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nurmukhametovnurmukhametov
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[LLD][COFF] Support /DEPENDENTLOADFLAGS[:flags]
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8 files changed

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8 files changed

+117
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lines changed

‎lld/COFF/Config.h

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@@ -287,6 +287,7 @@ struct Configuration {
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uint32_t timestamp = 0;
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uint32_t functionPadMin = 0;
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uint32_t timeTraceGranularity = 0;
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uint16_t dependentLoadFlags = 0;
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bool dynamicBase = true;
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bool allowBind = true;
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bool cetCompat = false;

‎lld/COFF/Driver.cpp

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@@ -2179,6 +2179,11 @@ void LinkerDriver::linkerMain(ArrayRef<const char *> argsArr) {
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for (auto *arg : args.filtered(OPT_functionpadmin, OPT_functionpadmin_opt))
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parseFunctionPadMin(arg);
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// Handle /dependentloadflag
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for (auto *arg :
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args.filtered(OPT_dependentloadflag, OPT_dependentloadflag_opt))
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parseDependentLoadFlags(arg);
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if (tar) {
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llvm::TimeTraceScope timeScope("Reproducer: response file");
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tar->append("response.txt",

‎lld/COFF/Driver.h

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@@ -233,6 +233,9 @@ class LinkerDriver {
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// Parses a string in the form of "[:<integer>]"
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void parseFunctionPadMin(llvm::opt::Arg *a);
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// Parses a string in the form of "[:<integer>]"
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void parseDependentLoadFlags(llvm::opt::Arg *a);
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// Parses a string in the form of "EMBED[,=<integer>]|NO".
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void parseManifest(StringRef arg);
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‎lld/COFF/DriverUtils.cpp

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@@ -265,6 +265,19 @@ void LinkerDriver::parseFunctionPadMin(llvm::opt::Arg *a) {
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}
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}
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// Parses /dependentloadflag option argument.
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void LinkerDriver::parseDependentLoadFlags(llvm::opt::Arg *a) {
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StringRef arg = a->getNumValues() ? a->getValue() : "";
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if (!arg.empty()) {
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if (arg.getAsInteger(0, ctx.config.dependentLoadFlags))
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error("/dependentloadflag: invalid argument: " + arg);
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return;
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}
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// MSVC linker reports error "no argument specified", although MSDN describes
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// argument as optional.
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error("no argument specified with option '/dependentloadflag'");
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}
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// Parses a string in the form of "EMBED[,=<integer>]|NO".
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// Results are directly written to
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// Config.

‎lld/COFF/Options.td

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@@ -56,6 +56,9 @@ def filealign : P<"filealign", "Section alignment in the output file">;
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def functionpadmin : F<"functionpadmin">;
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def functionpadmin_opt : P<"functionpadmin",
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"Prepares an image for hotpatching">;
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def dependentloadflag : F<"dependentloadflag">;
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def dependentloadflag_opt : P<"dependentloadflag",
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"Sets the default load flags used to resolve the statically linked imports of a module">;
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def guard : P<"guard", "Control flow guard">;
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def heap : P<"heap", "Size of the heap">;
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def ignore : P<"ignore", "Specify warning codes to ignore">;

‎lld/COFF/Writer.cpp

Lines changed: 32 additions & 0 deletions
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@@ -264,6 +264,9 @@ class Writer {
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uint32_t getSizeOfInitializedData();
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void changeLoadConfig();
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template <typename T> void changeLoadConfigGuardData(T *loadConfig);
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void checkLoadConfig();
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template <typename T> void checkLoadConfigGuardData(const T *loadConfig);
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@@ -696,6 +699,9 @@ void Writer::run() {
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writeHeader<pe32_header>();
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}
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writeSections();
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if (ctx.config.dependentLoadFlags) {
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changeLoadConfig();
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}
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checkLoadConfig();
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sortExceptionTable();
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@@ -2256,6 +2262,32 @@ void Writer::fixTlsAlignment() {
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}
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}
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void Writer::changeLoadConfig() {
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Symbol *sym = ctx.symtab.findUnderscore("_load_config_used");
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auto *b = cast_if_present<DefinedRegular>(sym);
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if (!b) {
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if (ctx.config.guardCF != GuardCFLevel::Off)
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warn("Control Flow Guard is enabled but '_load_config_used' is missing");
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return;
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}
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OutputSection *sec = ctx.getOutputSection(b->getChunk());
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uint8_t *buf = buffer->getBufferStart();
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uint8_t *secBuf = buf + sec->getFileOff();
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uint8_t *symBuf = secBuf + (b->getRVA() - sec->getRVA());
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if (ctx.config.is64())
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changeLoadConfigGuardData(
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reinterpret_cast<coff_load_configuration64 *>(symBuf));
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else
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changeLoadConfigGuardData(
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reinterpret_cast<coff_load_configuration32 *>(symBuf));
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}
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template <typename T> void Writer::changeLoadConfigGuardData(T *loadConfig) {
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if (ctx.config.dependentLoadFlags)
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loadConfig->DependentLoadFlags = ctx.config.dependentLoadFlags;
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}
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void Writer::checkLoadConfig() {
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Symbol *sym = ctx.symtab.findUnderscore("_load_config_used");
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auto *b = cast_if_present<DefinedRegular>(sym);

‎lld/test/COFF/dependentflags.test

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@@ -0,0 +1,29 @@
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// ---- precomp-a.obj - x86_64, hotpatch
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RUN: llvm-mc -triple x86_64-windows-msvc -filetype=obj %S/Inputs/loadconfig-cfg-x64.s -o %t.ldcfg.obj
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RUN: lld-link %S/Inputs/precomp-a.obj %t.ldcfg.obj /out:%t.exe /nodefaultlib /force
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RUN: llvm-readobj --coff-load-config %t.exe | FileCheck %s --check-prefix BASE
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RUN: lld-link %S/Inputs/precomp-a.obj %t.ldcfg.obj /out:%t.exe /nodefaultlib /force /dependentloadflag:0x800
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RUN: llvm-readobj --coff-load-config %t.exe | FileCheck %s --check-prefix FLAGS-800
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// ---- Many arguments
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RUN: lld-link %S/Inputs/precomp-a.obj %t.ldcfg.obj /out:%t.exe /nodefaultlib /force /dependentloadflag:0x400 /dependentloadflag:0x800
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RUN: llvm-readobj --coff-load-config %t.exe | FileCheck %s --check-prefix FLAGS-800
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RUN: lld-link %S/Inputs/precomp-a.obj %t.ldcfg.obj /out:%t.exe /nodefaultlib /force /dependentloadflag:0x800 /dependentloadflag:0x400
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RUN: llvm-readobj --coff-load-config %t.exe | FileCheck %s --check-prefix FLAGS-400
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RUN: not lld-link %S/Inputs/precomp-a.obj %t.ldcfg.obj /out:%t.exe /nodefaultlib /force /dependentloadflag 2>&1 | FileCheck %s --check-prefix FAIL-NOARG
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RUN: not lld-link %S/Inputs/precomp-a.obj %t.ldcfg.obj /out:%t.exe /nodefaultlib /force /dependentloadflag:zz 2>&1 | FileCheck %s --check-prefix FAIL
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RUN: not lld-link %S/Inputs/precomp-a.obj %t.ldcfg.obj /out:%t.exe /nodefaultlib /force /dependentloadflag:0xf0000 2>&1 | FileCheck %s --check-prefix FAIL-RANGE
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BASE: DependentLoadFlags: 0x0
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FLAGS-800: DependentLoadFlags: 0x800
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FLAGS-400: DependentLoadFlags: 0x400
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FAIL: lld-link: error: /dependentloadflag: invalid argument: zz
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FAIL-RANGE: lld-link: error: /dependentloadflag: invalid argument: 0xf0000
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FAIL-NOARG: lld-link: error: no argument specified with option '/dependentloadflag'
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‎lld/test/COFF/deploadflag-cfg-x64.s

Lines changed: 31 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,31 @@
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# RUN: llvm-mc -triple x86_64-windows-msvc -filetype=obj %s -o %t.ldcfg.obj
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# RUN: lld-link %S/Inputs/precomp-a.obj %t.ldcfg.obj /out:%t.exe /nodefaultlib /force
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# RUN: llvm-readobj --coff-load-config %t.exe | FileCheck %s --check-prefix FLAGS-400
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# RUN: lld-link %S/Inputs/precomp-a.obj %t.ldcfg.obj /out:%t.exe /nodefaultlib /force /dependentloadflag:0x800
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# RUN: llvm-readobj --coff-load-config %t.exe | FileCheck %s --check-prefix FLAGS-800
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# MSVC linker does not rewrite non-zero value of dependentloadflag in _load_config_used with zero
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# RUN: lld-link %S/Inputs/precomp-a.obj %t.ldcfg.obj /out:%t.exe /nodefaultlib /force /dependentloadflag:0x0
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# RUN: llvm-readobj --coff-load-config %t.exe | FileCheck %s --check-prefix FLAGS-400
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# RUN: lld-link %S/Inputs/precomp-a.obj %t.ldcfg.obj /out:%t.exe /nodefaultlib /force /dependentloadflag:0x800 /dependentloadflag:0x0
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# RUN: llvm-readobj --coff-load-config %t.exe | FileCheck %s --check-prefix FLAGS-400
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# FLAGS-800: DependentLoadFlags: 0x800
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# FLAGS-400: DependentLoadFlags: 0x400
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.section .rdata,"dr"
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.globl _load_config_used
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_load_config_used:
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.long 256
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.fill 74, 1, 0
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.byte 0x00
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.byte 0x40
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.fill 48, 1, 0
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.quad __guard_fids_table
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.quad __guard_fids_count
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.long __guard_flags
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.fill 128, 1, 0
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