[llvm-branch-commits] [lld] 3b0219a - [LLD] [COFF] Add support for a new, mingw specific embedded directive -exclude-symbols:
Tobias Hieta via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Thu Aug 11 23:37:18 PDT 2022
Author: Martin Storsjö
Date: 2022-08-12T08:36:08+02:00
New Revision: 3b0219ad84b8deb351f3b6978a2fa8029edb811d
URL: https://github.com/llvm/llvm-project/commit/3b0219ad84b8deb351f3b6978a2fa8029edb811d
DIFF: https://github.com/llvm/llvm-project/commit/3b0219ad84b8deb351f3b6978a2fa8029edb811d.diff
LOG: [LLD] [COFF] Add support for a new, mingw specific embedded directive -exclude-symbols:
This is an entirely new embedded directive - extending the GNU ld
command line option --exclude-symbols to be usable in embedded
directives too.
(GNU ld.bfd also got support for the same new directive, currently in
the latest git version, after the 2.39 branch.)
This works as an inverse to the regular embedded dllexport directives,
for cases when autoexport of all eligible symbols is performed.
Differential Revision: https://reviews.llvm.org/D130120
(cherry picked from commit 5d513ef6cf4646e64bbb1d5f8610afd530964588)
Added:
lld/test/COFF/exclude-symbols-embedded.s
Modified:
lld/COFF/Driver.cpp
lld/COFF/Driver.h
lld/COFF/DriverUtils.cpp
lld/COFF/MinGW.cpp
lld/COFF/MinGW.h
lld/docs/ReleaseNotes.rst
Removed:
################################################################################
diff --git a/lld/COFF/Driver.cpp b/lld/COFF/Driver.cpp
index 5e5c7a974fa9e..680f89b79b958 100644
--- a/lld/COFF/Driver.cpp
+++ b/lld/COFF/Driver.cpp
@@ -372,6 +372,14 @@ void LinkerDriver::parseDirectives(InputFile *file) {
for (StringRef inc : directives.includes)
addUndefined(inc);
+ // Handle /exclude-symbols: in bulk.
+ for (StringRef e : directives.excludes) {
+ SmallVector<StringRef, 2> vec;
+ e.split(vec, ',');
+ for (StringRef sym : vec)
+ excludedSymbols.insert(mangle(sym));
+ }
+
// https://docs.microsoft.com/en-us/cpp/preprocessor/comment-c-cpp?view=msvc-160
for (auto *arg : directives.args) {
switch (arg->getOption().getID()) {
@@ -1306,7 +1314,7 @@ void LinkerDriver::maybeExportMinGWSymbols(const opt::InputArgList &args) {
return;
}
- AutoExporter exporter;
+ AutoExporter exporter(excludedSymbols);
for (auto *arg : args.filtered(OPT_wholearchive_file))
if (Optional<StringRef> path = doFindFile(arg->getValue()))
diff --git a/lld/COFF/Driver.h b/lld/COFF/Driver.h
index 955ec200da7dc..129a3d9c7317a 100644
--- a/lld/COFF/Driver.h
+++ b/lld/COFF/Driver.h
@@ -54,6 +54,7 @@ extern COFFOptTable optTable;
struct ParsedDirectives {
std::vector<StringRef> exports;
std::vector<StringRef> includes;
+ std::vector<StringRef> excludes;
llvm::opt::InputArgList args;
};
@@ -160,6 +161,7 @@ class LinkerDriver {
std::vector<MemoryBufferRef> resources;
llvm::DenseSet<StringRef> directivesExports;
+ llvm::DenseSet<StringRef> excludedSymbols;
COFFLinkerContext &ctx;
diff --git a/lld/COFF/DriverUtils.cpp b/lld/COFF/DriverUtils.cpp
index 29a2d01658391..cdfe8587f3fa9 100644
--- a/lld/COFF/DriverUtils.cpp
+++ b/lld/COFF/DriverUtils.cpp
@@ -909,6 +909,9 @@ ParsedDirectives ArgParser::parseDirectives(StringRef s) {
else if (tok.startswith_insensitive("/include:") ||
tok.startswith_insensitive("-include:"))
result.includes.push_back(tok.substr(strlen("/include:")));
+ else if (tok.startswith_insensitive("/exclude-symbols:") ||
+ tok.startswith_insensitive("-exclude-symbols:"))
+ result.excludes.push_back(tok.substr(strlen("/exclude-symbols:")));
else {
// Copy substrings that are not valid C strings. The tokenizer may have
// already copied quoted arguments for us, so those do not need to be
diff --git a/lld/COFF/MinGW.cpp b/lld/COFF/MinGW.cpp
index 190f4388902e5..0689e44cc3639 100644
--- a/lld/COFF/MinGW.cpp
+++ b/lld/COFF/MinGW.cpp
@@ -23,7 +23,9 @@ using namespace llvm::COFF;
using namespace lld;
using namespace lld::coff;
-AutoExporter::AutoExporter() {
+AutoExporter::AutoExporter(
+ const llvm::DenseSet<StringRef> &manualExcludeSymbols)
+ : manualExcludeSymbols(manualExcludeSymbols) {
excludeLibs = {
"libgcc",
"libgcc_s",
@@ -135,7 +137,7 @@ bool AutoExporter::shouldExport(const COFFLinkerContext &ctx,
// disallow import symbols.
if (!isa<DefinedRegular>(sym) && !isa<DefinedCommon>(sym))
return false;
- if (excludeSymbols.count(sym->getName()))
+ if (excludeSymbols.count(sym->getName()) || manualExcludeSymbols.count(sym->getName()))
return false;
for (StringRef prefix : excludeSymbolPrefixes.keys())
diff --git a/lld/COFF/MinGW.h b/lld/COFF/MinGW.h
index 4b65c20ec4466..5f2bbe4e99201 100644
--- a/lld/COFF/MinGW.h
+++ b/lld/COFF/MinGW.h
@@ -13,6 +13,7 @@
#include "Symbols.h"
#include "lld/Common/LLVM.h"
#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/Option/ArgList.h"
#include <vector>
@@ -25,7 +26,7 @@ class COFFLinkerContext;
// symbols for MinGW.
class AutoExporter {
public:
- AutoExporter();
+ AutoExporter(const llvm::DenseSet<StringRef> &manualExcludeSymbols);
void addWholeArchive(StringRef path);
void addExcludedSymbol(StringRef symbol);
@@ -36,6 +37,8 @@ class AutoExporter {
llvm::StringSet<> excludeLibs;
llvm::StringSet<> excludeObjects;
+ const llvm::DenseSet<StringRef> &manualExcludeSymbols;
+
bool shouldExport(const COFFLinkerContext &ctx, Defined *sym) const;
};
diff --git a/lld/docs/ReleaseNotes.rst b/lld/docs/ReleaseNotes.rst
index 21b3bade9d440..5819d67d32971 100644
--- a/lld/docs/ReleaseNotes.rst
+++ b/lld/docs/ReleaseNotes.rst
@@ -90,6 +90,9 @@ MinGW Improvements
* The ``--exclude-symbols`` option is now supported.
(`D130118 <https://reviews.llvm.org/D130118>`_)
+* Support for an entirely new object file directive, ``-exclude-symbols:``,
+ has been implemented. (`D130120 <https://reviews.llvm.org/D130120>`_)
+
MachO Improvements
------------------
diff --git a/lld/test/COFF/exclude-symbols-embedded.s b/lld/test/COFF/exclude-symbols-embedded.s
new file mode 100644
index 0000000000000..9ea8ed479d20e
--- /dev/null
+++ b/lld/test/COFF/exclude-symbols-embedded.s
@@ -0,0 +1,24 @@
+// 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
+// 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
+
+.section .drectve,"yn"
+.ascii " -exclude-symbols:sym2,unknownsym"
+.ascii " -exclude-symbols:unkonwnsym,sym3"
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