Add support for reading ARM ELF build attributes.

Build attribute sections can now be read if they exist via ELFObjectFile, and
the llvm-readobj tool has been extended with an option to dump this information
if requested. Regression tests are also included which exercise these features.

Also update the docs with a fixed ARM ABI link and a new link to the Addenda
which provides the build attributes specification.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181009 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 70 insertions, 0 deletions

diff --git a/tools/llvm-readobj/ELFDumper.cpp b/tools/llvm-readobj/ELFDumper.cpp
index ea1b83f..6fa9026 100644
--- a/tools/llvm-readobj/ELFDumper.cpp
+++ b/tools/llvm-readobj/ELFDumper.cpp
@@ -51,6 +51,7 @@ public:
   virtual void printDynamicTable() LLVM_OVERRIDE;
   virtual void printNeededLibraries() LLVM_OVERRIDE;
   virtual void printProgramHeaders() LLVM_OVERRIDE;
+  virtual void printARMBuildAttributes() LLVM_OVERRIDE;
 
 private:
   typedef ELFObjectFile<ELFT> ELFO;
@@ -858,3 +859,65 @@ void ELFDumper<ELFT>::printProgramHeaders() {
     W.printNumber("Alignment", PI->p_align);
   }
 }
+
+#define LLVM_READOBJ_ARMATTR_NUMCASE(X) case ARMBuildAttrs::X: \
+  W.printNumber("  Tag_" #X, BuildAttrs.Tag_##X); \
+  break; \
+
+#define LLVM_READOBJ_ARMATTR_STRCASE(X) case ARMBuildAttrs::X: \
+  W.printString("  Tag_" #X, BuildAttrs.Tag_##X); \
+  break; \
+
+template<class ELFT>
+void ELFDumper<ELFT>::printARMBuildAttributes() {
+  if (Obj->getArch() != Triple::arm || !Obj->hasARMBuildAttributes())
+    return;
+  ARMBuildAttrs::ARMGenericBuildAttrInfo BuildAttrs;
+  SmallVector<unsigned, 16> AttrsRead;
+  error_code EC = Obj->readARMBuildAttributes(BuildAttrs, AttrsRead);
+  if (error(EC))
+    return;
+
+  DictScope D(W, "ARMBuildAttributes");
+
+  for (SmallVector<unsigned, 16>::iterator I = AttrsRead.begin(),
+       E = AttrsRead.end(); I != E; ++I) {
+    switch (*I) {
+    LLVM_READOBJ_ARMATTR_STRCASE(CPU_name)
+    LLVM_READOBJ_ARMATTR_STRCASE(CPU_raw_name)
+    LLVM_READOBJ_ARMATTR_NUMCASE(CPU_arch)
+    LLVM_READOBJ_ARMATTR_NUMCASE(CPU_arch_profile)
+    LLVM_READOBJ_ARMATTR_NUMCASE(ARM_ISA_use)
+    LLVM_READOBJ_ARMATTR_NUMCASE(THUMB_ISA_use)
+    LLVM_READOBJ_ARMATTR_NUMCASE(FP_arch)
+    LLVM_READOBJ_ARMATTR_NUMCASE(WMMX_arch)
+    LLVM_READOBJ_ARMATTR_NUMCASE(Advanced_SIMD_arch)
+    LLVM_READOBJ_ARMATTR_NUMCASE(PCS_config)
+    LLVM_READOBJ_ARMATTR_NUMCASE(ABI_PCS_R9_use)
+    LLVM_READOBJ_ARMATTR_NUMCASE(ABI_PCS_RW_data)
+    LLVM_READOBJ_ARMATTR_NUMCASE(ABI_PCS_RO_data)
+    LLVM_READOBJ_ARMATTR_NUMCASE(ABI_PCS_GOT_use)
+    LLVM_READOBJ_ARMATTR_NUMCASE(ABI_PCS_wchar_t)
+    LLVM_READOBJ_ARMATTR_NUMCASE(ABI_FP_rounding)
+    LLVM_READOBJ_ARMATTR_NUMCASE(ABI_FP_denormal)
+    LLVM_READOBJ_ARMATTR_NUMCASE(ABI_FP_exceptions)
+    LLVM_READOBJ_ARMATTR_NUMCASE(ABI_FP_user_exceptions)
+    LLVM_READOBJ_ARMATTR_NUMCASE(ABI_FP_number_model)
+    LLVM_READOBJ_ARMATTR_NUMCASE(ABI_align8_needed)
+    LLVM_READOBJ_ARMATTR_NUMCASE(ABI_align8_preserved)
+    LLVM_READOBJ_ARMATTR_NUMCASE(ABI_enum_size)
+    LLVM_READOBJ_ARMATTR_NUMCASE(ABI_HardFP_use)
+    LLVM_READOBJ_ARMATTR_NUMCASE(ABI_VFP_args)
+    LLVM_READOBJ_ARMATTR_NUMCASE(CPU_unaligned_access)
+    LLVM_READOBJ_ARMATTR_NUMCASE(FP_HP_extension)
+    LLVM_READOBJ_ARMATTR_NUMCASE(MPextension_use)
+    LLVM_READOBJ_ARMATTR_NUMCASE(DIV_use)
+    LLVM_READOBJ_ARMATTR_NUMCASE(T2EE_use)
+    LLVM_READOBJ_ARMATTR_NUMCASE(Virtualization_use)
+    LLVM_READOBJ_ARMATTR_NUMCASE(ABI_optimization_goals)
+    LLVM_READOBJ_ARMATTR_NUMCASE(ABI_FP_optimization_goals)
+    default:
+      break;
+    }
+  }
+}
diff --git a/tools/llvm-readobj/ObjDumper.h b/tools/llvm-readobj/ObjDumper.h
index 6918e28..9a8f0c1 100644
--- a/tools/llvm-readobj/ObjDumper.h
+++ b/tools/llvm-readobj/ObjDumper.h
@@ -39,6 +39,7 @@ public:
   virtual void printDynamicTable() { }
   virtual void printNeededLibraries() { }
   virtual void printProgramHeaders() { }
+  virtual void printARMBuildAttributes() { }
 
 protected:
   StreamWriter& W;
diff --git a/tools/llvm-readobj/llvm-readobj.cpp b/tools/llvm-readobj/llvm-readobj.cpp
index 2e95b6b..d5eb854 100644
--- a/tools/llvm-readobj/llvm-readobj.cpp
+++ b/tools/llvm-readobj/llvm-readobj.cpp
@@ -128,6 +128,10 @@ namespace opts {
   // -expand-relocs
   cl::opt<bool> ExpandRelocs("expand-relocs",
     cl::desc("Expand each shown relocation to multiple lines"));
+
+  // -arm-buildattrs
+  cl::opt<bool> ArmBuildAttrs("arm-buildattrs",
+    cl::desc("Display ARM ELF build attributes"));
 } // namespace opts
 
 namespace llvm {
@@ -221,6 +225,8 @@ static void dumpObject(const ObjectFile *Obj) {
     Dumper->printNeededLibraries();
   if (opts::ProgramHeaders)
     Dumper->printProgramHeaders();
+  if (opts::ArmBuildAttrs)
+    Dumper->printARMBuildAttributes();
 }