[llvm] r352019 - DebugInfo: Use assembly label arithmetic for address pool size for easier reading/editing

[David Blaikie via llvm-commits]

Author: dblaikie
Date: Wed Jan 23 19:27:57 2019
New Revision: 352019

URL: http://llvm.org/viewvc/llvm-project?rev=352019&view=rev
Log:
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.

Modified:
    llvm/trunk/lib/CodeGen/AsmPrinter/AddressPool.cpp
    llvm/trunk/lib/CodeGen/AsmPrinter/AddressPool.h
    llvm/trunk/test/DebugInfo/X86/addr_comments.ll

Modified: llvm/trunk/lib/CodeGen/AsmPrinter/AddressPool.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/AddressPool.cpp?rev=352019&r1=352018&r2=352019&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/AddressPool.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/AddressPool.cpp Wed Jan 23 19:27:57 2019
@@ -23,21 +23,24 @@ unsigned AddressPool::getIndex(const MCS
   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,
   // 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,
 
   for (const MCExpr *Entry : Entries)
     Asm.OutStreamer->EmitValue(Entry, Asm.getDataLayout().getPointerSize());
+
+  if (EndLabel)
+    Asm.OutStreamer->EmitLabel(EndLabel);
 }

Modified: llvm/trunk/lib/CodeGen/AsmPrinter/AddressPool.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/AddressPool.h?rev=352019&r1=352018&r2=352019&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/AddressPool.h (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/AddressPool.h Wed Jan 23 19:27:57 2019
@@ -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;

Modified: llvm/trunk/test/DebugInfo/X86/addr_comments.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/X86/addr_comments.ll?rev=352019&r1=352018&r2=352019&view=diff
==============================================================================
--- llvm/trunk/test/DebugInfo/X86/addr_comments.ll (original)
+++ llvm/trunk/test/DebugInfo/X86/addr_comments.ll Wed Jan 23 19:27:57 2019
@@ -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 {