add semantics for c

docs/README.md

@@ -10,6 +10,8 @@ examples. Contribution and pull-request requirements remain in
   long-term architecture and runtime model.
 - [Wrapper `.pyi` format](semantics/pyi_format.md): editable semantic
   interface syntax and conversion behavior.
+- [C to semantic IR mapping](semantics/c2ir_mapping.md): implemented C
+  semantic conversion subset and blocker policy.
 - [Self-contained C semantic `.pyi` specification](semantics/c_pyi_self_contained_specification.md):
   staged C wrapper interface design.
 
@@ -29,8 +31,8 @@ examples. Contribution and pull-request requirements remain in
 
 ### C
 
-- [C parser reference](c_parser/c_parser_reference.md): implemented parse-only
-  frontend behavior and testing workflow.
+- [C parser reference](c_parser/c_parser_reference.md): implemented parser
+  behavior, semantic handoff, and testing workflow.
 - [C parser architecture plan](c_parser/c_parser_architecture.md): design and
   integration decisions.
 - [C parser CLI workflow plan](c_parser/c_parser_cli_workflow.md): command

docs/c_parser/c_parser_architecture.md

@@ -12,7 +12,7 @@ The x2py CLI also has a shared C/Fortran preprocessing option surface and can
 run an exact compiler/preprocessor executable for C compiler mode. Compiler
 and preprocessed C inputs preserve `#line`/GCC linemarker source locations for
 parsed declarations and diagnostics. A separate compiler-derived standard-type
-probe supplies target ABI facts needed by later C semantic conversion.
+probe supplies target ABI facts consumed by C semantic conversion.
 
 This document records the target architecture for the C parser frontend in
 x2py. The initial skeleton has grown into a partial parser, and the remaining
@@ -91,12 +91,18 @@ Implemented now:
   preserving compiler/runner/source provenance for semantic conversion. It
   carries target-relevant include, macro, undefine, and compiler-argument flags
   and records the requested project standard as provenance.
-- `--language c --semantics`, `--language c --pyi`, and C wrap-readiness are
-  rejected until semantic conversion exists.
+- `semantics.c2ir` converts the supported C parser subset into semantic IR,
+  including scalar functions, pointer storage contracts, declared arrays,
+  structs/opaque structs, enum and numeric macro constants, local typedef
+  chains, target standard-type probe facts, and C-specific readiness blockers.
+- `--language c --semantics`, `--language c --wrap-readiness`, and starter
+  exact-contract `--language c --pyi` output are enabled for the supported C
+  semantic subset.
 - Focused partial CLI/API, declaration/function, diagnostic color, project
   include/index, raw lexer/directive, project golden, error golden, preprocessed
-  linemarker remapping, and JSON schema tests are active. Remaining
-  parser-suite skips are limited to the pinned corpus roadmap.
+  linemarker remapping, JSON schema, and cJSON partial-parse regression tests
+  are active. A separately pinned/provenanced corpus remains deferred work,
+  not a skipped test.
 - `tests/data/c/` contains general fixtures modeled after the Fortran general
   fixture themes, additional C-specific API shapes, fatal diagnostic inputs,
   and real-world cJSON/jsmn/tinyexpr/linmath/NanoSVG/stb inputs whose partial
@@ -110,7 +116,7 @@ Deferred:
 - compiler attributes and alignment specifiers
 - broader compiler-family validation for preprocessing; parsed declarations
   already retain preprocessed origin and mapped source identity
-- C semantic readiness, semantic IR conversion, and `.pyi` output
+- broader C callback/ownership policy beyond exact starter `.pyi` stubs
 
 Documentation rule: any future C parser implementation change must update all
 affected docs under `docs/c_parser/` in the same change. This applies to model,
@@ -328,8 +334,8 @@ class CParser:
 
 These entrypoints are exposed from both `c_parser` and `x2py.__init__`, using
 the same top-level file/project invocation pattern already provided for
-Fortran. C semantic conversion remains unavailable despite the parse API
-export.
+Fortran. C semantic conversion is exposed separately through
+`semantics.c2ir` and top-level `x2py` compatibility helpers.
 
 ## Core Model Families
 
@@ -723,9 +729,9 @@ Python APIs.
 
 ## `.pyi` Integration
 
-Generated `.pyi` stubs for C should come after parser models and semantic IR
-conversion are stable. Readiness, if added for C, should follow the semantic
-layer pattern already used by the project.
+Generated `.pyi` stubs for C are emitted from semantic IR for the supported
+exact-contract subset. Readiness follows the semantic-layer pattern already
+used by the project.
 
 Likely stub patterns:
 

docs/c_parser/c_parser_cli_workflow.md

@@ -13,8 +13,9 @@ represent parenthesized pointer/array precedence through concrete
 parameters expose both declared and C-adjusted effective type facts. The CLI
 also exposes shared C/Fortran preprocessing flags and can run exact
 compiler/preprocessor executables for compiler mode. Target-specific standard
-header type facts for later C semantics are available through the separate
-`python -m x2py.c_type_probe` command.
+header type facts for C semantics are available through the separate
+`python -m x2py.c_type_probe` command. C semantic IR, readiness, and starter
+exact-contract `.pyi` output are available through the shared `x2py` CLI.
 
 This document records the implemented C parse command shape, output schema,
 and diagnostic contract, plus deferred CLI behavior.
@@ -28,6 +29,9 @@ python -m x2py path/to/api.h --language c --parse
 python -m x2py path/to/api.h --language c --parse --json
 python -m x2py path/to/api.h --language c --parse --out report.json
 python -m x2py path/to/api.h --language c --parse --preprocess compiler --compiler clang-18 -I include -D API_EXPORT= --std c11
+python -m x2py path/to/api.h --language c --semantics
+python -m x2py path/to/api.h --language c --wrap-readiness
+python -m x2py path/to/api.h --language c --pyi
 ```
 
 The C parser accepts explicit `.c`, `.h`, and direct `.i` files, plus
@@ -86,17 +90,15 @@ as `int i; int i;` are also merged. Duplicate definitions and incompatible
 top-level redeclarations are reported as diagnostics. Local declarations inside
 function bodies are not parsed.
 
-Unsupported C stages:
+Unsupported C display controls:
 
 ```bash
-python -m x2py path/to/api.h --language c --semantics
-python -m x2py path/to/api.h --language c --pyi
-python -m x2py path/to/api.h --language c --wrap-readiness
+python -m x2py path/to/api.h --language c --parse --show-vars
+python -m x2py path/to/api.h --language c --parse --print-limit 20
 ```
 
-These commands return clear argparse errors until C semantic IR conversion and
-`.pyi` generation are implemented. Fortran-only parse display flags such as
-`--show-vars` and `--print-limit` are rejected in C mode.
+Fortran-only parse display flags such as `--show-vars` and `--print-limit`
+return clear argparse errors in C mode until C-specific display controls exist.
 
 ## Current CLI Baseline
 
@@ -402,9 +404,9 @@ JSON output for a file without raw directives:
 }
 ```
 
-The parser should not claim C files are wrappable. If C readiness is added
-later, it should follow the semantics-owned readiness boundary used elsewhere
-in x2py, not become parser JSON.
+The parser should not claim C files are wrappable. C readiness follows the
+semantics-owned readiness boundary used elsewhere in x2py and does not become
+parser JSON.
 
 For raw directives, the same JSON shape is used, but `includes`, `macros`,
 `raw_directives`, `macro_dependencies`, and `diagnostics` may contain populated
@@ -597,10 +599,9 @@ The active CLI/parser tests cover the current partial subset:
   by focused C tests.
 - `--show-vars` and `--print-limit` are rejected in C mode until C-specific
   display controls exist.
-- `--semantics` with `--language c` is rejected until C semantic conversion is
-  implemented.
-- `--pyi` with `--language c` is rejected until C `.pyi` emission is
-  implemented.
+- `--semantics`, `--wrap-readiness`, and `--pyi` with `--language c` use
+  `semantics.c2ir`, the semantic readiness checker, and the shared `.pyi`
+  emitter for the supported exact-contract subset.
 
 ## Integration Order
 
@@ -648,8 +649,10 @@ Completed order:
     including recursively mapped preprocessed provenance.
 21. Added `_Atomic(type)` type-specifier parsing on the shared declarator path
     and executable parser-developer walkthrough tests.
-22. Added compiler-derived standard-header ABI probing for future C semantic
-    mapping without hard-coded host type aliases.
+22. Added compiler-derived standard-header ABI probing for C semantic mapping
+    without hard-coded host type aliases.
+23. Added C semantic IR, readiness, and starter exact-contract `.pyi` output
+    through `x2py --language c`.
 
 Next implementation work should continue with fixture-driven compiler
 extension policy and broader project conflict policy

docs/c_parser/c_parser_reference.md

@@ -1,11 +1,11 @@
 # C Parser Reference
 
-Status: current reference for the parse-only C frontend. The `c_parser`
+Status: current reference for the partial C frontend. The `c_parser`
 package, typed parser models, explicit C CLI parse path, raw directive
 metadata, compiler-assisted preprocessing, source-location remapping, project
-indexes, parser goldens, and C standard-type probe are implemented. C semantic
-readiness, semantic IR conversion, and `.pyi` generation remain future work and
-are intentionally rejected by the CLI.
+indexes, parser goldens, C standard-type probe, first semantic IR conversion
+subset, semantic readiness path, and starter exact-contract C `.pyi`
+generation are implemented.
 
 ## Purpose
 
@@ -52,8 +52,11 @@ Implemented:
   the `c_parser` package entrypoints
 - `CParseError` with compiler-style diagnostic formatting
 - explicit `x2py --language c --parse` output
+- explicit `x2py --language c --semantics` and
+  `x2py --language c --wrap-readiness` output
+- starter exact-contract `x2py --language c --pyi` output for the supported C
+  semantic subset
 - C JSON partial output and `--out` behavior
-- rejection of C `--semantics`, `--pyi`, and `--wrap-readiness`
 - raw lexer records with comment stripping, line-continuation folding, and
   lightweight token source locations
 - top-level source splitting that tracks braces, parentheses, brackets, and
@@ -123,14 +126,19 @@ Implemented:
   `tests/data/c/errors/parser/`, and partial-parser regression inputs under
   `tests/data/c/json/`, `tests/data/c/tinyexpr/`, `tests/data/c/linmath/`,
   `tests/data/c/nanosvg/`, and top-level C inputs from `tests/data/c/stb/`
+- `semantics.c2ir` conversion for the first identity subset: scalar
+  functions, const/mutable pointer storage contracts, declared arrays,
+  structs/opaque structs, enums, numeric macro constants, local typedef
+  chains, standard-type probe facts, and explicit semantic readiness blockers
 
 Still deferred:
 
 - callback policy metadata beyond parser-side callback candidates
 - broad compiler-extension declarators
 - broader typedef/tag conflict policy beyond the implemented basic project
   resolution
-- semantic readiness, semantic IR conversion, and `.pyi` generation
+- richer C ownership/callback projection policy beyond exact starter `.pyi`
+  stubs
 
 ## Supported C Subset
 
@@ -292,9 +300,8 @@ target-relevant flags from the matching entry to the probe explicitly.
 For cross targets, provide a runner, for example `--runner=qemu-aarch64
 --runner=-L --runner=/opt/aarch64-sysroot`.
 
-The eventual C semantic converter should accept this report as target context.
-The parser model remains source-faithful and does not embed host ABI
-assumptions.
+The C semantic converter accepts this report as target context. The parser
+model remains source-faithful and does not embed host ABI assumptions.
 
 ## Public API
 
@@ -603,16 +610,16 @@ Test families should mirror the Fortran parser:
 - typedef tests
 - macro/constant tests
 - include/project tests
-- semantic readiness tests once C semantic conversion exists
+- C semantic readiness tests
 - CLI tests
 - semantic conversion tests
 - `.pyi` generation/parser tests
 - fixture/golden parser tests
 - error fixture/golden tests
 - corpus parse-only tests
 
-The C test area contains active partial-parser/raw-metadata tests plus narrowly
-scoped roadmap skips under `tests/parser/c/`. The active tests cover
+The C test area contains active partial-parser/raw-metadata tests, including
+parse-only cJSON regression coverage under `tests/parser/c/`. The active tests cover
 public entrypoints, empty model serialization, CLI discovery, JSON/output-file
 behavior, unsupported C stages, comment stripping, line-continuation folding,
 top-level splitting, include collection, simple macro collection, macro-shaped
@@ -625,8 +632,8 @@ prototypes/definitions, function-definition start/end locations, JSON golden
 serialization, fatal diagnostic goldens, and project-level callback typedef
 resolution. The `json` regression inputs
 intentionally retain recoverable diagnostics from unsupported constructs; they
-do not claim complete library parsing. Remaining parser-suite skips cover the
-pinned/provenanced corpus target. Golden comparison tests rewrite their baselines when
+do not claim complete library parsing. A separately pinned/provenanced corpus
+target remains deferred without disabling parser tests. Golden comparison tests rewrite their baselines when
 `C_PARSER_UPDATE_GOLDENS=1` is set. Future implementation branches should
 activate only the tests for the capability they implement.
 

docs/semantics/c2ir_mapping.md

@@ -0,0 +1,64 @@
+# C To Semantic IR Mapping
+
+Status: first C semantic conversion subset implemented in `semantics/c2ir.py`.
+The converter consumes `c_parser` models and emits the same language-neutral
+semantic IR used by Fortran and edited `.pyi` files.
+
+## Supported Identity Subset
+
+- C translation unit -> one `SemanticModule` named from the source file stem.
+- C function -> `SemanticFunction`, preserving native name and parameter order.
+- C parameter -> `SemanticArgument`.
+- `void` return -> `None`.
+- `_Bool` -> `Bool`.
+- `char` -> `Int8` with `c_char_policy` metadata; `signed char` -> `Int8`;
+  `unsigned char` -> `UInt8`.
+- `short`, `int`, `long`, and `long long` map to fixed signed integer names
+  using the current Linux-oriented defaults: `Int16`, `Int32`, `Int64`,
+  `Int64`.
+- Unsigned integer spellings map to `UInt16`, `UInt32`, `UInt64`, and
+  `UInt64`; fixed-width typedef spellings such as `uint32_t` map to the
+  matching `UInt*` fallback.
+- `float` -> `Float32`; `double` -> `Float64`.
+- `float _Complex` -> `Complex64`; `double _Complex` -> `Complex128`.
+- Local typedef chains are resolved when their parser model definitions are
+  available.
+- `size_t` maps to `SizeT` without a target probe; supplied
+  `x2py.c_type_probe` facts override standard typedefs with width-specific
+  `Int*`, `UInt*`, or `Float*` semantic names.
+- Opaque standard-type probe facts such as `FILE` create named opaque semantic
+  classes when referenced by converted declarations.
+- Object-like numeric macros and enum constants become `Final`-style semantic
+  variables through the `Constant` constraint.
+- Struct definitions become `SemanticClass` entries. Incomplete structs become
+  opaque classes and may be used through direct `Ptr(...)` identity contracts.
+- Declared C arrays, including adjusted array parameters, become semantic array
+  storage contracts with C order for rank greater than one.
+- Pointers become explicit `SemanticStorageContract` pointer/reference
+  metadata. `const` on the pointee makes the storage read-only, and `restrict`
+  is preserved as aliasing metadata.
+
+## Conservative Blockers
+
+The converter does not silently invent wrapper policy. It attaches
+`readiness_blockers` metadata that the semantic readiness checker reports:
+
+- unresolved typedef or unknown type references;
+- macro-dependent declarations in raw C input;
+- variadic functions;
+- function pointer/callback signatures without edited `.pyi` `Callable`
+  policy;
+- mutable numeric or `void *` pointer parameters without ownership,
+  scalar-reference, or array policy;
+- arrays with unknown extents;
+- incomplete structs used by value;
+- unions used in semantic signatures;
+- `long double`, `volatile`, `_Atomic`, bitfields, and unsupported declarator
+  compositions.
+
+The current C semantic path supports `--language c --semantics`,
+`--language c --wrap-readiness`, and starter exact-contract
+`--language c --pyi` output for this supported subset. Generated stubs remain
+conservative: ambiguous ownership, callback, ABI-extension, and Pythonic
+projection policy stays out of the generated `.pyi` until supplied by the
+semantic model or an edited interface.

docs/semantics/c_pyi_self_contained_specification.md

@@ -196,8 +196,8 @@ constraint is written.
    not part of the canonical public array annotation unless they produce an
    actual storage constraint. In particular, Fortran dummy bounds are
    established by native association rather than supplied as Python array
-   metadata. This does not add C semantic conversion support; C conversion
-   remains deferred.
+   metadata. The implemented C conversion subset is described in
+   [C to semantic IR mapping](c2ir_mapping.md).
 
 Stride-aware dimensions use a slice step marker:
 

docs/semantics/pyi_format.md

@@ -5,9 +5,8 @@ language-neutral: Fortran and future C inputs use the same type, storage,
 pointer, array, layout and metadata notation. Source language differences are
 represented by contracts and metadata, not by separate syntax families.
 
-This document describes the behavior implemented for the current Fortran path
-and the shared notation it establishes for later C semantic conversion. C
-semantic conversion and C `.pyi` generation remain deferred.
+This document describes the behavior implemented for the current Fortran and C
+semantic conversion paths.
 
 ## Canonical Type And Storage Contract
 
@@ -39,6 +38,10 @@ entries express range or stride contracts (`Float64[1:n]`,
 `Float64[::Strided]`, `Float64[:, 0:n:m]`). `Strided` means the runtime stride
 is part of the accepted storage contract.
 
+Generic semantic constraints are not represented as type subscriptions.
+Constants use `Final[T]`; other constraints and non-dimensional array metadata
+use `Annotated[T[...], Constraint, ...]`.
+
 `Annotated[...]` carries non-dimensional metadata:
 
 - `ORDER_F` for a Fortran-oriented multidimensional contract.
@@ -411,20 +414,21 @@ visible Python values
 The projection mechanism is language-neutral. It can later adapt exact
 Fortran or C contracts through the same notation and runtime concepts, but
 this milestone does not implement automatic Pythonic generation, current
-exact-reference adaptation, coercion/contract execution or C semantic
-conversion/output.
+exact-reference adaptation, coercion/contract execution or C wrapper lowering.
+The C frontend can generate starter exact-contract `.pyi` output for the
+implemented semantic subset.
 
 ## Deferred C Work
 
-The shared model is capable of representing future C functions, variables,
+The shared model represents the current C semantic conversion subset for
+functions, variables,
 fields, constants, scalar references, pointers, arrays with known contracts,
-origin metadata, mutability and ownership facts. This task does not implement:
+origin metadata, mutability and ownership facts. The C frontend can generate
+starter exact-contract stubs from that model. Remaining C work includes:
 
-- `semantics/c2ir.py`;
-- C semantic conversion;
-- C `.pyi` generation;
 - C wrapper lowering;
-- C ownership, callback or pointer policy inference.
+- C ownership, callback or pointer policy inference beyond facts already
+  present in exact contracts.
 
 Future C conversion should use the same notation: by-value scalars as bare
 types, unrefined pointers as `Ptr(T)` or `Ptr(Const(T))`, and array notation