Index: llvm/include/llvm/Object/ELFTypes.h =================================================================== --- llvm/include/llvm/Object/ELFTypes.h +++ llvm/include/llvm/Object/ELFTypes.h @@ -539,6 +539,7 @@ } ArrayRef values(unsigned DynamicSymCount) const { + assert(DynamicSymCount >= symndx); return ArrayRef(buckets().end(), DynamicSymCount - symndx); } }; Index: llvm/test/tools/llvm-readobj/ELF/gnuhash.test =================================================================== --- llvm/test/tools/llvm-readobj/ELF/gnuhash.test +++ llvm/test/tools/llvm-readobj/ELF/gnuhash.test @@ -229,15 +229,25 @@ ## which is one larger than the index of the last dynamic symbol. ## For empty tables however, this value is unimportant and can be ignored. -# RUN: yaml2obj --docnum=5 %s -o %t.empty -# RUN: llvm-readobj --gnu-hash-table %t.empty 2>&1 \ -# RUN: | FileCheck %s -DFILE=%t.empty --check-prefix=EMPTY --implicit-check-not="warning:" -# RUN: llvm-readelf --gnu-hash-table %t.empty 2>&1 \ -# RUN: | FileCheck %s -DFILE=%t.empty --check-prefix=EMPTY --implicit-check-not="warning:" +## Case A: set the index of the first symbol in the dynamic symbol table to +## the number of dynamic symbols. +# RUN: yaml2obj --docnum=5 -DSYMNDX=0x1 %s -o %t.empty.1 +# RUN: llvm-readobj --gnu-hash-table %t.empty.1 2>&1 \ +# RUN: | FileCheck %s -DFILE=%t.empty.1 -DSYMNDX=1 --check-prefix=EMPTY --implicit-check-not="warning:" +# RUN: llvm-readelf --gnu-hash-table %t.empty.1 2>&1 \ +# RUN: | FileCheck %s -DFILE=%t.empty.1 -DSYMNDX=1 --check-prefix=EMPTY --implicit-check-not="warning:" + +## Case B: set the index of the first symbol in the dynamic symbol table to +## an arbitrary value that is larger than the number of dynamic symbols. +# RUN: yaml2obj --docnum=5 -DSYMNDX=0x2 %s -o %t.empty.2 +# RUN: llvm-readobj --gnu-hash-table %t.empty.2 2>&1 \ +# RUN: | FileCheck %s -DFILE=%t.empty.2 -DSYMNDX=2 --check-prefix=EMPTY --implicit-check-not="warning:" +# RUN: llvm-readelf --gnu-hash-table %t.empty.2 2>&1 \ +# RUN: | FileCheck %s -DFILE=%t.empty.2 -DSYMNDX=2 --check-prefix=EMPTY --implicit-check-not="warning:" # EMPTY: GnuHashTable { # EMPTY-NEXT: Num Buckets: 1 -# EMPTY-NEXT: First Hashed Symbol Index: 1 +# EMPTY-NEXT: First Hashed Symbol Index: [[SYMNDX]] # EMPTY-NEXT: Num Mask Words: 1 # EMPTY-NEXT: Shift Count: 0 # EMPTY-NEXT: Bloom Filter: [0x0] @@ -256,7 +266,7 @@ Type: SHT_GNU_HASH Flags: [ SHF_ALLOC ] Header: - SymNdx: 0x1 + SymNdx: [[SYMNDX]] Shift2: 0x0 BloomFilter: [ 0x0 ] HashBuckets: [ 0x0 ] Index: llvm/test/tools/llvm-readobj/ELF/hash-histogram.test =================================================================== --- llvm/test/tools/llvm-readobj/ELF/hash-histogram.test +++ llvm/test/tools/llvm-readobj/ELF/hash-histogram.test @@ -211,8 +211,8 @@ ## Check we dump a histogram for the .gnu.hash table even when the .hash table is skipped. ## Case A: the .hash table has no data to build histogram and it is skipped. -## (NBUCKET == 0x1 is a no-op: it does not change the number of buckets described with the "Bucket" key). -# RUN: yaml2obj --docnum=5 -DNBUCKET=0x1 %s -o %t5.o +## (NBUCKET == 0x2 is a no-op: it does not change the number of buckets described with the "Bucket" key). +# RUN: yaml2obj --docnum=5 -DNBUCKET=0x2 %s -o %t5.o # RUN: llvm-readelf --elf-hash-histogram %t5.o 2>&1 | \ # RUN: FileCheck %s --check-prefix=GNU-HASH --implicit-check-not="Histogram" @@ -222,8 +222,8 @@ # RUN: llvm-readelf --elf-hash-histogram %t6.o 2>&1 | \ # RUN: FileCheck %s -DFILE=%t6.o --check-prefixes=WARN,GNU-HASH -# WARN: warning: '[[FILE]]': the hash table at offset 0x78 goes past the end of the file (0x350), nbucket = 4294967295, nchain = 1 -# GNU-HASH: Histogram for `.gnu.hash' bucket list length (total of 1 buckets) +# WARN: warning: '[[FILE]]': the hash table at offset 0x78 goes past the end of the file (0x358), nbucket = 4294967295, nchain = 2 +# GNU-HASH: Histogram for `.gnu.hash' bucket list length (total of 3 buckets) --- !ELF FileHeader: @@ -237,7 +237,7 @@ Flags: [ SHF_ALLOC ] Bucket: [ 0 ] NBucket: [[NBUCKET]] - Chain: [ 0 ] + Chain: [ 0, 0 ] - Name: .gnu.hash Type: SHT_GNU_HASH Flags: [ SHF_ALLOC ] @@ -254,8 +254,8 @@ - Tag: DT_HASH Value: 0x0 - Tag: DT_GNU_HASH -## sizeof(.hash) == 0x28. - Value: 0x28 +## sizeof(.hash) == 0x14. + Value: 0x14 - Tag: DT_NULL Value: 0x0 DynamicSymbols: Index: llvm/tools/llvm-readobj/ELFDumper.cpp =================================================================== --- llvm/tools/llvm-readobj/ELFDumper.cpp +++ llvm/tools/llvm-readobj/ELFDumper.cpp @@ -2731,18 +2731,19 @@ // A normal empty GNU hash table section produced by linker might have // symndx set to the number of dynamic symbols + 1 (for the zero symbol) // and have dummy null values in the Bloom filter and in the buckets - // vector. It happens because the value of symndx is not important for - // dynamic loaders when the GNU hash table is empty. They just skip the - // whole object during symbol lookup. In such cases, the symndx value is - // irrelevant and we should not report a warning. + // vector (or no values at all). It happens because the value of symndx is not + // important for dynamic loaders when the GNU hash table is empty. They just + // skip the whole object during symbol lookup. In such cases, the symndx value + // is irrelevant and we should not report a warning. ArrayRef Buckets = GnuHashTable->buckets(); if (!llvm::all_of(Buckets, [](typename ELFT::Word V) { return V == 0; })) return createError("the first hashed symbol index (" + Twine(GnuHashTable->symndx) + ") is larger than the number of dynamic symbols (" + Twine(NumSyms) + ")"); - - return GnuHashTable->values(NumSyms); + // There is no way to represent an array of (dynamic symbols count - symndx) + // length. + return ArrayRef(); } template