[PATCH] D40954: [ELF] - Teach LLD to hint about -fdebug-types-section.

[George Rimar via Phabricator via llvm-commits]

grimar updated this revision to Diff 128081.
grimar added a comment.

- Addressed comments, rebased.


https://reviews.llvm.org/D40954

Files:
  ELF/Target.cpp
  ELF/Target.h
  test/ELF/x86-64-reloc-debug-overflow.s


Index: test/ELF/x86-64-reloc-debug-overflow.s
===================================================================
--- test/ELF/x86-64-reloc-debug-overflow.s
+++ test/ELF/x86-64-reloc-debug-overflow.s
@@ -0,0 +1,12 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %S/Inputs/x86-64-reloc-error.s -o %tabs
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t
+# RUN: not ld.lld -shared %tabs %t -o %t2 2>&1 | FileCheck %s
+
+# CHECK: (.debug_info+0x1): relocation R_X86_64_32 out of range: 68719476736 is not in [0, 4294967295]; consider recompiling with -fdebug-types-section to reduce size of debug sections
+
+# CHECK: (.debug_info+0x8): relocation R_X86_64_32S out of range: -281474976710656 is not in [-2147483648, 2147483647]; consider recompiling with -fdebug-types-section to reduce size of debug sections
+
+.section .debug_info,"", at progbits
+  movl $big, %edx
+  movq $foo - 0x1000000000000, %rdx
Index: ELF/Target.h
===================================================================
--- ELF/Target.h
+++ ELF/Target.h
@@ -135,6 +135,7 @@
 template <class ELFT> TargetInfo *getMipsTargetInfo();
 
 std::string getErrorLocation(const uint8_t *Loc);
+InputSectionBase *getErrorSection(const uint8_t *Loc);
 
 uint64_t getPPC64TocBase();
 uint64_t getAArch64Page(uint64_t Expr);
@@ -146,9 +147,17 @@
 
 static inline void reportRangeError(uint8_t *Loc, RelType Type, const Twine &V,
                                     int64_t Min, uint64_t Max) {
-  error(getErrorLocation(Loc) + "relocation " + lld::toString(Type) +
-        " out of range: " + V + " is not in [" + Twine(Min) + ", " +
-        Twine(Max) + "]");
+  std::string Msg = getErrorLocation(Loc) +
+                    ("relocation " + lld::toString(Type) + " out of range: " +
+                     V + " is not in [" + Twine(Min) + ", " + Twine(Max) + "]")
+                        .str();
+
+  InputSectionBase *IS = getErrorSection(Loc);
+  if (IS && IS->Name.startswith(".debug"))
+    Msg += "; consider recompiling with -fdebug-types-section to reduce size "
+           "of debug sections";
+
+  error(Msg);
 }
 
 template <unsigned N>
Index: ELF/Target.cpp
===================================================================
--- ELF/Target.cpp
+++ ELF/Target.cpp
@@ -87,19 +87,33 @@
   fatal("unknown target machine");
 }
 
-template <class ELFT> static std::string getErrorLoc(const uint8_t *Loc) {
+// For given location in output file returns input section and offset.
+Optional<std::pair<InputSectionBase *, uint64_t>>
+getErrorInfo(const uint8_t *Loc) {
   for (InputSectionBase *D : InputSections) {
     auto *IS = dyn_cast<InputSection>(D);
     if (!IS || !IS->getParent())
       continue;
 
     uint8_t *ISLoc = IS->getParent()->Loc + IS->OutSecOff;
     if (ISLoc <= Loc && Loc < ISLoc + IS->getSize())
-      return IS->template getLocation<ELFT>(Loc - ISLoc) + ": ";
+      return std::make_pair(IS, Loc - ISLoc);
   }
+  return None;
+}
+
+template <class ELFT> static std::string getErrorLoc(const uint8_t *Loc) {
+  if (Optional<std::pair<InputSectionBase *, uint64_t>> Err = getErrorInfo(Loc))
+    return Err->first->template getLocation<ELFT>(Err->second) + ": ";
   return "";
 }
 
+InputSectionBase *elf::getErrorSection(const uint8_t *Loc) {
+  if (Optional<std::pair<InputSectionBase *, uint64_t>> Err = getErrorInfo(Loc))
+    return Err->first;
+  return nullptr;
+}
+
 std::string elf::getErrorLocation(const uint8_t *Loc) {
   switch (Config->EKind) {
   case ELF32LEKind:


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