitcast (i8* (%.qux.2585*)* @func35 to i8*)]
@g3 = internal unnamed_addr constant [1 x i8*] [i8* bitcast (i8* (%.qux.2585*)* @func35 to i8*)]
define internal hidden i32 @func1(i32* %ptr, { i32, i32 }* nocapture %method) align 2 {
define internal i32 @func1(i32* %ptr, { i32, i32 }* nocapture %method) align 2 {
bb:
br label %bb1
@ -21,30 +21,30 @@ bb2: ; preds = %bb1
ret i32 undef
}
define internal hidden i32 @func10(%.qux.2496* nocapture %this) align 2 {
define internal i32 @func10(%.qux.2496* nocapture %this) align 2 {
bb:
%tmp = getelementptr inbounds %.qux.2496* %this, i32 0, i32 1, i32 1
%tmp1 = load i32* %tmp, align 4
ret i32 %tmp1
}
define internal hidden i8* @func29(i32* nocapture %this) align 2 {
define internal i8* @func29(i32* nocapture %this) align 2 {
bb:
ret i8* getelementptr inbounds ([9 x i8]* @g2, i32 0, i32 0)
}
define internal hidden i32* @func33(%.qux.2585* nocapture %this) align 2 {
define internal i32* @func33(%.qux.2585* nocapture %this) align 2 {
bb:
ret i32* undef
}
define internal hidden i32* @func34(%.qux.2585* nocapture %this) align 2 {
define internal i32* @func34(%.qux.2585* nocapture %this) align 2 {
bb:
%tmp = getelementptr inbounds %.qux.2585* %this, i32 0
ret i32* undef
}
define internal hidden i8* @func35(%.qux.2585* nocapture %this) align 2 {
define internal i8* @func35(%.qux.2585* nocapture %this) align 2 {
bb:
; CHECK-LABEL: @func35(
; CHECK: %[[V2:.+]] = bitcast %.qux.2585* %{{.*}} to %.qux.2496*