Recommit "rL366894: [yaml2obj] - Allow custom fields for the SHT_UNDEF sections."
With fix: do not use `stat` tool.
Original commit message:
This is a follow-up refactoring patch for recently
introduced functionality which which reduces the code duplication
and also makes possible to redefine all possible fields of
the first SHT_NULL section (previously it was only possible to set
sh_link and sh_size).
Differential revision: https://reviews.llvm.org/D65140
llvm-svn: 367003
diff --git a/llvm/test/tools/yaml2obj/elf-custom-null-section.yaml b/llvm/test/tools/yaml2obj/elf-custom-null-section.yaml
index 23b877f..dc74a7b 100644
--- a/llvm/test/tools/yaml2obj/elf-custom-null-section.yaml
+++ b/llvm/test/tools/yaml2obj/elf-custom-null-section.yaml
@@ -42,10 +42,64 @@
Info: 0
Address: 0x0
-## Check we are still able to describe other sections too.
+## Check we can redefine fields of the first SHT_NULL section.
# RUN: yaml2obj --docnum=3 %s -o %t3
-# RUN: llvm-readelf --sections %t3 | FileCheck %s --check-prefix=OTHER-SECTION
+# RUN: llvm-readelf --sections %t3 | FileCheck %s --check-prefix=REDEFINE
+
+# REDEFINE: Section Headers:
+# REDEFINE-NEXT: [Nr] Name Type Address Off Size ES Flg Lk Inf Al
+# REDEFINE-NEXT: [ 0] .foo NULL 0000000000000006 000000 000002 03 A 4 5 1
+
+--- !ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_X86_64
+Sections:
+ - Type: SHT_NULL
+ Name: .foo
+ Flags: [ SHF_ALLOC ]
+ AddressAlign: 0x1
+ Size: 0x2
+ EntSize: 0x3
+ Link: 4
+ Info: 5
+ Address: 0x6
+
+## Check that file size does not change if we redefine the Size
+## of the first SHT_NULL section.
+
+# RUN: yaml2obj --docnum=4 %s -o %t4
+# RUN: ls -l %t3 | tr -s ' ' | cut -d ' ' -f 5 > %t.txt
+# RUN: ls -l %t4 | tr -s ' ' | cut -d ' ' -f 5 >> %t.txt
+# RUN: FileCheck %s --input-file=%t.txt --check-prefix=SIZE
+
+# SIZE: [[FILESIZE:.*]]
+# SIZE: [[FILESIZE]]
+
+--- !ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_X86_64
+Sections:
+ - Type: SHT_NULL
+ Name: .foo
+ Flags: [ SHF_ALLOC ]
+ AddressAlign: 0x1
+ Size: 0xFFFF
+ EntSize: 0x3
+ Link: 4
+ Info: 5
+ Address: 0x6
+
+## Check we are still able to describe other sections too.
+
+# RUN: yaml2obj --docnum=5 %s -o %t5
+# RUN: llvm-readelf --sections %t5 | FileCheck %s --check-prefix=OTHER-SECTION
# OTHER-SECTION: Section Headers:
# OTHER-SECTION-NEXT: [Nr] Name Type Address Off Size ES Flg Lk Inf Al
@@ -72,46 +126,6 @@
- Type: SHT_PROGBITS
Name: 'foo'
-## Check we can redefine sh_size and sh_link fields of the SHT_NULL section.
-
-# RUN: yaml2obj --docnum=4 %s -o %t4
-# RUN: llvm-readelf --sections %t4 | FileCheck %s --check-prefix=REDEFINE
-
-# REDEFINE: Section Headers:
-# REDEFINE-NEXT: [Nr] Name Type Address Off Size ES Flg Lk Inf Al
-# REDEFINE-NEXT: [ 0] NULL 0000000000000000 000000 000123 00 1 0 0
-
---- !ELF
-FileHeader:
- Class: ELFCLASS64
- Data: ELFDATA2LSB
- Type: ET_REL
- Machine: EM_X86_64
-Sections:
- - Type: SHT_NULL
- Link: .foo
- Size: 0x123
- - Type: SHT_PROGBITS
- Name: .foo
-
-## The same as above, but using a number as a Link value.
-
-# RUN: yaml2obj --docnum=5 %s -o %t5
-# RUN: llvm-readelf --sections %t5 | FileCheck %s --check-prefix=REDEFINE
-
---- !ELF
-FileHeader:
- Class: ELFCLASS64
- Data: ELFDATA2LSB
- Type: ET_REL
- Machine: EM_X86_64
-Sections:
- - Type: SHT_NULL
- Link: 1
- Size: 0x123
- - Type: SHT_PROGBITS
- Name: .foo
-
## Check we report an error if null section sh_link field refers to an unknown section.
# RUN: not yaml2obj --docnum=6 %s -o %t6 2>&1 | FileCheck %s --check-prefix=CASE4
@@ -150,7 +164,7 @@
# MULTIPLE: Section Headers:
# MULTIPLE-NEXT: [Nr] Name Type Address Off Size ES Flg Lk Inf Al
# MULTIPLE-NEXT: [ 0] NULL 0000000000000000 000000 000000 00 0 0 0
-# MULTIPLE-NEXT: [ 1] NULL 0000000000000123 000180 000020 10 A 1 2 0
+# MULTIPLE-NEXT: [ 1] .foo NULL 0000000000000123 000180 000020 10 A 1 2 0
--- !ELF
FileHeader:
@@ -161,9 +175,31 @@
Sections:
- Type: SHT_NULL
- Type: SHT_NULL
+ Name: .foo
Flags: [ SHF_ALLOC ]
Size: 0x20
EntSize: 0x10
Link: 1
Info: 2
Address: 0x123
+
+## Check we can override the sh_offset/sh_size fields of the first SHT_NULL section if requested.
+
+# RUN: yaml2obj --docnum=9 %s -o %t9
+# RUN: llvm-readelf --sections %t9 | FileCheck %s --check-prefix=OVERRIDE
+
+# OVERRIDE: Section Headers:
+# OVERRIDE-NEXT: [Nr] Name Type Address Off Size ES Flg Lk Inf Al
+# OVERRIDE-NEXT: [ 0] NULL 0000000000000000 000007 000008 00 0 0 0
+
+--- !ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_X86_64
+Sections:
+ - Type: SHT_NULL
+ Size: 0x2
+ ShOffset: 0x7
+ ShSize: 0x8
diff --git a/llvm/tools/yaml2obj/yaml2elf.cpp b/llvm/tools/yaml2obj/yaml2elf.cpp
index c6be508..e11d8fe 100644
--- a/llvm/tools/yaml2obj/yaml2elf.cpp
+++ b/llvm/tools/yaml2obj/yaml2elf.cpp
@@ -247,7 +247,7 @@
? (typename ELFT::uint)(*Doc.Header.SHOffset)
: sizeof(Header) + sizeof(Elf_Phdr) * Doc.ProgramHeaders.size();
Header.e_shnum =
- Doc.Header.SHNum ? (uint16_t)*Doc.Header.SHNum : SN2I.size() + 1;
+ Doc.Header.SHNum ? (uint16_t)*Doc.Header.SHNum : Doc.Sections.size();
Header.e_shstrndx = Doc.Header.SHStrNdx ? (uint16_t)*Doc.Header.SHStrNdx
: SN2I.get(".shstrtab");
}
@@ -327,30 +327,15 @@
SHeaders.resize(Doc.Sections.size());
for (size_t I = 0; I < Doc.Sections.size(); ++I) {
- Elf_Shdr &SHeader = SHeaders[I];
ELFYAML::Section *Sec = Doc.Sections[I].get();
-
- if (I == 0) {
- if (Sec->IsImplicit)
- continue;
-
- if (auto S = dyn_cast<ELFYAML::RawContentSection>(Sec))
- if (S->Size)
- SHeader.sh_size = *S->Size;
-
- if (!Sec->Link.empty()) {
- unsigned Index;
- if (!convertSectionIndex(SN2I, Sec->Name, Sec->Link, Index))
- return false;
- SHeader.sh_link = Index;
- }
+ if (I == 0 && Sec->IsImplicit)
continue;
- }
// We have a few sections like string or symbol tables that are usually
// added implicitly to the end. However, if they are explicitly specified
// in the YAML, we need to write them here. This ensures the file offset
// remains correct.
+ Elf_Shdr &SHeader = SHeaders[I];
if (initImplicitHeader(State, CBA, SHeader, Sec->Name,
Sec->IsImplicit ? nullptr : Sec))
continue;
@@ -372,7 +357,17 @@
SHeader.sh_link = Index;
}
- if (auto S = dyn_cast<ELFYAML::RawContentSection>(Sec)) {
+ if (I == 0) {
+ if (auto RawSec = dyn_cast<ELFYAML::RawContentSection>(Sec)) {
+ // We do not write any content for special SHN_UNDEF section.
+ if (RawSec->Size)
+ SHeader.sh_size = *RawSec->Size;
+ if (RawSec->Info)
+ SHeader.sh_info = *RawSec->Info;
+ }
+ if (Sec->EntSize)
+ SHeader.sh_entsize = *Sec->EntSize;
+ } else if (auto S = dyn_cast<ELFYAML::RawContentSection>(Sec)) {
if (!writeSectionContent(SHeader, *S, CBA))
return false;
} else if (auto S = dyn_cast<ELFYAML::RelocationSection>(Sec)) {
@@ -966,8 +961,11 @@
}
template <class ELFT> bool ELFState<ELFT>::buildSectionIndex() {
- for (unsigned I = 1, E = Doc.Sections.size(); I != E; ++I) {
+ for (unsigned I = 0, E = Doc.Sections.size(); I != E; ++I) {
StringRef Name = Doc.Sections[I]->Name;
+ if (Name.empty())
+ continue;
+
DotShStrtab.add(dropUniqueSuffix(Name));
if (!SN2I.addName(Name, I)) {
WithColor::error() << "Repeated section name: '" << Name