DebugInfo: Use assembly label arithmetic for address pool size for easier reading/editing

Recommits 350048, 350050 That broke buildbots because of some typos in
the test case.

llvm-svn: 352019

2 files changed, 17 insertions, 9 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/AddressPool.cpp b/llvm/lib/CodeGen/AsmPrinter/AddressPool.cpp
index 6591cd7a96c..f11c7de5ed8 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AddressPool.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AddressPool.cpp
@@ -23,21 +23,24 @@ unsigned AddressPool::getIndex(const MCSymbol *Sym, bool TLS) {
   return IterBool.first->second.Number;
 }
 
-
-void AddressPool::emitHeader(AsmPrinter &Asm, MCSection *Section) {
+MCSymbol *AddressPool::emitHeader(AsmPrinter &Asm, MCSection *Section) {
   static const uint8_t AddrSize = Asm.getDataLayout().getPointerSize();
-  uint64_t Length = sizeof(uint16_t) // version
-                  + sizeof(uint8_t)  // address_size
-                  + sizeof(uint8_t)  // segment_selector_size
-                  + AddrSize * Pool.size(); // entries
+  StringRef Prefix = "debug_addr_";
+  MCSymbol *BeginLabel = Asm.createTempSymbol(Prefix + "start");
+  MCSymbol *EndLabel = Asm.createTempSymbol(Prefix + "end");
+
   Asm.OutStreamer->AddComment("Length of contribution");
-  Asm.emitInt32(Length); // TODO: Support DWARF64 format.
+  Asm.EmitLabelDifference(EndLabel, BeginLabel,
+                          4); // TODO: Support DWARF64 format.
+  Asm.OutStreamer->EmitLabel(BeginLabel);
   Asm.OutStreamer->AddComment("DWARF version number");
   Asm.emitInt16(Asm.getDwarfVersion());
   Asm.OutStreamer->AddComment("Address size");
   Asm.emitInt8(AddrSize);
   Asm.OutStreamer->AddComment("Segment selector size");
   Asm.emitInt8(0); // TODO: Support non-zero segment_selector_size.
+
+  return EndLabel;
 }
 
 // Emit addresses into the section given.
@@ -48,8 +51,10 @@ void AddressPool::emit(AsmPrinter &Asm, MCSection *AddrSection) {
   // Start the dwarf addr section.
   Asm.OutStreamer->SwitchSection(AddrSection);
 
+  MCSymbol *EndLabel = nullptr;
+
   if (Asm.getDwarfVersion() >= 5)
-    emitHeader(Asm, AddrSection);
+    EndLabel = emitHeader(Asm, AddrSection);
 
   // Define the symbol that marks the start of the contribution.
   // It is referenced via DW_AT_addr_base.
@@ -66,4 +71,7 @@ void AddressPool::emit(AsmPrinter &Asm, MCSection *AddrSection) {
 
   for (const MCExpr *Entry : Entries)
     Asm.OutStreamer->EmitValue(Entry, Asm.getDataLayout().getPointerSize());
+
+  if (EndLabel)
+    Asm.OutStreamer->EmitLabel(EndLabel);
 }
diff --git a/llvm/lib/CodeGen/AsmPrinter/AddressPool.h b/llvm/lib/CodeGen/AsmPrinter/AddressPool.h
index 9ee98e56d3c..f92cf72093c 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AddressPool.h
+++ b/llvm/lib/CodeGen/AsmPrinter/AddressPool.h
@@ -54,7 +54,7 @@ public:
   void setLabel(MCSymbol *Sym) { AddressTableBaseSym = Sym; }
 
 private:
-  void emitHeader(AsmPrinter &Asm, MCSection *Section);
+  MCSymbol *emitHeader(AsmPrinter &Asm, MCSection *Section);
 
   /// Symbol designates the start of the contribution to the address table.
   MCSymbol *AddressTableBaseSym = nullptr;