From: Andrew Kaylor Date: Wed, 10 Oct 2012 01:41:33 +0000 (+0000) Subject: This patch adds new functions to the SectionRef and ObjectFile interfaces to determin... X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=3a129c85920404e7ccdb7e655c89fa60a0309cfd;p=oota-llvm.git 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 967420ec9f1..ba81058ae40 100644 --- a/include/llvm/Object/COFF.h +++ b/include/llvm/Object/COFF.h @@ -128,6 +128,7 @@ protected: 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 8391e6504cf..3ca69bcb153 100644 --- a/include/llvm/Object/ELF.h +++ b/include/llvm/Object/ELF.h @@ -640,6 +640,7 @@ protected: 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 @@ error_code ELFObjectFile } template -error_code ELFObjectFile::isSectionZeroInit(DataRefImpl Sec, +error_code ELFObjectFile + ::isSectionZeroInit(DataRefImpl Sec, bool &Result) const { const Elf_Shdr *sec = reinterpret_cast(Sec.p); // For ELF, all zero-init sections are virtual (that is, they occupy no space @@ -1300,6 +1302,18 @@ error_code ELFObjectFile::isSectionZeroInit(DataRef return object_error::success; } +template +error_code ELFObjectFile + ::isSectionReadOnlyData(DataRefImpl Sec, + bool &Result) const { + const Elf_Shdr *sec = reinterpret_cast(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 error_code ELFObjectFile ::sectionContainsSymbol(DataRefImpl Sec, diff --git a/include/llvm/Object/MachO.h b/include/llvm/Object/MachO.h index 0b73f948316..ecb9e256050 100644 --- a/include/llvm/Object/MachO.h +++ b/include/llvm/Object/MachO.h @@ -76,6 +76,7 @@ protected: 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 1709974ac56..99ddb3b87b8 100644 --- a/include/llvm/Object/ObjectFile.h +++ b/include/llvm/Object/ObjectFile.h @@ -163,6 +163,7 @@ public: 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 @@ protected: // 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 @@ inline error_code SectionRef::isZeroInit(bool &Result) const { 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 8ab54c62950..72759ff86e7 100644 --- a/lib/Object/COFFObjectFile.cpp +++ b/lib/Object/COFFObjectFile.cpp @@ -377,6 +377,13 @@ error_code COFFObjectFile::isSectionZeroInit(DataRefImpl Sec, 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 d229671954f..ed9449c50d3 100644 --- a/lib/Object/MachOObjectFile.cpp +++ b/lib/Object/MachOObjectFile.cpp @@ -612,6 +612,17 @@ error_code MachOObjectFile::isSectionZeroInit(DataRefImpl DRI, 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 {