[llvm] r374931 - [llvm-objdump] Use a counter for llvm-objdump -h instead of the section index.
Jordan Rupprecht via llvm-commits
llvm-commits at lists.llvm.org
Tue Oct 15 11:13:21 PDT 2019
Author: rupprecht
Date: Tue Oct 15 11:13:20 2019
New Revision: 374931
URL: http://llvm.org/viewvc/llvm-project?rev=374931&view=rev
Log:
[llvm-objdump] Use a counter for llvm-objdump -h instead of the section index.
Summary:
When listing the index in `llvm-objdump -h`, use a zero-based counter instead of the actual section index (e.g. shdr->sh_index for ELF).
While this is effectively a noop for now (except one unit test for XCOFF), the index values will change in a future patch that filters certain sections out (e.g. symbol tables). See D68669 for more context. Note: the test case in `test/tools/llvm-objdump/X86/section-index.s` already covers the case of incrementing the section index counter when sections are skipped.
Reviewers: grimar, jhenderson, espindola
Reviewed By: grimar
Subscribers: emaste, sbc100, arichardson, aheejin, arphaman, seiya, llvm-commits, MaskRay
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68848
Modified:
llvm/trunk/test/tools/llvm-objdump/xcoff-section-headers.test
llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp
llvm/trunk/tools/llvm-objdump/llvm-objdump.h
Modified: llvm/trunk/test/tools/llvm-objdump/xcoff-section-headers.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objdump/xcoff-section-headers.test?rev=374931&r1=374930&r2=374931&view=diff
==============================================================================
--- llvm/trunk/test/tools/llvm-objdump/xcoff-section-headers.test (original)
+++ llvm/trunk/test/tools/llvm-objdump/xcoff-section-headers.test Tue Oct 15 11:13:20 2019
@@ -13,11 +13,11 @@
# CHECK: xcoff-section-headers.o: file format aixcoff-rs6000
# CHECK: Sections:
# CHECK: Idx Name Size VMA Type
-# CHECK: 1 .text 00000080 00000000 TEXT
-# CHECK: 2 .data 00000024 00000080 DATA
-# CHECK: 3 .bss 00000004 000000a4 BSS
-# CHECK: 4 .tdata 00000008 00000000 DATA
-# CHECK: 5 .tbss 00000004 00000008 BSS
+# CHECK: 0 .text 00000080 00000000 TEXT
+# CHECK: 1 .data 00000024 00000080 DATA
+# CHECK: 2 .bss 00000004 000000a4 BSS
+# CHECK: 3 .tdata 00000008 00000000 DATA
+# CHECK: 4 .tbss 00000004 00000008 BSS
# xcoff-section-headers.o Compiled with IBM XL C/C++ for AIX, V16.1.0
# test.c:
@@ -32,10 +32,10 @@
# LONG: xcoff-long-sec-names.o: file format aixcoff-rs6000
# LONG: Sections:
-# LONG: Idx Name Size VMA Type
-# LONG: 1 .dwarnge 00000004 00000000
-# LONG: 2 .dwpbnms 00000004 00000000
-# LONG: 3 .dwpbtyp 00000004 00000000
+# LONG: Idx Name Size VMA Type
+# LONG: 0 .dwarnge 00000004 00000000
+# LONG: 1 .dwpbnms 00000004 00000000
+# LONG: 2 .dwpbtyp 00000004 00000000
# xcoff-long-sec-names.o was generated by assembling the following .s file:
# .dwsect 0x30000 # .dwpbnms section
Modified: llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp?rev=374931&r1=374930&r2=374931&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp (original)
+++ llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp Tue Oct 15 11:13:20 2019
@@ -342,14 +342,27 @@ static StringRef ToolName;
typedef std::vector<std::tuple<uint64_t, StringRef, uint8_t>> SectionSymbolsTy;
-static bool shouldKeep(object::SectionRef S) {
+namespace {
+struct FilterResult {
+ // True if the section should not be skipped.
+ bool Keep;
+
+ // True if the index counter should be incremented, even if the section should
+ // be skipped. For example, sections may be skipped if they are not included
+ // in the --section flag, but we still want those to count toward the section
+ // count.
+ bool IncrementIndex;
+};
+} // namespace
+
+static FilterResult checkSectionFilter(object::SectionRef S) {
if (FilterSections.empty())
- return true;
+ return {/*Keep=*/true, /*IncrementIndex=*/true};
Expected<StringRef> SecNameOrErr = S.getName();
if (!SecNameOrErr) {
consumeError(SecNameOrErr.takeError());
- return false;
+ return {/*Keep=*/false, /*IncrementIndex=*/false};
}
StringRef SecName = *SecNameOrErr;
@@ -357,11 +370,26 @@ static bool shouldKeep(object::SectionRe
// no name (such as the section with index 0) here.
if (!SecName.empty())
FoundSectionSet.insert(SecName);
- return is_contained(FilterSections, SecName);
-}
-SectionFilter ToolSectionFilter(object::ObjectFile const &O) {
- return SectionFilter([](object::SectionRef S) { return shouldKeep(S); }, O);
+ // Only show the section if it's in the FilterSections list, but always
+ // increment so the indexing is stable.
+ return {/*Keep=*/is_contained(FilterSections, SecName),
+ /*IncrementIndex=*/true};
+}
+
+SectionFilter ToolSectionFilter(object::ObjectFile const &O, uint64_t *Idx) {
+ // Start at UINT64_MAX so that the first index returned after an increment is
+ // zero (after the unsigned wrap).
+ if (Idx)
+ *Idx = UINT64_MAX;
+ return SectionFilter(
+ [Idx](object::SectionRef S) {
+ FilterResult Result = checkSectionFilter(S);
+ if (Idx != nullptr && Result.IncrementIndex)
+ *Idx += 1;
+ return Result.Keep;
+ },
+ O);
}
std::string getFileNameForError(const object::Archive::Child &C,
@@ -967,7 +995,7 @@ getRelocsMap(object::ObjectFile const &O
std::map<SectionRef, std::vector<RelocationRef>> Ret;
for (SectionRef Sec : Obj.sections()) {
section_iterator Relocated = Sec.getRelocatedSection();
- if (Relocated == Obj.section_end() || !shouldKeep(*Relocated))
+ if (Relocated == Obj.section_end() || !checkSectionFilter(*Relocated).Keep)
continue;
std::vector<RelocationRef> &V = Ret[*Relocated];
for (const RelocationRef &R : Sec.relocations())
@@ -1676,7 +1704,8 @@ void printSectionHeaders(const ObjectFil
<< left_justify("Name", NameWidth) << " Size "
<< left_justify("VMA", AddressWidth) << " Type\n";
- for (const SectionRef &Section : ToolSectionFilter(*Obj)) {
+ uint64_t Idx;
+ for (const SectionRef &Section : ToolSectionFilter(*Obj, &Idx)) {
StringRef Name = unwrapOrError(Section.getName(), Obj->getFileName());
uint64_t VMA = Section.getAddress();
if (shouldAdjustVA(Section))
@@ -1691,14 +1720,14 @@ void printSectionHeaders(const ObjectFil
Type += Type.empty() ? "BSS" : " BSS";
if (HasLMAColumn)
- outs() << format("%3d %-*s %08" PRIx64 " ", (unsigned)Section.getIndex(),
- NameWidth, Name.str().c_str(), Size)
+ outs() << format("%3d %-*s %08" PRIx64 " ", Idx, NameWidth,
+ Name.str().c_str(), Size)
<< format_hex_no_prefix(VMA, AddressWidth) << " "
<< format_hex_no_prefix(getELFSectionLMA(Section), AddressWidth)
<< " " << Type << "\n";
else
- outs() << format("%3d %-*s %08" PRIx64 " ", (unsigned)Section.getIndex(),
- NameWidth, Name.str().c_str(), Size)
+ outs() << format("%3d %-*s %08" PRIx64 " ", Idx, NameWidth,
+ Name.str().c_str(), Size)
<< format_hex_no_prefix(VMA, AddressWidth) << " " << Type << "\n";
}
outs() << "\n";
Modified: llvm/trunk/tools/llvm-objdump/llvm-objdump.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objdump/llvm-objdump.h?rev=374931&r1=374930&r2=374931&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objdump/llvm-objdump.h (original)
+++ llvm/trunk/tools/llvm-objdump/llvm-objdump.h Tue Oct 15 11:13:20 2019
@@ -31,6 +31,8 @@ extern cl::opt<bool> Demangle;
typedef std::function<bool(llvm::object::SectionRef const &)> FilterPredicate;
+/// A filtered iterator for SectionRefs that skips sections based on some given
+/// predicate.
class SectionFilterIterator {
public:
SectionFilterIterator(FilterPredicate P,
@@ -60,6 +62,8 @@ private:
llvm::object::section_iterator End;
};
+/// Creates an iterator range of SectionFilterIterators for a given Object and
+/// predicate.
class SectionFilter {
public:
SectionFilter(FilterPredicate P, llvm::object::ObjectFile const &O)
@@ -79,7 +83,15 @@ private:
};
// Various helper functions.
-SectionFilter ToolSectionFilter(llvm::object::ObjectFile const &O);
+
+/// Creates a SectionFilter with a standard predicate that conditionally skips
+/// sections when the --section objdump flag is provided.
+///
+/// Idx is an optional output parameter that keeps track of which section index
+/// this is. This may be different than the actual section number, as some
+/// sections may be filtered (e.g. symbol tables).
+SectionFilter ToolSectionFilter(llvm::object::ObjectFile const &O,
+ uint64_t *Idx = nullptr);
Error getELFRelocationValueString(const object::ELFObjectFileBase *Obj,
const object::RelocationRef &Rel,
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