Split address information for DWARF5 split dwarf proposal. This involves

using the DW_FORM_GNU_addr_index and a separate .debug_addr section which
stays in the executable and is fully linked.

Sneak in two other small changes:

a) Print out the debug_str_offsets.dwo section.
b) Change form we're expecting the entries in the debug_str_offsets.dwo
   section to take from ULEB128 to U32.

Add tests for all of this in the fission-cu.ll test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172578 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 44 insertions, 4 deletions

diff --git a/lib/DebugInfo/DWARFCompileUnit.h b/lib/DebugInfo/DWARFCompileUnit.h
index c58664f..de70b2e 100644
--- a/lib/DebugInfo/DWARFCompileUnit.h
+++ b/lib/DebugInfo/DWARFCompileUnit.h
@@ -29,6 +29,7 @@ class DWARFCompileUnit {
   StringRef RangeSection;
   StringRef StringSection;
   StringRef StringOffsetSection;
+  StringRef AddrOffsetSection;
   const RelocAddrMap *RelocMap;
   bool isLittleEndian;
 
@@ -43,16 +44,17 @@ class DWARFCompileUnit {
 public:
 
   DWARFCompileUnit(const DWARFDebugAbbrev *DA, StringRef IS, StringRef AS,
-                   StringRef RS, StringRef SS, StringRef SOS,
+                   StringRef RS, StringRef SS, StringRef SOS, StringRef AOS,
                    const RelocAddrMap *M, bool LE) :
     Abbrev(DA), InfoSection(IS), AbbrevSection(AS),
     RangeSection(RS), StringSection(SS), StringOffsetSection(SOS),
-    RelocMap(M), isLittleEndian(LE) {
+    AddrOffsetSection(AOS), RelocMap(M), isLittleEndian(LE) {
     clear();
   }
 
   StringRef getStringSection() const { return StringSection; }
   StringRef getStringOffsetSection() const { return StringOffsetSection; }
+  StringRef getAddrOffsetSection() const { return AddrOffsetSection; }
   const RelocAddrMap *getRelocMap() const { return RelocMap; }
   DataExtractor getDebugInfoExtractor() const;
 
diff --git a/lib/DebugInfo/DWARFContext.cpp b/lib/DebugInfo/DWARFContext.cpp
index 247ee5b..13a527b 100644
--- a/lib/DebugInfo/DWARFContext.cpp
+++ b/lib/DebugInfo/DWARFContext.cpp
@@ -86,6 +86,14 @@ void DWARFContext::dump(raw_ostream &OS) {
     OS << format("0x%8.8x: \"%s\"\n", strDWOOffset, s);
     strDWOOffset = offset;
   }
+
+  OS << "\n.debug_str_offsets.dwo contents:\n";
+  DataExtractor strOffsetExt(getStringOffsetDWOSection(), isLittleEndian(), 0);
+  offset = 0;
+  while (offset < getStringOffsetDWOSection().size()) {
+    OS << format("0x%8.8x: ", offset);
+    OS << format("%8.8x\n", strOffsetExt.getU32(&offset));
+  }
 }
 
 const DWARFDebugAbbrev *DWARFContext::getDebugAbbrev() {
@@ -152,7 +160,8 @@ void DWARFContext::parseCompileUnits() {
   while (DIData.isValidOffset(offset)) {
     CUs.push_back(DWARFCompileUnit(getDebugAbbrev(), getInfoSection(),
                                    getAbbrevSection(), getRangeSection(),
-                                   getStringSection(), "",
+                                   getStringSection(), StringRef(),
+                                   getAddrSection(),
                                    &infoRelocMap(),
                                    isLittleEndian()));
     if (!CUs.back().extract(DIData, &offset)) {
@@ -174,6 +183,7 @@ void DWARFContext::parseDWOCompileUnits() {
                                       getRangeDWOSection(),
                                       getStringDWOSection(),
                                       getStringOffsetDWOSection(),
+                                      getAddrSection(),
                                       &infoDWORelocMap(),
                                       isLittleEndian()));
     if (!DWOCUs.back().extract(DIData, &offset)) {
@@ -386,6 +396,8 @@ DWARFContextInMemory::DWARFContextInMemory(object::ObjectFile *Obj) :
       StringDWOSection = data;
     else if (name == "debug_str_offsets.dwo")
       StringOffsetDWOSection = data;
+    else if (name == "debug_addr")
+      AddrSection = data;
     // Any more debug info sections go here.
     else
       continue;
diff --git a/lib/DebugInfo/DWARFContext.h b/lib/DebugInfo/DWARFContext.h
index 687ff93..7da5c85 100644
--- a/lib/DebugInfo/DWARFContext.h
+++ b/lib/DebugInfo/DWARFContext.h
@@ -108,6 +108,7 @@ public:
   virtual StringRef getStringDWOSection() = 0;
   virtual StringRef getStringOffsetDWOSection() = 0;
   virtual StringRef getRangeDWOSection() = 0;
+  virtual StringRef getAddrSection() = 0;
   virtual const RelocAddrMap &infoDWORelocMap() const = 0;
 
   static bool isSupportedVersion(unsigned version) {
@@ -143,6 +144,7 @@ class DWARFContextInMemory : public DWARFContext {
   StringRef StringDWOSection;
   StringRef StringOffsetDWOSection;
   StringRef RangeDWOSection;
+  StringRef AddrSection;
 
 public:
   DWARFContextInMemory(object::ObjectFile *);
@@ -163,6 +165,9 @@ public:
     return StringOffsetDWOSection;
   }
   virtual StringRef getRangeDWOSection() { return RangeDWOSection; }
+  virtual StringRef getAddrSection() {
+    return AddrSection;
+  }
   virtual const RelocAddrMap &infoDWORelocMap() const {
     return InfoDWORelocMap;
   }
diff --git a/lib/DebugInfo/DWARFFormValue.cpp b/lib/DebugInfo/DWARFFormValue.cpp
index 14c6804..d1bcf96 100644
--- a/lib/DebugInfo/DWARFFormValue.cpp
+++ b/lib/DebugInfo/DWARFFormValue.cpp
@@ -325,6 +325,16 @@ DWARFFormValue::dump(raw_ostream &OS, const DWARFCompileUnit *cu) const {
 
   switch (Form) {
   case DW_FORM_addr:      OS << format("0x%016" PRIx64, uvalue); break;
+  case DW_FORM_GNU_addr_index: {
+    StringRef AddrOffsetSec = cu->getAddrOffsetSection();
+    OS << format(" indexed (%8.8x) address = ", (uint32_t)uvalue);
+    if (AddrOffsetSec.size() != 0) {
+      DataExtractor DA(AddrOffsetSec, true, cu->getAddressByteSize());
+      OS << format("0x%016" PRIx64, getIndirectAddress(&DA, cu));
+    } else
+      OS << "<no .debug_addr section>";
+    break;
+  }
   case DW_FORM_flag_present: OS << "true"; break;
   case DW_FORM_flag:
   case DW_FORM_data1:     OS << format("0x%02x", (uint8_t)uvalue); break;
@@ -452,10 +462,19 @@ DWARFFormValue::getIndirectCString(const DataExtractor *DS,
   if (!DS || !DSO) return NULL;
 
   uint32_t offset = Value.uval * 4;
-  uint32_t soffset = DSO->getULEB128(&offset);
+  uint32_t soffset = DSO->getU32(&offset);
   return DS->getCStr(&soffset);
 }
 
+uint64_t
+DWARFFormValue::getIndirectAddress(const DataExtractor *DA,
+                                   const DWARFCompileUnit *cu) const {
+  if (!DA) return 0;
+
+  uint32_t offset = Value.uval * cu->getAddressByteSize();
+  return DA->getAddress(&offset);
+}
+
 uint64_t DWARFFormValue::getReference(const DWARFCompileUnit *cu) const {
   uint64_t die_offset = Value.uval;
   switch (Form) {
diff --git a/lib/DebugInfo/DWARFFormValue.h b/lib/DebugInfo/DWARFFormValue.h
index 7768c18..b863001 100644
--- a/lib/DebugInfo/DWARFFormValue.h
+++ b/lib/DebugInfo/DWARFFormValue.h
@@ -66,6 +66,8 @@ public:
   const char *getAsCString(const DataExtractor *debug_str_data_ptr) const;
   const char *getIndirectCString(const DataExtractor *,
                                  const DataExtractor *) const;
+  uint64_t getIndirectAddress(const DataExtractor *,
+                              const DWARFCompileUnit *) const;
   bool skipValue(DataExtractor debug_info_data, uint32_t *offset_ptr,
                  const DWARFCompileUnit *cu) const;
   static bool skipValue(uint16_t form, DataExtractor debug_info_data,