[lld] r303374 - Merge IAT and ILT.
Rui Ueyama via llvm-commits
llvm-commits at lists.llvm.org
Thu May 18 12:59:22 PDT 2017
Author: ruiu
Date: Thu May 18 14:59:22 2017
New Revision: 303374
URL: http://llvm.org/viewvc/llvm-project?rev=303374&view=rev
Log:
Merge IAT and ILT.
Previously, LLD-produced executables had IAT (Import Address Table) and
ILT (Import Lookup Table) as separate chunks of data, although their
contents are identical. My interpretation of the COFF spec when I wrote
the COFF linker is that they need to be separate tables even though they
are the same.
But Peter found that the Windows loader is fine with executables in
which IAT and ILT are merged. This is a patch to merge IAT and ILT.
I confirmed that an lld-link self-hosted with this patch works fine.
Fixes https://bugs.llvm.org/show_bug.cgi?id=33064
Differential Revision: https://reviews.llvm.org/D33326
Modified:
lld/trunk/COFF/DLL.cpp
lld/trunk/COFF/DLL.h
lld/trunk/test/COFF/armnt-imports.test
lld/trunk/test/COFF/hello32.test
lld/trunk/test/COFF/imports.test
Modified: lld/trunk/COFF/DLL.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/COFF/DLL.cpp?rev=303374&r1=303373&r2=303374&view=diff
==============================================================================
--- lld/trunk/COFF/DLL.cpp (original)
+++ lld/trunk/COFF/DLL.cpp Thu May 18 14:59:22 2017
@@ -100,13 +100,17 @@ public:
void writeTo(uint8_t *Buf) const override {
auto *E = (coff_import_directory_table_entry *)(Buf + OutputSectionOff);
- E->ImportLookupTableRVA = LookupTab->getRVA();
E->NameRVA = DLLName->getRVA();
+
+ // The import descriptor table contains two pointers to
+ // the tables describing dllimported symbols. But the
+ // Windows loader actually uses only one. So we create
+ // only one table and set both fields to its address.
+ E->ImportLookupTableRVA = AddressTab->getRVA();
E->ImportAddressTableRVA = AddressTab->getRVA();
}
Chunk *DLLName;
- Chunk *LookupTab;
Chunk *AddressTab;
};
@@ -388,7 +392,6 @@ std::vector<Chunk *> IdataContents::getC
// Add each type in the correct order.
std::vector<Chunk *> V;
V.insert(V.end(), Dirs.begin(), Dirs.end());
- V.insert(V.end(), Lookups.begin(), Lookups.end());
V.insert(V.end(), Addresses.begin(), Addresses.end());
V.insert(V.end(), Hints.begin(), Hints.end());
V.insert(V.end(), DLLNames.begin(), DLLNames.end());
@@ -404,21 +407,18 @@ void IdataContents::create() {
// we need to create HintName chunks to store the names.
// If they don't (if they are import-by-ordinals), we store only
// ordinal values to the table.
- size_t Base = Lookups.size();
+ size_t Base = Addresses.size();
for (DefinedImportData *S : Syms) {
uint16_t Ord = S->getOrdinal();
if (S->getExternalName().empty()) {
- Lookups.push_back(make<OrdinalOnlyChunk>(Ord));
Addresses.push_back(make<OrdinalOnlyChunk>(Ord));
continue;
}
auto *C = make<HintNameChunk>(S->getExternalName(), Ord);
- Lookups.push_back(make<LookupChunk>(C));
Addresses.push_back(make<LookupChunk>(C));
Hints.push_back(C);
}
// Terminate with null values.
- Lookups.push_back(make<NullChunk>(ptrSize()));
Addresses.push_back(make<NullChunk>(ptrSize()));
for (int I = 0, E = Syms.size(); I < E; ++I)
@@ -427,7 +427,6 @@ void IdataContents::create() {
// Create the import table header.
DLLNames.push_back(make<StringChunk>(Syms[0]->getDLLName()));
auto *Dir = make<ImportDirectoryChunk>(DLLNames.back());
- Dir->LookupTab = Lookups[Base];
Dir->AddressTab = Addresses[Base];
Dirs.push_back(Dir);
}
Modified: lld/trunk/COFF/DLL.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/COFF/DLL.h?rev=303374&r1=303373&r2=303374&view=diff
==============================================================================
--- lld/trunk/COFF/DLL.h (original)
+++ lld/trunk/COFF/DLL.h Thu May 18 14:59:22 2017
@@ -36,7 +36,6 @@ private:
std::vector<DefinedImportData *> Imports;
std::vector<Chunk *> Dirs;
- std::vector<Chunk *> Lookups;
std::vector<Chunk *> Addresses;
std::vector<Chunk *> Hints;
std::vector<Chunk *> DLLNames;
Modified: lld/trunk/test/COFF/armnt-imports.test
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/COFF/armnt-imports.test?rev=303374&r1=303373&r2=303374&view=diff
==============================================================================
--- lld/trunk/test/COFF/armnt-imports.test (original)
+++ lld/trunk/test/COFF/armnt-imports.test Thu May 18 14:59:22 2017
@@ -6,7 +6,7 @@
# CHECK: Import {
# CHECK: Name: library.dll
# CHECK: ImportLookupTableRVA: 0x2028
-# CHECK: ImportAddressTableRVA: 0x2030
+# CHECK: ImportAddressTableRVA: 0x2028
# CHECK: Symbol: function (0)
# CHECK: }
Modified: lld/trunk/test/COFF/hello32.test
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/COFF/hello32.test?rev=303374&r1=303373&r2=303374&view=diff
==============================================================================
--- lld/trunk/test/COFF/hello32.test (original)
+++ lld/trunk/test/COFF/hello32.test Thu May 18 14:59:22 2017
@@ -77,7 +77,7 @@ HEADER-NEXT: LoadConfigTableRVA: 0x0
HEADER-NEXT: LoadConfigTableSize: 0x0
HEADER-NEXT: BoundImportRVA: 0x0
HEADER-NEXT: BoundImportSize: 0x0
-HEADER-NEXT: IATRVA: 0x3034
+HEADER-NEXT: IATRVA: 0x3028
HEADER-NEXT: IATSize: 0xC
HEADER-NEXT: DelayImportDescriptorRVA: 0x0
HEADER-NEXT: DelayImportDescriptorSize: 0x0
@@ -113,7 +113,7 @@ IMPORTS: AddressSize: 32bit
IMPORTS: Import {
IMPORTS: Name: std32.dll
IMPORTS: ImportLookupTableRVA: 0x3028
-IMPORTS: ImportAddressTableRVA: 0x3034
+IMPORTS: ImportAddressTableRVA: 0x3028
IMPORTS: Symbol: ExitProcess (0)
IMPORTS: Symbol: MessageBoxA (1)
IMPORTS: }
Modified: lld/trunk/test/COFF/imports.test
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/COFF/imports.test?rev=303374&r1=303373&r2=303374&view=diff
==============================================================================
--- lld/trunk/test/COFF/imports.test (original)
+++ lld/trunk/test/COFF/imports.test Thu May 18 14:59:22 2017
@@ -21,14 +21,14 @@ TEXT-NEXT: callq 60
TEXT-NEXT: movl $0, %ecx
TEXT-NEXT: callq 18
TEXT-NEXT: callq 29
-TEXT: jmpq *4098(%rip)
-TEXT: jmpq *4090(%rip)
-TEXT: jmpq *4082(%rip)
+TEXT: jmpq *4066(%rip)
+TEXT: jmpq *4058(%rip)
+TEXT: jmpq *4050(%rip)
IMPORT: Import {
IMPORT-NEXT: Name: std64.dll
IMPORT-NEXT: ImportLookupTableRVA: 0x3028
-IMPORT-NEXT: ImportAddressTableRVA: 0x3048
+IMPORT-NEXT: ImportAddressTableRVA: 0x3028
IMPORT-NEXT: Symbol: ExitProcess (0)
IMPORT-NEXT: Symbol: (50)
IMPORT-NEXT: Symbol: MessageBoxA (1)
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