[XRay] Implement `llvm-xray extract`, start of the llvm-xray tool

Usage:

  llvm-xray extract <object file> [-o <filename or '-'>]

The tool gets the XRay instrumentation map from an object file and turns
it into YAML.  We first support ELF64 sleds on x86_64 binaries, with
provision for supporting other supported platforms and formats later.

This is the first of a many-part change to fully implement the
`llvm-xray` tool.

We also define a subcommand registration and dispatch mechanism to be
used by other further subcommand implementations for llvm-xray.

llvm-svn: 285155

1 files changed, 15 insertions, 0 deletions

diff --git a/llvm/test/tools/llvm-xray/X86/extract-instrmap.ll b/llvm/test/tools/llvm-xray/X86/extract-instrmap.ll
new file mode 100644
index 00000000000..8155d57f814
--- /dev/null
+++ b/llvm/test/tools/llvm-xray/X86/extract-instrmap.ll
@@ -0,0 +1,15 @@
+; This test makes sure we can extract the instrumentation map from an
+; XRay-instrumented object file.
+;
+; RUN: llvm-xray extract %S/Inputs/elf64-example.bin | FileCheck %s
+
+; CHECK:      ---
+; CHECK-NEXT: - { id: 1, address: 0x000000000041C900, function: 0x000000000041C900, kind: function-enter,
+; CHECK-NEXT:     always-instrument: true }
+; CHECK-NEXT: - { id: 1, address: 0x000000000041C912, function: 0x000000000041C900, kind: function-exit,
+; CHECK-NEXT:     always-instrument: true }
+; CHECK-NEXT: - { id: 2, address: 0x000000000041C930, function: 0x000000000041C930, kind: function-enter,
+; CHECK-NEXT:    always-instrument: true }
+; CHECK-NEXT: - { id: 2, address: 0x000000000041C946, function: 0x000000000041C930, kind: function-exit,
+; CHECK-NEXT:     always-instrument: true }
+; CHECK-NEXT: ...