[lld] f2d6d74 - [llvm-dlltool] Fix renamed imports without a separate regular import entry (#98229)
via llvm-commits
llvm-commits at lists.llvm.org
Tue Jul 16 13:19:43 PDT 2024
Author: Martin Storsjö
Date: 2024-07-16T23:19:39+03:00
New Revision: f2d6d74cd2a8dccc5ec47bb5debb003e06249db3
URL: https://github.com/llvm/llvm-project/commit/f2d6d74cd2a8dccc5ec47bb5debb003e06249db3
DIFF: https://github.com/llvm/llvm-project/commit/f2d6d74cd2a8dccc5ec47bb5debb003e06249db3.diff
LOG: [llvm-dlltool] Fix renamed imports without a separate regular import entry (#98229)
Normally, when doing renamed imports, we do this by providing a
weak alias, towards another regular import, for the symbol we
want to actually import. In a def file, this looks like this:
regularfunc
renamedfunc == regularfunc
However, if we want to link against a function in a DLL, where we
(intentionally) don't provide a regular import for that symbol
with the name in its DLL, doing the renamed import with a weak
alias doesn't work, as there's no symbol that the weak alias can
point towards.
We can't make up such an import either, as we may intentionally
not want to provide a regular import for that name.
This situation can either be resolved by using the "long" import
library format (as e.g. produced by GNU dlltool), or by using the
new short import library name type "export as".
This patch implements it by using the "export as" name type.
When producing a renamed import, defer emitting it until all regular
imports have been produced. If the renamed import refers to a
symbol that does exist as a regular import entry, produce a
weak alias, just as before. (This implementation also avoids needing
to know whether the symbol that the alias points towards actually
is prefixed or not, too.)
If the renamed import points at a symbol that isn't otherwise
available (or is available as a renamed symbol itself), generate
an "export as" import entry.
This name type is new, and is normally used in ARM64EC import
libraries, but can also be used for other architectures.
Added:
llvm/test/tools/llvm-dlltool/renaming.def
Modified:
lld/test/COFF/lib.test
llvm/include/llvm/Object/COFFImportFile.h
llvm/lib/Object/COFFImportFile.cpp
llvm/lib/ToolDrivers/llvm-dlltool/DlltoolDriver.cpp
llvm/test/tools/llvm-dlltool/coff-decorated.def
llvm/test/tools/llvm-dlltool/coff-weak-exports.def
Removed:
################################################################################
diff --git a/lld/test/COFF/lib.test b/lld/test/COFF/lib.test
index 7525ef4226cda..82abca6ec9307 100644
--- a/lld/test/COFF/lib.test
+++ b/lld/test/COFF/lib.test
@@ -1,6 +1,14 @@
# RUN: lld-link /machine:x64 /def:%S/Inputs/library.def /out:%t.lib
# RUN: llvm-nm %t.lib | FileCheck %s
+CHECK: 00000000 R __imp_constant
+CHECK: 00000000 R constant
+
+CHECK: 00000000 D __imp_data
+
+CHECK: 00000000 T __imp_function
+CHECK: 00000000 T function
+
CHECK: 00000000 a @comp.id
CHECK: 00000000 a @feat.00
CHECK: 00000000 W alias
@@ -11,11 +19,3 @@ CHECK: 00000000 a @feat.00
CHECK: 00000000 W __imp_alias
CHECK: U __imp_function
-CHECK: 00000000 R __imp_constant
-CHECK: 00000000 R constant
-
-CHECK: 00000000 D __imp_data
-
-CHECK: 00000000 T __imp_function
-CHECK: 00000000 T function
-
diff --git a/llvm/include/llvm/Object/COFFImportFile.h b/llvm/include/llvm/Object/COFFImportFile.h
index e91d5a9b3198a..649fb4930934d 100644
--- a/llvm/include/llvm/Object/COFFImportFile.h
+++ b/llvm/include/llvm/Object/COFFImportFile.h
@@ -135,11 +135,10 @@ struct COFFShortExport {
/// linking both ARM64EC and pure ARM64 objects, and the linker will pick only
/// the exports relevant to the target platform. For non-hybrid targets,
/// the NativeExports parameter should not be used.
-Error writeImportLibrary(StringRef ImportName, StringRef Path,
- ArrayRef<COFFShortExport> Exports,
- COFF::MachineTypes Machine, bool MinGW,
- ArrayRef<COFFShortExport> NativeExports = std::nullopt,
- bool AddUnderscores = true);
+Error writeImportLibrary(
+ StringRef ImportName, StringRef Path, ArrayRef<COFFShortExport> Exports,
+ COFF::MachineTypes Machine, bool MinGW,
+ ArrayRef<COFFShortExport> NativeExports = std::nullopt);
} // namespace object
} // namespace llvm
diff --git a/llvm/lib/Object/COFFImportFile.cpp b/llvm/lib/Object/COFFImportFile.cpp
index 1ddc5d954de68..2458a53cb6d54 100644
--- a/llvm/lib/Object/COFFImportFile.cpp
+++ b/llvm/lib/Object/COFFImportFile.cpp
@@ -12,6 +12,8 @@
#include "llvm/Object/COFFImportFile.h"
#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Object/Archive.h"
#include "llvm/Object/ArchiveWriter.h"
@@ -657,8 +659,7 @@ NewArchiveMember ObjectFactory::createWeakExternal(StringRef Sym,
Error writeImportLibrary(StringRef ImportName, StringRef Path,
ArrayRef<COFFShortExport> Exports,
MachineTypes Machine, bool MinGW,
- ArrayRef<COFFShortExport> NativeExports,
- bool AddUnderscores) {
+ ArrayRef<COFFShortExport> NativeExports) {
MachineTypes NativeMachine = Machine;
if (isArm64EC(Machine)) {
@@ -680,6 +681,13 @@ Error writeImportLibrary(StringRef ImportName, StringRef Path,
auto addExports = [&](ArrayRef<COFFShortExport> Exp,
MachineTypes M) -> Error {
+ StringMap<std::string> RegularImports;
+ struct Deferred {
+ std::string Name;
+ ImportType ImpType;
+ const COFFShortExport *Export;
+ };
+ SmallVector<Deferred, 0> Renames;
for (const COFFShortExport &E : Exp) {
if (E.Private)
continue;
@@ -724,15 +732,11 @@ Error writeImportLibrary(StringRef ImportName, StringRef Path,
else if (Name == E.ImportName)
NameType = IMPORT_NAME;
else {
- StringRef Prefix = "";
- if (Machine == IMAGE_FILE_MACHINE_I386 && AddUnderscores)
- Prefix = "_";
-
- if (ImportType == IMPORT_CODE)
- Members.push_back(OF.createWeakExternal(
- (Prefix + E.ImportName).str(), Name, false, M));
- Members.push_back(OF.createWeakExternal((Prefix + E.ImportName).str(),
- Name, true, M));
+ Deferred D;
+ D.Name = Name;
+ D.ImpType = ImportType;
+ D.Export = &E;
+ Renames.push_back(D);
continue;
}
} else {
@@ -754,9 +758,25 @@ Error writeImportLibrary(StringRef ImportName, StringRef Path,
}
}
+ RegularImports[applyNameType(NameType, Name)] = Name;
Members.push_back(OF.createShortImport(Name, E.Ordinal, ImportType,
NameType, ExportName, M));
}
+ for (const auto &D : Renames) {
+ auto It = RegularImports.find(D.Export->ImportName);
+ if (It != RegularImports.end()) {
+ // We have a regular import entry for a symbol with the name we
+ // want to reference; produce an alias pointing at that.
+ StringRef Symbol = It->second;
+ if (D.ImpType == IMPORT_CODE)
+ Members.push_back(OF.createWeakExternal(Symbol, D.Name, false, M));
+ Members.push_back(OF.createWeakExternal(Symbol, D.Name, true, M));
+ } else {
+ Members.push_back(OF.createShortImport(D.Name, D.Export->Ordinal,
+ D.ImpType, IMPORT_NAME_EXPORTAS,
+ D.Export->ImportName, M));
+ }
+ }
return Error::success();
};
diff --git a/llvm/lib/ToolDrivers/llvm-dlltool/DlltoolDriver.cpp b/llvm/lib/ToolDrivers/llvm-dlltool/DlltoolDriver.cpp
index 012ad246888f9..15e4cac08cd4e 100644
--- a/llvm/lib/ToolDrivers/llvm-dlltool/DlltoolDriver.cpp
+++ b/llvm/lib/ToolDrivers/llvm-dlltool/DlltoolDriver.cpp
@@ -243,9 +243,8 @@ int llvm::dlltoolDriverMain(llvm::ArrayRef<const char *> ArgsArr) {
}
std::string Path = std::string(Args.getLastArgValue(OPT_l));
- if (!Path.empty() &&
- writeImportLibrary(OutputFile, Path, Exports, Machine,
- /*MinGW=*/true, NativeExports, AddUnderscores))
+ if (!Path.empty() && writeImportLibrary(OutputFile, Path, Exports, Machine,
+ /*MinGW=*/true, NativeExports))
return 1;
return 0;
}
diff --git a/llvm/test/tools/llvm-dlltool/coff-decorated.def b/llvm/test/tools/llvm-dlltool/coff-decorated.def
index 773e3762cc3d7..f5685fb1cf0c6 100644
--- a/llvm/test/tools/llvm-dlltool/coff-decorated.def
+++ b/llvm/test/tools/llvm-dlltool/coff-decorated.def
@@ -7,7 +7,7 @@ EXPORTS
CdeclFunction
StdcallFunction at 4
@FastcallFunction at 4
-StdcallAlias at 4==StdcallFunction at 4
+StdcallAlias at 4==StdcallFunction
??_7exception@@6B@
StdcallExportName at 4=StdcallInternalFunction at 4
OtherStdcallExportName at 4=CdeclInternalFunction
diff --git a/llvm/test/tools/llvm-dlltool/coff-weak-exports.def b/llvm/test/tools/llvm-dlltool/coff-weak-exports.def
index 67f0013bf170f..b08040e29fa42 100644
--- a/llvm/test/tools/llvm-dlltool/coff-weak-exports.def
+++ b/llvm/test/tools/llvm-dlltool/coff-weak-exports.def
@@ -5,6 +5,9 @@
LIBRARY test.dll
EXPORTS
+AltTestFunction
+AltTestFunction2
+AltTestData
TestFunction==AltTestFunction
TestData DATA == AltTestData
; When creating an import library, the DLL internal function name of
@@ -17,6 +20,14 @@ ImpLibName2 = Implementation2 == AltTestFunction2
; matter for the import library
ImpLibName3 = kernel32.Sleep
+; CHECK: T AltTestFunction
+; CHECK-NEXT: T __imp_AltTestFunction
+; CHECK: T AltTestFunction2
+; CHECK-NEXT: T __imp_AltTestFunction2
+; CHECK: T ImpLibName
+; CHECK-NEXT: T __imp_ImpLibName
+; CHECK: T ImpLibName3
+; CHECK-NEXT: T __imp_ImpLibName3
; CHECK: U AltTestFunction
; CHECK-NEXT: W TestFunction
; CHECK: U __imp_AltTestFunction
@@ -24,14 +35,10 @@ ImpLibName3 = kernel32.Sleep
; CHECK-NOT: W TestData
; CHECK: U __imp_AltTestData
; CHECK-NEXT: W __imp_TestData
-; CHECK: T ImpLibName
-; CHECK-NEXT: T __imp_ImpLibName
; CHECK: U AltTestFunction2
; CHECK-NEXT: W ImpLibName2
; CHECK: U __imp_AltTestFunction2
; CHECK-NEXT: W __imp_ImpLibName2
-; CHECK: T ImpLibName3
-; CHECK-NEXT: T __imp_ImpLibName3
; ARCH-NOT: unknown arch
diff --git a/llvm/test/tools/llvm-dlltool/renaming.def b/llvm/test/tools/llvm-dlltool/renaming.def
new file mode 100644
index 0000000000000..57fd472aa37cf
--- /dev/null
+++ b/llvm/test/tools/llvm-dlltool/renaming.def
@@ -0,0 +1,39 @@
+; RUN: llvm-dlltool -k -m i386 --input-def %s --output-lib %t.a
+; RUN: llvm-readobj %t.a | FileCheck %s
+; RUN: llvm-nm %t.a | FileCheck %s -check-prefix=CHECK-NM
+
+LIBRARY test.dll
+EXPORTS
+
+symbolname == actualimport
+
+dataname DATA == actualdata
+
+_wcstok == wcstok
+wcstok == wcstok_s
+
+; CHECK-NM-NOT: actualimport
+; CHECK-NM-NOT: actualdata
+
+; CHECK: Type: code
+; CHECK-NEXT: Name type: export as
+; CHECK-NEXT: Export name: actualimport
+; CHECK-NEXT: Symbol: __imp__symbolname
+; CHECK-NEXT: Symbol: _symbolname
+
+; CHECK: Type: data
+; CHECK-NEXT: Name type: export as
+; CHECK-NEXT: Export name: actualdata
+; CHECK-NEXT: Symbol: __imp__dataname
+
+; CHECK: Type: code
+; CHECK-NEXT: Name type: export as
+; CHECK-NEXT: Export name: wcstok
+; CHECK-NEXT: Symbol: __imp___wcstok
+; CHECK-NEXT: Symbol: __wcstok
+
+; CHECK: Type: code
+; CHECK-NEXT: Name type: export as
+; CHECK-NEXT: Export name: wcstok_s
+; CHECK-NEXT: Symbol: __imp__wcstok
+; CHECK-NEXT: Symbol: _wcstok
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