Use get_if instead of holds_alternative to avoid repetition #703
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also some more modernization Signed-off-by: Elazar Gershuni <[email protected]>
WalkthroughThe pull request introduces a series of changes across multiple source files, primarily focusing on enhancing type safety and clarity in handling Changes
Possibly related PRs
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Actionable comments posted: 12
🧹 Outside diff range comments (1)
src/test/test_print.cpp (1)
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1-73: Consider further modernization opportunitiesWhile the current changes effectively modernize the variant handling, there are a couple of additional areas where modern C++ features could potentially be applied:
The
PRINT_CASEmacro could be replaced with a function template usingstd::source_location(C++20) for improved debugging information. This would provide more precise location information and make the code more type-safe.File path handling could be improved using
std::filesystem(C++17) for more robust and portable path manipulations. This would replace string concatenations with more idiomatic path operations.These suggestions are not directly related to the current PR's scope but could be considered for future modernization efforts.
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📒 Files selected for processing (14)
- src/asm_cfg.cpp (9 hunks)
- src/asm_marshal.cpp (4 hunks)
- src/asm_ostream.cpp (11 hunks)
- src/asm_ostream.hpp (2 hunks)
- src/asm_unmarshal.cpp (31 hunks)
- src/assertions.cpp (5 hunks)
- src/crab/cfg.hpp (1 hunks)
- src/crab/ebpf_domain.cpp (6 hunks)
- src/crab/fwd_analyzer.cpp (7 hunks)
- src/ebpf_yaml.cpp (1 hunks)
- src/main/check.cpp (1 hunks)
- src/test/test_marshal.cpp (1 hunks)
- src/test/test_print.cpp (1 hunks)
- src/test/test_verify.cpp (3 hunks)
🧰 Additional context used
📓 Learnings (1)
src/crab/ebpf_domain.cpp (1)
Learnt from: elazarg PR: vbpf/ebpf-verifier#692 File: src/crab/ebpf_domain.cpp:1366-1367 Timestamp: 2024-09-27T00:34:47.474Z Learning: The project is compiled with C++20.
🪛 cppcheck
src/assertions.cpp
[error] 193-193: Syntax Error
(internalAstError)
src/test/test_marshal.cpp
[performance] 321-321: Function parameter 'expected_error_message' should be passed by const reference.
(passedByValue)
🔇 Additional comments (78)
src/test/test_print.cpp (1)
29-31: Excellent use ofstd::get_ifto simplify variant handlingThe changes effectively replace
std::holds_alternativeandstd::getwithstd::get_if, which aligns with the PR objective. This modification offers several benefits:
- It combines the type check and value retrieval into a single operation, reducing code complexity.
- It potentially improves efficiency by avoiding multiple accesses to the variant.
- It follows modern C++ practices, enhancing code maintainability.
The error handling is appropriately adjusted with the
REQUIRE(program != nullptr)check. The subsequent dereference in theget_ifreturns a pointer.These changes successfully modernize the code and reduce redundancy as intended.
src/asm_ostream.hpp (2)
32-33: Approved: Improved parameter passing forThe change from
std::optional<const label_t>toconst std::optional<const label_t>&for thelabel_to_printparameter is a good optimization. Passing by const reference avoids unnecessary copies, potentially improving performance, especially for largerlabel_ttypes. This change aligns well with modern C++ best practices and the PR's objective of modernizing the codebase.
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1-70: Overall assessment: Positive improvementsThe changes in this file align well with the PR objectives of modernizing the codebase and reducing repetition. Both modifications (the function signature update and the variant handling improvement) contribute to better performance and more idiomatic C++ code. These changes enhance the overall quality of the codebase without introducing any apparent issues.
src/crab/fwd_analyzer.cpp (8)
22-22: Improved efficiency in constructor parameter passingThe change from
label_ttoconst label_t&in the constructor parameter is a good optimization. It avoids unnecessary copying and follows best practices for passing non-primitive types.
51-51: Simplified type alias declarationThe removal of the
typenamekeyword in theiteratortype alias is correct and simplifies the code. This change maintains the same functionality while making the code more concise.
77-77: Optimized parameter passing inextrapolatemethodChanging the first parameter from
ebpf_domain_ttoconst ebpf_domain_t&is a good optimization. It avoids unnecessary copying and clearly indicates that the parameter won't be modified within the function.
87-87: Consistent optimization inrefinemethodThe change from
ebpf_domain_ttoconst ebpf_domain_t&for the first parameter is consistent with theextrapolatemethod. This optimization improves efficiency and maintains a clear indication of the parameter's immutability within the function.
128-129: Improved variant handling withstd::get_ifThe change from
std::holds_alternativeandstd::gettostd::get_ifis an excellent improvement. It simplifies the code by combining the type check and value retrieval into a single operation, making it more concise and potentially more efficient. This change also provides a safer way to access the variant by returning a pointer, which can be easily checked for nullness.This modification aligns well with the PR objective of replacing
holds_alternativewithget_ifto reduce redundancy.
193-194: Consistent improvement in variant handlingThe change to use
std::get_ifinstead ofstd::holds_alternativeandstd::getis consistent with the earlier modification in therun_forward_analyzerfunction. This change simplifies the code, provides safer variant access, and aligns with the PR objective of reducing redundancy.
214-215: Consistent application of variant handling improvementThis change to use
std::get_ifis consistent with the previous modifications in the file. It further demonstrates a thorough application of this improvement throughout the codebase, enhancing readability and safety while supporting the PR's objective of reducing redundancy.
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1-232: Summary of changes and overall assessmentThe changes in this file consistently improve code efficiency and safety, particularly in the areas of:
- Parameter passing optimization (using const references)
- Simplified type alias declarations
- Enhanced variant handling using
std::get_ifThese modifications align well with the PR objectives, reducing redundancy and modernizing the code. The changes are applied consistently throughout the file, demonstrating a thorough approach to the improvement.
Overall, these changes enhance the code quality without altering its core functionality. No issues or concerns were identified during this review.
src/main/check.cpp (1)
223-224: Excellent use ofstd::get_iffor concise error handlingThis change effectively replaces the previous
holds_alternativecheck withget_if, as per the PR objective. The new implementation is more concise and potentially more efficient, combining the type check and value retrieval into a single operation. It maintains the same error handling logic while improving code readability.src/asm_marshal.cpp (4)
112-114: Improved type safety withstd::get_ifThe use of
std::get_ifhere is a good improvement. It combines the check for the correct variant type and access to its value in a single, safe operation. This change reduces the chance of errors and improves code readability.
312-314: Improved efficiency and consistency insizefunctionThe changes to the
sizefunction are beneficial:
- Taking a const reference (
const Instruction&) instead of a value improves efficiency by avoiding unnecessary copies.- Using
std::get_ifis consistent with the changes made elsewhere in the file and provides a safe way to check and access theBinvariant.These modifications enhance both performance and code consistency.
312-312: Improved efficiency insizefunction signatureThe change in the
sizefunction signature fromstatic int size(Instruction inst)tostatic int size(const Instruction& inst)is a good improvement. Taking a const reference instead of a value avoids unnecessary copying of theInstructionobject, which can lead to better performance, especially ifInstructionis a larger struct.This change is consistent with modern C++ best practices and aligns well with the modifications made within the function body.
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1-349: Overall improvements in type safety, readability, and efficiencyThe changes made to this file consistently improve the code quality:
- The use of
std::get_ifthroughout the file enhances type safety when accessing variants.- The modifications to the
sizefunction, both in its signature and body, improve efficiency by avoiding unnecessary copies.- The changes make the code more readable and consistent with modern C++ best practices.
These improvements align well with the PR objectives of reducing redundancy and modernizing the codebase. The changes should lead to more robust and maintainable code.
src/asm_cfg.cpp (9)
22-23: Improved type safety and code simplicityThe change from
std::holds_alternativetostd::get_ifis a good improvement. It combines type checking and value retrieval into a single operation, which is both safer and more concise. This modification reduces the risk of exceptions and simplifies the code.
55-56: Consistent improvement in type safetyThe change to use
std::get_ifin theadd_cfg_nodesfunction is consistent with the previous modifications. This continues to improve type safety and simplify the code throughout the file.
76-79: Consistent application of type-safe checksThe changes in this segment continue the pattern of replacing
std::holds_alternativewithstd::get_if. This consistent application of the new pattern throughout the file is commendable. It not only improves type safety but also makes the code more concise and easier to read.
136-136: Improved parameter constnessThe addition of
constto themust_have_exitparameter is a good practice. It clearly communicates that the function doesn't modify this value, potentially preventing accidental modifications and improving code readability.
163-164: Improved code efficiency and readabilityThe change to use
auto jump_target = get_jump(inst)is a good improvement. It simplifies the code and potentially improves efficiency by avoiding multiple calls toget_jump. This change also enhances readability by clearly separating the retrieval of the jump target from its usage.
183-184: Consistent application of type-safe checksThe use of
std::get_ifhere maintains consistency with the earlier changes in the file. This continued application of the pattern improves type safety and maintains a consistent coding style throughout the function.
192-192: Improved parameter passing efficiencyThe changes to both
reversefunctions to take their parameters by const reference are good improvements. This can enhance performance by avoiding unnecessary copying, especially for larger structs. While it doesn't change the functionality, it's a good practice that can lead to more efficient code.Also applies to: 217-217
336-337: Consistent application of type-safe checksThe changes in the
collect_statsfunction to usestd::get_ifmaintain consistency with the modifications made throughout the file. This continued application of the pattern improves type safety and maintains a consistent coding style, which enhances the overall quality and readability of the code.Also applies to: 341-342, 346-347
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1-384: Summary: Successful modernization and improved type safetyThe changes made in this file successfully achieve the objectives outlined in the PR description. The consistent replacement of
std::holds_alternativewithstd::get_ifthroughout the file has several benefits:
- Improved type safety by combining type checking and value retrieval.
- Reduced code redundancy and improved readability.
- Potential performance improvements by avoiding unnecessary function calls.
Additionally, the updates to function signatures to use const references for parameters contribute to better performance and clearer intent.
These modifications align well with modern C++ practices and should make the code more robust and maintainable. Great job on consistently applying these improvements throughout the file!
src/ebpf_yaml.cpp (1)
341-342: Improved error handling usingstd::get_ifThe change from
std::holds_alternative<string>tostd::get_if<std::string>is a good improvement. This modification:
- Reduces code verbosity by combining the type check and value retrieval into a single operation.
- Eliminates the potential for exceptions that could be thrown by
std::get.- Maintains the same logical flow while making the code more efficient.
This change aligns well with the PR objective of replacing
holds_alternativewithget_ifto avoid repetition.src/asm_ostream.cpp (7)
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123-127: Improved type safety with explicit castingThe use of
static_cast<Value>(Imm{0})instead of directly comparing withImm{0}enhances type safety and makes the intention clearer. This change aligns with modern C++ best practices for explicit type conversions.
141-143: Enhanced const-correctnessThe change from
autotoconst autofor theopvariable improves code clarity and enforces const-correctness. This modification makes the code more self-documenting and helps prevent accidental modifications of the variable.
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227-240: Modernized code with std::rangesThe transition from
std::find_iftostd::ranges::find_ifis a positive change that leverages C++20 features. This modification simplifies the syntax, improves readability, and makes the code more concise. It's a good step towards adopting modern C++ practices.
271-272: Consistent application of const-correctnessThe consistent change from
autotoconst autoacross multiple variable declarations enhances code clarity and enforces const-correctness. This modification makes the code more self-documenting and helps prevent accidental modifications of the variables. The consistent application of this principle throughout the code is commendable.Also applies to: 285-301
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380-387: Improved performance and type safetyThe function signature change to take a const reference (
const Instruction&) instead of a copy can improve performance, especially for largerInstructionobjects. Additionally, the use ofstd::get_ifprovides a safer way to check and access variant types compared tostd::holds_alternative. These changes align with modern C++ best practices for performance and type safety.
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402-433: Comprehensive improvements in performance, clarity, and type safetyThis section demonstrates several positive changes:
- The function signature update to take a const reference for
label_to_printcan improve performance by avoiding unnecessary copies.- Consistent use of
const autoimproves code clarity and enforces const-correctness.- The introduction of
std::get_ifprovides a safer way to check and access variant types.These changes collectively align with modern C++ best practices, enhancing performance, clarity, and type safety throughout the code.
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1-533: Summary: Successful modernization and improvement of code qualityThe changes in this file consistently demonstrate a commitment to modernizing the codebase and improving code quality. Key improvements include:
- Enhanced type safety through explicit casting and the use of
std::get_if.- Improved const-correctness with consistent use of
const auto.- Adoption of modern C++ features like
std::ranges.- Performance optimizations by using const references in function parameters.
These changes align well with the PR objectives of reducing redundancy and modernizing the codebase. The modifications make the code more robust, self-documenting, and easier to maintain without altering the core functionality.
src/crab/cfg.hpp (1)
619-619: Approved: Improved parameter passing forget_assertionsThe change from
std::optional<label_t> labeltoconst std::optional<label_t>& labelis a good improvement. Passing thelabelparameter by const reference instead of by value can enhance performance by avoiding unnecessary copies, especially iflabel_tis a non-trivial type or if this function is called frequently.This modification aligns well with modern C++ best practices for passing read-only complex types and contributes to the PR's objective of reducing redundancy and modernizing the codebase. The change is backwards compatible and doesn't affect the function's behavior.
src/asm_unmarshal.cpp (21)
14-15: LGTM: Improved const-correctnessThe addition of the
constqualifier to theopcodeparameter is a good practice. It clearly indicates that the function doesn't modify the input and can potentially help the compiler with optimizations.
25-26: LGTM: Consistent const-correctness improvementThe addition of the
constqualifier to thewidthparameter is consistent with the previous change and improves the overall const-correctness of the codebase.
39-40: LGTM: Improved type safety with static_castThe change from C-style casts to
static_cast<int>is a good improvement.static_castis safer and more explicit about the conversion being performed. It also allows for better compile-time checking and makes the code more maintainable.
44-46: LGTM: Consistent improvements in const-correctness and type safetyThe changes in the
make_opcode_messagefunction are well-aligned with the previous improvements. The addition ofconstqualifiers and the use ofstatic_cast<int>enhance both const-correctness and type safety. These modifications contribute to a more robust and maintainable codebase.
52-54: LGTM: Improved const-correctness and potential performance gainThe modifications to the
InvalidInstructionstruct constructors are beneficial:
- Adding
constqualifiers improves const-correctness.- Changing the
std::stringparameter to a const reference (const std::string&) can improve performance by avoiding unnecessary copying of the string.These changes contribute to a more efficient and robust implementation.
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62-72: LGTM: Consistent const-correctness improvementsThe addition of
constqualifiers to theopcodeparameters in bothgetMemIsLoadandgetMemWidthfunctions is consistent with the previous changes. This continues to enhance the const-correctness of the codebase, making the functions' intentions clearer and potentially allowing for compiler optimizations.
92-93: LGTM: Enhanced const-correctness and explicit return typeThe changes to the
shift32function are positive:
- Adding
constqualifiers to both parameters improves const-correctness.- Explicitly specifying the return type as
Instructionenhances code readability and can help catch potential errors if the return type changes in the future.These modifications contribute to a more robust and self-documenting codebase.
105-107: LGTM: Improved const-correctness and variable immutabilityThe changes in the
getAluOpfunction are beneficial:
- Adding
constqualifiers to both parameters enhances const-correctness.- Declaring the
is64variable asconstprevents accidental modifications and clearly communicates that its value should not change after initialization.These improvements contribute to code safety and can potentially aid compiler optimizations.
229-230: LGTM: Consistent const-correctness improvementsThe changes in the
getAtomicOpfunction maintain consistency with previous modifications:
- Adding
constqualifiers to both parameters enhances const-correctness.- Declaring the
opvariable asconstin the switch statement prevents accidental modifications and clearly communicates that its value should not change after initialization.These improvements contribute to a more robust and maintainable codebase.
244-246: LGTM: Improved const-correctness and function encapsulationThe changes to the
sign_extendandzero_extendfunctions are beneficial:
- Adding
constqualifiers to theimmparameters enhances const-correctness.- Marking the functions as
staticlimits their visibility to this translation unit, improving encapsulation. This is particularly useful if these functions are only used within this file, as it prevents name conflicts and clarifies the functions' scope.These modifications contribute to a more robust and well-structured codebase.
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248-262: LGTM: Enhanced type safety and consistent improvementsThe changes in the
getBinValuefunction are positive:
- Adding
constqualifiers to parameters and marking the function asstaticis consistent with previous improvements.- The use of
std::get_ifinstead of direct comparisons is a significant improvement in type safety.std::get_ifreturns a pointer to the held value if it exists, or nullptr if it doesn't, providing a safer way to check and access variant types. This change helps prevent potential undefined behavior that could occur with incorrect variant access.These modifications contribute to a more robust and safer implementation.
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263-286: LGTM: Consistent improvements in const-correctness and encapsulationThe changes to the
getJmpOpfunction maintain consistency with previous modifications:
- Adding
constqualifiers to both parameters enhances const-correctness.- Marking the function as
staticimproves encapsulation by limiting its visibility to this translation unit.These changes contribute to the overall improvement in code quality and maintainability of the codebase.
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286-362: LGTM: Comprehensive improvements in const-correctness and type safetyThe changes in the
makeMemOpfunction are substantial and beneficial:
- Adding
constqualifiers to parameters enhances const-correctness.- Declaring local variables as
const(e.g.,width,isLD,isLoad,isImm,basereg) prevents accidental modifications and can aid compiler optimizations.- The use of
std::get_iffor variant access is consistent with previous changes and improves type safety by providing null-checking.These modifications significantly contribute to the robustness and safety of the code, making it less prone to errors and more maintainable.
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393-425: LGTM: Consistent improvements in const-correctness and type safetyThe changes in the
makeAluOpfunction maintain consistency with previous modifications:
- Adding
constqualifiers to parameters enhances const-correctness.- Declaring local variables as
const(e.g.,is64) prevents accidental modifications and can aid compiler optimizations.- The use of
std::get_iffor variant access improves type safety by providing implicit null-checking.These changes contribute to the overall improvement in code quality, maintainability, and type safety of the codebase.
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427-466: LGTM: Thorough application of const-correctnessThe changes in the
makeLddwfunction demonstrate a comprehensive approach to improving const-correctness:
- Adding
constqualifiers to most parameters (exceptinsts) enhances const-correctness and clearly communicates which inputs should not be modified.- Declaring local variables as
const(e.g.,next) prevents accidental modifications and can aid compiler optimizations.This thorough application of const-correctness contributes to code safety and maintainability by making the function's intentions clearer and reducing the risk of unintended modifications.
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467-489: LGTM: Consistent improvements in const-correctness and encapsulationThe changes to the
toArgSingleKindandtoArgPairKindfunctions maintain consistency with previous modifications:
- Adding
constqualifiers to parameters enhances const-correctness.- Marking the functions as
staticimproves encapsulation by limiting their visibility to this translation unit.These changes contribute to the overall improvement in code quality and maintainability of the codebase, following the pattern established in other functions.
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490-554: LGTM: Comprehensive application of const-correctnessThe changes in the
makeCallfunction demonstrate a thorough approach to improving const-correctness:
- Adding the
constqualifier to theimmparameter enhances const-correctness of the function input.- Declaring local variables and the
argsarray asconstprevents accidental modifications and can aid compiler optimizations.- The consistent application of
constthroughout the function body improves code safety and readability.These modifications contribute significantly to the robustness and maintainability of the code by clearly communicating intentions and reducing the risk of unintended modifications.
558-565: LGTM: Consistent improvements in const-correctness and encapsulationThe changes to the
getJumpTargetfunction maintain consistency with previous modifications:
- Adding
constqualifiers to all parameters enhances const-correctness.- Marking the function as
staticimproves encapsulation by limiting its visibility to this translation unit.- Declaring
new_pcasconstprevents accidental modifications and can aid compiler optimizations.These changes contribute to the overall improvement in code quality, safety, and maintainability of the codebase, following the pattern established in other functions.
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568-594: LGTM: Consistent improvements and enhanced type safetyThe changes to the
makeCallLocalandmakeCallxfunctions are positive and consistent with previous modifications:
- Adding
constqualifiers to parameters and marking the functions asstaticenhances const-correctness and encapsulation.- The use of
static_castinmakeCallxinstead of a C-style cast is a significant improvement in type safety. It's more explicit about the conversion being performed and allows for better compile-time checking.These modifications contribute to the overall improvement in code quality, maintainability, and type safety of the codebase.
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596-816: LGTM: Consistent and comprehensive improvements throughout the fileThe changes in the
makeJmpfunction and subsequent code, including themake_callfunction at the end of the file, demonstrate a consistent approach to improving code quality:
- Adding
constqualifiers to function parameters enhances const-correctness.- Declaring local variables as
const(e.g.,is64,op,offset,target,cond) prevents accidental modifications and can aid compiler optimizations.- The use of
std::get_iffor variant access improves type safety by providing implicit null-checking.These modifications maintain consistency with the improvements made throughout the entire file, contributing to a more robust, maintainable, and type-safe codebase.
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1-818: Overall: Excellent improvements in code quality and safetyThe changes made throughout the
src/asm_unmarshal.cppfile demonstrate a systematic and thorough approach to improving code quality, safety, and maintainability. Key improvements include:
- Consistent application of
constqualifiers to function parameters and local variables, enhancing const-correctness.- Improved type safety through the use of
static_castandstd::get_iffor variant access.- Better encapsulation by marking appropriate functions as
static.- More explicit and safer handling of types and conversions.
These changes contribute to a more robust, maintainable, and potentially more performant codebase. The consistent application of these improvements across the entire file indicates a well-planned refactoring effort that will likely make the code easier to reason about and less prone to errors.
Great job on this refactoring effort!
src/test/test_verify.cpp (5)
41-44: Improved code efficiency and readabilityThe change from using
std::holds_alternativeandstd::gettostd::get_ifis a good improvement. It simplifies the code by combining the check and retrieval of theInstructionSeqinto a single operation, making it more concise and potentially more efficient.
57-60: Consistent improvement in code structureThe changes in this segment mirror those made earlier, consistently replacing
std::holds_alternativeandstd::getwithstd::get_if. This uniformity in changes enhances the overall code quality and maintainability.
601-604: Consistently applied code improvementThe same pattern of replacing
std::holds_alternativeandstd::getwithstd::get_ifis applied here as well. This consistent application of the new pattern throughout different parts of the file is commendable and aligns well with the PR objectives.
609-612: Comprehensive and consistent code refactoringThis final instance of replacing
std::holds_alternativeandstd::getwithstd::get_ifcompletes the consistent application of this change throughout the file. These changes collectively contribute to a more streamlined and potentially more efficient codebase, fully aligning with the PR objectives.
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41-612: Summary: Successful implementation of PR objectivesThe changes made in this file consistently replace the use of
std::holds_alternativefollowed bystd::getwithstd::get_if. This refactoring aligns perfectly with the PR objectives, reducing redundancy and potentially improving code efficiency. The consistent application of this change throughout the file enhances overall code quality and maintainability.src/test/test_marshal.cpp (1)
302-306: Excellent modernization of thecheck_unmarshal_failfunction!The changes in this function are well-implemented and align with the PR objectives:
- The use of
std::vectorwithout explicit type parameters leverages C++17's class template argument deduction (CTAD), which improves code readability.- Replacing
std::holds_alternativeandstd::getwithstd::get_ifsimplifies the error checking process and makes the code more concise.These modifications contribute to a more modern and maintainable codebase.
src/crab/ebpf_domain.cpp (5)
1642-1649: LGTM: New helper function improves code organization.The new
lb_ub_access_pairfunction is a well-designed addition that encapsulates the logic for calculating lower and upper bounds for access checks. It handles both immediate and register-based width calculations efficiently, which should reduce code duplication and improve maintainability.
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1660-1704: LGTM: Improved code organization and consistency in ValidAccess operator.The changes to the
ValidAccessoperator improve code organization and consistency by utilizing the newlb_ub_access_pairfunction. This refactoring simplifies the handling of different memory types (packet, stack, context, shared) while maintaining the existing logic. The minor adjustment in the packet access check, using an empty optional for comparison checks, is a sensible optimization.
1225-1227: LGTM: Improved safety and efficiency in Assume operator.The changes to the
Assumeoperator enhance both safety and efficiency. The use ofstd::get_ifinstead ofstd::holds_alternativefollowed bystd::getis a more robust approach, reducing the risk of undefined behavior. This change also improves code readability and maintains the existing logic while providing better error handling for unsupported cases.
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2013-2023: LGTM: Enhanced safety and efficiency in Mem operator.The modifications to the
Memoperator significantly improve both safety and efficiency. The switch tostd::get_iffromstd::holds_alternativefollowed bystd::getis a more robust approach, minimizing the risk of undefined behavior. This change not only enhances code readability but also maintains the existing logic while providing improved error handling for various cases. The overall structure of the function has been streamlined, making it easier to understand and maintain.
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1-3000: Overall improvements enhance code quality and maintainability.The changes made to
src/crab/ebpf_domain.cppconsistently improve the code's safety, efficiency, and readability. Key improvements include:
- Introduction of the
lb_ub_access_pairfunction, which reduces code duplication and improves maintainability.- Refactoring of the
ValidAccess,Assume, andMemoperators to use more efficient and safer constructs.- Enhanced error handling and code organization throughout the file.
These modifications align well with the project's goals of enhancing the abstract interpretation framework for eBPF programs. The changes should contribute to easier maintenance and potential future extensions of the codebase.
src/assertions.cpp (12)
130-130: Efficient parameter passing by const referencePassing
condas aconst Condition&inexplicateavoids unnecessary copies and improves performance.
147-147: Ensurereg_rightis valid before useAfter safely extracting
reg_right, confirm that it is valid before using it inValidAccess.
151-151: Validate comparability of operandsThe
Comparableassertion correctly ensures thatcond.leftandreg_rightcan be compared. Ensure both registers have been validated.
156-156: Consistent use of const referencesUsing
const Assume& insinoperator()promotes efficiency by avoiding unnecessary copies.
158-161: Simplify conditional logic inoperator()(const Jmp& ins)Properly checks if
ins.condexists before callingexplicate, which prevents potential null reference issues.
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165-187: Robust memory access validation inoperator()(const Mem& ins)The changes enhance the validation of memory accesses and handle both stack and non-stack pointers appropriately.
181-187: Correct validation for store operationsThe nested conditions ensure that, for non-privileged code performing a store operation, the value register is validated based on the width.
210-250: Ensure safe variant extraction inoperator()(const Bin& ins)When extracting from
ins.v, the code correctly usesstd::get_if<Reg>(&ins.v)to prevent exceptions ifins.vdoes not hold aReg.
216-220: Handle potential absence of register operandIn the
MOVSXoperations, ensure that the case whereins.vis not aRegis appropriately handled, returning an empty assertion set when necessary.
221-227: Proper assertions forADDoperation operandsThe code adds type constraints and check for addable operands, ensuring that addition operations are safe and valid.
228-238: Accurate comparability checks forSUBoperationThe assertions correctly enforce that the operands in the subtraction are comparable and handle both pointer and number types.
242-248: Validation of divisors in division operationsBy asserting
ValidDivisor, the code prevents division by zero and ensures that the divisor is of the correct type for the operation.
Also some more modernization, a-la #673.
Summary by CodeRabbit
Release Notes
New Features
Instructiontypes across various components.Bug Fixes
Refactor
std::holds_alternativewithstd::get_iffor safer type checking across the codebase.Documentation