[llvm-branch-commits] [llvm] [llvm-debuginfo-analyzer] Add support for LLVM IR format. (PR #135440)

[Jeremy Morse via llvm-branch-commits]

================
@@ -2124,6 +2125,138 @@ layout and given the number of matches.
   -----------------------------
   Total           71          8
 
+IR (Textual representation and bitcode) SUPPORT
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The below example is used to show the IR output generated by
+:program:`llvm-debuginfo-analyzer`. We compiled the example for a
+IR 64-bit target with Clang (-O0 -g --target=x86_64-linux):
+
+.. code-block:: c++
+
+  1  using INTPTR = const int *;
+  2  int foo(INTPTR ParamPtr, unsigned ParamUnsigned, bool ParamBool) {
+  3    if (ParamBool) {
+  4      typedef int INTEGER;
+  5      const INTEGER CONSTANT = 7;
+  6      return CONSTANT;
+  7    }
+  8    return ParamUnsigned;
+  9  }
+
+PRINT BASIC DETAILS
+^^^^^^^^^^^^^^^^^^^
+The following command prints basic details for all the logical elements
+sorted by the debug information internal offset; it includes its lexical
+level and debug info format.
+
+.. code-block:: none
+
+  llvm-debuginfo-analyzer --attribute=level,format
+                          --output-sort=offset
+                          --print=scopes,symbols,types,lines,instructions
+                          test-clang.ll
+
+or
+
+.. code-block:: none
+
+  llvm-debuginfo-analyzer --attribute=level,format
+                          --output-sort=offset
+                          --print=elements
+                          test-clang.ll
+
+Each row represents an element that is present within the debug
+information. The first column represents the scope level, followed by
+the associated line number (if any), and finally the description of
+the element.
+
+.. code-block:: none
+
+  Logical View:
+  [000]           {File} 'test-clang.ll' -> Textual IR
+
+  [001]             {CompileUnit} 'test.cpp'
+  [002]     2         {Function} extern not_inlined 'foo' -> 'int'
+  [003]                 {Block}
+  [004]     5             {Variable} 'CONSTANT' -> 'const INTEGER'
+  [004]     5             {Line}
+  [004]                   {Code} 'store i32 7, ptr %CONSTANT, align 4, !dbg !32'
+  [004]     6             {Line}
+  [004]                   {Code} 'store i32 7, ptr %retval, align 4, !dbg !33'
+  [004]     6             {Line}
+  [004]                   {Code} 'br label %return, !dbg !33'
+  [003]     2           {Parameter} 'ParamPtr' -> 'INTPTR'
+  [003]     2           {Parameter} 'ParamUnsigned' -> 'unsigned int'
+  [003]     2           {Parameter} 'ParamBool' -> 'bool'
+  [003]     4           {TypeAlias} 'INTEGER' -> 'int'
+  [003]     2           {Line}
+  [003]                 {Code} '%retval = alloca i32, align 4'
+  [003]                 {Code} '%ParamPtr.addr = alloca ptr, align 8'
+  [003]                 {Code} '%ParamUnsigned.addr = alloca i32, align 4'
+  [003]                 {Code} '%ParamBool.addr = alloca i8, align 1'
+  [003]                 {Code} '%CONSTANT = alloca i32, align 4'
+  [003]                 {Code} 'store ptr %ParamPtr, ptr %ParamPtr.addr, align 8'
+  [003]                 {Code} 'store i32 %ParamUnsigned, ptr %ParamUnsigned.addr, align 4'
+  [003]                 {Code} '%storedv = zext i1 %ParamBool to i8'
+  [003]                 {Code} 'store i8 %storedv, ptr %ParamBool.addr, align 1'
+  [003]     8           {Line}
+  [003]                 {Code} '%1 = load i32, ptr %ParamUnsigned.addr, align 4, !dbg !34'
+  [003]     8           {Line}
+  [003]                 {Code} 'store i32 %1, ptr %retval, align 4, !dbg !35'
+  [003]     8           {Line}
+  [003]                 {Code} 'br label %return, !dbg !35'
+  [003]     9           {Line}
+  [003]                 {Code} '%2 = load i32, ptr %retval, align 4, !dbg !36'
+  [003]     9           {Line}
+  [003]                 {Code} 'ret i32 %2, !dbg !36'
+  [003]     3           {Line}
+  [003]     3           {Line}
+  [003]     3           {Line}
+  [003]                 {Code} 'br i1 %loadedv, label %if.then, label %if.end, !dbg !26'
+  [002]     1         {TypeAlias} 'INTPTR' -> '* const int'
+
+SELECT LOGICAL ELEMENTS
+^^^^^^^^^^^^^^^^^^^^^^^
+The following prints all *instructions*, *symbols* and *types* that
+contain **'block'** or **'.store'** in their names or types, using a tab
+layout and given the number of matches.
+
+.. code-block:: none
----------------
jmorse wrote:

I wonder if there's a more illustrative example to motivate the reader -- is it possible to search for  "INTPTR" and discover both the type alias and the parameter? That's the sort of query I think I'd end up making: "I can see this type in the output format, but why is it present? -> Ah, it's a parameter to a function".

(The current example is fine, I'm just trying to imagine a better one).

https://github.com/llvm/llvm-project/pull/135440