Add basic compiler plugins (#2566)

This change adds a framework for compiler plugins. Plugins are
specified through the new `--plugin` command line option and can
observe the compiler data structures at various stages of the
compilation process. Only read-only plugins are supported.

An example of this functionality is a plugin that reports detailed
metrics about the compilation process.

src/common/platform.h

@@ -319,6 +319,7 @@ inline uint64_t __pony_clzl(uint64_t x)
 #    error "Clang doesn't support `static_assert` or `_Static_assert`."
 #  endif
 #else
+#  include <assert.h>
 #  define pony_static_assert(c, m) static_assert(c, m)
 #endif
 

src/libponyc/ast/ast.c

@@ -55,13 +55,17 @@
 // The private bits of the flags values
 enum
 {
-  AST_ORPHAN = 0x10,
+  AST_ORPHAN = 0x20,
   AST_INHERIT_FLAGS = (AST_FLAG_CAN_ERROR | AST_FLAG_CAN_SEND |
     AST_FLAG_MIGHT_SEND | AST_FLAG_RECURSE_1 | AST_FLAG_RECURSE_2),
-  AST_ALL_FLAGS = 0x3FFFFF
+  AST_ALL_FLAGS = 0x7FFFFF
 };
 
 
+pony_static_assert((int)PASS_ALL <= (int)AST_FLAG_PASS_MASK, "Wrong pass mask");
+pony_static_assert(AST_ORPHAN == (AST_FLAG_PASS_MASK + 1), "Wrong AST_ORPHAN");
+
+
 struct ast_t
 {
   token_t* t;

src/libponyc/ast/ast.h

@@ -28,24 +28,24 @@ typedef enum
 
 enum
 {
-  AST_FLAG_PASS_MASK    = 0x0F,
-  AST_FLAG_CAN_ERROR    = 0x20,
-  AST_FLAG_CAN_SEND     = 0x40,
-  AST_FLAG_MIGHT_SEND   = 0x80,
-  AST_FLAG_IN_PARENS    = 0x100,
-  AST_FLAG_AMBIGUOUS    = 0x200,
-  AST_FLAG_BAD_SEMI     = 0x400,
-  AST_FLAG_MISSING_SEMI = 0x800,
-  AST_FLAG_PRESERVE     = 0x1000, // Do not process
-  AST_FLAG_RECURSE_1    = 0x2000,
-  AST_FLAG_DONE_1       = 0x4000,
-  AST_FLAG_ERROR_1      = 0x8000,
-  AST_FLAG_RECURSE_2    = 0x10000,
-  AST_FLAG_DONE_2       = 0x20000,
-  AST_FLAG_ERROR_2      = 0x40000,
-  AST_FLAG_JUMPS_AWAY   = 0x80000, // Jumps away (control flow) without a value.
-  AST_FLAG_INCOMPLETE   = 0x100000, // Not all fields are defined.
-  AST_FLAG_IMPORT       = 0x200000, // Import the referenced package.
+  AST_FLAG_PASS_MASK    = 0x1F,
+  AST_FLAG_CAN_ERROR    = 0x40,
+  AST_FLAG_CAN_SEND     = 0x80,
+  AST_FLAG_MIGHT_SEND   = 0x100,
+  AST_FLAG_IN_PARENS    = 0x200,
+  AST_FLAG_AMBIGUOUS    = 0x400,
+  AST_FLAG_BAD_SEMI     = 0x800,
+  AST_FLAG_MISSING_SEMI = 0x1000,
+  AST_FLAG_PRESERVE     = 0x2000, // Do not process
+  AST_FLAG_RECURSE_1    = 0x4000,
+  AST_FLAG_DONE_1       = 0x8000,
+  AST_FLAG_ERROR_1      = 0x10000,
+  AST_FLAG_RECURSE_2    = 0x20000,
+  AST_FLAG_DONE_2       = 0x40000,
+  AST_FLAG_ERROR_2      = 0x80000,
+  AST_FLAG_JUMPS_AWAY   = 0x100000, // Jumps away (control flow) without a value.
+  AST_FLAG_INCOMPLETE   = 0x200000, // Not all fields are defined.
+  AST_FLAG_IMPORT       = 0x400000, // Import the referenced package.
 };
 
 DECLARE_LIST(astlist, astlist_t, ast_t);

src/libponyc/codegen/genexe.c

@@ -8,6 +8,7 @@
 #include "../reach/paint.h"
 #include "../pkg/package.h"
 #include "../pkg/program.h"
+#include "../plugin/plugin.h"
 #include "../type/assemble.h"
 #include "../type/lookup.h"
 #include "../../libponyrt/mem/pool.h"
@@ -506,6 +507,8 @@ bool genexe(compile_t* c, ast_t* program)
     fprintf(stderr, " Selector painting\n");
   paint(&c->reach->types);
 
+  plugin_visit_reach(c->reach, c->opt, true);
+
   if(c->opt->limit == PASS_PAINT)
   {
     ast_free(main_ast);
@@ -534,6 +537,8 @@ bool genexe(compile_t* c, ast_t* program)
 
   gen_main(c, t_main, t_env);
 
+  plugin_visit_compile(c, c->opt);
+
   if(!genopt(c, true))
     return false;
 

src/libponyc/codegen/genlib.c

@@ -3,6 +3,7 @@
 #include "genobj.h"
 #include "genheader.h"
 #include "genprim.h"
+#include "../plugin/plugin.h"
 #include "../reach/paint.h"
 #include "../type/assemble.h"
 #include "../../libponyrt/mem/pool.h"
@@ -102,6 +103,9 @@ static bool reachable_actors(compile_t* c, ast_t* program)
   if(c->opt->verbosity >= VERBOSITY_INFO)
     fprintf(stderr, " Selector painting\n");
   paint(&c->reach->types);
+
+  plugin_visit_reach(c->reach, c->opt, true);
+
   return true;
 }
 
@@ -177,6 +181,8 @@ bool genlib(compile_t* c, ast_t* program)
     )
     return false;
 
+  plugin_visit_compile(c, c->opt);
+
   if(!genopt(c, true))
     return false;
 

src/libponyc/options/options.c

@@ -1,17 +1,17 @@
 #include "options.h"
 
-#include "../libponyc/ponyc.h"
-#include "../libponyc/ast/parserapi.h"
-#include "../libponyc/ast/bnfprint.h"
-#include "../libponyc/pkg/package.h"
-#include "../libponyc/pkg/buildflagset.h"
-#include "../libponyc/ast/stringtab.h"
-#include "../libponyc/ast/treecheck.h"
-#include "../libponyc/options/options.h"
-#include "../libponyc/pass/pass.h"
-#include <platform.h>
+#include "../ponyc.h"
+#include "../ast/parserapi.h"
+#include "../ast/bnfprint.h"
+#include "../pkg/package.h"
+#include "../pkg/buildflagset.h"
+#include "../ast/stringtab.h"
+#include "../ast/treecheck.h"
+#include "../pass/pass.h"
+#include "../plugin/plugin.h"
 #include "../libponyrt/options/options.h"
 #include "../libponyrt/mem/pool.h"
+#include <platform.h>
 
 #include <string.h>
 #include <stdio.h>
@@ -48,6 +48,7 @@ enum
   OPT_STATS,
   OPT_LINK_ARCH,
   OPT_LINKER,
+  OPT_PLUGIN,
 
   OPT_VERBOSE,
   OPT_PASSES,
@@ -92,6 +93,7 @@ static opt_arg_t std_args[] =
   {"stats", '\0', OPT_ARG_NONE, OPT_STATS},
   {"link-arch", '\0', OPT_ARG_REQUIRED, OPT_LINK_ARCH},
   {"linker", '\0', OPT_ARG_REQUIRED, OPT_LINKER},
+  {"plugin", '\0', OPT_ARG_REQUIRED, OPT_PLUGIN},
 
   {"verbose", 'V', OPT_ARG_REQUIRED, OPT_VERBOSE},
   {"pass", 'r', OPT_ARG_REQUIRED, OPT_PASSES},
@@ -159,6 +161,8 @@ static void usage(void)
     "    =name          Default is the host architecture.\n"
     "  --linker         Set the linker command to use.\n"
     "    =name          Default is the compiler used to compile ponyc.\n"
+    "  --plugin         Use the specified plugin(s).\n"
+    "    =name\n"
     "  --define, -D     Define which openssl version to use default is " PONY_DEFAULT_SSL "\n"
     "    =openssl_1.1.0\n"
     "    =openssl_0.9.0\n"
@@ -212,6 +216,34 @@ static void usage(void)
     );
 }
 
+static void print_passes()
+{
+  printf("  ");
+  size_t cur_len = 2;
+
+  for(pass_id p = PASS_PARSE; p < PASS_ALL; p = pass_next(p))
+  {
+    const char* name = pass_name(p);
+    size_t len = strlen(name) + 1; // Add 1 for the comma.
+
+    if((cur_len + len) < 80)
+    {
+      printf("%s,", name);
+      cur_len += len;
+    } else {
+      printf("\n  %s,", name);
+      cur_len = len + 2;
+    }
+  }
+
+  const char* name = pass_name(PASS_ALL);
+
+  if((cur_len + strlen(name)) < 80)
+    printf("%s\n", name);
+  else
+    printf("\n%s\n", name);
+}
+
 #define OPENSSL_LEADER "openssl_"
 static const char* valid_openssl_flags[] =
   { OPENSSL_LEADER "1.1.0", OPENSSL_LEADER "0.9.0", NULL };
@@ -274,7 +306,9 @@ ponyc_opt_process_t ponyc_opt_process(opt_state_t* s, pass_opt_t* opt,
   exit_code = special_opt_processing(opt);
   if(exit_code != CONTINUE)
     return exit_code;
-
+
+  bool wants_help = false;
+
   while((id = ponyint_opt_next(s)) != -1)
   {
     switch(id)
@@ -286,8 +320,7 @@ ponyc_opt_process_t ponyc_opt_process(opt_state_t* s, pass_opt_t* opt,
         return EXIT_0;
 
       case OPT_HELP:
-        usage();
-        return EXIT_0;
+        wants_help = true; break;
       case OPT_DEBUG: opt->release = false; break;
       case OPT_BUILDFLAG:
         if(is_openssl_flag(s->arg_val))
@@ -340,6 +373,13 @@ ponyc_opt_process_t ponyc_opt_process(opt_state_t* s, pass_opt_t* opt,
       case OPT_STATS: opt->print_stats = true; break;
       case OPT_LINK_ARCH: opt->link_arch = s->arg_val; break;
       case OPT_LINKER: opt->linker = s->arg_val; break;
+      case OPT_PLUGIN:
+        if(!plugin_load(opt, s->arg_val))
+        {
+          printf("Error loading plugins: %s\n", s->arg_val);
+          exit_code = EXIT_255;
+        }
+        break;
 
       case OPT_AST: *print_program_ast = true; break;
       case OPT_ASTPACKAGE: *print_package_ast = true; break;
@@ -373,9 +413,8 @@ ponyc_opt_process_t ponyc_opt_process(opt_state_t* s, pass_opt_t* opt,
       case OPT_PASSES:
         if(!limit_passes(opt, s->arg_val))
         {
-          printf("Invalid pass=%s it should be one of:\n%s", s->arg_val,
-             "  parse,syntax,sugar,scope,import,name,flatten,traits,docs,\n"
-             "  refer,expr,verify,final,reach,paint,ir,bitcode,asm,obj,all\n");
+          printf("Invalid pass=%s it should be one of:\n", s->arg_val);
+          print_passes();
           exit_code = EXIT_255;
         }
         break;
@@ -386,6 +425,20 @@ ponyc_opt_process_t ponyc_opt_process(opt_state_t* s, pass_opt_t* opt,
     }
   }
 
+  if(!plugin_parse_options(opt, s->argc, s->argv))
+    exit_code = EXIT_255;
+
+  if(wants_help)
+  {
+    usage();
+    plugin_print_help(opt);
+
+    if(exit_code != EXIT_255)
+      exit_code = EXIT_0;
+
+    return exit_code;
+  }
+
   for(int i = 1; i < (*s->argc); i++)
   {
     if(s->argv[i][0] == '-')