From: Fangrui Song <maskray@google.com>
Date: Wed, 22 May 2019 15:12:51 +0000 (+0000)
Subject: [llvm-objdump] Dump inline relocations if the relocated section is specified with... 
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=93cf9afa9eb5262fadedc17b33c5185a2405bade;p=llvm

[llvm-objdump] Dump inline relocations if the relocated section is specified with --section

This fixes PR41886: llvm-objdump -d -r -j .text doesn't show inline relocations of .text

While here, switch to stable_sort() because we don't want to change the order of relocations applied to the same location. gABI says consecutive relocation records are composed together and their order matters. In practise it is difficult to see relocations applied to the same location not consecutive, we just have to keep the relative order of relocations with the same offset.

Reviewed By: grimar

Differential Revision: https://reviews.llvm.org/D62253

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@361395 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/test/tools/llvm-objdump/X86/section-filter-relocs.test b/test/tools/llvm-objdump/X86/section-filter-relocs.test
index f36627e4c9a..5411288019d 100644
--- a/test/tools/llvm-objdump/X86/section-filter-relocs.test
+++ b/test/tools/llvm-objdump/X86/section-filter-relocs.test
@@ -1,7 +1,4 @@
 ## Test that --section works correctly for -d with -r.
-## FIXME: Inline relocations are only printed if the relocation section itself is
-##        specified with --section. This test just characterizes the existing behavior.
-##        See https://bugs.llvm.org/show_bug.cgi?id=41886
 # RUN: yaml2obj %s -o %t.o
 
 ## Show non-executable sections are not disassembled even if specified,
@@ -12,21 +9,15 @@
 ##        executable sections if requested explicitly.
 ##        See https://bugs.llvm.org/show_bug.cgi?id=41897.
 # RUN: llvm-objdump -d -r %t.o --section=.text --section=.rodata \
-# RUN:   | FileCheck %s --check-prefix=DISASM --implicit-check-not=.text2 \
-# RUN:           --implicit-check-not=.rodata --implicit-check-not=R_X86_64
-
-## Show that only the specified relocation sections that patch the
-## disassembled sections are dumped.
-# RUN: llvm-objdump -d -r %t.o --section=.text \
-# RUN:                         --section=.rela.text --section=.rela.text2 \
 # RUN:   | FileCheck %s --check-prefixes=DISASM,RELOC --implicit-check-not=.text2 \
-# RUN:           --implicit-check-not=R_X86_64
+# RUN:           --implicit-check-not=.rodata
 
 # DISASM:       Disassembly of section .text:
 # DISASM-EMPTY:
 # DISASM-NEXT:  0000000000000400 .text:
 # DISASM-NEXT:  400: e8 00 00 00 00                callq   0 <.text+0x5>
 # RELOC-NEXT:                      00000401:  R_X86_64_PC32        foo+1
+# RELOC-NEXT:                      00000401:  R_X86_64_GOT32       foo
 
 --- !ELF
 FileHeader:
diff --git a/tools/llvm-objdump/llvm-objdump.cpp b/tools/llvm-objdump/llvm-objdump.cpp
index c16b0c16700..318e0ade942 100644
--- a/tools/llvm-objdump/llvm-objdump.cpp
+++ b/tools/llvm-objdump/llvm-objdump.cpp
@@ -334,18 +334,18 @@ static StringRef ToolName;
 
 typedef std::vector<std::tuple<uint64_t, StringRef, uint8_t>> SectionSymbolsTy;
 
+static bool shouldKeep(object::SectionRef S) {
+  if (FilterSections.empty())
+    return true;
+  StringRef String;
+  std::error_code error = S.getName(String);
+  if (error)
+    return false;
+  return is_contained(FilterSections, String);
+}
+
 SectionFilter ToolSectionFilter(object::ObjectFile const &O) {
-  return SectionFilter(
-      [](object::SectionRef const &S) {
-        if (FilterSections.empty())
-          return true;
-        StringRef String;
-        std::error_code error = S.getName(String);
-        if (error)
-          return false;
-        return is_contained(FilterSections, String);
-      },
-      O);
+  return SectionFilter([](object::SectionRef S) { return shouldKeep(S); }, O);
 }
 
 void error(std::error_code EC) {
@@ -922,15 +922,15 @@ static size_t countSkippableZeroBytes(ArrayRef<uint8_t> Buf) {
 static std::map<SectionRef, std::vector<RelocationRef>>
 getRelocsMap(object::ObjectFile const &Obj) {
   std::map<SectionRef, std::vector<RelocationRef>> Ret;
-  for (const SectionRef &Section : ToolSectionFilter(Obj)) {
-    section_iterator RelSec = Section.getRelocatedSection();
-    if (RelSec == Obj.section_end())
+  for (SectionRef Sec : Obj.sections()) {
+    section_iterator Relocated = Sec.getRelocatedSection();
+    if (Relocated == Obj.section_end() || !shouldKeep(*Relocated))
       continue;
-    std::vector<RelocationRef> &V = Ret[*RelSec];
-    for (const RelocationRef &R : Section.relocations())
+    std::vector<RelocationRef> &V = Ret[*Relocated];
+    for (const RelocationRef &R : Sec.relocations())
       V.push_back(R);
     // Sort relocations by address.
-    llvm::sort(V, isRelocAddressLess);
+    llvm::stable_sort(V, isRelocAddressLess);
   }
   return Ret;
 }