From df7c6ef96fde9369baf4cdd5a343088e5b3e65cc Mon Sep 17 00:00:00 2001
From: Sam Parker <sam.parker@arm.com>
Date: Wed, 18 Jan 2017 13:52:12 +0000
Subject: [ARM] Create objdump subtarget from build attrs

Enable an ELFObjectFile to read the its arm build attributes to
produce a target triple with a specific ARM architecture.
llvm-objdump now uses this functionality to automatically produce
a more accurate target.

Differential Revision: https://reviews.llvm.org/D28769

llvm-svn: 292366
---
 llvm/tools/llvm-objdump/llvm-objdump.cpp | 21 +++++++++++++++++++--
 llvm/tools/llvm-readobj/ELFDumper.cpp    |  2 +-
 2 files changed, 20 insertions(+), 3 deletions(-)

(limited to 'llvm/tools')

diff --git a/llvm/tools/llvm-objdump/llvm-objdump.cpp b/llvm/tools/llvm-objdump/llvm-objdump.cpp
index 8373f0ce3f1..6b8a43ea1bd 100644
--- a/llvm/tools/llvm-objdump/llvm-objdump.cpp
+++ b/llvm/tools/llvm-objdump/llvm-objdump.cpp
@@ -357,7 +357,16 @@ static const Target *getTarget(const ObjectFile *Obj = nullptr) {
   llvm::Triple TheTriple("unknown-unknown-unknown");
   if (TripleName.empty()) {
     if (Obj) {
-      TheTriple.setArch(Triple::ArchType(Obj->getArch()));
+      auto Arch = Obj->getArch();
+      TheTriple.setArch(Triple::ArchType(Arch));
+
+      // For ARM targets, try to use the build attributes to build determine
+      // the build target. Target features are also added, but later during
+      // disassembly.
+      if (Arch == Triple::arm || Arch == Triple::armeb) {
+        Obj->setARMSubArch(TheTriple);
+      }
+
       // TheTriple defaults to ELF, and COFF doesn't have an environment:
       // the best we can do here is indicate that it is mach-o.
       if (Obj->isMachO())
@@ -369,8 +378,16 @@ static const Target *getTarget(const ObjectFile *Obj = nullptr) {
           TheTriple.setTriple("thumbv7-windows");
       }
     }
-  } else
+  } else {
     TheTriple.setTriple(Triple::normalize(TripleName));
+    // Use the triple, but also try to combine with ARM build attributes.
+    if (Obj) {
+      auto Arch = Obj->getArch();
+      if (Arch == Triple::arm || Arch == Triple::armeb) {
+        Obj->setARMSubArch(TheTriple);
+      }
+    }
+  }
 
   // Get the target specific parser.
   std::string Error;
diff --git a/llvm/tools/llvm-readobj/ELFDumper.cpp b/llvm/tools/llvm-readobj/ELFDumper.cpp
index 54ef7fbdd30..0a3cd7a4f62 100644
--- a/llvm/tools/llvm-readobj/ELFDumper.cpp
+++ b/llvm/tools/llvm-readobj/ELFDumper.cpp
@@ -1892,7 +1892,7 @@ template <> void ELFDumper<ELFType<support::little, false>>::printAttributes() {
     if (Contents.size() == 1)
       continue;
 
-    ARMAttributeParser(W).Parse(Contents);
+    ARMAttributeParser(&W).Parse(Contents, true);
   }
 }
 }
-- 
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