[PATCH 2/2] covoar: Store address-to-line info outside of DWARF
Chris Johns
chrisj at rtems.org
Wed May 26 00:24:23 UTC 2021
On 1/5/21 8:01 am, Alex White wrote:
> This adds the AddressToLineMapper class and supporting classes to
> assume responsibility of tracking address-to-line information.
>
> This allows the DWARF library to properly cleanup all of its resources
> and leads to significant memory savings.
>
> Closes #4383
> ---
> rtemstoolkit/rld-dwarf.cpp | 5 +
> rtemstoolkit/rld-dwarf.h | 5 +
> tester/covoar/AddressToLineMapper.cc | 105 +++++++++++++++
> tester/covoar/AddressToLineMapper.h | 193 +++++++++++++++++++++++++++
> tester/covoar/ExecutableInfo.cc | 73 +++++-----
> tester/covoar/ExecutableInfo.h | 11 +-
> tester/covoar/wscript | 1 +
> 7 files changed, 351 insertions(+), 42 deletions(-)
> create mode 100644 tester/covoar/AddressToLineMapper.cc
> create mode 100644 tester/covoar/AddressToLineMapper.h
>
> diff --git a/rtemstoolkit/rld-dwarf.cpp b/rtemstoolkit/rld-dwarf.cpp
> index 2fce0e4..1eae50c 100644
> --- a/rtemstoolkit/rld-dwarf.cpp
> +++ b/rtemstoolkit/rld-dwarf.cpp
> @@ -1893,6 +1893,11 @@ namespace rld
> return false;
> }
>
> + const addresses& compilation_unit::get_addresses () const
> + {
> + return addr_lines_;
> + }
> +
> functions&
> compilation_unit::get_functions ()
> {
> diff --git a/rtemstoolkit/rld-dwarf.h b/rtemstoolkit/rld-dwarf.h
> index 1210813..eadb50d 100644
> --- a/rtemstoolkit/rld-dwarf.h
> +++ b/rtemstoolkit/rld-dwarf.h
> @@ -707,6 +707,11 @@ namespace rld
> */
> unsigned int pc_high () const;
>
> + /**
> + * The addresses associated with this compilation unit.
> + */
> + const addresses& get_addresses () const;
> +
> /**
> * Get the source and line for an address. If the address does not match
> * false is returned the file is set to 'unknown' and the line is set to
> diff --git a/tester/covoar/AddressToLineMapper.cc b/tester/covoar/AddressToLineMapper.cc
> new file mode 100644
> index 0000000..1062fd7
> --- /dev/null
> +++ b/tester/covoar/AddressToLineMapper.cc
> @@ -0,0 +1,105 @@
> +/*! @file AddressToLineMapper.cc
> + * @brief AddressToLineMapper Implementation
> + *
> + * This file contains the implementation of the functionality
> + * of the AddressToLineMapper class.
> + */
> +
> +#include "AddressToLineMapper.h"
> +
> +namespace Coverage {
> +
> + uint64_t SourceLine::location() const
> + {
> + return address;
> + }
> +
> + bool SourceLine::is_an_end_sequence() const
> + {
> + return is_end_sequence;
> + }
> +
> + std::string SourceLine::path() const
> + {
> + return *sourceIterator;
> + }
> +
> + uint64_t SourceLine::line() const
> + {
> + return line_num;
> + }
> +
> + void AddressLineRange::addSourceLine(const rld::dwarf::address& address)
> + {
> + auto insertResult = sourcePaths.insert(address.path());
> +
> + sourceLines.emplace_back(
> + SourceLine (
> + address.location(),
> + insertResult.first,
> + address.line(),
> + address.is_an_end_sequence()
> + )
> + );
> + }
> +
> + const SourceLine* AddressLineRange::getSourceLine(uint32_t address) const
> + {
> + if (address < lowAddress || address > highAddress) {
> + return nullptr;
> + }
> +
> + const SourceLine* last_line = nullptr;
> + for (const auto &line : sourceLines) {
> + if (address <= line.location())
> + {
> + if (address == line.location())
> + last_line = &line;
> + break;
> + }
> + last_line = &line;
> + }
> +
> + return last_line;
> + }
> +
> + void AddressToLineMapper::getSource(
> + uint32_t address,
> + std::string& sourceFile,
> + int& sourceLine
> + ) const {
> + sourceFile = "unknown";
> + sourceLine = -1;
> +
> + const SourceLine* match = nullptr;
> + for (const auto &range : addressLineRanges) {
> + const SourceLine* potential_match = range.getSourceLine(address);
> +
> + if (potential_match != nullptr) {
> + if (match == nullptr) {
> + match = potential_match;
> + } else if (match->is_an_end_sequence() || !potential_match->is_an_end_sequence()) {
> + match = potential_match;
> + }
> + }
> + }
> +
> + if (match != nullptr) {
> + sourceFile = match->path();
> + sourceLine = match->line();
> + }
> + }
> +
> + AddressLineRange& AddressToLineMapper::makeRange(
> + uint32_t low,
> + uint32_t high
> + )
> + {
> + addressLineRanges.emplace_back(
> + AddressLineRange(low, high)
> + );
> +
> + return addressLineRanges.back();
> + }
> +
> +}
> diff --git a/tester/covoar/AddressToLineMapper.h b/tester/covoar/AddressToLineMapper.h
> new file mode 100644
> index 0000000..ee0a633
> --- /dev/null
> +++ b/tester/covoar/AddressToLineMapper.h
> @@ -0,0 +1,193 @@
> +/*! @file AddressToLineMapper.h
> + * @brief AddressToLineMapper Specification
> + *
> + * This file contains the specification of the AddressToLineMapper class.
> + */
> +
> +#ifndef __ADDRESS_TO_LINE_MAPPER_H__
> +#define __ADDRESS_TO_LINE_MAPPER_H__
> +
> +#include <cstdint>
> +#include <set>
> +#include <string>
> +#include <vector>
> +
> +#include <rld-dwarf.h>
> +
> +namespace Coverage {
> +
> + /*! @class SourceLine
> + *
> + * This class stores source information for a specific address.
> + */
> + class SourceLine {
> +
> + public:
> +
> + SourceLine(
> + uint64_t addr,> + std::set<std::string>::const_iterator src,
Why not just pass in a reference to the object the iterator references? You do
not touch the iterator which is a good thing because the iterator held in the
object is a copy of a copy of the outside iterator.
> + int64_t ln,
> + bool end_sequence
> + ) : address(addr),
> + sourceIterator(src),
> + line_num(ln),
> + is_end_sequence(end_sequence)
> + {
> + }
> +
> + /*!
> + * This method gets the address of this source information.
> + *
> + * @return Returns the address of this source information
> + */
> + uint64_t location() const;
> +
> + /*!
> + * This method gets a value indicating whether this address represents an
> + * end sequence.
> + *
> + * @return Returns whether this address represents an end sequence or not
> + */
> + bool is_an_end_sequence() const;
> +
> + /*!
> + * This method gets the source file path of this address.
> + *
> + * @return Returns the source file path of this address
> + */
> + std::string path() const;
> +
> + /*!
> + * This method gets the source line number of this address.
> + *
> + * @return Returns the source line number of this address
> + */
> + uint64_t line() const;
Why not `unsigned int` or `size_t`?
> +
> + private:
> +
> + /*!
> + * The address of this source information.
> + */
> + uint64_t address;
> +
> + /*!
> + * An iterator pointing to the location in the set that contains the
> + * source file path of the address.
> + */
> + std::set<std::string>::const_iterator sourceIterator;
Would `const std::string& path_;` work ?
> +
> + /*!
> + * The source line number of the address.
> + */
> + int64_t line_num;
> +
> + /*!
> + * Whether the address represents an end sequence or not.
> + */
> + bool is_end_sequence;
> +
> + };
> +
> + /*! @class AddressLineRange
> + *
> + * This class stores source information for an address range.
> + */
> + class AddressLineRange {
> +
> + public:
> +
> + AddressLineRange(
> + uint32_t low,
> + uint32_t high
> + ) : lowAddress(low), highAddress(high)
> + {
> + }
> +
> + /*!
> + * This method adds source and line information for a specified address.
> + *
> + * @param[in] address specifies the DWARF address information
> + */
> + void addSourceLine(const rld::dwarf::address& address);
> +
> + /*!
> + * This method gets the source file name and line number for a given
> + * address.
> + *
> + * @param[in] address specifies the address to look up
> + *
> + * @return Returns the source information for the specified address or
> + * nullptr if not found.
> + */
> + const SourceLine* getSourceLine(uint32_t address) const;
Why a pointer? Returning `nullptr` is a potential source of bugs where the
pointer is not checked. All you have done is encoded an address and a state in
the one variable, something that is done in C.
An `operator[](uint32_t address)` could be used here that throws an exception on
an invalid address. You just need to catch the exception in
`AddressToLineMapper::getSource()` and make `match` be in instance. Just add a
default constructor to SourceLine with the path set to "uknown" and line to
"-1". This however means you need to make the change to not use an iterator as a
reference. It seems the choice to use the iterator in the class has cascaded out
into other areas.
> +
> + private:
> +
> + /*!
> + * The low address for this range.
> + */
> + uint32_t lowAddress;
> +
> + /*!
> + * The high address for this range.
> + */
> + uint32_t highAddress;
> +
> + /*!
> + * The source information for addresses in this range.
> + */
> + std::vector<SourceLine> sourceLines;
> +
> + /*!
> + * The set of source file names for this range.
> + */
> + std::set<std::string> sourcePaths;
I always add a local class/struct typedef for containers.
> +
> + };
> +
> + /*! @class AddressToLineMapper
> + *
> + * This class provides address-to-line capabilities.
> + */
> + class AddressToLineMapper {
> +
> + public:
> +
> + /*!
> + * This method gets the source file name and line number for a given
> + * address.
> + *
> + * @param[in] address specifies the address to look up
> + * @param[out] sourceFile specifies the name of the source file
> + * @param[out] sourceLine specifies the line number in the source file
> + */
> + void getSource(
> + uint32_t address,
> + std::string& sourceFile,
> + int& sourceLine
> + ) const;
> +
> + /*!
> + * This method creates a new range with the specified addresses.
> + *
> + * @param[in] low specifies the low address of the range
> + * @param[in] high specifies the high address of the range
> + *
> + * @return Returns a reference to the newly created range
> + */
> + AddressLineRange& makeRange(uint32_t low, uint32_t high);
> +
> + private:
> +
> + /*!
> + * The address and line information ranges.
> + */
> + std::vector<AddressLineRange> addressLineRanges;
Why is this private? :)
Chris
> +
> + };
> +
> +}
> +
> +#endif
> diff --git a/tester/covoar/ExecutableInfo.cc b/tester/covoar/ExecutableInfo.cc
> index 861e60d..a6184e7 100644
> --- a/tester/covoar/ExecutableInfo.cc
> +++ b/tester/covoar/ExecutableInfo.cc
> @@ -40,61 +40,60 @@ namespace Coverage {
> executable.begin();
> executable.load_symbols(symbols);
>
> + rld::dwarf::file debug;
> +
> debug.begin(executable.elf());
> debug.load_debug();
> debug.load_functions();
>
> - try {
> - for (auto& cu : debug.get_cus()) {
> - for (auto& func : cu.get_functions()) {
> - if (!func.has_machine_code()) {
> - continue;
> - }
> + for (auto& cu : debug.get_cus()) {
> + AddressLineRange& range = mapper.makeRange(cu.pc_low(), cu.pc_high());
> + // Does not filter on desired symbols under the assumption that the test
> + // code and any support code is small relative to what is being tested.
> + for (const auto &address : cu.get_addresses()) {
> + range.addSourceLine(address);
> + }
>
> - if (!SymbolsToAnalyze->isDesired(func.name())) {
> - continue;
> + for (auto& func : cu.get_functions()) {
> + if (!func.has_machine_code()) {
> + continue;
> + }
> +
> + if (!SymbolsToAnalyze->isDesired(func.name())) {
> + continue;
> + }
> +
> + if (func.is_inlined()) {
> + if (func.is_external()) {
> + // Flag it
> + std::cerr << "Function is both external and inlined: "
> + << func.name() << std::endl;
> }
>
> - if (func.is_inlined()) {
> - if (func.is_external()) {
> - // Flag it
> - std::cerr << "Function is both external and inlined: "
> - << func.name() << std::endl;
> - }
> -
> - if (func.has_entry_pc()) {
> - continue;
> - }
> -
> - // If the low PC address is zero, the symbol does not appear in
> - // this executable.
> - if (func.pc_low() == 0) {
> - continue;
> - }
> + if (func.has_entry_pc()) {
> + continue;
> }
>
> - // We can't process a zero size function.
> - if (func.pc_high() == 0) {
> + // If the low PC address is zero, the symbol does not appear in
> + // this executable.
> + if (func.pc_low() == 0) {
> continue;
> }
> + }
>
> - createCoverageMap (cu.name(), func.name(),
> - func.pc_low(), func.pc_high() - 1);
> + // We can't process a zero size function.
> + if (func.pc_high() == 0) {
> + continue;
> }
> +
> + createCoverageMap (cu.name(), func.name(),
> + func.pc_low(), func.pc_high() - 1);
> }
> - } catch (...) {
> - debug.end();
> - throw;
> }
> -
> - // Can't cleanup handles until the destructor because the information is
> - // referenced elsewhere. NOTE: This could cause problems from too many open
> - // file descriptors.
> }
>
> ExecutableInfo::~ExecutableInfo()
> {
> - debug.end();
> }
>
> void ExecutableInfo::dumpCoverageMaps( void ) {
> @@ -197,7 +196,7 @@ namespace Coverage {
> {
> std::string file;
> int lno;
> - debug.get_source (address, file, lno);
> + mapper.getSource (address, file, lno);
> std::ostringstream ss;
> ss << file << ':' << lno;
> line = ss.str ();
> diff --git a/tester/covoar/ExecutableInfo.h b/tester/covoar/ExecutableInfo.h
> index 5d5a595..dfc71aa 100644
> --- a/tester/covoar/ExecutableInfo.h
> +++ b/tester/covoar/ExecutableInfo.h
> @@ -15,6 +15,7 @@
> #include <rld-files.h>
> #include <rld-symbols.h>
>
> +#include "AddressToLineMapper.h"
> #include "CoverageMapBase.h"
> #include "SymbolTable.h"
>
> @@ -157,11 +158,6 @@ namespace Coverage {
> uint32_t highAddress
> );
>
> - /*!
> - * The DWARF data to the ELF executable.
> - */
> - rld::dwarf::file debug;
> -
> /*!
> * The executable's file name.
> */
> @@ -172,6 +168,11 @@ namespace Coverage {
> */
> rld::symbols::table symbols;
>
> + /*!
> + * The address-to-line mapper for this executable.
> + */
> + AddressToLineMapper mapper;
> +
> /*!
> * This map associates a symbol with its coverage map.
> */
> diff --git a/tester/covoar/wscript b/tester/covoar/wscript
> index 82599b0..a928b1b 100644
> --- a/tester/covoar/wscript
> +++ b/tester/covoar/wscript
> @@ -83,6 +83,7 @@ def build(bld):
>
> bld.stlib(target = 'ccovoar',
> source = ['app_common.cc',
> + 'AddressToLineMapper.cc',
> 'CoverageFactory.cc',
> 'CoverageMap.cc',
> 'CoverageMapBase.cc',
>
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