Re-apply "[JITLink][ELF] Don't skip debug info sections by default."

lhames · lhames · commit f05ac803ffe7 · 2023-03-20T22:24:04.000Z
This reapplies 57aeb30, which was reverted in f721fcb due to buildbot failures. The cause of the failure was missing support for R_AARCH64_ABS32, which was added in fb1b994.
diff --git a/llvm/lib/ExecutionEngine/JITLink/ELFLinkGraphBuilder.h b/llvm/lib/ExecutionEngine/JITLink/ELFLinkGraphBuilder.h
@@ -62,6 +62,14 @@ class ELFLinkGraphBuilder : public ELFLinkGraphBuilderBase {
                       StringRef FileName,
                       LinkGraph::GetEdgeKindNameFunction GetEdgeKindName);
 
+  /// Debug sections are included in the graph by default. Use
+  /// setProcessDebugSections(false) to ignore them if debug info is not
+  /// needed.
+  ELFLinkGraphBuilder &setProcessDebugSections(bool ProcessDebugSections) {
+    this->ProcessDebugSections = ProcessDebugSections;
+    return *this;
+  }
+
   /// Attempt to construct and return the LinkGraph.
   Expected<std::unique_ptr<LinkGraph>> buildGraph();
 
@@ -115,8 +123,7 @@ class ELFLinkGraphBuilder : public ELFLinkGraphBuilderBase {
   ///
   template <typename RelocHandlerMethod>
   Error forEachRelaRelocation(const typename ELFT::Shdr &RelSect,
-                              RelocHandlerMethod &&Func,
-                              bool ProcessDebugSections = false);
+                              RelocHandlerMethod &&Func);
 
   /// Traverse all matching ELFT::Rel relocation records in the given section.
   /// The handler function Func should be callable with this signature:
@@ -125,44 +132,40 @@ class ELFLinkGraphBuilder : public ELFLinkGraphBuilderBase {
   ///
   template <typename RelocHandlerMethod>
   Error forEachRelRelocation(const typename ELFT::Shdr &RelSect,
-                             RelocHandlerMethod &&Func,
-                             bool ProcessDebugSections = false);
+                             RelocHandlerMethod &&Func);
 
   /// Traverse all matching rela relocation records in the given section.
   /// Convenience wrapper to allow passing a member function for the handler.
   ///
   template <typename ClassT, typename RelocHandlerMethod>
   Error forEachRelaRelocation(const typename ELFT::Shdr &RelSect,
-                              ClassT *Instance, RelocHandlerMethod &&Method,
-                              bool ProcessDebugSections = false) {
+                              ClassT *Instance, RelocHandlerMethod &&Method) {
     return forEachRelaRelocation(
         RelSect,
         [Instance, Method](const auto &Rel, const auto &Target, auto &GS) {
           return (Instance->*Method)(Rel, Target, GS);
-        },
-        ProcessDebugSections);
+        });
   }
 
   /// Traverse all matching rel relocation records in the given section.
   /// Convenience wrapper to allow passing a member function for the handler.
   ///
   template <typename ClassT, typename RelocHandlerMethod>
   Error forEachRelRelocation(const typename ELFT::Shdr &RelSect,
-                             ClassT *Instance, RelocHandlerMethod &&Method,
-                             bool ProcessDebugSections = false) {
+                             ClassT *Instance, RelocHandlerMethod &&Method) {
     return forEachRelRelocation(
         RelSect,
         [Instance, Method](const auto &Rel, const auto &Target, auto &GS) {
           return (Instance->*Method)(Rel, Target, GS);
-        },
-        ProcessDebugSections);
+        });
   }
 
   const ELFFile &Obj;
 
   typename ELFFile::Elf_Shdr_Range Sections;
   const typename ELFFile::Elf_Shdr *SymTabSec = nullptr;
   StringRef SectionStringTab;
+  bool ProcessDebugSections = true;
 
   // Maps ELF section indexes to LinkGraph Blocks.
   // Only SHF_ALLOC sections will have graph blocks.
@@ -318,7 +321,7 @@ template <typename ELFT> Error ELFLinkGraphBuilder<ELFT>::graphifySections() {
 
     // If the name indicates that it's a debug section then skip it: We don't
     // support those yet.
-    if (isDwarfSection(*Name)) {
+    if (!ProcessDebugSections && isDwarfSection(*Name)) {
       LLVM_DEBUG({
         dbgs() << "    " << SecIndex << ": \"" << *Name
                << "\" is a debug section: "
@@ -522,8 +525,7 @@ template <typename ELFT> Error ELFLinkGraphBuilder<ELFT>::graphifySymbols() {
 template <typename ELFT>
 template <typename RelocHandlerFunction>
 Error ELFLinkGraphBuilder<ELFT>::forEachRelaRelocation(
-    const typename ELFT::Shdr &RelSect, RelocHandlerFunction &&Func,
-    bool ProcessDebugSections) {
+    const typename ELFT::Shdr &RelSect, RelocHandlerFunction &&Func) {
   // Only look into sections that store relocation entries.
   if (RelSect.sh_type != ELF::SHT_RELA)
     return Error::success();
@@ -569,8 +571,7 @@ Error ELFLinkGraphBuilder<ELFT>::forEachRelaRelocation(
 template <typename ELFT>
 template <typename RelocHandlerFunction>
 Error ELFLinkGraphBuilder<ELFT>::forEachRelRelocation(
-    const typename ELFT::Shdr &RelSect, RelocHandlerFunction &&Func,
-    bool ProcessDebugSections) {
+    const typename ELFT::Shdr &RelSect, RelocHandlerFunction &&Func) {
   // Only look into sections that store relocation entries.
   if (RelSect.sh_type != ELF::SHT_REL)
     return Error::success();
diff --git a/llvm/test/ExecutionEngine/JITLink/X86/ELF_debug_section_lifetime_is_NoAlloc.yaml b/llvm/test/ExecutionEngine/JITLink/X86/ELF_debug_section_lifetime_is_NoAlloc.yaml
@@ -0,0 +1,195 @@
+# REQUIRES: asserts
+# RUN: yaml2obj -o %t.o %s
+# RUN: llvm-jitlink -debug-only=jitlink -noexec %t.o 2>&1 | FileCheck %s
+#
+# Check that debug sections get NoAlloc lifetimes.
+#
+# CHECK: ".debug_str" is not a SHF_ALLOC section. Using NoAlloc lifetime.
+# CHECK: ".debug_abbrev" is not a SHF_ALLOC section. Using NoAlloc lifetime.
+# CHECK: ".debug_info" is not a SHF_ALLOC section. Using NoAlloc lifetime.
+# CHECK: ".debug_line" is not a SHF_ALLOC section. Using NoAlloc lifetime.
+
+
+--- !ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_X86_64
+  SectionHeaderStringTable: .strtab
+Sections:
+  - Name:            .text
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x10
+    Content:         B82A000000C3662E0F1F840000000000B82A000000C3
+  - Name:            .debug_abbrev
+    Type:            SHT_PROGBITS
+    AddressAlign:    0x1
+    Content:         011101250E1305030E10171B0E110112060000022E00110112064018974219030E3A0B3B0B271949133F190000032E01110112064018974219030E3A0B3B0B271949133F1900000405000218030E3A0B3B0B49130000052400030E3E0B0B0B0000060F004913000000
+  - Name:            .debug_info
+    Type:            SHT_PROGBITS
+    AddressAlign:    0x1
+    Content:         8C0000000400000000000801000000000C000000000000000000000000000000000000000000160000000200000000000000000600000001570000000001017700000003000000000000000006000000015700000000010577000000040155000000000105770000000401540000000001057E0000000005000000000504068300000006880000000500000000060100
+  - Name:            .comment
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_MERGE, SHF_STRINGS ]
+    AddressAlign:    0x1
+    EntSize:         0x1
+    Content:         00636C616E672076657273696F6E2031302E302E302D347562756E7475312000
+  - Name:            .note.GNU-stack
+    Type:            SHT_PROGBITS
+    AddressAlign:    0x1
+  - Name:            .debug_line
+    Type:            SHT_PROGBITS
+    AddressAlign:    0x1
+    Content:         58000000040036000000010101FB0E0D0001010101000000010000012F746D700000454C465F736B69705F64656275675F73656374696F6E732E63000100000000090200000000000000000105030A130500F505030A130206000101
+  - Name:            .eh_frame
+    Type:            SHT_X86_64_UNWIND
+    Flags:           [ SHF_ALLOC ]
+    AddressAlign:    0x8
+    Content:         1400000000000000017A5200017810011B0C070890010000100000001C0000000000000006000000000000001000000030000000000000000600000000000000
+  - Name:            .rela.debug_info
+    Type:            SHT_RELA
+    Flags:           [ SHF_INFO_LINK ]
+    Link:            .symtab
+    AddressAlign:    0x8
+    Info:            .debug_info
+    Relocations:
+      - Offset:          0x6
+        Symbol:          .debug_abbrev
+        Type:            R_X86_64_32
+      - Offset:          0xC
+        Symbol:          .debug_str
+        Type:            R_X86_64_32
+      - Offset:          0x12
+        Symbol:          .debug_str
+        Type:            R_X86_64_32
+        Addend:          31
+      - Offset:          0x16
+        Symbol:          .debug_line
+        Type:            R_X86_64_32
+      - Offset:          0x1A
+        Symbol:          .debug_str
+        Type:            R_X86_64_32
+        Addend:          57
+      - Offset:          0x1E
+        Symbol:          .text
+        Type:            R_X86_64_64
+      - Offset:          0x2B
+        Symbol:          .text
+        Type:            R_X86_64_64
+      - Offset:          0x39
+        Symbol:          .debug_str
+        Type:            R_X86_64_32
+        Addend:          62
+      - Offset:          0x44
+        Symbol:          .text
+        Type:            R_X86_64_64
+        Addend:          16
+      - Offset:          0x52
+        Symbol:          .debug_str
+        Type:            R_X86_64_32
+        Addend:          70
+      - Offset:          0x5F
+        Symbol:          .debug_str
+        Type:            R_X86_64_32
+        Addend:          75
+      - Offset:          0x6C
+        Symbol:          .debug_str
+        Type:            R_X86_64_32
+        Addend:          80
+      - Offset:          0x78
+        Symbol:          .debug_str
+        Type:            R_X86_64_32
+        Addend:          66
+      - Offset:          0x89
+        Symbol:          .debug_str
+        Type:            R_X86_64_32
+        Addend:          85
+  - Name:            .rela.debug_line
+    Type:            SHT_RELA
+    Flags:           [ SHF_INFO_LINK ]
+    Link:            .symtab
+    AddressAlign:    0x8
+    Info:            .debug_line
+    Relocations:
+      - Offset:          0x43
+        Symbol:          .text
+        Type:            R_X86_64_64
+  - Name:            .rela.eh_frame
+    Type:            SHT_RELA
+    Flags:           [ SHF_INFO_LINK ]
+    Link:            .symtab
+    AddressAlign:    0x8
+    Info:            .eh_frame
+    Relocations:
+      - Offset:          0x20
+        Symbol:          .text
+        Type:            R_X86_64_PC32
+      - Offset:          0x34
+        Symbol:          .text
+        Type:            R_X86_64_PC32
+        Addend:          16
+  - Name:            .llvm_addrsig
+    Type:            SHT_LLVM_ADDRSIG
+    Flags:           [ SHF_EXCLUDE ]
+    Link:            .symtab
+    AddressAlign:    0x1
+    Offset:          0x4C0
+    Symbols:         [  ]
+  - Type:            SectionHeaderTable
+    Sections:
+      - Name:            .strtab
+      - Name:            .text
+      - Name:            .debug_str
+      - Name:            .debug_abbrev
+      - Name:            .debug_info
+      - Name:            .rela.debug_info
+      - Name:            .comment
+      - Name:            .note.GNU-stack
+      - Name:            .debug_line
+      - Name:            .rela.debug_line
+      - Name:            .eh_frame
+      - Name:            .rela.eh_frame
+      - Name:            .llvm_addrsig
+      - Name:            .symtab
+Symbols:
+  - Name:            ELF_skip_debug_sections.c
+    Type:            STT_FILE
+    Index:           SHN_ABS
+  - Name:            .text
+    Type:            STT_SECTION
+    Section:         .text
+  - Name:            .debug_str
+    Type:            STT_SECTION
+    Section:         .debug_str
+  - Name:            .debug_abbrev
+    Type:            STT_SECTION
+    Section:         .debug_abbrev
+  - Name:            .debug_line
+    Type:            STT_SECTION
+    Section:         .debug_line
+  - Name:            foo
+    Type:            STT_FUNC
+    Section:         .text
+    Binding:         STB_GLOBAL
+    Size:            0x6
+  - Name:            main
+    Type:            STT_FUNC
+    Section:         .text
+    Binding:         STB_GLOBAL
+    Value:           0x10
+    Size:            0x6
+DWARF:
+  debug_str:
+    - 'clang version 10.0.0-4ubuntu1 '
+    - ELF_skip_debug_sections.c
+    - '/tmp'
+    - foo
+    - int
+    - main
+    - argc
+    - argv
+    - char
+...
diff --git a/llvm/test/ExecutionEngine/JITLink/X86/ELF_skip_debug_sections.s b/llvm/test/ExecutionEngine/JITLink/X86/ELF_skip_debug_sections.s
