Reland "[CodeView] Use assembler directives for line tables"
This reverts commit r259126 and relands r259117.
This time with updated library dependencies.
llvm-svn: 259130
diff --git a/llvm/lib/MC/MCCodeView.cpp b/llvm/lib/MC/MCCodeView.cpp
new file mode 100644
index 0000000..992edd0
--- /dev/null
+++ b/llvm/lib/MC/MCCodeView.cpp
@@ -0,0 +1,222 @@
+//===- MCCodeView.h - Machine Code CodeView support -------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Holds state from .cv_file and .cv_loc directives for later emission.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/MC/MCCodeView.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/DebugInfo/CodeView/CodeView.h"
+#include "llvm/DebugInfo/CodeView/Line.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCObjectStreamer.h"
+#include "llvm/Support/COFF.h"
+
+using namespace llvm;
+using namespace llvm::codeview;
+
+CodeViewContext::CodeViewContext() {}
+
+CodeViewContext::~CodeViewContext() {
+ // If someone inserted strings into the string table but never actually
+ // emitted them somewhere, clean up the fragment.
+ if (!InsertedStrTabFragment)
+ delete StrTabFragment;
+}
+
+/// This is a valid number for use with .cv_loc if we've already seen a .cv_file
+/// for it.
+bool CodeViewContext::isValidFileNumber(unsigned FileNumber) const {
+ unsigned Idx = FileNumber - 1;
+ if (Idx < Filenames.size())
+ return !Filenames[Idx].empty();
+ return false;
+}
+
+bool CodeViewContext::addFile(unsigned FileNumber, StringRef Filename) {
+ assert(FileNumber > 0);
+ Filename = addToStringTable(Filename);
+ unsigned Idx = FileNumber - 1;
+ if (Idx >= Filenames.size())
+ Filenames.resize(Idx + 1);
+
+ if (Filename.empty())
+ Filename = "<stdin>";
+
+ if (!Filenames[Idx].empty())
+ return false;
+
+ // FIXME: We should store the string table offset of the filename, rather than
+ // the filename itself for efficiency.
+ Filename = addToStringTable(Filename);
+
+ Filenames[Idx] = Filename;
+ return true;
+}
+
+MCDataFragment *CodeViewContext::getStringTableFragment() {
+ if (!StrTabFragment) {
+ StrTabFragment = new MCDataFragment();
+ // Start a new string table out with a null byte.
+ StrTabFragment->getContents().push_back('\0');
+ }
+ return StrTabFragment;
+}
+
+StringRef CodeViewContext::addToStringTable(StringRef S) {
+ SmallVectorImpl<char> &Contents = getStringTableFragment()->getContents();
+ auto Insertion =
+ StringTable.insert(std::make_pair(S, unsigned(Contents.size())));
+ // Return the string from the table, since it is stable.
+ S = Insertion.first->first();
+ if (Insertion.second) {
+ // The string map key is always null terminated.
+ Contents.append(S.begin(), S.end() + 1);
+ }
+ return S;
+}
+
+unsigned CodeViewContext::getStringTableOffset(StringRef S) {
+ // A string table offset of zero is always the empty string.
+ if (S.empty())
+ return 0;
+ auto I = StringTable.find(S);
+ assert(I != StringTable.end());
+ return I->second;
+}
+
+void CodeViewContext::emitStringTable(MCObjectStreamer &OS) {
+ MCContext &Ctx = OS.getContext();
+ MCSymbol *StringBegin = Ctx.createTempSymbol("strtab_begin"),
+ *StringEnd = Ctx.createTempSymbol("strtab_end");
+
+ OS.EmitIntValue(unsigned(ModuleSubstreamKind::StringTable), 4);
+ OS.emitAbsoluteSymbolDiff(StringEnd, StringBegin, 4);
+ OS.EmitLabel(StringBegin);
+
+ // Put the string table data fragment here, if we haven't already put it
+ // somewhere else. If somebody wants two string tables in their .s file, one
+ // will just be empty.
+ if (!InsertedStrTabFragment) {
+ OS.insert(getStringTableFragment());
+ InsertedStrTabFragment = true;
+ }
+
+ OS.EmitValueToAlignment(4, 0);
+
+ OS.EmitLabel(StringEnd);
+}
+
+void CodeViewContext::emitFileChecksums(MCObjectStreamer &OS) {
+ MCContext &Ctx = OS.getContext();
+ MCSymbol *FileBegin = Ctx.createTempSymbol("filechecksums_begin"),
+ *FileEnd = Ctx.createTempSymbol("filechecksums_end");
+
+ OS.EmitIntValue(unsigned(ModuleSubstreamKind::FileChecksums), 4);
+ OS.emitAbsoluteSymbolDiff(FileEnd, FileBegin, 4);
+ OS.EmitLabel(FileBegin);
+
+ // Emit an array of FileChecksum entries. We index into this table using the
+ // user-provided file number. Each entry is currently 8 bytes, as we don't
+ // emit checksums.
+ for (StringRef Filename : Filenames) {
+ OS.EmitIntValue(getStringTableOffset(Filename), 4);
+ // Zero the next two fields and align back to 4 bytes. This indicates that
+ // no checksum is present.
+ OS.EmitIntValue(0, 4);
+ }
+
+ OS.EmitLabel(FileEnd);
+}
+
+void CodeViewContext::emitLineTableForFunction(MCObjectStreamer &OS,
+ unsigned FuncId,
+ const MCSymbol *FuncBegin,
+ const MCSymbol *FuncEnd) {
+ MCContext &Ctx = OS.getContext();
+ MCSymbol *LineBegin = Ctx.createTempSymbol("linetable_begin"),
+ *LineEnd = Ctx.createTempSymbol("linetable_end");
+
+ OS.EmitIntValue(unsigned(ModuleSubstreamKind::Lines), 4);
+ OS.emitAbsoluteSymbolDiff(LineEnd, LineBegin, 4);
+ OS.EmitLabel(LineBegin);
+ OS.EmitCOFFSecRel32(FuncBegin);
+ OS.EmitCOFFSectionIndex(FuncBegin);
+
+ // Actual line info.
+ ArrayRef<MCCVLineEntry> Locs = getFunctionLineEntries(FuncId);
+ bool HaveColumns = any_of(Locs, [](const MCCVLineEntry &LineEntry) {
+ return LineEntry.getColumn() != 0;
+ });
+ OS.EmitIntValue(HaveColumns ? int(codeview::LineFlags::HaveColumns) : 0, 2);
+ OS.emitAbsoluteSymbolDiff(FuncEnd, FuncBegin, 4);
+
+ for (auto I = Locs.begin(), E = Locs.end(); I != E;) {
+ // Emit a file segment for the run of locations that share a file id.
+ unsigned CurFileNum = I->getFileNum();
+ auto FileSegEnd =
+ std::find_if(I, E, [CurFileNum](const MCCVLineEntry &Loc) {
+ return Loc.getFileNum() != CurFileNum;
+ });
+ unsigned EntryCount = FileSegEnd - I;
+ OS.AddComment("Segment for file '" + Twine(Filenames[CurFileNum - 1]) +
+ "' begins");
+ OS.EmitIntValue(8 * (CurFileNum - 1), 4);
+ OS.EmitIntValue(EntryCount, 4);
+ uint32_t SegmentSize = 12;
+ SegmentSize += 8 * EntryCount;
+ if (HaveColumns)
+ SegmentSize += 4 * EntryCount;
+ OS.EmitIntValue(SegmentSize, 4);
+
+ for (auto J = I; J != FileSegEnd; ++J) {
+ OS.emitAbsoluteSymbolDiff(J->getLabel(), FuncBegin, 4);
+ unsigned LineData = J->getLine();
+ if (J->isStmt())
+ LineData |= codeview::LineInfo::StatementFlag;
+ OS.EmitIntValue(LineData, 4);
+ }
+ if (HaveColumns) {
+ for (auto J = I; J != FileSegEnd; ++J) {
+ OS.EmitIntValue(J->getColumn(), 2);
+ OS.EmitIntValue(0, 2);
+ }
+ }
+ I = FileSegEnd;
+ }
+ OS.EmitLabel(LineEnd);
+}
+
+//
+// This is called when an instruction is assembled into the specified section
+// and if there is information from the last .cv_loc directive that has yet to have
+// a line entry made for it is made.
+//
+void MCCVLineEntry::Make(MCObjectStreamer *MCOS) {
+ if (!MCOS->getContext().getCVLocSeen())
+ return;
+
+ // Create a symbol at in the current section for use in the line entry.
+ MCSymbol *LineSym = MCOS->getContext().createTempSymbol();
+ // Set the value of the symbol to use for the MCCVLineEntry.
+ MCOS->EmitLabel(LineSym);
+
+ // Get the current .loc info saved in the context.
+ const MCCVLoc &CVLoc = MCOS->getContext().getCurrentCVLoc();
+
+ // Create a (local) line entry with the symbol and the current .loc info.
+ MCCVLineEntry LineEntry(LineSym, CVLoc);
+
+ // clear CVLocSeen saying the current .loc info is now used.
+ MCOS->getContext().clearCVLocSeen();
+
+ // Add the line entry to this section's entries.
+ MCOS->getContext().getCVContext().addLineEntry(LineEntry);
+}