[llvm] r252268 - docs: Document function-attached metadata and IR changes from r252219.
Peter Collingbourne via llvm-commits
llvm-commits at lists.llvm.org
Thu Nov 5 18:41:02 PST 2015
Author: pcc
Date: Thu Nov 5 20:41:02 2015
New Revision: 252268
URL: http://llvm.org/viewvc/llvm-project?rev=252268&view=rev
Log:
docs: Document function-attached metadata and IR changes from r252219.
Modified:
llvm/trunk/docs/LangRef.rst
llvm/trunk/docs/SourceLevelDebugging.rst
Modified: llvm/trunk/docs/LangRef.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/LangRef.rst?rev=252268&r1=252267&r2=252268&view=diff
==============================================================================
--- llvm/trunk/docs/LangRef.rst (original)
+++ llvm/trunk/docs/LangRef.rst Thu Nov 5 20:41:02 2015
@@ -640,6 +640,7 @@ an optional :ref:`comdat <langref_comdat
an optional :ref:`garbage collector name <gc>`, an optional :ref:`prefix <prefixdata>`,
an optional :ref:`prologue <prologuedata>`,
an optional :ref:`personality <personalityfn>`,
+an optional list of attached :ref:`metadata <metadata>`,
an opening curly brace, a list of basic blocks, and a closing curly brace.
LLVM function declarations consist of the "``declare``" keyword, an
@@ -688,7 +689,7 @@ Syntax::
<ResultType> @<FunctionName> ([argument list])
[unnamed_addr] [fn Attrs] [section "name"] [comdat [($name)]]
[align N] [gc] [prefix Constant] [prologue Constant]
- [personality Constant] { ... }
+ [personality Constant] (!name !N)* { ... }
The argument list is a comma separated sequence of arguments where each
argument is of the following form:
@@ -3624,13 +3625,22 @@ function is using two metadata arguments
call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
-Metadata can be attached with an instruction. Here metadata ``!21`` is
-attached to the ``add`` instruction using the ``!dbg`` identifier:
+Metadata can be attached to an instruction. Here metadata ``!21`` is attached
+to the ``add`` instruction using the ``!dbg`` identifier:
.. code-block:: llvm
%indvar.next = add i64 %indvar, 1, !dbg !21
+Metadata can also be attached to a function definition. Here metadata ``!22``
+is attached to the ``foo`` function using the ``!dbg`` identifier:
+
+.. code-block:: llvm
+
+ define void @foo() !dbg !22 {
+ ret void
+ }
+
More information about specific metadata nodes recognized by the
optimizers and code generator is found below.
@@ -3901,20 +3911,26 @@ All global variables should be reference
DISubprogram
""""""""""""
-``DISubprogram`` nodes represent functions from the source language. The
-``variables:`` field points at :ref:`variables <DILocalVariable>` that must be
-retained, even if their IR counterparts are optimized out of the IR. The
-``type:`` field must point at an :ref:`DISubroutineType`.
+``DISubprogram`` nodes represent functions from the source language. A
+``DISubprogram`` may be attached to a function definition using ``!dbg``
+metadata. The ``variables:`` field points at :ref:`variables <DILocalVariable>`
+that must be retained, even if their IR counterparts are optimized out of
+the IR. The ``type:`` field must point at an :ref:`DISubroutineType`.
.. code-block:: llvm
- !0 = !DISubprogram(name: "foo", linkageName: "_Zfoov", scope: !1,
- file: !2, line: 7, type: !3, isLocal: true,
- isDefinition: false, scopeLine: 8, containingType: !4,
- virtuality: DW_VIRTUALITY_pure_virtual, virtualIndex: 10,
- flags: DIFlagPrototyped, isOptimized: true,
- function: void ()* @_Z3foov,
- templateParams: !5, declaration: !6, variables: !7)
+ define void @_Z3foov() !dbg !0 {
+ ...
+ }
+
+ !0 = distinct !DISubprogram(name: "foo", linkageName: "_Zfoov", scope: !1,
+ file: !2, line: 7, type: !3, isLocal: true,
+ isDefinition: false, scopeLine: 8,
+ containingType: !4,
+ virtuality: DW_VIRTUALITY_pure_virtual,
+ virtualIndex: 10, flags: DIFlagPrototyped,
+ isOptimized: true, templateParams: !5,
+ declaration: !6, variables: !7)
.. _DILexicalBlock:
Modified: llvm/trunk/docs/SourceLevelDebugging.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/SourceLevelDebugging.rst?rev=252268&r1=252267&r2=252268&view=diff
==============================================================================
--- llvm/trunk/docs/SourceLevelDebugging.rst (original)
+++ llvm/trunk/docs/SourceLevelDebugging.rst Thu Nov 5 20:41:02 2015
@@ -231,7 +231,7 @@ Compiled to LLVM, this function would be
.. code-block:: llvm
; Function Attrs: nounwind ssp uwtable
- define void @foo() #0 {
+ define void @foo() #0 !dbg !4 {
entry:
%X = alloca i32, align 4
%Y = alloca i32, align 4
@@ -263,7 +263,7 @@ Compiled to LLVM, this function would be
!1 = !DIFile(filename: "/dev/stdin", directory: "/Users/dexonsmith/data/llvm/debug-info")
!2 = !{}
!3 = !{!4}
- !4 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 1, type: !5, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: false, function: void ()* @foo, variables: !2)
+ !4 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 1, type: !5, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: false, variables: !2)
!5 = !DISubroutineType(types: !6)
!6 = !{null}
!7 = !{i32 2, !"Dwarf Version", i32 2}
@@ -304,10 +304,9 @@ scope information for the variable ``X``
.. code-block:: llvm
!14 = !DILocation(line: 2, column: 9, scope: !4)
- !4 = !DISubprogram(name: "foo", scope: !1, file: !1, line: 1, type: !5,
- isLocal: false, isDefinition: true, scopeLine: 1,
- isOptimized: false, function: void ()* @foo,
- variables: !2)
+ !4 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 1, type: !5,
+ isLocal: false, isDefinition: true, scopeLine: 1,
+ isOptimized: false, variables: !2)
Here ``!14`` is metadata providing `location information
<LangRef.html#dilocation>`_. In this example, scope is encoded by ``!4``, a
@@ -463,12 +462,12 @@ a C/C++ front-end would generate the fol
!4 = !DISubprogram(name: "main", scope: !1, file: !1, line: 1, type: !5,
isLocal: false, isDefinition: true, scopeLine: 1,
flags: DIFlagPrototyped, isOptimized: false,
- function: i32 (i32, i8**)* @main, variables: !2)
+ variables: !2)
;;
;; Define the subprogram itself.
;;
- define i32 @main(i32 %argc, i8** %argv) {
+ define i32 @main(i32 %argc, i8** %argv) !dbg !4 {
...
}
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