Establish R0 compiler foundation

.gitignore

@@ -1,9 +1,26 @@
-.*
-*~
+# Generated host frontend and build products
+/build/
+
+# Python bytecode caches
+__pycache__/
+*.py[cod]
+
+# Legacy generated frontend files
 lex.yy.c
 lex
 y.tab.c
 y.tab.h
 y.output
-# except for .gitignore
-!.gitignore
+final
+*.o
+*.d
+
+# Compiler artifacts and dumps
+*.adi
+*.elf
+*.s
+*.S.tmp
+*.ast
+*.sem
+*.ir
+*.asm

Makefile

@@ -1,41 +1,103 @@
-final: y.tab.o lex.yy.o errormsg.o util.o absyn.o symbol.o table.o prabsyn.o type.o
-	cc -g y.tab.o lex.yy.o errormsg.o util.o absyn.o symbol.o table.o prabsyn.o type.o -o final -lm
+CC ?= cc
+FLEX ?= flex
+BISON ?= bison
+PYTHON ?= python3
 
-y.tab.o: y.tab.c
-	cc -g -c y.tab.c
+BUILD_DIR := build
+BIN_DIR := $(BUILD_DIR)/bin
+GEN_DIR := $(BUILD_DIR)/generated
+OBJ_DIR := $(BUILD_DIR)/obj
+ADAC := $(BIN_DIR)/adac
 
-y.tab.c: parser.y
-	yacc --debug -vd parser.y
+CPPFLAGS := -D_POSIX_C_SOURCE=200809L -I. -I$(GEN_DIR)
+CFLAGS := -std=c11 -g -O0 -Wall -Wextra -Wpedantic -Werror
+LDLIBS := -lm
 
-y.tab.h: y.tab.c
-	echo "y.tab.h was created at the same time as y.tab.c"
+PARSER_C := $(GEN_DIR)/parser.c
+PARSER_H := $(GEN_DIR)/parser.h
+PARSER_REPORT := $(GEN_DIR)/parser.output
+LEXER_C := $(GEN_DIR)/lexer.c
 
-errormsg.o: errormsg.c errormsg.h util.h
-	cc -g -c errormsg.c
+HOST_SOURCES := driver.c compile.c errormsg.c util.c absyn.c symbol.c table.c prabsyn.c type.c
+HOST_OBJECTS := $(HOST_SOURCES:%.c=$(OBJ_DIR)/%.o)
+GENERATED_OBJECTS := $(OBJ_DIR)/parser.o $(OBJ_DIR)/lexer.o
+OBJECTS := $(HOST_OBJECTS) $(GENERATED_OBJECTS)
 
-lex.yy.o: lex.yy.c y.tab.h errormsg.h util.h
-	cc -g -c lex.yy.c
+.PHONY: all strict clean test host-tools coverage contract
 
-lex.yy.c: lexer.l
-	lex lexer.l
+# Build only: validation is deliberately reserved for `make strict`.
+all: $(ADAC)
 
-util.o: util.c util.h
-	cc -g -c util.c
+strict: host-tools all coverage contract
 
-absyn.o: absyn.c absyn.h
-	cc -g -c absyn.c
+$(ADAC): $(OBJECTS) | $(BIN_DIR)
+	$(CC) $(CFLAGS) $(OBJECTS) $(LDLIBS) -o $@
 
-prabsyn.o: prabsyn.c prabsyn.h
-	cc -g -c prabsyn.c
-
-symbol.o: symbol.c symbol.h
-	cc -g -c symbol.c
+$(PARSER_C) $(PARSER_H) $(PARSER_REPORT) &: parser.y | $(GEN_DIR)
+	$(BISON) --defines=$(PARSER_H) --output=$(PARSER_C) --report=all --report-file=$(PARSER_REPORT) parser.y
 
-table.o: table.c table.h
-	cc -g -c table.c
+$(LEXER_C): lexer.l $(PARSER_H) | $(GEN_DIR)
+	$(FLEX) --outfile=$@ lexer.l
 
-type.o: type.c type.h
-	cc -g -c type.c
-
-clean: 
-	rm -f final *.o lex.yy.c y.tab.c y.tab.h y.output
+$(OBJ_DIR)/%.o: %.c | $(OBJ_DIR)
+	@mkdir -p $(@D)
+	$(CC) $(CPPFLAGS) $(CFLAGS) -MMD -MP -c $< -o $@
+
+$(OBJ_DIR)/parser.o: $(PARSER_C) | $(OBJ_DIR)
+	@mkdir -p $(@D)
+	$(CC) $(CPPFLAGS) $(CFLAGS) -Wno-unused-function -MMD -MP -c $< -o $@
+
+$(OBJ_DIR)/lexer.o: $(LEXER_C) | $(OBJ_DIR)
+	@mkdir -p $(@D)
+	$(CC) $(CPPFLAGS) $(CFLAGS) -Wno-unused-function -MMD -MP -c $< -o $@
+
+$(BIN_DIR) $(GEN_DIR) $(OBJ_DIR):
+	mkdir -p $@
+
+host-tools:
+	@command -v $(CC) >/dev/null || { echo "missing host C compiler: $(CC)" >&2; exit 1; }
+	@command -v $(FLEX) >/dev/null || { echo "missing flex: $(FLEX)" >&2; exit 1; }
+	@command -v $(BISON) >/dev/null || { echo "missing bison: $(BISON)" >&2; exit 1; }
+	@command -v $(PYTHON) >/dev/null || { echo "missing Python: $(PYTHON)" >&2; exit 1; }
+	@$(FLEX) --version | grep -F 'flex 2.6.4' >/dev/null || { echo "expected flex 2.6.4" >&2; exit 1; }
+	@$(BISON) --version | head -n 1 | grep -F '3.8.2' >/dev/null || { echo "expected bison 3.8.2" >&2; exit 1; }
+
+coverage:
+	$(PYTHON) tools/inventory_grammar.py --check-baseline
+	$(PYTHON) tools/check_coverage.py
+
+contract:
+	$(PYTHON) tests/run_tests.py
+
+clean:
+	rm -rf $(BUILD_DIR)
+
+test: $(ADAC)
+	@set -eu; \
+	workdir=$$(mktemp -d "$${TMPDIR:-/tmp}/adac-host-test.XXXXXX"); \
+	trap 'rm -rf "$$workdir"' EXIT HUP INT TERM; \
+	printf 'procedure Empty is\nbegin\n   null;\nend Empty;\n' > "$$workdir/empty.adb"; \
+	printf 'procedure Token_Test is\n   type T is null record;\n   V : Integer := 16#fF#;\nbegin\n   for I in reverse 1 .. 1 loop\n      null;\n   end loop;\nend Token_Test;\n' > "$$workdir/token.adb"; \
+	$(ADAC) --help > "$$workdir/help"; \
+	grep -F 'usage: adac <check|compile|build>' "$$workdir/help" >/dev/null; \
+	$(ADAC) check "$$workdir/empty.adb"; \
+	$(ADAC) check "$$workdir/token.adb"; \
+	printf 'private procedure Private_Unit is\nbegin\n   null;\nend Private_Unit;\n' > "$$workdir/private.adb"; \
+	$(ADAC) check --emit-ast "$$workdir/private.adb" > "$$workdir/private.ast"; \
+	grep -F 'stringExp(private)' "$$workdir/private.ast" >/dev/null; \
+	$(ADAC) check --emit-ast --emit-sem --emit-ir --emit-asm "$$workdir/empty.adb" > "$$workdir/dumps"; \
+	grep -F 'semantic dump unavailable in R0' "$$workdir/dumps" >/dev/null; \
+	if $(ADAC) compile -o "$$workdir/out.o" "$$workdir/empty.adb" > "$$workdir/compile.out" 2> "$$workdir/compile.err"; then exit 1; fi; \
+	grep -F 'unsupported-in-release: compile phase is not available in R0' "$$workdir/compile.err" >/dev/null; \
+	test ! -e "$$workdir/out.o"; \
+	printf 'procedure Bad is begin\n' > "$$workdir/bad.adb"; \
+	if $(ADAC) check "$$workdir/bad.adb" > "$$workdir/bad.out" 2> "$$workdir/bad.err"; then exit 1; fi; \
+	grep -F "$$workdir/bad.adb:2:1: error: syntax error" "$$workdir/bad.err" >/dev/null; \
+	printf 'procedure Broken is\n  @\nbegin\n   null;\nend Broken;\n' > "$$workdir/line-column.adb"; \
+	if $(ADAC) check "$$workdir/line-column.adb" > "$$workdir/line-column.out" 2> "$$workdir/line-column.err"; then exit 1; fi; \
+	grep -F "$$workdir/line-column.adb:2:3: error: Illegal token" "$$workdir/line-column.err" >/dev/null; \
+	if $(ADAC) check "$$workdir/missing.adb" > "$$workdir/missing.out" 2> "$$workdir/missing.err"; then exit 1; fi; \
+	grep -F 'No such file or directory' "$$workdir/missing.err" >/dev/null; \
+	$(ADAC) check "$$workdir/empty.adb"
+
+-include $(OBJECTS:.o=.d)

README.md

@@ -1,4 +1,56 @@
-ada-compiler
-============
-Course Project for CS335.  
-*This project is no longer maintained.*
+# Ada compiler restoration
+
+This repository is being restored as a staged Ada compiler targeting static
+Linux MIPS32r2 executables. R0 provides a deterministic host frontend build and
+an honest command-line foundation; target code generation and semantic analysis
+are release-owned work that is not yet available.
+
+## Host prerequisites
+
+- C11 compiler
+- GNU Make
+- Flex 2.6.4
+- Bison 3.8.2
+
+Build the host driver with:
+
+```sh
+make strict
+```
+
+Generated lexer/parser files, objects, dependency files, and the executable are
+contained under `build/`; source files are never regenerated in place.
+
+## CLI
+
+```text
+adac check [--emit-ast] [--emit-sem] [--emit-ir] [--emit-asm] SOURCE
+adac compile [--unit-dir DIR] [-o PATH] SOURCE
+adac build [--unit-dir DIR] [-o PATH] SOURCE
+```
+
+Use `build/bin/adac --help` for the full option list.
+
+- `check` parses the source and returns a nonzero status for input or syntax
+  diagnostics.
+- `compile` and `build` parse successfully but return a stable
+  `unsupported-in-release` diagnostic in R0. They intentionally leave no output
+  artifacts.
+- `--emit-ast` dumps the current frontend AST. Semantic, IR, and assembly dumps
+  explicitly report their R0-unavailable status rather than pretending to
+  produce later-phase output.
+- Based-literal digits are case-insensitive (`16#fF#` is accepted); spelling is
+  otherwise preserved by the lexer for later syntax diagnostics and dumps.
+
+## Validation
+
+```sh
+make strict
+make test
+```
+
+`make strict` validates host tools, the grammar-coverage baseline and manifest,
+and the direct Linux/MIPS ELF/QEMU/ABI contract. `make test` runs the focused
+host CLI smoke coverage: help, valid input, malformed input, missing input,
+unsupported phases, dump flags, and repeated invocations. `make all` is
+build-only.

absyn.c

@@ -2,7 +2,6 @@
  * absyn.c - Abstract Syntax Functions. Most functions create an instance of an
  *           abstract syntax rule.
  */
-#include <stdio.h>
 #include "util.h"
 #include "symbol.h" /* symbol table data structures */
 #include "absyn.h"  /* abstract syntax data structures */
@@ -58,13 +57,11 @@ A_exp A_NumberExp(A_pos pos, string s)
  return p;
 }
 
-A_exp A_StringExp(A_pos pos, S_table table, string s)
+A_exp A_StringExp(A_pos pos, string s)
 {A_exp p = checked_malloc(sizeof(*p));
  p->kind=A_stringExp;
  p->pos=pos;
- A_ty t=S_look(table,S_Symbol(s));
- if(t==NULL) p->dec_type=S_Symbol(s);
- else p->dec_type=t->dec_type;
+ p->dec_type=S_Symbol(s);
  p->u.stringg=s;
  return p;
 }
@@ -456,7 +453,7 @@ A_dec A_VarDec(A_pos pos, S_symbol var, S_symbol typ, A_exp init)
  p->u.var.var=var;
  p->u.var.typ=typ;
  p->u.var.init=init;
- p->u.var.escape=TRUE;
+ p->u.var.escape=true;
  return p;
 }
 
@@ -532,7 +529,7 @@ A_field A_Field(A_pos pos, S_symbol name, S_symbol typ)
  p->pos=pos;
  p->name=name;
  p->typ=typ;
- p->escape=TRUE;
+ p->escape=true;
  return p;
 }
 

absyn.h

@@ -5,6 +5,11 @@
  * Linked list types end with "..list"
  */
 
+#ifndef ADA_ABSYN_H
+#define ADA_ABSYN_H
+
+#include "symbol.h"
+
 /* Type Definitions */
 
 typedef int A_pos;
@@ -155,7 +160,7 @@ A_var A_SubscriptVar(A_pos pos, A_var var, A_exp exp);
 A_exp A_VarExp(A_pos pos, A_var var);
 A_exp A_NilExp(A_pos pos);
 A_exp A_NumberExp(A_pos pos, string number);
-A_exp A_StringExp(A_pos pos, S_table table, string s);
+A_exp A_StringExp(A_pos pos, string s);
 A_exp A_CallExp(A_pos pos, S_symbol func, A_expList args);
 A_exp A_OpExp(A_pos pos, A_oper oper, A_exp left, A_exp right);
 A_exp A_UnaryOpExp(A_pos pos, A_unaryOper oper, A_exp exp);
@@ -217,3 +222,5 @@ A_namety A_Namety(S_symbol name, A_ty ty);
 A_nametyList A_NametyList(A_namety head, A_nametyList tail);
 A_efield A_Efield(S_symbol name, A_exp exp);
 A_efieldList A_EfieldList(A_efield head, A_efieldList tail);
+
+#endif

ci/Containerfile

@@ -0,0 +1,23 @@
+# syntax=docker/dockerfile:1
+FROM ubuntu:24.04
+
+ARG DEBIAN_FRONTEND=noninteractive
+
+# Keep the target development libc deliberately absent.  The runtime is linked
+# with ld directly, so accidentally introducing a CRT, libc, or libgcc object
+# becomes a link failure rather than a host-dependent success.
+RUN apt-get update \
+ && apt-get install -y --no-install-recommends \
+      bison=2:3.8.2+dfsg-1build2 \
+      flex=2.6.4-8.2build1 \
+      gcc=4:13.2.0-7ubuntu1 \
+      make=4.3-4.1build2 \
+      gcc-13-mipsel-linux-gnu=13.3.0-6ubuntu2~24.04cross1 \
+      binutils-mipsel-linux-gnu=2.42-2ubuntu1cross5 \
+      qemu-user=1:8.2.2+ds-0ubuntu1.17 \
+      linux-libc-dev-mipsel-cross=6.8.0-25.25cross2 \
+      gnat-13=13.3.0-6ubuntu2~24.04.1 \
+      python3 \
+ && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /work

ci/toolchain.lock

@@ -0,0 +1,34 @@
+# R0 Linux/mipsel toolchain lock
+#
+# Distribution: Ubuntu 24.04 (Noble)
+# This lock intentionally does not contain libc6-dev-mipsel-cross.  The
+# compiler-owned runtime must remain freestanding and link without target CRT,
+# libc, or libgcc objects.
+
+HOST_CC=gcc
+HOST_CC_PACKAGE=gcc=4:13.2.0-7ubuntu1
+MAKE_PACKAGE=make=4.3-4.1build2
+FLEX_PACKAGE=flex=2.6.4-8.2build1
+BISON_PACKAGE=bison=2:3.8.2+dfsg-1build2
+GNAT_PACKAGE=gnat-13=13.3.0-6ubuntu2~24.04.1
+PYTHON_PACKAGE=python3
+
+TARGET_TRIPLE=mipsel-linux-gnu
+TARGET_CC=mipsel-linux-gnu-gcc-13
+TARGET_CC_PACKAGE=gcc-13-mipsel-linux-gnu=13.3.0-6ubuntu2~24.04cross1
+TARGET_BINUTILS_PACKAGE=binutils-mipsel-linux-gnu=2.42-2ubuntu1cross5
+TARGET_AS=mipsel-linux-gnu-as
+TARGET_LD=mipsel-linux-gnu-ld
+TARGET_NM=mipsel-linux-gnu-nm
+TARGET_READELF=mipsel-linux-gnu-readelf
+TARGET_OBJDUMP=mipsel-linux-gnu-objdump
+QEMU=qemu-mipsel
+QEMU_PACKAGE=qemu-user=1:8.2.2+ds-0ubuntu1.17
+TARGET_LINUX_HEADERS_PACKAGE=linux-libc-dev-mipsel-cross=6.8.0-25.25cross2
+TARGET_UNISTD=/usr/mipsel-linux-gnu/include/asm/unistd.h
+
+# These are individual argument lists rather than implicit compiler defaults.
+TARGET_AS_FLAGS=-EL -32 -mips32r2 -mhard-float -mfp32 -mnan=legacy
+TARGET_CFLAGS=-march=mips32r2 -mabi=32 -EL -mhard-float -mfp32 -mnan=legacy -fno-pic -mno-abicalls -G0 -ffreestanding -fno-stack-protector -fno-builtin -Wall -Wextra -Werror
+TARGET_LD_FLAGS=-m elf32ltsmip -EL -static -T runtime/mipsel-linux.ld -e _start --orphan-handling=error
+EXPECTED_E_FLAGS=0x70001001