[llvm-dwp] Initial partial prototype

This just concatenates the common DWP sections without doing any of the
fancy DWP things like:

1) update str_offsets
2) deduplicating strings
3) merging/creating cu/tu_index

Patches for these will follow shortly.

(also not sure about target triple/object file type for this tool - do I
really need a whole triple just to write an object file that contains
purely static/hardcoded bytes in each section? & I guess I should just
pick it based on the first input, maybe, rather than hardcoding for now
- but we only produce .dwo on ELF platforms with objcopy for now anyway)

llvm-svn: 254355

6 files changed, 67 insertions, 0 deletions

diff --git a/llvm/test/tools/llvm-dwp/Inputs/simple/a.cpp b/llvm/test/tools/llvm-dwp/Inputs/simple/a.cpp
new file mode 100644
index 00000000000..f85d105a99f
--- /dev/null
+++ b/llvm/test/tools/llvm-dwp/Inputs/simple/a.cpp
@@ -0,0 +1,2 @@
+struct foo { };
+foo a;
diff --git a/llvm/test/tools/llvm-dwp/Inputs/simple/a.dwo b/llvm/test/tools/llvm-dwp/Inputs/simple/a.dwo
new file mode 100644
index 00000000000..7bdb2a7b9f8
--- /dev/null
+++ b/llvm/test/tools/llvm-dwp/Inputs/simple/a.dwo
diff --git a/llvm/test/tools/llvm-dwp/Inputs/simple/b.cpp b/llvm/test/tools/llvm-dwp/Inputs/simple/b.cpp
new file mode 100644
index 00000000000..fedcc160f41
--- /dev/null
+++ b/llvm/test/tools/llvm-dwp/Inputs/simple/b.cpp
@@ -0,0 +1,3 @@
+struct bar { };
+void b(bar) {
+}
diff --git a/llvm/test/tools/llvm-dwp/Inputs/simple/b.dwo b/llvm/test/tools/llvm-dwp/Inputs/simple/b.dwo
new file mode 100644
index 00000000000..f41243dc722
--- /dev/null
+++ b/llvm/test/tools/llvm-dwp/Inputs/simple/b.dwo
diff --git a/llvm/test/tools/llvm-dwp/X86/lit.local.cfg b/llvm/test/tools/llvm-dwp/X86/lit.local.cfg
new file mode 100644
index 00000000000..05f8b38b334
--- /dev/null
+++ b/llvm/test/tools/llvm-dwp/X86/lit.local.cfg
@@ -0,0 +1,4 @@
+if not 'X86' in config.root.targets:
+    config.unsupported = True
+
+config.suffixes = ['.test', '.cpp', '.m', '.s']
diff --git a/llvm/test/tools/llvm-dwp/X86/simple.test b/llvm/test/tools/llvm-dwp/X86/simple.test
new file mode 100644
index 00000000000..26215bdc8c9
--- /dev/null
+++ b/llvm/test/tools/llvm-dwp/X86/simple.test
@@ -0,0 +1,58 @@
+RUN: llvm-dwp %p/../Inputs/simple/a.dwo %p/../Inputs/simple/b.dwo -o %t
+RUN: llvm-dwarfdump %t | FileCheck %s
+
+FIXME: For some reason, piping straight from llvm-dwp to llvm-dwarfdump doesn't behave well - looks like dwarfdump is reading/closes before dwp has finished.
+
+DWP from non-type-unit debug info for these two translation units:
+a.cpp:
+  struct foo { };
+  foo a;
+
+b.cpp:
+  struct bar { };
+  void b(bar) {
+  }
+
+CHECK: .debug_abbrev.dwo contents:
+CHECK: Abbrev table for offset: 0x00000000
+CHECK: DW_TAG_compile_unit
+CHECK: DW_TAG_variable
+CHECK: DW_TAG_structure_type
+CHECK: Abbrev table for offset: 0x00000031
+CHECK: DW_TAG_compile_unit
+CHECK: DW_TAG_structure_type
+CHECK: DW_TAG_subprogram
+CHECK: DW_TAG_formal_parameter
+
+CHECK: .debug_info.dwo contents:
+CHECK: 0x00000000: Compile Unit: length = 0x00000025 version = 0x0004 abbr_offset = 0x0000 addr_size = 0x08 (next unit at 0x00000029)
+CHECK: DW_TAG_compile_unit
+CHECK:   DW_AT_name {{.*}} "a.cpp"
+CHECK:   DW_TAG_variable
+CHECK:     DW_AT_name {{.*}} "a"
+CHECK:   DW_TAG_structure_type
+CHECK:     DW_AT_name {{.*}} "foo"
+
+FIXME: Using cu_index, identify that abbr_offset is 0x0031, not 0x0000
+CHECK: 0x00000029: Compile Unit: length = 0x00000031 version = 0x0004 abbr_offset = 0x0000 addr_size = 0x08 (next unit at 0x0000005e)
+FIXME: Using cu_index, use strings based on the right str index offset
+CHECK:   DW_AT_name {{.*}} "a.cpp"
+FIXME: Using cu_index to find the right abbrevs at abbr_offset, this abbrevation should actually be structure_type
+CHECK:   DW_TAG_variable
+
+CHECK: .debug_cu_index contents:
+FIXME: Emit and verify the cu_index contents
+
+CHECK: .debug_str.dwo contents:
+CHECK: "clang version
+CHECK: 0x[[ACPP:.*]]: "a.cpp"
+FIXME: Remove duplicates
+CHECK: "clang version
+CHECK: 0x[[BCPP:.*]]: "b.cpp"
+
+CHECK: .debug_str_offsets.dwo contents:
+CHECK: : 00000000
+CHECK: : [[ACPP]]
+CHECK: : 00000000
+FIXME: Update str offset indexes, this should be BCPP \/
+CHECK: : [[ACPP]]