ssa: fix map value closure check

[visualfc]

fix map value func decl to closure check.

fix #1411

[gemini-code-assist]

Summary of Changes

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This pull request addresses a critical issue in the Static Single Assignment (SSA) construction phase of the compiler, specifically targeting the correct handling and type checking of function declarations (closures) when they are used as values within map assignments. The changes ensure that the compiler properly processes these function values, preventing potential inconsistencies or errors in the generated SSA form. A dedicated test case has been introduced to validate the robustness of this fix.

Highlights

• SSA Fix for Map Value Closures: Implemented a fix within the SSA builder to correctly handle function declarations (closures) when they are assigned as values in map data structures. This ensures proper type checking and SSA representation for such assignments.
• New Test Case Added: A new Go program (_demo/go/mapclosure/main.go) has been added to demonstrate the specific scenario where function values are stored in maps and slices, serving as a validation test for the SSA fix.
• MapUpdate Function Enhancement: The MapUpdate function in ssa/datastruct.go now includes a conditional check to identify vkFuncDecl (function declaration kind) values and applies checkExpr to them, ensuring they are correctly processed during map assignments.

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[gemini-code-assist]

Code Review

This pull request aims to fix an issue with handling closures as map values. A test case is added to reproduce the issue. The fix in ssa/datastruct.go attempts to convert function declarations to closures before map assignment.

However, the implementation of the fix has a logical error: it uses the function's own type as the target for conversion, which is incorrect. My review includes a correction to use the map's value type as the target, which should properly fix the underlying issue.

[xgopilot]

Code Review Summary

Recommendation: APPROVE ✅

This is a well-executed, minimal fix that correctly addresses a closure handling issue when storing function values in maps. The implementation:

• Follows established patterns: Mirrors the proven approach from MakeInterface (interface.go:115-118)
• Maintains type safety: Properly uses checkExpr for function declaration conversion
• Includes proper test coverage: The demo test validates the fix effectively
• Performance impact: Negligible - only adds an O(1) type check with conditional processing for the uncommon case

One minor suggestion: Added an inline comment to improve code maintainability for future developers.

All specialized reviews (code quality, performance, security, documentation) found no blocking issues.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.93%. Comparing base (380a6d5) to head (211b890).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1509   +/-   ##
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  Coverage   90.93%   90.93%           
=======================================
  Files          44       44           
  Lines       11525    11528    +3     
=======================================
+ Hits        10480    10483    +3     
  Misses        883      883           
  Partials      162      162           

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