Skip to content

[LLD][COFF] Add support for IMPORT_NAME_EXPORTAS import library names. #83211

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Mar 10, 2024
Merged

[LLD][COFF] Add support for IMPORT_NAME_EXPORTAS import library names. #83211

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
17 changes: 11 additions & 6 deletions lld/COFF/InputFiles.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -944,18 +944,20 @@ ImportFile::ImportFile(COFFLinkerContext &ctx, MemoryBufferRef m)
: InputFile(ctx, ImportKind, m), live(!ctx.config.doGC), thunkLive(live) {}

void ImportFile::parse() {
const char *buf = mb.getBufferStart();
const auto *hdr = reinterpret_cast<const coff_import_header *>(buf);
const auto *hdr =
reinterpret_cast<const coff_import_header *>(mb.getBufferStart());

// Check if the total size is valid.
if (mb.getBufferSize() != sizeof(*hdr) + hdr->SizeOfData)
if (mb.getBufferSize() < sizeof(*hdr) ||
mb.getBufferSize() != sizeof(*hdr) + hdr->SizeOfData)
fatal("broken import library");

// Read names and create an __imp_ symbol.
StringRef name = saver().save(StringRef(buf + sizeof(*hdr)));
StringRef buf = mb.getBuffer().substr(sizeof(*hdr));
StringRef name = saver().save(buf.split('\0').first);
StringRef impName = saver().save("__imp_" + name);
const char *nameStart = buf + sizeof(coff_import_header) + name.size() + 1;
dllName = std::string(StringRef(nameStart));
buf = buf.substr(name.size() + 1);
dllName = buf.split('\0').first;
StringRef extName;
switch (hdr->getNameType()) {
case IMPORT_ORDINAL:
Expand All @@ -971,6 +973,9 @@ void ImportFile::parse() {
extName = ltrim1(name, "?@_");
extName = extName.substr(0, extName.find('@'));
break;
case IMPORT_NAME_EXPORTAS:
extName = buf.substr(dllName.size() + 1).split('\0').first;
break;
}

this->hdr = hdr;
Expand Down
19 changes: 19 additions & 0 deletions lld/test/COFF/exportas.test
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,19 @@
REQUIRES: x86
RUN: split-file %s %t.dir && cd %t.dir

Link to an import library containing EXPORTAS and verify that we use proper name for the import.

RUN: llvm-mc -filetype=obj -triple=x86_64-windows test.s -o test.obj
RUN: llvm-lib -machine:amd64 -out:test.lib -def:test.def
RUN: lld-link -out:out1.dll -dll -noentry test.obj test.lib
RUN: llvm-readobj --coff-imports out1.dll | FileCheck --check-prefix=IMPORT %s
IMPORT: Symbol: expfunc

#--- test.s
.section ".test", "rd"
.rva __imp_func

#--- test.def
LIBRARY test.dll
EXPORTS
func EXPORTAS expfunc