[lld] r286713 - [ELF] - Add support for locals list in version script.
Rafael Espíndola via llvm-commits
llvm-commits at lists.llvm.org
Tue Nov 15 08:42:29 PST 2016
"local:" is special in that it is not actually part of any version.
Having two "local: *" will not change the result. I would then suggest
moving the Locals vector out of VersionDefinition and into
Configuration.
Cheers,
Rafael
On 12 November 2016 at 02:04, George Rimar via llvm-commits
<llvm-commits at lists.llvm.org> wrote:
> Author: grimar
> Date: Sat Nov 12 01:04:15 2016
> New Revision: 286713
>
> URL: http://llvm.org/viewvc/llvm-project?rev=286713&view=rev
> Log:
> [ELF] - Add support for locals list in version script.
>
> Previously we did not support anything except "local: *", patch changes that.
>
> Actually GNU rules of proccessing wildcards are more complex than that (http://www.airs.com/blog/archives/300):
> There are 2 iteration for wildcards, at first iteration "*" wildcards are ignored and handled at second iteration.
>
> Since we previously decided not to implement such complex rules,
> I suggest solution that is implemented in this patch. So for "local: *" case nothing changes,
> but if we have wildcarded locals,
> they are processed before wildcarded globals.
>
> This should fix several FreeBSD ports, one of them is jpeg-turbo-1.5.1 and
> currently blocks about 5k of ports.
>
> Differential revision: https://reviews.llvm.org/D26395
>
> Added:
> lld/trunk/test/ELF/version-script-locals.s
> Modified:
> lld/trunk/ELF/Config.h
> lld/trunk/ELF/LinkerScript.cpp
> lld/trunk/ELF/SymbolTable.cpp
>
> Modified: lld/trunk/ELF/Config.h
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Config.h?rev=286713&r1=286712&r2=286713&view=diff
> ==============================================================================
> --- lld/trunk/ELF/Config.h (original)
> +++ lld/trunk/ELF/Config.h Sat Nov 12 01:04:15 2016
> @@ -62,6 +62,7 @@ struct VersionDefinition {
> llvm::StringRef Name;
> size_t Id;
> std::vector<SymbolVersion> Globals;
> + std::vector<SymbolVersion> Locals;
> size_t NameOff; // Offset in string table.
> };
>
>
> Modified: lld/trunk/ELF/LinkerScript.cpp
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LinkerScript.cpp?rev=286713&r1=286712&r2=286713&view=diff
> ==============================================================================
> --- lld/trunk/ELF/LinkerScript.cpp (original)
> +++ lld/trunk/ELF/LinkerScript.cpp Sat Nov 12 01:04:15 2016
> @@ -968,7 +968,7 @@ private:
> void readExtern(std::vector<SymbolVersion> *Globals);
> void readVersionDeclaration(StringRef VerStr);
> void readGlobal(StringRef VerStr);
> - void readLocal();
> + void readLocal(StringRef VerStr);
>
> ScriptConfiguration &Opt = *ScriptConfig;
> bool IsUnderSysroot;
> @@ -1778,7 +1778,7 @@ void ScriptParser::readVersionDeclaratio
> if (consume("global:") || peek() != "local:")
> readGlobal(VerStr);
> if (consume("local:"))
> - readLocal();
> + readLocal(VerStr);
> expect("}");
>
> // Each version may have a parent version. For example, "Ver2" defined as
> @@ -1790,10 +1790,22 @@ void ScriptParser::readVersionDeclaratio
> expect(";");
> }
>
> -void ScriptParser::readLocal() {
> - Config->DefaultSymbolVersion = VER_NDX_LOCAL;
> - expect("*");
> - expect(";");
> +void ScriptParser::readLocal(StringRef VerStr) {
> + if (consume("*")) {
> + Config->DefaultSymbolVersion = VER_NDX_LOCAL;
> + expect(";");
> + return;
> + }
> +
> + if (VerStr.empty())
> + setError("locals list for anonymous version is not supported");
> +
> + std::vector<SymbolVersion> &Locals = Config->VersionDefinitions.back().Locals;
> + while (!Error && peek() != "}") {
> + StringRef Tok = next();
> + Locals.push_back({unquote(Tok), false, hasWildcard(Tok)});
> + expect(";");
> + }
> }
>
> void ScriptParser::readExtern(std::vector<SymbolVersion> *Globals) {
>
> Modified: lld/trunk/ELF/SymbolTable.cpp
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/SymbolTable.cpp?rev=286713&r1=286712&r2=286713&view=diff
> ==============================================================================
> --- lld/trunk/ELF/SymbolTable.cpp (original)
> +++ lld/trunk/ELF/SymbolTable.cpp Sat Nov 12 01:04:15 2016
> @@ -700,28 +700,37 @@ template <class ELFT> void SymbolTable<E
> }
> setVersionId(find(N), V.Name, N, V.Id);
> }
> + for (SymbolVersion Sym : V.Locals) {
> + if (Sym.HasWildcards)
> + continue;
> + setVersionId(find(Sym.Name), V.Name, Sym.Name, VER_NDX_LOCAL);
> + }
> }
>
> // Next, we assign versions to fuzzy matching symbols,
> // i.e. version definitions containing glob meta-characters.
> // Note that because the last match takes precedence over previous matches,
> // we iterate over the definitions in the reverse order.
> + auto assignFuzzyVersion = [&](SymbolVersion &Sym, size_t Version) {
> + if (!Sym.HasWildcards)
> + return;
> + StringMatcher M({Sym.Name});
> + std::vector<SymbolBody *> Syms =
> + Sym.IsExternCpp ? findAllDemangled(Demangled, M) : findAll(M);
> + // Exact matching takes precendence over fuzzy matching,
> + // so we set a version to a symbol only if no version has been assigned
> + // to the symbol. This behavior is compatible with GNU.
> + for (SymbolBody *B : Syms)
> + if (B->symbol()->VersionId == Config->DefaultSymbolVersion)
> + B->symbol()->VersionId = Version;
> + };
> +
> for (size_t I = Config->VersionDefinitions.size() - 1; I != (size_t)-1; --I) {
> VersionDefinition &V = Config->VersionDefinitions[I];
> - for (SymbolVersion &Sym : V.Globals) {
> - if (!Sym.HasWildcards)
> - continue;
> - StringMatcher M({Sym.Name});
> - std::vector<SymbolBody *> Syms =
> - Sym.IsExternCpp ? findAllDemangled(Demangled, M) : findAll(M);
> -
> - // Exact matching takes precendence over fuzzy matching,
> - // so we set a version to a symbol only if no version has been assigned
> - // to the symbol. This behavior is compatible with GNU.
> - for (SymbolBody *B : Syms)
> - if (B->symbol()->VersionId == Config->DefaultSymbolVersion)
> - B->symbol()->VersionId = V.Id;
> - }
> + for (SymbolVersion &Sym : V.Locals)
> + assignFuzzyVersion(Sym, VER_NDX_LOCAL);
> + for (SymbolVersion &Sym : V.Globals)
> + assignFuzzyVersion(Sym, V.Id);
> }
> }
>
>
> Added: lld/trunk/test/ELF/version-script-locals.s
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/version-script-locals.s?rev=286713&view=auto
> ==============================================================================
> --- lld/trunk/test/ELF/version-script-locals.s (added)
> +++ lld/trunk/test/ELF/version-script-locals.s Sat Nov 12 01:04:15 2016
> @@ -0,0 +1,50 @@
> +# REQUIRES: x86
> +# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
> +
> +# RUN: echo "VERSION_1.0 { local: foo1; };" > %t.script
> +# RUN: ld.lld --version-script %t.script -shared %t.o -o %t.so
> +# RUN: llvm-readobj -dyn-symbols %t.so | FileCheck --check-prefix=EXACT %s
> +# EXACT: DynamicSymbols [
> +# EXACT: _start
> +# EXACT-NOT: foo1
> +# EXACT: foo2
> +# EXACT: foo3
> +
> +# RUN: echo "VERSION_1.0 { local: foo*; };" > %t.script
> +# RUN: ld.lld --version-script %t.script -shared %t.o -o %t.so
> +# RUN: llvm-readobj -dyn-symbols %t.so | FileCheck --check-prefix=WC %s
> +# WC: DynamicSymbols [
> +# WC: _start
> +# WC-NOT: foo1
> +# WC-NOT: foo2
> +# WC-NOT: foo3
> +
> +# RUN: echo "VERSION_1.0 { global: *; local: foo*; };" > %t.script
> +# RUN: ld.lld --version-script %t.script -shared %t.o -o %t.so
> +# RUN: llvm-readobj -dyn-symbols %t.so | FileCheck --check-prefix=MIX %s
> +# MIX: DynamicSymbols [
> +# MIX: _start@@VERSION_1.0
> +# MIX-NOT: foo1
> +# MIX-NOT: foo2
> +# MIX-NOT: foo3
> +
> +# RUN: echo "VERSION_1.0 { global: *; local: extern \"C++\" { foo*; } };" > %t.script
> +# RUN: not ld.lld --version-script %t.script -shared %t.o -o %t.so 2>&1 \
> +# RUN: | FileCheck --check-prefix=EXTERNERR %s
> +# EXTERNERR: ; expected, but got "C++"
> +
> +.globl foo1
> +foo1:
> + ret
> +
> +.globl foo2
> +foo2:
> + ret
> +
> +.globl foo3
> +foo3:
> + ret
> +
> +.globl _start
> +_start:
> + ret
>
>
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