diff options
Diffstat (limited to 'AGENTS')
| -rw-r--r-- | AGENTS/ARCH.md | 3 | ||||
| -rw-r--r-- | AGENTS/PITFALLS.md | 8 | ||||
| -rw-r--r-- | AGENTS/SUBSYSTEMS.md | 13 |
3 files changed, 22 insertions, 2 deletions
diff --git a/AGENTS/ARCH.md b/AGENTS/ARCH.md index cb0bc20..0479641 100644 --- a/AGENTS/ARCH.md +++ b/AGENTS/ARCH.md @@ -25,7 +25,8 @@ imports cover standard C integer/real types, _Bool, void and object pointers. CScalar/CPointer identities are canonical C types, not pseudocode alias names; native widths and signedness come from sizeof/type traits, while floating formats come from numeric_limits (long double size alone is insufficient). Programs use -the compiler's build ABI; cross-target emission and EXTERN are not implemented. +the compiler's build ABI; cross-target emission is not implemented. EXTERN "C" +declarations call C functions from INCLUDE_OBJ objects (see SUBSYSTEMS.md). CTypeGen handles typed numeric conversions, casts, native arithmetic and I/O. Crossing C/pseudocode domains requires a cast, including literals. C arithmetic uses C++ promotions, except that / always returns pseudocode REAL. diff --git a/AGENTS/PITFALLS.md b/AGENTS/PITFALLS.md index 8f35c3d..551a64c 100644 --- a/AGENTS/PITFALLS.md +++ b/AGENTS/PITFALLS.md @@ -145,7 +145,13 @@ test programs. require casts even for literals. C scalar arithmetic uses native promotions, but / always returns REAL. Cast aliases must precede their use. long double may have padding; sizeof does not identify its floating-point format. Native - C support is verified on Linux LLVM 23; cross-target and EXTERN are unsupported. + C support is verified on Linux LLVM 23; cross-target is unsupported. +- **EXTERN "C" extension.** Top-level, body-less; parameters/results are C types only, + no BYREF/OVERLOAD/structs. Variadic arguments must be C values (default promotions). + The driver checks every EXTERN symbol against INCLUDE_OBJ inputs before CodeGen; + `"__libc"` must be included explicitly even though the runtime always links libc. + Only `.o` user objects; INCLUDE_OBJ is global across inputs. `-S` does not link them. + Two EXTERNs differing only in case conflict (pseudocode names are case insensitive). ## Not implemented (9618 features) diff --git a/AGENTS/SUBSYSTEMS.md b/AGENTS/SUBSYSTEMS.md index dab3146..866d39e 100644 --- a/AGENTS/SUBSYSTEMS.md +++ b/AGENTS/SUBSYSTEMS.md @@ -43,6 +43,19 @@ compile error (no extern is fabricated). Functions inherit visible GLOBAL storag `StmtEmitter` callback, and must restore its own insert point (and the exchanged ArrayTable) afterwards. +**EXTERN "C"** (`ExternDeclAST`, `IncludeObjStmtAST`): the parser builds a body-less +`PrototypeAST` (IsExternal, IsVariadic, unnamed `argN` params). `FunctionGen::emitExternPrototype` +validates C types, records a `FuncSig` with `IsExternal`, the declared `FunctionType` and +sext/zext attributes for sub-32-bit integers, and `getOrInsertFunction`s the exact symbol. +Calls go through `FunctionGen::emitCall(const FuncSig &, ...)` with that type, so a +runtime declaration of the same libc symbol with another type is harmless. +`CodeGen::emitVariadicArgument` applies C default promotions. The driver (`main.cc`) +resolves INCLUDE_OBJ paths, reads defined global symbols with `llvm::object` +(`collectObjectSymbols`; `"__libc"` uses `collectLibcSymbols` over the embedded runtime's +libc/libm inputs, copied to aligned buffers), rejects missing symbols, and passes objects +to `compileNative`, `runEmbedded` (`addObjectFile`) or lli (`-extra-object=`). +Linux is verified; the Windows/macOS libc file-name rules and the lli path are not. + **User types** (`TypeSystem` + `Designator.cc` + `TypeCheckGen.cc`): `Designator.cc` owns the type pre-pass and lvalue access; `TypeCheckGen.cc` owns type admission and user-kind binary operators. TYPE declarations are top-level only |