[llvm-objcopy] Add --strip-unneeded-symbol(s)
Differential revision: https://reviews.llvm.org/D58027
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353919 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/tools/llvm-objcopy/COFF/strip-unneeded.test b/test/tools/llvm-objcopy/COFF/strip-unneeded.test
index 569bc8a..ca3efe4 100644
--- a/test/tools/llvm-objcopy/COFF/strip-unneeded.test
+++ b/test/tools/llvm-objcopy/COFF/strip-unneeded.test
@@ -5,6 +5,13 @@
RUN: llvm-objcopy --strip-unneeded %t.in.o %t.out.o
RUN: llvm-objdump -t %t.out.o | FileCheck %s --check-prefix=SYMBOLS
+RUN: llvm-objcopy --strip-unneeded-symbol=external_undefined_unreferenced \
+RUN: --strip-unneeded-symbol=local_unreferenced \
+RUN: --strip-unneeded-symbol=local_undefined_unreferenced \
+RUN: --strip-unneeded-symbol='@feat.00' \
+RUN: %t.in.o %t.out2.o
+RUN: cmp %t.out.o %t.out2.o
+
SYMBOLS: SYMBOL TABLE:
SYMBOLS-NEXT: external
SYMBOLS-NEXT: external_undefined
diff --git a/test/tools/llvm-objcopy/ELF/strip-unneeded.test b/test/tools/llvm-objcopy/ELF/strip-unneeded.test
index 6d5682f..60d8388 100644
--- a/test/tools/llvm-objcopy/ELF/strip-unneeded.test
+++ b/test/tools/llvm-objcopy/ELF/strip-unneeded.test
@@ -5,6 +5,24 @@
# RUN: cmp %t %t1
# RUN: llvm-readobj --symbols %t2 | FileCheck %s
+# RUN: llvm-objcopy --strip-unneeded-symbol=bar \
+# RUN: %t %t3
+# RUN: llvm-readobj --symbols %t3 | FileCheck %s --check-prefixes=STRIP-BAR,REMAIN
+
+# RUN: llvm-objcopy --regex --strip-unneeded-symbol='.*' %t %t4
+# RUN: cmp %t2 %t4
+
+# RUN: echo " bar # bar " > %t.list.txt
+# RUN: echo "foobar" >> %t.list.txt
+# RUN: echo "foobaz" >> %t.list.txt
+# RUN: echo " # comment " >> %t.list.txt
+# RUN: llvm-objcopy --strip-unneeded-symbols %t.list.txt %t %t5
+# RUN: cmp %t2 %t5
+
+# RUN: echo " .* # * - remove all " > %t.list2.txt
+# RUN: llvm-objcopy --regex --strip-unneeded-symbols %t.list2.txt %t %t6
+# RUN: cmp %t2 %t6
+
# Verify that llvm-strip modifies the symbol table the same way.
# RUN: llvm-strip --strip-unneeded %t
# RUN: cmp %t %t2
@@ -141,3 +159,7 @@
#CHECK-NEXT: Section: .text
#CHECK-NEXT: }
#CHECK-NEXT:]
+
+#STRIP-BAR-NOT: Name: bar ({{.*}})
+#REMAIN: Name: foobar
+#REMAIN: Name: foobaz
diff --git a/tools/llvm-objcopy/COFF/COFFObjcopy.cpp b/tools/llvm-objcopy/COFF/COFFObjcopy.cpp
index 72161e1..7923ef2 100644
--- a/tools/llvm-objcopy/COFF/COFFObjcopy.cpp
+++ b/tools/llvm-objcopy/COFF/COFFObjcopy.cpp
@@ -151,10 +151,13 @@
if (!Sym.Referenced) {
// With --strip-unneeded, GNU objcopy removes all unreferenced local
// symbols, and any unreferenced undefined external.
- if (Config.StripUnneeded &&
- (Sym.Sym.StorageClass == IMAGE_SYM_CLASS_STATIC ||
- Sym.Sym.SectionNumber == 0))
- return true;
+ // With --strip-unneeded-symbol we strip only specific unreferenced
+ // local symbol instead of removing all of such.
+ if (Sym.Sym.StorageClass == IMAGE_SYM_CLASS_STATIC ||
+ Sym.Sym.SectionNumber == 0)
+ if (Config.StripUnneeded ||
+ is_contained(Config.UnneededSymbolsToRemove, Sym.Name))
+ return true;
// GNU objcopy keeps referenced local symbols and external symbols
// if --discard-all is set, similar to what --strip-unneeded does,
diff --git a/tools/llvm-objcopy/CopyConfig.cpp b/tools/llvm-objcopy/CopyConfig.cpp
index f643cb4..811f8b7 100644
--- a/tools/llvm-objcopy/CopyConfig.cpp
+++ b/tools/llvm-objcopy/CopyConfig.cpp
@@ -468,6 +468,11 @@
for (auto Arg : InputArgs.filtered(OBJCOPY_strip_symbols))
addSymbolsFromFile(Config.SymbolsToRemove, DC.Alloc, Arg->getValue(),
UseRegex);
+ for (auto Arg : InputArgs.filtered(OBJCOPY_strip_unneeded_symbol))
+ Config.UnneededSymbolsToRemove.emplace_back(Arg->getValue(), UseRegex);
+ for (auto Arg : InputArgs.filtered(OBJCOPY_strip_unneeded_symbols))
+ addSymbolsFromFile(Config.UnneededSymbolsToRemove, DC.Alloc,
+ Arg->getValue(), UseRegex);
for (auto Arg : InputArgs.filtered(OBJCOPY_keep_symbol))
Config.SymbolsToKeep.emplace_back(Arg->getValue(), UseRegex);
diff --git a/tools/llvm-objcopy/CopyConfig.h b/tools/llvm-objcopy/CopyConfig.h
index b038604..f1d5cf2 100644
--- a/tools/llvm-objcopy/CopyConfig.h
+++ b/tools/llvm-objcopy/CopyConfig.h
@@ -91,6 +91,7 @@
std::vector<NameOrRegex> SymbolsToKeep;
std::vector<NameOrRegex> SymbolsToLocalize;
std::vector<NameOrRegex> SymbolsToRemove;
+ std::vector<NameOrRegex> UnneededSymbolsToRemove;
std::vector<NameOrRegex> SymbolsToWeaken;
std::vector<NameOrRegex> ToRemove;
std::vector<NameOrRegex> SymbolsToKeepGlobal;
diff --git a/tools/llvm-objcopy/ELF/ELFObjcopy.cpp b/tools/llvm-objcopy/ELF/ELFObjcopy.cpp
index fc34387..4d2e78a 100644
--- a/tools/llvm-objcopy/ELF/ELFObjcopy.cpp
+++ b/tools/llvm-objcopy/ELF/ELFObjcopy.cpp
@@ -268,6 +268,12 @@
};
}
+static bool isUnneededSymbol(const Symbol &Sym) {
+ return !Sym.Referenced &&
+ (Sym.Binding == STB_LOCAL || Sym.getShndx() == SHN_UNDEF) &&
+ Sym.Type != STT_FILE && Sym.Type != STT_SECTION;
+}
+
// This function handles the high level operations of GNU objcopy including
// handling command line options. It's important to outline certain properties
// we expect to hold of the command line operations. Any operation that "keeps"
@@ -336,7 +342,7 @@
// The purpose of this loop is to mark symbols referenced by sections
// (like GroupSection or RelocationSection). This way, we know which
// symbols are still 'needed' and which are not.
- if (Config.StripUnneeded) {
+ if (Config.StripUnneeded || !Config.UnneededSymbolsToRemove.empty()) {
for (auto &Section : Obj.sections())
Section.markSymbols();
}
@@ -359,9 +365,9 @@
if (is_contained(Config.SymbolsToRemove, Sym.Name))
return true;
- if (Config.StripUnneeded && !Sym.Referenced &&
- (Sym.Binding == STB_LOCAL || Sym.getShndx() == SHN_UNDEF) &&
- Sym.Type != STT_FILE && Sym.Type != STT_SECTION)
+ if ((Config.StripUnneeded ||
+ is_contained(Config.UnneededSymbolsToRemove, Sym.Name)) &&
+ isUnneededSymbol(Sym))
return true;
return false;
diff --git a/tools/llvm-objcopy/ObjcopyOpts.td b/tools/llvm-objcopy/ObjcopyOpts.td
index 12d619e..b317219 100644
--- a/tools/llvm-objcopy/ObjcopyOpts.td
+++ b/tools/llvm-objcopy/ObjcopyOpts.td
@@ -122,6 +122,15 @@
HelpText<"Remove all non-allocated sections">;
def strip_unneeded : Flag<["-", "--"], "strip-unneeded">,
HelpText<"Remove all symbols not needed by relocations">;
+defm strip_unneeded_symbol
+ : Eq<"strip-unneeded-symbol",
+ "Remove symbol <symbol> if it is not needed by relocations">,
+ MetaVarName<"symbol">;
+defm strip_unneeded_symbols
+ : Eq<"strip-unneeded-symbols",
+ "Reads a list of symbols from <filename> and removes them "
+ "if they are not needed by relocations">,
+ MetaVarName<"filename">;
def extract_dwo
: Flag<["-", "--"], "extract-dwo">,
