Make the big switch: Change MCSectionMachO to represent a section *semantically*
instead of syntactically as a string. This means that it keeps track of the
segment, section, flags, etc directly and asmprints them in the right format.
This also includes parsing and validation support for llvm-mc and
"attribute(section)", so we should now start getting errors about invalid
section attributes from the compiler instead of the assembler on darwin.
Still todo:
1) Uniquing of darwin mcsections
2) Move all the Darwin stuff out to MCSectionMachO.[cpp|h]
3) there are a few FIXMEs, for example what is the syntax to get the
S_GB_ZEROFILL segment type?
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78547 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCSection.cpp b/lib/MC/MCSection.cpp
index 65e86d3..291e40d 100644
--- a/lib/MC/MCSection.cpp
+++ b/lib/MC/MCSection.cpp
@@ -115,25 +115,272 @@
// MCSectionMachO
//===----------------------------------------------------------------------===//
-MCSectionMachO *MCSectionMachO::
-Create(const StringRef &Name, bool IsDirective, SectionKind K, MCContext &Ctx) {
- return new (Ctx) MCSectionMachO(Name, IsDirective, K, Ctx);
-}
+/// SectionTypeDescriptors - These are strings that describe the various section
+/// types. This *must* be kept in order with and stay synchronized with the
+/// section type list.
+static const struct {
+ const char *AssemblerName, *EnumName;
+} SectionTypeDescriptors[MCSectionMachO::LAST_KNOWN_SECTION_TYPE+1] = {
+ { "regular", "S_REGULAR" }, // 0x00
+ { 0, "S_ZEROFILL" }, // 0x01
+ { "cstring_literals", "S_CSTRING_LITERALS" }, // 0x02
+ { "4byte_literals", "S_4BYTE_LITERALS" }, // 0x03
+ { "8byte_literals", "S_8BYTE_LITERALS" }, // 0x04
+ { "literal_pointers", "S_LITERAL_POINTERS" }, // 0x05
+ { "non_lazy_symbol_pointers", "S_NON_LAZY_SYMBOL_POINTERS" }, // 0x06
+ { "lazy_symbol_pointers", "S_LAZY_SYMBOL_POINTERS" }, // 0x07
+ { "symbol_stubs", "S_SYMBOL_STUBS" }, // 0x08
+ { "mod_init_funcs", "S_MOD_INIT_FUNC_POINTERS" }, // 0x09
+ { "mod_term_funcs", "S_MOD_TERM_FUNC_POINTERS" }, // 0x0A
+ { "coalesced", "S_COALESCED" }, // 0x0B
+ { 0, /*FIXME??*/ "S_GB_ZEROFILL" }, // 0x0C
+ { "interposing", "S_INTERPOSING" }, // 0x0D
+ { "16byte_literals", "S_16BYTE_LITERALS" }, // 0x0E
+ { 0, /*FIXME??*/ "S_DTRACE_DOF" }, // 0x0F
+ { 0, /*FIXME??*/ "S_LAZY_DYLIB_SYMBOL_POINTERS" } // 0x10
+};
-MCSectionMachO::MCSectionMachO(const StringRef &name, bool isDirective,
- SectionKind K, MCContext &Ctx)
- : MCSection(K), Name(name), IsDirective(isDirective) {
- Ctx.SetSection(Name, this);
+
+/// SectionAttrDescriptors - This is an array of descriptors for section
+/// attributes. Unlike the SectionTypeDescriptors, this is not directly indexed
+/// by attribute, instead it is searched. The last entry has a zero AttrFlag
+/// value.
+static const struct {
+ unsigned AttrFlag;
+ const char *AssemblerName, *EnumName;
+} SectionAttrDescriptors[] = {
+#define ENTRY(ASMNAME, ENUM) \
+ { MCSectionMachO::ENUM, ASMNAME, #ENUM },
+ENTRY("pure_instructions", S_ATTR_PURE_INSTRUCTIONS)
+ENTRY("no_toc", S_ATTR_NO_TOC)
+ENTRY("strip_static_syms", S_ATTR_STRIP_STATIC_SYMS)
+ENTRY("no_dead_strip", S_ATTR_NO_DEAD_STRIP)
+ENTRY("live_support", S_ATTR_LIVE_SUPPORT)
+ENTRY("self_modifying_code", S_ATTR_SELF_MODIFYING_CODE)
+ENTRY("debug", S_ATTR_DEBUG)
+ENTRY(0 /*FIXME*/, S_ATTR_SOME_INSTRUCTIONS)
+ENTRY(0 /*FIXME*/, S_ATTR_EXT_RELOC)
+ENTRY(0 /*FIXME*/, S_ATTR_LOC_RELOC)
+#undef ENTRY
+ { 0, "none", 0 }
+};
+
+
+MCSectionMachO *MCSectionMachO::
+Create(const StringRef &Segment, const StringRef &Section,
+ unsigned TypeAndAttributes, unsigned Reserved2,
+ SectionKind K, MCContext &Ctx) {
+ // S_SYMBOL_STUBS must be set for Reserved2 to be non-zero.
+ return new (Ctx) MCSectionMachO(Segment, Section, TypeAndAttributes,
+ Reserved2, K);
}
void MCSectionMachO::PrintSwitchToSection(const TargetAsmInfo &TAI,
raw_ostream &OS) const {
- if (!isDirective())
- OS << "\t.section\t" << getName() << '\n';
+ OS << "\t.section\t" << getSegmentName() << ',' << getSectionName();
+
+ // Get the section type and attributes.
+ unsigned TAA = getTypeAndAttributes();
+ if (TAA == 0) {
+ OS << '\n';
+ return;
+ }
+
+ OS << ',';
+
+ unsigned SectionType = TAA & MCSectionMachO::SECTION_TYPE;
+ assert(SectionType <= MCSectionMachO::LAST_KNOWN_SECTION_TYPE &&
+ "Invalid SectionType specified!");
+
+ if (SectionTypeDescriptors[SectionType].AssemblerName)
+ OS << SectionTypeDescriptors[SectionType].AssemblerName;
else
- OS << getName() << '\n';
+ OS << "<<" << SectionTypeDescriptors[SectionType].EnumName << ">>";
+
+ // If we don't have any attributes, we're done.
+ unsigned SectionAttrs = TAA & MCSectionMachO::SECTION_ATTRIBUTES;
+ if (SectionAttrs == 0) {
+ // If we have a S_SYMBOL_STUBS size specified, print it along with 'none' as
+ // the attribute specifier.
+ if (Reserved2 != 0)
+ OS << ",none," << Reserved2;
+ OS << '\n';
+ return;
+ }
+
+ // Check each attribute to see if we have it.
+ char Separator = ',';
+ for (unsigned i = 0; SectionAttrDescriptors[i].AttrFlag; ++i) {
+ // Check to see if we have this attribute.
+ if ((SectionAttrDescriptors[i].AttrFlag & SectionAttrs) == 0)
+ continue;
+
+ // Yep, clear it and print it.
+ SectionAttrs &= ~SectionAttrDescriptors[i].AttrFlag;
+
+ OS << Separator;
+ if (SectionAttrDescriptors[i].AssemblerName)
+ OS << SectionAttrDescriptors[i].AssemblerName;
+ else
+ OS << "<<" << SectionAttrDescriptors[i].EnumName << ">>";
+ Separator = '+';
+ }
+
+ assert(SectionAttrs == 0 && "Unknown section attributes!");
+
+ // If we have a S_SYMBOL_STUBS size specified, print it.
+ if (Reserved2 != 0)
+ OS << ',' << Reserved2;
+ OS << '\n';
}
+/// StripSpaces - This removes leading and trailing spaces from the StringRef.
+static void StripSpaces(StringRef &Str) {
+ while (!Str.empty() && isspace(Str[0]))
+ Str = Str.substr(1);
+ while (!Str.empty() && isspace(Str.back()))
+ Str = Str.substr(0, Str.size()-1);
+}
+
+/// ParseSectionSpecifier - Parse the section specifier indicated by "Spec".
+/// This is a string that can appear after a .section directive in a mach-o
+/// flavored .s file. If successful, this fills in the specified Out
+/// parameters and returns an empty string. When an invalid section
+/// specifier is present, this returns a string indicating the problem.
+std::string MCSectionMachO::ParseSectionSpecifier(StringRef Spec, // In.
+ StringRef &Segment, // Out.
+ StringRef &Section, // Out.
+ unsigned &TAA, // Out.
+ unsigned &StubSize) { // Out.
+ // Find the first comma.
+ std::pair<StringRef, StringRef> Comma = Spec.split(',');
+
+ // If there is no comma, we fail.
+ if (Comma.second.empty())
+ return "mach-o section specifier requires a segment and section "
+ "separated by a comma";
+
+ // Capture segment, remove leading and trailing whitespace.
+ Segment = Comma.first;
+ StripSpaces(Segment);
+
+ // Verify that the segment is present and not too long.
+ if (Segment.empty() || Segment.size() > 16)
+ return "mach-o section specifier requires a segment whose length is "
+ "between 1 and 16 characters";
+
+ // Split the section name off from any attributes if present.
+ Comma = Comma.second.split(',');
+
+ // Capture section, remove leading and trailing whitespace.
+ Section = Comma.first;
+ StripSpaces(Section);
+
+ // Verify that the section is present and not too long.
+ if (Section.empty() || Section.size() > 16)
+ return "mach-o section specifier requires a section whose length is "
+ "between 1 and 16 characters";
+
+ // If there is no comma after the section, we're done.
+ TAA = 0;
+ StubSize = 0;
+ if (Comma.second.empty())
+ return "";
+
+ // Otherwise, we need to parse the section type and attributes.
+ Comma = Comma.second.split(',');
+
+ // Get the section type.
+ StringRef SectionType = Comma.first;
+ StripSpaces(SectionType);
+
+ // Figure out which section type it is.
+ unsigned TypeID;
+ for (TypeID = 0; TypeID !=MCSectionMachO::LAST_KNOWN_SECTION_TYPE+1; ++TypeID)
+ if (SectionTypeDescriptors[TypeID].AssemblerName &&
+ SectionType == SectionTypeDescriptors[TypeID].AssemblerName)
+ break;
+
+ // If we didn't find the section type, reject it.
+ if (TypeID > MCSectionMachO::LAST_KNOWN_SECTION_TYPE)
+ return "mach-o section specifier uses an unknown section type";
+
+ // Remember the TypeID.
+ TAA = TypeID;
+
+ // If we have no comma after the section type, there are no attributes.
+ if (Comma.second.empty()) {
+ // S_SYMBOL_STUBS always require a symbol stub size specifier.
+ if (TAA == MCSectionMachO::S_SYMBOL_STUBS)
+ return "mach-o section specifier of type 'symbol_stubs' requires a size "
+ "specifier";
+ return "";
+ }
+
+ // Otherwise, we do have some attributes. Split off the size specifier if
+ // present.
+ Comma = Comma.second.split(',');
+ StringRef Attrs = Comma.first;
+
+ // The attribute list is a '+' separated list of attributes.
+ std::pair<StringRef, StringRef> Plus = Attrs.split('+');
+
+ while (1) {
+ StringRef Attr = Plus.first;
+ StripSpaces(Attr);
+
+ // Look up the attribute.
+ for (unsigned i = 0; ; ++i) {
+ if (SectionAttrDescriptors[i].AttrFlag == 0)
+ return "mach-o section specifier has invalid attribute";
+
+ if (SectionAttrDescriptors[i].AssemblerName &&
+ Attr == SectionAttrDescriptors[i].AssemblerName) {
+ TAA |= SectionAttrDescriptors[i].AttrFlag;
+ break;
+ }
+ }
+
+ if (Plus.second.empty()) break;
+ Plus = Plus.second.split('+');
+ };
+
+ // Okay, we've parsed the section attributes, see if we have a stub size spec.
+ if (Comma.second.empty()) {
+ // S_SYMBOL_STUBS always require a symbol stub size specifier.
+ if (TAA == MCSectionMachO::S_SYMBOL_STUBS)
+ return "mach-o section specifier of type 'symbol_stubs' requires a size "
+ "specifier";
+ return "";
+ }
+
+ // If we have a stub size spec, we must have a sectiontype of S_SYMBOL_STUBS.
+ if ((TAA & MCSectionMachO::SECTION_TYPE) != MCSectionMachO::S_SYMBOL_STUBS)
+ return "mach-o section specifier cannot have a stub size specified because "
+ "it does not have type 'symbol_stubs'";
+
+ // Okay, if we do, it must be a number.
+ StringRef StubSizeStr = Comma.second;
+ StripSpaces(StubSizeStr);
+
+ // Convert the a null terminated buffer for strtoul.
+ char TmpBuffer[32];
+ if (StubSizeStr.size() >= 32)
+ return"mach-o section specifier has a stub size specifier that is too long";
+
+ memcpy(TmpBuffer, StubSizeStr.data(), StubSizeStr.size());
+ TmpBuffer[StubSizeStr.size()] = 0;
+
+ char *EndPtr;
+ StubSize = strtoul(TmpBuffer, &EndPtr, 0);
+
+ if (EndPtr[0] != 0)
+ return "mach-o section specifier has a malformed stub size";
+
+ return "";
+}
+
+
//===----------------------------------------------------------------------===//
// MCSectionCOFF
//===----------------------------------------------------------------------===//