[yaml2elf] - Support describing .stack_sizes sections using unique suffixes.

Currently we can't use unique suffixes in section names to describe
stack sizes sections. E.g. '.stack_sizes [1]' will be treated as a regular section.
This happens because we recognize stack sizes section by name and
do not yet drop the suffix before the check.

The patch fixes it.

Differential revision: https://reviews.llvm.org/D68018

llvm-svn: 372853

include/llvm/ObjectYAML/ELFYAML.h

@@ -25,6 +25,8 @@
 namespace llvm {
 namespace ELFYAML {
 
+StringRef dropUniqueSuffix(StringRef S);
+
 // These types are invariant across 32/64-bit ELF, so for simplicity just
 // directly give them their exact sizes. We don't need to worry about
 // endianness because these are just the types in the YAMLIO structures,

lib/ObjectYAML/ELFEmitter.cpp

@@ -340,7 +340,7 @@ bool ELFState<ELFT>::initImplicitHeader(ContiguousBlobAccumulator &CBA,
   return true;
 }
 
-static StringRef dropUniqueSuffix(StringRef S) {
+StringRef llvm::ELFYAML::dropUniqueSuffix(StringRef S) {
   size_t SuffixPos = S.rfind(" [");
   if (SuffixPos == StringRef::npos)
     return S;
@@ -371,7 +371,8 @@ void ELFState<ELFT>::initSectionHeaders(std::vector<Elf_Shdr> &SHeaders,
     assert(Sec && "It can't be null unless it is an implicit section. But all "
                   "implicit sections should already have been handled above.");
 
-    SHeader.sh_name = DotShStrtab.getOffset(dropUniqueSuffix(Sec->Name));
+    SHeader.sh_name =
+        DotShStrtab.getOffset(ELFYAML::dropUniqueSuffix(Sec->Name));
     SHeader.sh_type = Sec->Type;
     if (Sec->Flags)
       SHeader.sh_flags = *Sec->Flags;
@@ -473,7 +474,7 @@ ELFState<ELFT>::toELFSymbols(ArrayRef<ELFYAML::Symbol> Symbols,
     if (Sym.NameIndex)
       Symbol.st_name = *Sym.NameIndex;
     else if (!Sym.Name.empty())
-      Symbol.st_name = Strtab.getOffset(dropUniqueSuffix(Sym.Name));
+      Symbol.st_name = Strtab.getOffset(ELFYAML::dropUniqueSuffix(Sym.Name));
 
     Symbol.setBindingAndType(Sym.Binding, Sym.Type);
     if (!Sym.Section.empty())
@@ -962,7 +963,7 @@ template <class ELFT> void ELFState<ELFT>::buildSectionIndex() {
     if (Name.empty())
       continue;
 
-    DotShStrtab.add(dropUniqueSuffix(Name));
+    DotShStrtab.add(ELFYAML::dropUniqueSuffix(Name));
     if (!SN2I.addName(Name, I))
       reportError("repeated section name: '" + Name +
                   "' at YAML section number " + Twine(I));
@@ -987,12 +988,12 @@ template <class ELFT> void ELFState<ELFT>::buildSymbolIndexes() {
 template <class ELFT> void ELFState<ELFT>::finalizeStrings() {
   // Add the regular symbol names to .strtab section.
   for (const ELFYAML::Symbol &Sym : Doc.Symbols)
-    DotStrtab.add(dropUniqueSuffix(Sym.Name));
+    DotStrtab.add(ELFYAML::dropUniqueSuffix(Sym.Name));
   DotStrtab.finalize();
 
   // Add the dynamic symbol names to .dynstr section.
   for (const ELFYAML::Symbol &Sym : Doc.DynamicSymbols)
-    DotDynstr.add(dropUniqueSuffix(Sym.Name));
+    DotDynstr.add(ELFYAML::dropUniqueSuffix(Sym.Name));
 
   // SHT_GNU_verdef and SHT_GNU_verneed sections might also
   // add strings to .dynstr section.

lib/ObjectYAML/ELFYAML.cpp

@@ -1152,6 +1152,7 @@ void MappingTraits<std::unique_ptr<ELFYAML::Section>>::mapping(
     if (!IO.outputting()) {
       StringRef Name;
       IO.mapOptional("Name", Name, StringRef());
+      Name = ELFYAML::dropUniqueSuffix(Name);
 
       if (ELFYAML::StackSizesSection::nameMatches(Name))
         Section = std::make_unique<ELFYAML::StackSizesSection>();

test/tools/yaml2obj/elf-stack-sizes.yaml

@@ -311,3 +311,34 @@ Sections:
     Type: SHT_PROGBITS
     Size: 0x1
     Content: "1122"
+
+## Check we can describe multiple .stack_sizes sections using unique suffixes.
+
+# RUN: yaml2obj --docnum=14 %s -o %t11
+# RUN: llvm-readobj --sections --section-data %t11 | FileCheck %s --check-prefix=UNIQUE
+
+# UNIQUE:      Name: .stack_sizes
+# UNIQUE:      SectionData (
+# UNIQUE-NEXT:   0000: 10000000 00000000 20 |
+
+# UNIQUE:      Name: .stack_sizes
+# UNIQUE:      SectionData (
+# UNIQUE-NEXT:   0000: 30000000 00000000 40 |
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_X86_64
+Sections:
+  - Name:    '.stack_sizes [1]'
+    Type:    SHT_PROGBITS
+    Entries:
+      - Address: 0x10
+        Size:    0x20
+  - Name:    '.stack_sizes [2]'
+    Type:    SHT_PROGBITS
+    Entries:
+      - Address: 0x30
+        Size:    0x40