unittests: fix -Wnarrowing build errors

src/common/dwarf/bytereader.h

 // -*- mode: C++ -*-

[Mark Mentovai, 2016/01/25 15:08:43]

CL description: “start a byte”—did you mean “stuff a byte?” And can you use 0xea
instead of 0xff in the text to match the compiler warning?

 
 // Copyright (c) 2010 Google Inc. All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
@@ skipping 11 matching lines @@
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef COMMON_DWARF_BYTEREADER_H__
 #define COMMON_DWARF_BYTEREADER_H__
 

[Mark Mentovai, 2016/01/25 15:08:43]

#include <stdint.h>

 #include <string>
 #include "common/dwarf/types.h"
 #include "common/dwarf/dwarf2enums.h"
 
 namespace dwarf2reader {
 
 // We can't use the obvious name of LITTLE_ENDIAN and BIG_ENDIAN
 // because it conflicts with a macro
 enum Endianness {
   ENDIANNESS_BIG,
   ENDIANNESS_LITTLE
 };
 
 // A ByteReader knows how to read single- and multi-byte values of
 // various endiannesses, sizes, and encodings, as used in DWARF
 // debugging information and Linux C++ exception handling data.
 class ByteReader {
  public:
   // Construct a ByteReader capable of reading one-, two-, four-, and
   // eight-byte values according to ENDIANNESS, absolute machine-sized
   // addresses, DWARF-style "initial length" values, signed and
   // unsigned LEB128 numbers, and Linux C++ exception handling data's
   // encoded pointers.
   explicit ByteReader(enum Endianness endianness);
   virtual ~ByteReader();
 
   // Read a single byte from BUFFER and return it as an unsigned 8 bit
   // number.
-  uint8 ReadOneByte(const char* buffer) const;
+  uint8 ReadOneByte(const uint8_t *buffer) const;
 
   // Read two bytes from BUFFER and return them as an unsigned 16 bit
   // number, using this ByteReader's endianness.
-  uint16 ReadTwoBytes(const char* buffer) const;
+  uint16 ReadTwoBytes(const uint8_t *buffer) const;
 
   // Read four bytes from BUFFER and return them as an unsigned 32 bit
   // number, using this ByteReader's endianness. This function returns
   // a uint64 so that it is compatible with ReadAddress and
   // ReadOffset. The number it returns will never be outside the range
   // of an unsigned 32 bit integer.
-  uint64 ReadFourBytes(const char* buffer) const;
+  uint64 ReadFourBytes(const uint8_t *buffer) const;
 
   // Read eight bytes from BUFFER and return them as an unsigned 64
   // bit number, using this ByteReader's endianness.
-  uint64 ReadEightBytes(const char* buffer) const;
+  uint64 ReadEightBytes(const uint8_t *buffer) const;
 
   // Read an unsigned LEB128 (Little Endian Base 128) number from
   // BUFFER and return it as an unsigned 64 bit integer. Set LEN to
   // the number of bytes read.
   //
   // The unsigned LEB128 representation of an integer N is a variable
   // number of bytes:
   //
   // - If N is between 0 and 0x7f, then its unsigned LEB128
   //   representation is a single byte whose value is N.
   //
   // - Otherwise, its unsigned LEB128 representation is (N & 0x7f) |
   //   0x80, followed by the unsigned LEB128 representation of N /
   //   128, rounded towards negative infinity.
   //
   // In other words, we break VALUE into groups of seven bits, put
   // them in little-endian order, and then write them as eight-bit
   // bytes with the high bit on all but the last.
-  uint64 ReadUnsignedLEB128(const char* buffer, size_t* len) const;
+  uint64 ReadUnsignedLEB128(const uint8_t *buffer, size_t *len) const;
 
   // Read a signed LEB128 number from BUFFER and return it as an
   // signed 64 bit integer. Set LEN to the number of bytes read.
   //
   // The signed LEB128 representation of an integer N is a variable
   // number of bytes:
   //
   // - If N is between -0x40 and 0x3f, then its signed LEB128
   //   representation is a single byte whose value is N in two's
   //   complement.
   //
   // - Otherwise, its signed LEB128 representation is (N & 0x7f) |
   //   0x80, followed by the signed LEB128 representation of N / 128,
   //   rounded towards negative infinity.
   //
   // In other words, we break VALUE into groups of seven bits, put
   // them in little-endian order, and then write them as eight-bit
   // bytes with the high bit on all but the last.
-  int64 ReadSignedLEB128(const char* buffer, size_t* len) const;
+  int64 ReadSignedLEB128(const uint8_t *buffer, size_t *len) const;
 
   // Indicate that addresses on this architecture are SIZE bytes long. SIZE
   // must be either 4 or 8. (DWARF allows addresses to be any number of
   // bytes in length from 1 to 255, but we only support 32- and 64-bit
   // addresses at the moment.) You must call this before using the
   // ReadAddress member function.
   //
   // For data in a .debug_info section, or something that .debug_info
   // refers to like line number or macro data, the compilation unit
   // header's address_size field indicates the address size to use. Call
   // frame information doesn't indicate its address size (a shortcoming of
   // the spec); you must supply the appropriate size based on the
   // architecture of the target machine.
   void SetAddressSize(uint8 size);
 
   // Return the current address size, in bytes. This is either 4,
   // indicating 32-bit addresses, or 8, indicating 64-bit addresses.
   uint8 AddressSize() const { return address_size_; }
 
   // Read an address from BUFFER and return it as an unsigned 64 bit
   // integer, respecting this ByteReader's endianness and address size. You
   // must call SetAddressSize before calling this function.
-  uint64 ReadAddress(const char* buffer) const;
+  uint64 ReadAddress(const uint8_t *buffer) const;
 
   // DWARF actually defines two slightly different formats: 32-bit DWARF
   // and 64-bit DWARF. This is *not* related to the size of registers or
   // addresses on the target machine; it refers only to the size of section
   // offsets and data lengths appearing in the DWARF data. One only needs
   // 64-bit DWARF when the debugging data itself is larger than 4GiB.
   // 32-bit DWARF can handle x86_64 or PPC64 code just fine, unless the
   // debugging data itself is very large.
   //
   // DWARF information identifies itself as 32-bit or 64-bit DWARF: each
@@ skipping 16 matching lines @@
   //
   // A DWARF initial length is either:
   //
   // - a byte count stored as an unsigned 32-bit value less than
   //   0xffffff00, indicating that the data whose length is being
   //   measured uses the 32-bit DWARF format, or
   //
   // - The 32-bit value 0xffffffff, followed by a 64-bit byte count,
   //   indicating that the data whose length is being measured uses
   //   the 64-bit DWARF format.
-  uint64 ReadInitialLength(const char* start, size_t* len);
+  uint64 ReadInitialLength(const uint8_t *start, size_t *len);
 
   // Read an offset from BUFFER and return it as an unsigned 64 bit
   // integer, respecting the ByteReader's endianness. In 32-bit DWARF, the
   // offset is 4 bytes long; in 64-bit DWARF, the offset is eight bytes
   // long. You must call ReadInitialLength or SetOffsetSize before calling
   // this function; see the comments above for details.
-  uint64 ReadOffset(const char* buffer) const;
+  uint64 ReadOffset(const uint8_t *buffer) const;
 
   // Return the current offset size, in bytes.
   // A return value of 4 indicates that we are reading 32-bit DWARF.
   // A return value of 8 indicates that we are reading 64-bit DWARF.
   uint8 OffsetSize() const { return offset_size_; }
 
   // Indicate that section offsets and lengths are SIZE bytes long. SIZE
   // must be either 4 (meaning 32-bit DWARF) or 8 (meaning 64-bit DWARF).
   // Usually, you should not call this function yourself; instead, let a
   // call to ReadInitialLength establish the data's offset size
@@ skipping 34 matching lines @@
   // There are also two options that fall outside that matrix
   // altogether: the pointer may be omitted, or it may have padding to
   // align it on an appropriate address boundary. (That last option
   // may seem like it should be just another axis, but it is not.)
 
   // Indicate that the exception handling data is loaded starting at
   // SECTION_BASE, and that the start of its buffer in our own memory
   // is BUFFER_BASE. This allows us to find the address that a given
   // byte in our buffer would have when loaded into the program the
   // data describes. We need this to resolve DW_EH_PE_pcrel pointers.
-  void SetCFIDataBase(uint64 section_base, const char *buffer_base);
+  void SetCFIDataBase(uint64 section_base, const uint8_t *buffer_base);
 
   // Indicate that the base address of the program's ".text" section
   // is TEXT_BASE. We need this to resolve DW_EH_PE_textrel pointers.
   void SetTextBase(uint64 text_base);
 
   // Indicate that the base address for DW_EH_PE_datarel pointers is
   // DATA_BASE. The proper value depends on the ABI; it is usually the
   // address of the global offset table, held in a designated register in
   // position-independent code. You will need to look at the startup code
   // for the target system to be sure. I tried; my eyes bled.
@@ skipping 18 matching lines @@
   bool UsableEncoding(DwarfPointerEncoding encoding) const;
 
   // Read an encoded pointer from BUFFER using ENCODING; return the
   // absolute address it represents, and set *LEN to the pointer's
   // length in bytes, including any padding for aligned pointers.
   //
   // This function calls 'abort' if ENCODING is invalid or refers to a
   // base address this reader hasn't been given, so you should check
   // with ValidEncoding and UsableEncoding first if you would rather
   // die in a more helpful way.
-  uint64 ReadEncodedPointer(const char *buffer, DwarfPointerEncoding encoding,
+  uint64 ReadEncodedPointer(const uint8_t *buffer,
+                            DwarfPointerEncoding encoding,
                             size_t *len) const;
 
  private:
 
   // Function pointer type for our address and offset readers.
-  typedef uint64 (ByteReader::*AddressReader)(const char*) const;
+  typedef uint64 (ByteReader::*AddressReader)(const uint8_t *) const;
 
   // Read an offset from BUFFER and return it as an unsigned 64 bit
   // integer.  DWARF2/3 define offsets as either 4 or 8 bytes,
   // generally depending on the amount of DWARF2/3 info present.
   // This function pointer gets set by SetOffsetSize.
   AddressReader offset_reader_;
 
   // Read an address from BUFFER and return it as an unsigned 64 bit
   // integer.  DWARF2/3 allow addresses to be any size from 0-255
   // bytes currently.  Internally we support 4 and 8 byte addresses,
   // and will CHECK on anything else.
   // This function pointer gets set by SetAddressSize.
   AddressReader address_reader_;
 
   Endianness endian_;
   uint8 address_size_;
   uint8 offset_size_;
 
   // Base addresses for Linux C++ exception handling data's encoded pointers.
   bool have_section_base_, have_text_base_, have_data_base_;
   bool have_function_base_;
   uint64 section_base_, text_base_, data_base_, function_base_;
-  const char *buffer_base_;
+  const uint8_t *buffer_base_;
 };
 
 }  // namespace dwarf2reader
 
 #endif  // COMMON_DWARF_BYTEREADER_H__