Add DWARF discriminator support to DILexicalBlocks.

This adds support for emitting discriminators from DILexicalBlocks.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202736 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/docs/SourceLevelDebugging.rst b/docs/SourceLevelDebugging.rst
index a6349fba86a4557f9d86303bac32c2eaec6da3f0..5d7a528c2eb9a2b70e0cf4c4bc0fbc69e52fffdb 100644 (file)
--- a/docs/SourceLevelDebugging.rst
+++ b/docs/SourceLevelDebugging.rst
@@ -319,6 +319,7 @@ Block descriptors
     metadata,;; Reference to context descriptor
     i32,     ;; Line number
     i32,     ;; Column number
+    i32,     ;; DWARF path discriminator value
     i32      ;; Unique ID to identify blocks from a template function
   }
 
@@ -724,7 +725,8 @@ Compiled to LLVM, this function would be represented like this:
   !15 = metadata !{i32 786688, metadata !16, metadata !"Z", metadata !5, i32 5,
                    metadata !11, i32 0, i32 0} ; [ DW_TAG_auto_variable ] [Z] \
                      [line 5]
-  !16 = metadata !{i32 786443, metadata !1, metadata !4, i32 4, i32 0, i32 0} \
+  !16 = metadata !{i32 786443, metadata !1, metadata !4, i32 4, i32 0, i32 0,
+                   i32 0} \
                    ; [ DW_TAG_lexical_block ] [/private/tmp/t.c]
   !17 = metadata !{i32 5, i32 0, metadata !16, null}
   !18 = metadata !{i32 6, i32 0, metadata !16, null}
@@ -776,7 +778,8 @@ scope information for the variable ``Z``.
 
 .. code-block:: llvm
 
-  !16 = metadata !{i32 786443, metadata !1, metadata !4, i32 4, i32 0, i32 0}
+  !16 = metadata !{i32 786443, metadata !1, metadata !4, i32 4, i32 0, i32 0,
+                   i32 0}
                    ; [ DW_TAG_lexical_block ] [/private/tmp/t.c]
   !17 = metadata !{i32 5, i32 0, metadata !16, null}
 

diff --git a/include/llvm/DIBuilder.h b/include/llvm/DIBuilder.h
index ba7bca7ac5d979d44806a26f5a75f6e88837ff22..df900e29ef12562122665dd04ae0ab762a64ab30 100644 (file)
--- a/include/llvm/DIBuilder.h
+++ b/include/llvm/DIBuilder.h
@@ -633,12 +633,14 @@ namespace llvm {
 
     /// createLexicalBlock - This creates a descriptor for a lexical block
     /// with the specified parent context.
-    /// @param Scope       Parent lexical scope.
-    /// @param File        Source file
-    /// @param Line        Line number
-    /// @param Col         Column number
+    /// @param Scope         Parent lexical scope.
+    /// @param File          Source file.
+    /// @param Line          Line number.
+    /// @param Col           Column number.
+    /// @param Discriminator DWARF path discriminator value.
     DILexicalBlock createLexicalBlock(DIDescriptor Scope, DIFile File,
-                                      unsigned Line, unsigned Col);
+                                      unsigned Line, unsigned Col,
+                                      unsigned Discriminator);
 
     /// \brief Create a descriptor for an imported module.
     /// @param Context The scope this module is imported into

diff --git a/include/llvm/DebugInfo.h b/include/llvm/DebugInfo.h
index 930f7eba6724151cd1ef6076cbb452965e996069..e6ec6592dce69209d70868e3322b00de38499f27 100644 (file)
--- a/include/llvm/DebugInfo.h
+++ b/include/llvm/DebugInfo.h
@@ -522,6 +522,7 @@ public:
   DIScope getContext() const { return getFieldAs<DIScope>(2); }
   unsigned getLineNumber() const { return getUnsignedField(3); }
   unsigned getColumnNumber() const { return getUnsignedField(4); }
+  unsigned getDiscriminator() const { return getUnsignedField(5); }
   bool Verify() const;
 };
 

diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 57e5cd6be927ee9bff76416578fb6660a643d645..5d46620423360d423d18793d69a1a8d705454724 100644 (file)
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -1825,6 +1825,7 @@ void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
   StringRef Fn;
   StringRef Dir;
   unsigned Src = 1;
+  unsigned Discriminator = 0;
   if (S) {
     DIDescriptor Scope(S);
 
@@ -1848,13 +1849,15 @@ void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
       DILexicalBlock DB(S);
       Fn = DB.getFilename();
       Dir = DB.getDirectory();
+      Discriminator = DB.getDiscriminator();
     } else
       llvm_unreachable("Unexpected scope info");
 
     Src = getOrCreateSourceID(
         Fn, Dir, Asm->OutStreamer.getContext().getDwarfCompileUnitID());
   }
-  Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0, 0, Fn);
+  Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
+                                         Discriminator, Fn);
 }
 
 //===----------------------------------------------------------------------===//

diff --git a/lib/IR/DIBuilder.cpp b/lib/IR/DIBuilder.cpp
index d15de61479f8094caa6ff8ab6ad10f06aaab222b..773a8cf0f52d918aa638ad6fba8f78618a226d31 100644 (file)
--- a/lib/IR/DIBuilder.cpp
+++ b/lib/IR/DIBuilder.cpp
@@ -1186,7 +1186,8 @@ DILexicalBlockFile DIBuilder::createLexicalBlockFile(DIDescriptor Scope,
 }
 
 DILexicalBlock DIBuilder::createLexicalBlock(DIDescriptor Scope, DIFile File,
-                                             unsigned Line, unsigned Col) {
+                                             unsigned Line, unsigned Col,
+                                             unsigned Discriminator) {
   // Defeat MDNode uniquing for lexical blocks by using unique id.
   static unsigned int unique_id = 0;
   Value *Elts[] = {
@@ -1195,6 +1196,7 @@ DILexicalBlock DIBuilder::createLexicalBlock(DIDescriptor Scope, DIFile File,
     getNonCompileUnitScope(Scope),
     ConstantInt::get(Type::getInt32Ty(VMContext), Line),
     ConstantInt::get(Type::getInt32Ty(VMContext), Col),
+    ConstantInt::get(Type::getInt32Ty(VMContext), Discriminator),
     ConstantInt::get(Type::getInt32Ty(VMContext), unique_id++)
   };
   DILexicalBlock R(MDNode::get(VMContext, Elts));

diff --git a/lib/IR/DebugInfo.cpp b/lib/IR/DebugInfo.cpp
index 506f2dd926e7616893c27a041d798ef1d94fe779..749e0b5057a76e05414bdfe28d9ad31108813719 100644 (file)
--- a/lib/IR/DebugInfo.cpp
+++ b/lib/IR/DebugInfo.cpp
@@ -600,7 +600,7 @@ bool DISubrange::Verify() const {
 
 /// \brief Verify that the lexical block descriptor is well formed.
 bool DILexicalBlock::Verify() const {
-  return isLexicalBlock() && DbgNode->getNumOperands() == 6;
+  return isLexicalBlock() && DbgNode->getNumOperands() == 7;
 }
 
 /// \brief Verify that the file-scoped lexical block descriptor is well formed.

diff --git a/test/DebugInfo/X86/discriminator.ll b/test/DebugInfo/X86/discriminator.ll
new file mode 100644 (file)
index 0000000..df025bc
--- /dev/null
+++ b/test/DebugInfo/X86/discriminator.ll
@@ -0,0 +1,63 @@
+; RUN: llc -mtriple=i386-unknown-unknown %s -o %t -filetype=obj
+; RUN: llvm-dwarfdump -debug-dump=line %t | FileCheck %s
+;
+; Generated from:
+;
+;   int foo(int i) {
+;     if (i < 10) return i - 1;
+;     return 0;
+;   }
+;
+; Manually generated debug nodes !14 and !15 to incorporate an
+; arbitrary discriminator with value 42.
+
+define i32 @foo(i32 %i) #0 {
+entry:
+  %retval = alloca i32, align 4
+  %i.addr = alloca i32, align 4
+  store i32 %i, i32* %i.addr, align 4
+  %0 = load i32* %i.addr, align 4, !dbg !10
+  %cmp = icmp slt i32 %0, 10, !dbg !10
+  br i1 %cmp, label %if.then, label %if.end, !dbg !10
+
+if.then:                                          ; preds = %entry
+  %1 = load i32* %i.addr, align 4, !dbg !14
+  %sub = sub nsw i32 %1, 1, !dbg !14
+  store i32 %sub, i32* %retval, !dbg !14
+  br label %return, !dbg !14
+
+if.end:                                           ; preds = %entry
+  store i32 0, i32* %retval, !dbg !12
+  br label %return, !dbg !12
+
+return:                                           ; preds = %if.end, %if.then
+  %2 = load i32* %retval, !dbg !13
+  ret i32 %2, !dbg !13
+}
+
+attributes #0 = { nounwind uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!7, !8}
+!llvm.ident = !{!9}
+
+!0 = metadata !{i32 786449, metadata !1, i32 12, metadata !"clang version 3.5 ", i1 false, metadata !"", i32 0, metadata !2, metadata !2, metadata !3, metadata !2, metadata !2, metadata !""} ; [ DW_TAG_compile_unit ] [./discriminator.c] [DW_LANG_C99]
+!1 = metadata !{metadata !"discriminator.c", metadata !"."}
+!2 = metadata !{}
+!3 = metadata !{metadata !4}
+!4 = metadata !{i32 786478, metadata !1, metadata !5, metadata !"foo", metadata !"foo", metadata !"", i32 1, metadata !6, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, i32 (i32)* @foo, null, null, metadata !2, i32 1} ; [ DW_TAG_subprogram ] [line 1] [def] [foo]
+!5 = metadata !{i32 786473, metadata !1}          ; [ DW_TAG_file_type ] [./discriminator.c]
+!6 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !2, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!7 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
+!8 = metadata !{i32 1, metadata !"Debug Info Version", i32 1}
+!9 = metadata !{metadata !"clang version 3.5 "}
+!10 = metadata !{i32 2, i32 0, metadata !11, null}
+!11 = metadata !{i32 786443, metadata !1, metadata !4, i32 2, i32 0, i32 0, i32 0} ; [ DW_TAG_lexical_block ] [./discriminator.c]
+!12 = metadata !{i32 3, i32 0, metadata !4, null}
+!13 = metadata !{i32 4, i32 0, metadata !4, null}
+!14 = metadata !{i32 2, i32 0, metadata !15, null}
+!15 = metadata !{i32 786443, metadata !1, metadata !4, i32 2, i32 0, i32 42, i32 1} ; [ DW_TAG_lexical_block ] [./discriminator.c]
+
+; CHECK: Address            Line   Column File   ISA Discriminator Flags
+; CHECK: ------------------ ------ ------ ------ --- ------------- -------------
+; CHECK: 0x0000000000000011      2      0      1   0            42  is_stmt