From: David Blaikie <dblaikie@gmail.com>
Date: Thu, 24 Jan 2019 03:27:57 +0000 (+0000)
Subject: DebugInfo: Use assembly label arithmetic for address pool size for easier reading... 
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=76453833c975f9014a9c296477f30c8a02a27303;p=llvm

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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@352019 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/AsmPrinter/AddressPool.cpp b/lib/CodeGen/AsmPrinter/AddressPool.cpp
index 6591cd7a96c..f11c7de5ed8 100644
--- a/lib/CodeGen/AsmPrinter/AddressPool.cpp
+++ b/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/lib/CodeGen/AsmPrinter/AddressPool.h b/lib/CodeGen/AsmPrinter/AddressPool.h
index 9ee98e56d3c..f92cf72093c 100644
--- a/lib/CodeGen/AsmPrinter/AddressPool.h
+++ b/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;
diff --git a/test/DebugInfo/X86/addr_comments.ll b/test/DebugInfo/X86/addr_comments.ll
index 780b37915a4..160f380bed6 100644
--- a/test/DebugInfo/X86/addr_comments.ll
+++ b/test/DebugInfo/X86/addr_comments.ll
@@ -1,12 +1,14 @@
 ; RUN: llc %s -mtriple=i386-unknown-linux-gnu -filetype=asm -o - | FileCheck %s
 
 ; CHECK:   .section .debug_addr
-; CHECK:   .long   8 # Length of contribution
-; CHECK:   .short  5 # DWARF version number
-; CHECK:   .byte   4 # Address size
-; CHECK:   .byte   0 # Segment selector size
-; CHECK: .Laddr_table_base0:
-; CHECK:   .long   .Lfunc_begin0
+; CHECK-NEXT:   .long   .Ldebug_addr_end0-.Ldebug_addr_start0 # Length of contribution
+; CHECK-NEXT: .Ldebug_addr_start0:
+; CHECK-NEXT:   .short  5 # DWARF version number
+; CHECK-NEXT:   .byte   4 # Address size
+; CHECK-NEXT:   .byte   0 # Segment selector size
+; CHECK-NEXT: .Laddr_table_base0:
+; CHECK-NEXT:   .long   .Lfunc_begin0
+; CHECK-NEXT: .Ldebug_addr_end0:
  
 ; Function Attrs: noinline nounwind optnone uwtable
 define dso_local void @foo() #0 !dbg !7 {