DI: Update and prune metadata examples

Update a couple of the examples of debug info metadata, and prune the
rest.  Point to the true reference implementation in the source.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219051 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Duncan P. N. Exon Smith 2014-10-04 14:56:56 +00:00
parent 9e8c2e8568
commit ffd2f5051e

View File

@ -849,8 +849,11 @@ to provide completely different forms if they don't fit into the DWARF model.
As support for debugging information gets added to the various LLVM
source-language front-ends, the information used should be documented here.
The following sections provide examples of various C/C++ constructs and the
debug information that would best describe those constructs.
The following sections provide examples of a few C/C++ constructs and the debug
information that would best describe those constructs. The canonical
references are the ``DIDescriptor`` classes defined in
``include/llvm/IR/DebugInfo.h`` and the implementations of the helper functions
in ``lib/IR/DIBuilder.cpp``.
C/C++ source file information
-----------------------------
@ -955,25 +958,35 @@ a C/C++ front-end would generate the following descriptors:
;; Define the compile unit.
!0 = metadata !{
i32 786449, ;; Tag
i32 0, ;; Context
i32 4, ;; Language
metadata !"foo.cpp", ;; File
metadata !"/Volumes/Data/tmp", ;; Directory
metadata !"clang version 3.1 ", ;; Producer
i1 true, ;; Deprecated field
i1 false, ;; "isOptimized"?
metadata !"", ;; Flags
i32 0, ;; Runtime Version
metadata !1, ;; Enum Types
metadata !1, ;; Retained Types
metadata !1, ;; Subprograms
metadata !3, ;; Global Variables
metadata !1, ;; Imported entities
"", ;; Split debug filename
1, ;; Full debug info
; Header(
; i32 17, ;; Tag
; i32 0, ;; Context
; i32 4, ;; Language
; metadata !"clang version 3.6.0 ", ;; Producer
; i1 false, ;; "isOptimized"?
; metadata !"", ;; Flags
; i32 0, ;; Runtime Version
; "", ;; Split debug filename
; 1 ;; Full debug info
; )
metadata !"0x11\0012\00clang version 3.6.0 \000\00\000\00\001",
metadata !1, ;; File
metadata !2, ;; Enum Types
metadata !2, ;; Retained Types
metadata !2, ;; Subprograms
metadata !3, ;; Global Variables
metadata !2 ;; Imported entities
} ; [ DW_TAG_compile_unit ]
;; The file/directory pair.
!1 = metadata !{
metadata !"foo.c", ;; Filename
metadata !"/Users/dexonsmith/data/llvm/debug-info" ;; Directory
}
;; An empty array.
!2 = metadata !{}
;; The Array of Global Variables
!3 = metadata !{
metadata !4
@ -983,17 +996,19 @@ a C/C++ front-end would generate the following descriptors:
;; Define the global variable itself.
;;
!4 = metadata !{
i32 786484, ;; Tag
i32 0, ;; Unused
; Header(
; i32 52, ;; Tag
; metadata !"MyGlobal", ;; Name
; metadata !"MyGlobal", ;; Display Name
; metadata !"", ;; Linkage Name
; i32 1, ;; Line
; i32 0, ;; IsLocalToUnit
; i32 1 ;; IsDefinition
; )
metadata !"0x34\00MyGlobal\00MyGlobal\00\001\000\001",
null, ;; Unused
metadata !"MyGlobal", ;; Name
metadata !"MyGlobal", ;; Display Name
metadata !"", ;; Linkage Name
metadata !6, ;; File
i32 1, ;; Line
metadata !7, ;; Type
i32 0, ;; IsLocalToUnit
i32 1, ;; IsDefinition
metadata !5, ;; File
metadata !6, ;; Type
i32* @MyGlobal, ;; LLVM-IR Value
null ;; Static member declaration
} ; [ DW_TAG_variable ]
@ -1002,28 +1017,29 @@ a C/C++ front-end would generate the following descriptors:
;; Define the file
;;
!5 = metadata !{
metadata !"foo.cpp", ;; File
metadata !"/Volumes/Data/tmp", ;; Directory
}
!6 = metadata !{
i32 786473, ;; Tag
metadata !5 ;; Unused
Header(
i32 41 ;; Tag
), ;; metadata !"0x29"
metadata !1 ;; File/directory pair
} ; [ DW_TAG_file_type ]
;;
;; Define the type
;;
!7 = metadata !{
i32 786468, ;; Tag
null, ;; Unused
null, ;; Unused
metadata !"int", ;; Name
i32 0, ;; Line
i64 32, ;; Size in Bits
i64 32, ;; Align in Bits
i64 0, ;; Offset
i32 0, ;; Flags
i32 5 ;; Encoding
!6 = metadata !{
; Header(
; i32 36, ;; Tag
; metadata !"int", ;; Name
; i32 0, ;; Line
; i64 32, ;; Size in Bits
; i64 32, ;; Align in Bits
; i64 0, ;; Offset
; i32 0, ;; Flags
; i32 5 ;; Encoding
; )
metadata !"0x24\00int\000\0032\0032\000\000\005",
null, ;; Unused
null ;; Unused
} ; [ DW_TAG_base_type ]
C/C++ function information
@ -1045,26 +1061,31 @@ a C/C++ front-end would generate the following descriptors:
;; Define the anchor for subprograms.
;;
!6 = metadata !{
i32 786484, ;; Tag
metadata !1, ;; File
metadata !1, ;; Context
metadata !"main", ;; Name
metadata !"main", ;; Display name
metadata !"main", ;; Linkage name
i32 1, ;; Line number
metadata !4, ;; Type
i1 false, ;; Is local
i1 true, ;; Is definition
i32 0, ;; Virtuality attribute, e.g. pure virtual function
i32 0, ;; Index into virtual table for C++ methods
i32 0, ;; Type that holds virtual table.
i32 0, ;; Flags
i1 false, ;; True if this function is optimized
Function *, ;; Pointer to llvm::Function
null, ;; Function template parameters
null, ;; List of function variables (emitted when optimizing)
1 ;; Line number of the opening '{' of the function
; Header(
; i32 46, ;; Tag
; metadata !"main", ;; Name
; metadata !"main", ;; Display name
; metadata !"", ;; Linkage name
; i32 1, ;; Line number
; i1 false, ;; Is local
; i1 true, ;; Is definition
; i32 0, ;; Virtuality attribute, e.g. pure virtual function
; i32 0, ;; Index into virtual table for C++ methods
; i32 256, ;; Flags
; i1 0, ;; True if this function is optimized
; 1 ;; Line number of the opening '{' of the function
; )
metadata !"0x2e\00main\00main\00\001\000\001\000\000\00256\000\001",
metadata !1, ;; File
metadata !5, ;; Context
metadata !6, ;; Type
null, ;; Containing type
i32 (i32, i8**)* @main, ;; Pointer to llvm::Function
null, ;; Function template parameters
null, ;; Function declaration
metadata !2 ;; List of function variables (emitted when optimizing)
}
;;
;; Define the subprogram itself.
;;
@ -1072,443 +1093,6 @@ a C/C++ front-end would generate the following descriptors:
...
}
C/C++ basic types
-----------------
The following are the basic type descriptors for C/C++ core types:
bool
^^^^
.. code-block:: llvm
!2 = metadata !{
i32 786468, ;; Tag
null, ;; File
null, ;; Context
metadata !"bool", ;; Name
i32 0, ;; Line number
i64 8, ;; Size in Bits
i64 8, ;; Align in Bits
i64 0, ;; Offset in Bits
i32 0, ;; Flags
i32 2 ;; Encoding
}
char
^^^^
.. code-block:: llvm
!2 = metadata !{
i32 786468, ;; Tag
null, ;; File
null, ;; Context
metadata !"char", ;; Name
i32 0, ;; Line number
i64 8, ;; Size in Bits
i64 8, ;; Align in Bits
i64 0, ;; Offset in Bits
i32 0, ;; Flags
i32 6 ;; Encoding
}
unsigned char
^^^^^^^^^^^^^
.. code-block:: llvm
!2 = metadata !{
i32 786468, ;; Tag
null, ;; File
null, ;; Context
metadata !"unsigned char",
i32 0, ;; Line number
i64 8, ;; Size in Bits
i64 8, ;; Align in Bits
i64 0, ;; Offset in Bits
i32 0, ;; Flags
i32 8 ;; Encoding
}
short
^^^^^
.. code-block:: llvm
!2 = metadata !{
i32 786468, ;; Tag
null, ;; File
null, ;; Context
metadata !"short int",
i32 0, ;; Line number
i64 16, ;; Size in Bits
i64 16, ;; Align in Bits
i64 0, ;; Offset in Bits
i32 0, ;; Flags
i32 5 ;; Encoding
}
unsigned short
^^^^^^^^^^^^^^
.. code-block:: llvm
!2 = metadata !{
i32 786468, ;; Tag
null, ;; File
null, ;; Context
metadata !"short unsigned int",
i32 0, ;; Line number
i64 16, ;; Size in Bits
i64 16, ;; Align in Bits
i64 0, ;; Offset in Bits
i32 0, ;; Flags
i32 7 ;; Encoding
}
int
^^^
.. code-block:: llvm
!2 = metadata !{
i32 786468, ;; Tag
null, ;; File
null, ;; Context
metadata !"int", ;; Name
i32 0, ;; Line number
i64 32, ;; Size in Bits
i64 32, ;; Align in Bits
i64 0, ;; Offset in Bits
i32 0, ;; Flags
i32 5 ;; Encoding
}
unsigned int
^^^^^^^^^^^^
.. code-block:: llvm
!2 = metadata !{
i32 786468, ;; Tag
null, ;; File
null, ;; Context
metadata !"unsigned int",
i32 0, ;; Line number
i64 32, ;; Size in Bits
i64 32, ;; Align in Bits
i64 0, ;; Offset in Bits
i32 0, ;; Flags
i32 7 ;; Encoding
}
long long
^^^^^^^^^
.. code-block:: llvm
!2 = metadata !{
i32 786468, ;; Tag
null, ;; File
null, ;; Context
metadata !"long long int",
i32 0, ;; Line number
i64 64, ;; Size in Bits
i64 64, ;; Align in Bits
i64 0, ;; Offset in Bits
i32 0, ;; Flags
i32 5 ;; Encoding
}
unsigned long long
^^^^^^^^^^^^^^^^^^
.. code-block:: llvm
!2 = metadata !{
i32 786468, ;; Tag
null, ;; File
null, ;; Context
metadata !"long long unsigned int",
i32 0, ;; Line number
i64 64, ;; Size in Bits
i64 64, ;; Align in Bits
i64 0, ;; Offset in Bits
i32 0, ;; Flags
i32 7 ;; Encoding
}
float
^^^^^
.. code-block:: llvm
!2 = metadata !{
i32 786468, ;; Tag
null, ;; File
null, ;; Context
metadata !"float",
i32 0, ;; Line number
i64 32, ;; Size in Bits
i64 32, ;; Align in Bits
i64 0, ;; Offset in Bits
i32 0, ;; Flags
i32 4 ;; Encoding
}
double
^^^^^^
.. code-block:: llvm
!2 = metadata !{
i32 786468, ;; Tag
null, ;; File
null, ;; Context
metadata !"double",;; Name
i32 0, ;; Line number
i64 64, ;; Size in Bits
i64 64, ;; Align in Bits
i64 0, ;; Offset in Bits
i32 0, ;; Flags
i32 4 ;; Encoding
}
C/C++ derived types
-------------------
Given the following as an example of C/C++ derived type:
.. code-block:: c
typedef const int *IntPtr;
a C/C++ front-end would generate the following descriptors:
.. code-block:: llvm
;;
;; Define the typedef "IntPtr".
;;
!2 = metadata !{
i32 786454, ;; Tag
metadata !3, ;; File
metadata !1, ;; Context
metadata !"IntPtr", ;; Name
i32 0, ;; Line number
i64 0, ;; Size in bits
i64 0, ;; Align in bits
i64 0, ;; Offset in bits
i32 0, ;; Flags
metadata !4 ;; Derived From type
}
;;
;; Define the pointer type.
;;
!4 = metadata !{
i32 786447, ;; Tag
null, ;; File
null, ;; Context
metadata !"", ;; Name
i32 0, ;; Line number
i64 64, ;; Size in bits
i64 64, ;; Align in bits
i64 0, ;; Offset in bits
i32 0, ;; Flags
metadata !5 ;; Derived From type
}
;;
;; Define the const type.
;;
!5 = metadata !{
i32 786470, ;; Tag
null, ;; File
null, ;; Context
metadata !"", ;; Name
i32 0, ;; Line number
i64 0, ;; Size in bits
i64 0, ;; Align in bits
i64 0, ;; Offset in bits
i32 0, ;; Flags
metadata !6 ;; Derived From type
}
;;
;; Define the int type.
;;
!6 = metadata !{
i32 786468, ;; Tag
null, ;; File
null, ;; Context
metadata !"int", ;; Name
i32 0, ;; Line number
i64 32, ;; Size in bits
i64 32, ;; Align in bits
i64 0, ;; Offset in bits
i32 0, ;; Flags
i32 5 ;; Encoding
}
C/C++ struct/union types
------------------------
Given the following as an example of C/C++ struct type:
.. code-block:: c
struct Color {
unsigned Red;
unsigned Green;
unsigned Blue;
};
a C/C++ front-end would generate the following descriptors:
.. code-block:: llvm
;;
;; Define basic type for unsigned int.
;;
!5 = metadata !{
i32 786468, ;; Tag
null, ;; File
null, ;; Context
metadata !"unsigned int",
i32 0, ;; Line number
i64 32, ;; Size in Bits
i64 32, ;; Align in Bits
i64 0, ;; Offset in Bits
i32 0, ;; Flags
i32 7 ;; Encoding
}
;;
;; Define composite type for struct Color.
;;
!2 = metadata !{
i32 786451, ;; Tag
metadata !1, ;; Compile unit
null, ;; Context
metadata !"Color", ;; Name
i32 1, ;; Line number
i64 96, ;; Size in bits
i64 32, ;; Align in bits
i64 0, ;; Offset in bits
i32 0, ;; Flags
null, ;; Derived From
metadata !3, ;; Elements
i32 0, ;; Runtime Language
null, ;; Base type containing the vtable pointer for this type
null ;; Template parameters
}
;;
;; Define the Red field.
;;
!4 = metadata !{
i32 786445, ;; Tag
metadata !1, ;; File
metadata !1, ;; Context
metadata !"Red", ;; Name
i32 2, ;; Line number
i64 32, ;; Size in bits
i64 32, ;; Align in bits
i64 0, ;; Offset in bits
i32 0, ;; Flags
metadata !5 ;; Derived From type
}
;;
;; Define the Green field.
;;
!6 = metadata !{
i32 786445, ;; Tag
metadata !1, ;; File
metadata !1, ;; Context
metadata !"Green", ;; Name
i32 3, ;; Line number
i64 32, ;; Size in bits
i64 32, ;; Align in bits
i64 32, ;; Offset in bits
i32 0, ;; Flags
metadata !5 ;; Derived From type
}
;;
;; Define the Blue field.
;;
!7 = metadata !{
i32 786445, ;; Tag
metadata !1, ;; File
metadata !1, ;; Context
metadata !"Blue", ;; Name
i32 4, ;; Line number
i64 32, ;; Size in bits
i64 32, ;; Align in bits
i64 64, ;; Offset in bits
i32 0, ;; Flags
metadata !5 ;; Derived From type
}
;;
;; Define the array of fields used by the composite type Color.
;;
!3 = metadata !{metadata !4, metadata !6, metadata !7}
C/C++ enumeration types
-----------------------
Given the following as an example of C/C++ enumeration type:
.. code-block:: c
enum Trees {
Spruce = 100,
Oak = 200,
Maple = 300
};
a C/C++ front-end would generate the following descriptors:
.. code-block:: llvm
;;
;; Define composite type for enum Trees
;;
!2 = metadata !{
i32 786436, ;; Tag
metadata !1, ;; File
metadata !1, ;; Context
metadata !"Trees", ;; Name
i32 1, ;; Line number
i64 32, ;; Size in bits
i64 32, ;; Align in bits
i64 0, ;; Offset in bits
i32 0, ;; Flags
null, ;; Derived From type
metadata !3, ;; Elements
i32 0 ;; Runtime language
}
;;
;; Define the array of enumerators used by composite type Trees.
;;
!3 = metadata !{metadata !4, metadata !5, metadata !6}
;;
;; Define Spruce enumerator.
;;
!4 = metadata !{i32 786472, metadata !"Spruce", i64 100}
;;
;; Define Oak enumerator.
;;
!5 = metadata !{i32 786472, metadata !"Oak", i64 200}
;;
;; Define Maple enumerator.
;;
!6 = metadata !{i32 786472, metadata !"Maple", i64 300}
Debugging information format
============================