Most of a C implementation of jq

c/Makefile

@@ -0,0 +1,21 @@
+CC=gcc -Wall -std=gnu99 -ggdb
+
+.PHONY: all clean
+all: parsertest
+
+clean:
+	make -Bnd | grep 'Must remake target' | \
+	sed 's/.*`\(.*\)'\''.*/\1/' | grep -v '^all$$' | \
+	xargs rm
+
+
+lexer.yy.c: lexer.l
+	flex -o lexer.yy.c --header-file=lexer.yy.h lexer.l
+lexer.yy.h: lexer.yy.c
+
+parser.tab.c: parser.y lexer.yy.h
+	bison -W -d parser.y
+parser.tab.h: parser.tab.c
+
+parsertest: parser.tab.c lexer.yy.c main.c opcode.c bytecode.c compile.c execute.c builtin.c
+	$(CC) -o $@ $^ -ljansson

c/builtin.c

@@ -0,0 +1,18 @@
+#include "builtin.h"
+
+#include <jansson.h>
+
+
+void f_false(json_t* input[], json_t* output[]) {
+  output[0] = json_false();
+}
+
+void f_true(json_t* input[], json_t* output[]) {
+  output[0] = json_true();
+}
+
+struct cfunction function_list[] = {
+  {f_true, "true", CALL_BUILTIN_1_1},
+  {f_false, "false", CALL_BUILTIN_1_1},
+};
+struct symbol_table builtins = {function_list, sizeof(function_list)/sizeof(function_list[0])};

c/builtin.h

@@ -0,0 +1,8 @@
+#ifndef BUILTIN_H
+#define BUILTIN_H
+
+#include "bytecode.h"
+
+extern struct symbol_table builtins;
+
+#endif

c/bytecode.c

@@ -0,0 +1,35 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <jansson.h>
+#include "bytecode.h"
+#include "opcode.h"
+
+void dump_disassembly(struct bytecode* bc) {
+  int pc = 0;
+  while (pc < bc->codelen) {
+    dump_operation(bc, bc->code + pc);
+    printf("\n");
+    pc += opcode_length(bc->code[pc]);
+  }
+}
+
+void dump_operation(struct bytecode* bc, uint16_t* codeptr) {
+  int pc = codeptr - bc->code;
+  printf("%04d ", pc);
+  const struct opcode_description* op = opcode_describe(bc->code[pc++]);
+  printf("%s", op->name);
+  if (op->flags & OP_HAS_IMMEDIATE) {
+    uint16_t imm = bc->code[pc++];
+    printf(" ");
+    if (op->flags & OP_HAS_BRANCH) {
+      printf("%04d", pc + imm);
+    } else if (op->flags & OP_HAS_CONSTANT) {
+      json_dumpf(json_array_get(bc->constants, imm),
+                 stdout, JSON_ENCODE_ANY);
+    } else if (op->flags & OP_HAS_VARIABLE) {
+      printf("v%d", imm);
+    } else {
+      printf("%d", imm);
+    }
+  }  
+}

c/bytecode.h

@@ -0,0 +1,33 @@
+#ifndef BYTECODE_H
+#define BYTECODE_H
+#include <jansson.h>
+#include <stdint.h>
+
+#include "opcode.h"
+
+typedef void (*cfunction_ptr)(json_t* input[], json_t* output[]);
+
+struct cfunction {
+  cfunction_ptr fptr;
+  const char* name;
+  opcode callop;
+};
+
+#define MAX_CFUNCTION_ARGS 10
+struct symbol_table {
+  struct cfunction* cfunctions;
+  int ncfunctions;
+};
+
+
+struct bytecode {
+  uint16_t* code;
+  int codelen;
+  int framesize;
+  json_t* constants;
+  struct symbol_table* globals;
+};
+
+void dump_disassembly(struct bytecode* code);
+void dump_operation(struct bytecode* bc, uint16_t* op);
+#endif