This patch adds new functions to the SectionRef and ObjectFile interfaces to determine whether or not a section is meant to be read-only. These functions will be used by the MCJIT RuntimeDyld to give hints to the memory manager during the object loading process in a future patch.
Patch by Ashok Thirumurthi.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165586 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/Object/COFF.h b/include/llvm/Object/COFF.h
index 967420e..ba81058 100644
--- a/include/llvm/Object/COFF.h
+++ b/include/llvm/Object/COFF.h
@@ -128,6 +128,7 @@
virtual error_code isSectionBSS(DataRefImpl Sec, bool &Res) const;
virtual error_code isSectionVirtual(DataRefImpl Sec, bool &Res) const;
virtual error_code isSectionZeroInit(DataRefImpl Sec, bool &Res) const;
+ virtual error_code isSectionReadOnlyData(DataRefImpl Sec, bool &Res) const;
virtual error_code isSectionRequiredForExecution(DataRefImpl Sec,
bool &Res) const;
virtual error_code sectionContainsSymbol(DataRefImpl Sec, DataRefImpl Symb,
diff --git a/include/llvm/Object/ELF.h b/include/llvm/Object/ELF.h
index 8391e65..3ca69bc 100644
--- a/include/llvm/Object/ELF.h
+++ b/include/llvm/Object/ELF.h
@@ -640,6 +640,7 @@
bool &Res) const;
virtual error_code isSectionVirtual(DataRefImpl Sec, bool &Res) const;
virtual error_code isSectionZeroInit(DataRefImpl Sec, bool &Res) const;
+ virtual error_code isSectionReadOnlyData(DataRefImpl Sec, bool &Res) const;
virtual error_code sectionContainsSymbol(DataRefImpl Sec, DataRefImpl Symb,
bool &Result) const;
virtual relocation_iterator getSectionRelBegin(DataRefImpl Sec) const;
@@ -1288,7 +1289,8 @@
}
template<support::endianness target_endianness, bool is64Bits>
-error_code ELFObjectFile<target_endianness, is64Bits>::isSectionZeroInit(DataRefImpl Sec,
+error_code ELFObjectFile<target_endianness, is64Bits>
+ ::isSectionZeroInit(DataRefImpl Sec,
bool &Result) const {
const Elf_Shdr *sec = reinterpret_cast<const Elf_Shdr *>(Sec.p);
// For ELF, all zero-init sections are virtual (that is, they occupy no space
@@ -1302,6 +1304,18 @@
template<support::endianness target_endianness, bool is64Bits>
error_code ELFObjectFile<target_endianness, is64Bits>
+ ::isSectionReadOnlyData(DataRefImpl Sec,
+ bool &Result) const {
+ const Elf_Shdr *sec = reinterpret_cast<const Elf_Shdr *>(Sec.p);
+ if (sec->sh_flags & ELF::SHF_WRITE || sec->sh_flags & ELF::SHF_EXECINSTR)
+ Result = false;
+ else
+ Result = true;
+ return object_error::success;
+}
+
+template<support::endianness target_endianness, bool is64Bits>
+error_code ELFObjectFile<target_endianness, is64Bits>
::sectionContainsSymbol(DataRefImpl Sec,
DataRefImpl Symb,
bool &Result) const {
diff --git a/include/llvm/Object/MachO.h b/include/llvm/Object/MachO.h
index 0b73f94..ecb9e25 100644
--- a/include/llvm/Object/MachO.h
+++ b/include/llvm/Object/MachO.h
@@ -76,6 +76,7 @@
bool &Res) const;
virtual error_code isSectionVirtual(DataRefImpl Sec, bool &Res) const;
virtual error_code isSectionZeroInit(DataRefImpl Sec, bool &Res) const;
+ virtual error_code isSectionReadOnlyData(DataRefImpl Sec, bool &Res) const;
virtual error_code sectionContainsSymbol(DataRefImpl DRI, DataRefImpl S,
bool &Result) const;
virtual relocation_iterator getSectionRelBegin(DataRefImpl Sec) const;
diff --git a/include/llvm/Object/ObjectFile.h b/include/llvm/Object/ObjectFile.h
index 1709974..99ddb3b 100644
--- a/include/llvm/Object/ObjectFile.h
+++ b/include/llvm/Object/ObjectFile.h
@@ -163,6 +163,7 @@
error_code isRequiredForExecution(bool &Result) const;
error_code isVirtual(bool &Result) const;
error_code isZeroInit(bool &Result) const;
+ error_code isReadOnlyData(bool &Result) const;
error_code containsSymbol(SymbolRef S, bool &Result) const;
@@ -316,6 +317,7 @@
// A section is 'virtual' if its contents aren't present in the object image.
virtual error_code isSectionVirtual(DataRefImpl Sec, bool &Res) const = 0;
virtual error_code isSectionZeroInit(DataRefImpl Sec, bool &Res) const = 0;
+ virtual error_code isSectionReadOnlyData(DataRefImpl Sec, bool &Res) const = 0;
virtual error_code sectionContainsSymbol(DataRefImpl Sec, DataRefImpl Symb,
bool &Result) const = 0;
virtual relocation_iterator getSectionRelBegin(DataRefImpl Sec) const = 0;
@@ -510,6 +512,10 @@
return OwningObject->isSectionZeroInit(SectionPimpl, Result);
}
+inline error_code SectionRef::isReadOnlyData(bool &Result) const {
+ return OwningObject->isSectionReadOnlyData(SectionPimpl, Result);
+}
+
inline error_code SectionRef::containsSymbol(SymbolRef S, bool &Result) const {
return OwningObject->sectionContainsSymbol(SectionPimpl, S.SymbolPimpl,
Result);
diff --git a/lib/Object/COFFObjectFile.cpp b/lib/Object/COFFObjectFile.cpp
index 8ab54c6..72759ff 100644
--- a/lib/Object/COFFObjectFile.cpp
+++ b/lib/Object/COFFObjectFile.cpp
@@ -377,6 +377,13 @@
return object_error::success;
}
+error_code COFFObjectFile::isSectionReadOnlyData(DataRefImpl Sec,
+ bool &Result) const {
+ // FIXME: Unimplemented.
+ Result = false;
+ return object_error::success;
+}
+
error_code COFFObjectFile::sectionContainsSymbol(DataRefImpl Sec,
DataRefImpl Symb,
bool &Result) const {
diff --git a/lib/Object/MachOObjectFile.cpp b/lib/Object/MachOObjectFile.cpp
index d229671..ed9449c 100644
--- a/lib/Object/MachOObjectFile.cpp
+++ b/lib/Object/MachOObjectFile.cpp
@@ -612,6 +612,17 @@
return object_error::success;
}
+error_code MachOObjectFile::isSectionReadOnlyData(DataRefImpl Sec,
+ bool &Result) const {
+ // Consider using the code from isSectionText to look for __const sections.
+ // Alternately, emit S_ATTR_PURE_INSTRUCTIONS and/or S_ATTR_SOME_INSTRUCTIONS
+ // to use section attributes to distinguish code from data.
+
+ // FIXME: Unimplemented.
+ Result = false;
+ return object_error::success;
+}
+
error_code MachOObjectFile::sectionContainsSymbol(DataRefImpl Sec,
DataRefImpl Symb,
bool &Result) const {