[llvm-objcopy] Add change-section-lma *+/-offset

llvm/docs/CommandGuide/llvm-objcopy.rst

@@ -299,6 +299,10 @@ them.
  Allow :program:`llvm-objcopy` to remove sections even if it would leave invalid
  section references. Any invalid sh_link fields will be set to zero.
 
+.. option:: --change-section-lma \*{+-}<val>
+
+ Shift LMA of non-zero-sized segments by ``<val>``.
+
 .. option:: --change-start <incr>, --adjust-start
 
  Add ``<incr>`` to the program's start address. Can be specified multiple

llvm/include/llvm/ObjCopy/CommonConfig.h

@@ -245,6 +245,9 @@ struct CommonConfig {
   // Symbol info specified by --add-symbol option.
   SmallVector<NewSymbolInfo, 0> SymbolsToAdd;
 
+  // Integer options
+  int64_t ChangeSectionLMAValAll = 0;
+
   // Boolean options
   bool DeterministicArchives = true;
   bool ExtractDWO = false;

llvm/lib/ObjCopy/ConfigManager.cpp

@@ -25,7 +25,8 @@ Expected<const COFFConfig &> ConfigManager::getCOFFConfig() const {
       Common.StripNonAlloc || Common.StripSections || Common.Weaken ||
       Common.DecompressDebugSections ||
       Common.DiscardMode == DiscardType::Locals ||
-      !Common.SymbolsToAdd.empty() || Common.GapFill != 0 || Common.PadTo != 0)
+      !Common.SymbolsToAdd.empty() || Common.GapFill != 0 ||
+      Common.PadTo != 0 || Common.ChangeSectionLMAValAll != 0)
     return createStringError(llvm::errc::invalid_argument,
                              "option is not supported for COFF");
 
@@ -46,7 +47,8 @@ Expected<const MachOConfig &> ConfigManager::getMachOConfig() const {
       Common.StripNonAlloc || Common.StripSections ||
       Common.DecompressDebugSections || Common.StripUnneeded ||
       Common.DiscardMode == DiscardType::Locals ||
-      !Common.SymbolsToAdd.empty() || Common.GapFill != 0 || Common.PadTo != 0)
+      !Common.SymbolsToAdd.empty() || Common.GapFill != 0 ||
+      Common.PadTo != 0 || Common.ChangeSectionLMAValAll != 0)
     return createStringError(llvm::errc::invalid_argument,
                              "option is not supported for MachO");
 
@@ -66,7 +68,7 @@ Expected<const WasmConfig &> ConfigManager::getWasmConfig() const {
       !Common.SectionsToRename.empty() || !Common.SetSectionAlignment.empty() ||
       !Common.SetSectionFlags.empty() || !Common.SetSectionType.empty() ||
       !Common.SymbolsToRename.empty() || Common.GapFill != 0 ||
-      Common.PadTo != 0)
+      Common.PadTo != 0 || Common.ChangeSectionLMAValAll != 0)
     return createStringError(llvm::errc::invalid_argument,
                              "only flags for section dumping, removal, and "
                              "addition are supported");
@@ -94,7 +96,8 @@ Expected<const XCOFFConfig &> ConfigManager::getXCOFFConfig() const {
       Common.PreserveDates || Common.StripAllGNU || Common.StripDWO ||
       Common.StripDebug || Common.StripNonAlloc || Common.StripSections ||
       Common.Weaken || Common.StripUnneeded || Common.DecompressDebugSections ||
-      Common.GapFill != 0 || Common.PadTo != 0) {
+      Common.GapFill != 0 || Common.PadTo != 0 ||
+      Common.ChangeSectionLMAValAll != 0) {
     return createStringError(
         llvm::errc::invalid_argument,
         "no flags are supported yet, only basic copying is allowed");

llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp

@@ -670,6 +670,33 @@ static Error handleArgs(const CommonConfig &Config, const ELFConfig &ELFConfig,
     }
   }
 
+  if (Config.ChangeSectionLMAValAll != 0) {
+    for (Segment &Seg : Obj.segments()) {
+      if (Seg.FileSize > 0) {
+        if (Config.ChangeSectionLMAValAll > 0 &&
+            Seg.PAddr > std::numeric_limits<uint64_t>::max() -
+                            Config.ChangeSectionLMAValAll) {
+          return createStringError(
+              errc::invalid_argument,
+              "address 0x" + Twine::utohexstr(Seg.PAddr) +
+                  " cannot be increased by 0x" +
+                  Twine::utohexstr(Config.ChangeSectionLMAValAll) +
+                  ". The result would overflow");
+        } else if (Config.ChangeSectionLMAValAll < 0 &&
+                   Seg.PAddr < std::numeric_limits<uint64_t>::min() -
+                                   Config.ChangeSectionLMAValAll) {
+          return createStringError(
+              errc::invalid_argument,
+              "address 0x" + Twine::utohexstr(Seg.PAddr) +
+                  " cannot be decreased by 0x" +
+                  Twine::utohexstr(std::abs(Config.ChangeSectionLMAValAll)) +
+                  ". The result would underflow");
+        }
+        Seg.PAddr += Config.ChangeSectionLMAValAll;
+      }
+    }
+  }
+
   if (Config.OnlyKeepDebug)
     for (auto &Sec : Obj.sections())
       if (Sec.Flags & SHF_ALLOC && Sec.Type != SHT_NOTE)

llvm/test/tools/llvm-objcopy/ELF/change-section-lma.test

@@ -0,0 +1,79 @@
+# RUN: yaml2obj %s -o %t
+# RUN: llvm-objcopy --change-section-lma *+0x20 %t %t2
+# RUN: llvm-readelf --program-headers %t2 | FileCheck %s --check-prefix=CHECK-PLUS-PROGRAMS
+# RUN: llvm-readelf --section-headers %t2 | FileCheck %s --check-prefix=CHECK-PLUS-SECTIONS
+# RUN: llvm-objcopy --change-section-lma *-0x30 %t %t3
+# RUN: llvm-readelf --program-headers %t3 | FileCheck %s --check-prefix=CHECK-MINUS-PROGRAMS
+# RUN: llvm-readelf --section-headers %t3 | FileCheck %s --check-prefix=CHECK-MINUS-SECTIONS
+# RUN: not llvm-objcopy --change-section-lma .text3=0x5000 %t  2>&1 | FileCheck %s --check-prefix=ERR-SET-ADDRESS
+# RUN: not llvm-objcopy --change-section-lma .text3+0x30 %t  2>&1 | FileCheck %s --check-prefix=ERR-SPECIFIC-SEC
+# RUN: not llvm-objcopy --change-section-lma *+0c50 %t  2>&1 | FileCheck %s --check-prefix=ERR-INVALID-VAL
+# RUN: not llvm-objcopy --change-section-lma 0 %t  2>&1 | FileCheck %s --check-prefix=ERR-MISSING-OFFSET
+# RUN: not llvm-objcopy --change-section-lma *-0x2000 %t  2>&1 | FileCheck %s --check-prefix=ERR-UNDERFLOW
+# RUN: not llvm-objcopy --change-section-lma *+0x100000000 %t  2>&1 | FileCheck %s --check-prefix=ERR-OVERFLOW
+
+# CHECK-PLUS-PROGRAMS:  Type           Offset   VirtAddr           PhysAddr           FileSiz  MemSiz
+# CHECK-PLUS-PROGRAMS:  PHDR           0x000002 0x0000000000001102 0x0000000000001122 0x000038 0x000000
+# CHECK-PLUS-PROGRAMS:  LOAD           0x000000 0x0000000000001100 0x0000000000001120 0x000258 0x000258
+# CHECK-PLUS-PROGRAMS:  LOAD           0x000258 0xffffffff00005100 0xffffffff00006120 0x000100 0x000100
+# CHECK-PLUS-PROGRAMS:  NOTE           0x000358 0x0000000000001200 0x0000000000001220 0x000010 0x000000
+# CHECK-PLUS-PROGRAMS:  NOTE           0x000368 0x0000000000000000 0x0000000000000000 0x000000 0x000000
+
+# CHECK-MINUS-PROGRAMS:  PHDR           0x000002 0x0000000000001102 0x00000000000010d2 0x000038 0x000000
+# CHECK-MINUS-PROGRAMS:  LOAD           0x000000 0x0000000000001100 0x00000000000010d0 0x000258 0x000258
+# CHECK-MINUS-PROGRAMS:  LOAD           0x000258 0xffffffff00005100 0xffffffff000060d0 0x000100 0x000100
+# CHECK-MINUS-PROGRAMS:  NOTE           0x000358 0x0000000000001200 0x00000000000011d0 0x000010 0x000000
+# CHECK-MINUS-PROGRAMS:  NOTE           0x000368 0x0000000000000000 0x0000000000000000 0x000000 0x000000
+
+# CHECK-PLUS-SECTIONS:      [Nr] Name              Type            Address          Off    Size   ES Flg Lk Inf Al
+# CHECK-PLUS-SECTIONS:           .text1
+# CHECK-PLUS-SECTIONS-SAME:                                        0000000000000000
+# CHECK-PLUS-SECTIONS:           .text2
+# CHECK-PLUS-SECTIONS-SAME:                                        0000000000000000
+
+# CHECK-MINUS-SECTIONS:           .text1
+# CHECK-MINUS-SECTIONS-SAME:                                        0000000000000000
+# CHECK-MINUS-SECTIONS:           .text2
+# CHECK-MINUS-SECTIONS-SAME:                                        0000000000000000
+
+# ERR-SET-ADDRESS: error: bad format for --change-section-lma: changing LMA to a specific value is not supported. Use *+val or *-val instead
+# ERR-SPECIFIC-SEC: error: bad format for --change-section-lma: changing a specific section LMA is not supported. Use *+val or *-val instead
+# ERR-INVALID-VAL: error: bad format for --change-section-lma: value after *+ is 0c50 when it should be an integer
+# ERR-MISSING-OFFSET: error: bad format for --change-section-lma: missing LMA offset
+# ERR-UNDERFLOW: : address 0x1102 cannot be decreased by 0x2000. The result would underflow
+# ERR-OVERFLOW: address 0xffffffff00006100 cannot be increased by 0x100000000. The result would overflow
+
+!ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_EXEC
+Sections:
+  - Name:          .text1
+    Type:          SHT_PROGBITS
+    Size:          0x100
+  - Name:          .text2
+    Type:          SHT_PROGBITS
+    Size:          0x100
+ProgramHeaders:
+  - Type:          PT_PHDR
+    FileSize:      0x38
+    Offset:        0x2
+    VAddr:         0x1102
+  - Type:          PT_LOAD
+    Offset:        0x0
+    VAddr:         0x1100
+    FirstSec:      .text1
+    LastSec:       .text1
+  - Type:          PT_LOAD
+    VAddr:         0xFFFFFFFF00005100
+    PAddr:         0xFFFFFFFF00006100
+    FirstSec:      .text2
+    LastSec:       .text2
+  - Type:          PT_NOTE
+    FileSize:      0x10
+    VAddr:         0x1200
+    Offset:        0x358
+  - Type:          PT_NOTE
+    FileSize:      0x0
+    Offset:        0x368

llvm/tools/llvm-objcopy/ObjcopyOptions.cpp

@@ -552,6 +552,38 @@ static Error loadNewSectionData(StringRef ArgValue, StringRef OptionName,
   return Error::success();
 }
 
+static Expected<int64_t> parseChangeSectionLMA(StringRef ArgValue,
+                                               StringRef OptionName) {
+  StringRef StringValue;
+  if (ArgValue.starts_with("*+")) {
+    StringValue = ArgValue.slice(2, StringRef::npos);
+  } else if (ArgValue.starts_with("*-")) {
+    StringValue = ArgValue.slice(1, StringRef::npos);
+  } else if (ArgValue.contains("=")) {
+    return createStringError(errc::invalid_argument,
+                             "bad format for " + OptionName +
+                                 ": changing LMA to a specific value is not "
+                                 "supported. Use *+val or *-val instead");
+  } else if (ArgValue.contains("+") || ArgValue.contains("-")) {
+    return createStringError(errc::invalid_argument,
+                             "bad format for " + OptionName +
+                                 ": changing a specific section LMA is not "
+                                 "supported. Use *+val or *-val instead");
+  }
+  if (StringValue.empty())
+    return createStringError(errc::invalid_argument,
+                             "bad format for " + OptionName +
+                                 ": missing LMA offset");
+
+  auto LMAValue = getAsInteger<int64_t>(StringValue);
+  if (!LMAValue)
+    return createStringError(LMAValue.getError(),
+                             "bad format for " + OptionName + ": value after " +
+                                 ArgValue.slice(0, 2) + " is " + StringValue +
+                                 " when it should be an integer");
+  return *LMAValue;
+}
+
 // parseObjcopyOptions returns the config and sets the input arguments. If a
 // help flag is set then parseObjcopyOptions will print the help messege and
 // exit.
@@ -833,6 +865,14 @@ objcopy::parseObjcopyOptions(ArrayRef<const char *> RawArgsArr,
     Config.PadTo = *Addr;
   }
 
+  if (const auto *Arg = InputArgs.getLastArg(OBJCOPY_change_section_lma)) {
+    Expected<int64_t> LMAValue =
+        parseChangeSectionLMA(Arg->getValue(), Arg->getSpelling());
+    if (!LMAValue)
+      return LMAValue.takeError();
+    Config.ChangeSectionLMAValAll = *LMAValue;
+  }
+
   for (auto *Arg : InputArgs.filtered(OBJCOPY_redefine_symbol)) {
     if (!StringRef(Arg->getValue()).contains('='))
       return createStringError(errc::invalid_argument,

llvm/tools/llvm-objcopy/ObjcopyOpts.td

@@ -254,6 +254,10 @@ def adjust_start : JoinedOrSeparate<["--"], "adjust-start">,
                    Alias<change_start>,
                    HelpText<"Alias for --change-start">;
 
+defm change_section_lma
+    : Eq<"change-section-lma", "Shift LMA of non-zero-sized sections in the program header by <val>">,
+      MetaVarName<"*{+|-}val">;
+
 defm add_symbol
     : Eq<"add-symbol", "Add new symbol <name> to .symtab. Accepted flags: "
          "global, local, weak, default, hidden, protected, file, section, object, "