Author: Martin Storsjö
Date: 2022-08-12T08:36:08+02:00
New Revision: 871a78eeaedfa6a8e8616e017ff0626cb6d09b66
URL: https://github.com/llvm/llvm-project/commit/871a78eeaedfa6a8e8616e017ff0626cb6d09b66
DIFF: https://github.com/llvm/llvm-project/commit/871a78eeaedfa6a8e8616e017ff0626cb6d09b66.diff
LOG: [LLD] [MinGW] Implement the --exclude-symbols option
This adds support for the existing GNU ld command line option, which
allows excluding individual symbols from autoexport (when linking a
DLL and no symbols are marked explicitly as dllexported).
Differential Revision: https://reviews.llvm.org/D130118
(cherry picked from commit d1da6469f9ea9b078276ee2e098241f0440468be)
Added:
lld/test/COFF/exclude-symbols.s
Modified:
lld/COFF/Driver.cpp
lld/COFF/MinGW.cpp
lld/COFF/MinGW.h
lld/COFF/Options.td
lld/MinGW/Driver.cpp
lld/MinGW/Options.td
lld/docs/ReleaseNotes.rst
lld/test/MinGW/driver.test
Removed:
################################################################################
diff --git a/lld/COFF/Driver.cpp b/lld/COFF/Driver.cpp
index 155e4ca6ee3fe..5e5c7a974fa9e 100644
--- a/lld/COFF/Driver.cpp
+++ b/lld/COFF/Driver.cpp
@@ -1312,6 +1312,13 @@ void LinkerDriver::maybeExportMinGWSymbols(const opt::InputArgList &args) {
if (Optional<StringRef> path = doFindFile(arg->getValue()))
exporter.addWholeArchive(*path);
+ for (auto *arg : args.filtered(OPT_exclude_symbols)) {
+ SmallVector<StringRef, 2> vec;
+ StringRef(arg->getValue()).split(vec, ',');
+ for (StringRef sym : vec)
+ exporter.addExcludedSymbol(mangle(sym));
+ }
+
ctx.symtab.forEachSymbol([&](Symbol *s) {
auto *def = dyn_cast<Defined>(s);
if (!exporter.shouldExport(ctx, def))
diff --git a/lld/COFF/MinGW.cpp b/lld/COFF/MinGW.cpp
index 7a3a3853572f3..190f4388902e5 100644
--- a/lld/COFF/MinGW.cpp
+++ b/lld/COFF/MinGW.cpp
@@ -122,6 +122,10 @@ void AutoExporter::addWholeArchive(StringRef path) {
excludeLibs.erase(libName);
}
+void AutoExporter::addExcludedSymbol(StringRef symbol) {
+ excludeSymbols.insert(symbol);
+}
+
bool AutoExporter::shouldExport(const COFFLinkerContext &ctx,
Defined *sym) const {
if (!sym || !sym->getChunk())
diff --git a/lld/COFF/MinGW.h b/lld/COFF/MinGW.h
index 8f9343784fa07..4b65c20ec4466 100644
--- a/lld/COFF/MinGW.h
+++ b/lld/COFF/MinGW.h
@@ -28,6 +28,7 @@ class AutoExporter {
AutoExporter();
void addWholeArchive(StringRef path);
+ void addExcludedSymbol(StringRef symbol);
llvm::StringSet<> excludeSymbols;
llvm::StringSet<> excludeSymbolPrefixes;
diff --git a/lld/COFF/Options.td b/lld/COFF/Options.td
index 5135f4ea34af6..c728279ef5cca 100644
--- a/lld/COFF/Options.td
+++ b/lld/COFF/Options.td
@@ -45,6 +45,8 @@ def diasdkdir : P<"diasdkdir", "Set the location of the DIA SDK">;
def entry : P<"entry", "Name of entry point symbol">;
def errorlimit : P<"errorlimit",
"Maximum number of errors to emit before stopping (0 = no limit)">;
+def exclude_symbols : P<"exclude-symbols", "Exclude symbols from automatic export">,
+ MetaVarName<"<symbol[,symbol,...]>">;
def export : P<"export", "Export a function">;
// No help text because /failifmismatch is not intended to be used by the user.
def failifmismatch : P<"failifmismatch", "">;
diff --git a/lld/MinGW/Driver.cpp b/lld/MinGW/Driver.cpp
index 5920a5061d9cd..37d2439c39258 100644
--- a/lld/MinGW/Driver.cpp
+++ b/lld/MinGW/Driver.cpp
@@ -398,6 +398,8 @@ bool mingw::link(ArrayRef<const char *> argsArr, llvm::raw_ostream &stdoutOS,
add("-delayload:" + StringRef(a->getValue()));
for (auto *a : args.filtered(OPT_wrap))
add("-wrap:" + StringRef(a->getValue()));
+ for (auto *a : args.filtered(OPT_exclude_symbols))
+ add("-exclude-symbols:" + StringRef(a->getValue()));
std::vector<StringRef> searchPaths;
for (auto *a : args.filtered(OPT_L)) {
diff --git a/lld/MinGW/Options.td b/lld/MinGW/Options.td
index bfdd4af288000..cc94b93e388a3 100644
--- a/lld/MinGW/Options.td
+++ b/lld/MinGW/Options.td
@@ -62,6 +62,8 @@ def enable_stdcall_fixup: F<"enable-stdcall-fixup">,
defm entry: Eq<"entry", "Name of entry point symbol">, MetaVarName<"<entry>">;
def exclude_all_symbols: F<"exclude-all-symbols">,
HelpText<"Don't automatically export any symbols">;
+defm exclude_symbols: Eq<"exclude-symbols",
+ "Exclude symbols from automatic export">, MetaVarName<"<symbol[,symbol,...]>">;
def export_all_symbols: F<"export-all-symbols">,
HelpText<"Export all symbols even if a def file or dllexport attributes are used">;
defm fatal_warnings: B<"fatal-warnings",
diff --git a/lld/docs/ReleaseNotes.rst b/lld/docs/ReleaseNotes.rst
index 7759c149b1428..21b3bade9d440 100644
--- a/lld/docs/ReleaseNotes.rst
+++ b/lld/docs/ReleaseNotes.rst
@@ -87,6 +87,8 @@ MinGW Improvements
* The ``--disable-reloc-section`` option is now supported.
(`D127478 <https://reviews.llvm.org/D127478>`_)
+* The ``--exclude-symbols`` option is now supported.
+ (`D130118 <https://reviews.llvm.org/D130118>`_)
MachO Improvements
------------------
diff --git a/lld/test/COFF/exclude-symbols.s b/lld/test/COFF/exclude-symbols.s
new file mode 100644
index 0000000000000..cd358712382d2
--- /dev/null
+++ b/lld/test/COFF/exclude-symbols.s
@@ -0,0 +1,20 @@
+// REQUIRES: x86
+// RUN: llvm-mc -filetype=obj -triple=i686-win32-gnu %s -o %t.o
+
+// RUN: lld-link -lldmingw -dll -out:%t.dll %t.o -noentry -exclude-symbols:sym2,unknownsym -exclude-symbols:unknownsym,sym3
+// RUN: llvm-readobj --coff-exports %t.dll | FileCheck --implicit-check-not=Name: %s
+
+// CHECK: Name:
+// CHECK: Name: sym1
+
+.global _sym1
+_sym1:
+ ret
+
+.global _sym2
+_sym2:
+ ret
+
+.global _sym3
+_sym3:
+ ret
diff --git a/lld/test/MinGW/driver.test b/lld/test/MinGW/driver.test
index c67717d1a0001..9c56bfa42f6bd 100644
--- a/lld/test/MinGW/driver.test
+++ b/lld/test/MinGW/driver.test
@@ -321,6 +321,10 @@ RUN: ld.lld -### -m i386pep foo.o -wrap foo1 --wrap foo2 2>&1 | FileCheck -check
RUN: ld.lld -### -m i386pep foo.o -wrap=foo1 --wrap=foo2 2>&1 | FileCheck -check-prefix WRAP %s
WRAP: -wrap:foo1 -wrap:foo2
+RUN: ld.lld -### -m i386pep foo.o -exclude-symbols sym1,sym2 --exclude-symbols sym3 2>&1 | FileCheck -check-prefix EXCLUDE_SYMBOLS %s
+RUN: ld.lld -### -m i386pep foo.o -exclude-symbols=sym1,sym2 --exclude-symbols=sym3 2>&1 | FileCheck -check-prefix EXCLUDE_SYMBOLS %s
+EXCLUDE_SYMBOLS: -exclude-symbols:sym1,sym2 -exclude-symbols:sym3
+
RUN: ld.lld -### -m i386pep foo.o 2>&1 | FileCheck -check-prefix DEMANGLE %s
RUN: ld.lld -### -m i386pep foo.o -demangle 2>&1 | FileCheck -check-prefix DEMANGLE %s
RUN: ld.lld -### -m i386pep foo.o --demangle 2>&1 | FileCheck -check-prefix DEMANGLE %s