Codegen: don't use init flag for string constants

src/compiler/crystal/codegen/codegen.cr

@@ -245,7 +245,7 @@ module Crystal
       # to avoid some memory being allocated with plain malloc.
       codgen_well_known_functions @node
 
-      initialize_argv_and_argc
+      initialize_predefined_constants
 
       if @debug.line_numbers?
         set_current_debug_location Location.new(@program.filename || "(no name)", 1, 1)

src/compiler/crystal/codegen/const.cr

@@ -31,18 +31,12 @@ require "./codegen"
 class Crystal::CodeGenVisitor
   @const_mutex : LLVM::Value?
 
-  # The special constants ARGC_UNSAFE and ARGV_UNSAFE need to be initialized
+  # The special constants ARGC_UNSAFE and ARGV_UNSAFE (and others) need to be initialized
   # as soon as the program starts, because we have access to argc and argv
-  # in the main function
-  def initialize_argv_and_argc
-    {"ARGC_UNSAFE", "ARGV_UNSAFE"}.each do |name|
-      const = @program.types[name].as(Const)
-      global = declare_const(const)
-      request_value do
-        accept const.value
-      end
-      store @last, global
-      global.initializer = @last.type.null
+  # in the main function.
+  def initialize_predefined_constants
+    @program.predefined_constants.each do |const|
+      initialize_no_init_flag_const(const)
     end
   end
 
@@ -209,7 +203,7 @@ class Crystal::CodeGenVisitor
   def read_const_pointer(const)
     const.read = true
 
-    if const == @program.argc || const == @program.argv || const.initializer || const.no_init_flag?
+    if !const.needs_init_flag?
       global_name = const.llvm_name
       global = declare_const(const)
 

src/compiler/crystal/codegen/types.cr

@@ -183,9 +183,17 @@ module Crystal
     # Returns `true` if this constant's value is a simple literal, like
     # `nil`, a number, char, string or symbol literal.
     def simple?
+      return false if pointer_read?
+
       value.simple_literal?
     end
 
+    def needs_init_flag?
+      return true if pointer_read?
+
+      !(initializer || no_init_flag? || simple?)
+    end
+
     @compile_time_value : (Int16 | Int32 | Int64 | Int8 | UInt16 | UInt32 | UInt64 | UInt8 | Bool | Char | Nil)
     @computed_compile_time_value = false
 

src/compiler/crystal/program.cr

@@ -118,6 +118,8 @@ module Crystal
 
     property codegen_target = Config.host_target
 
+    getter predefined_constants = Array(Const).new
+
     def initialize
       super(self, self, "main")
 
@@ -209,6 +211,12 @@ module Crystal
       types["ARGC_UNSAFE"] = @argc = argc_unsafe = Const.new self, self, "ARGC_UNSAFE", Primitive.new("argc", int32)
       types["ARGV_UNSAFE"] = @argv = argv_unsafe = Const.new self, self, "ARGV_UNSAFE", Primitive.new("argv", pointer_of(pointer_of(uint8)))
 
+      argc_unsafe.no_init_flag = true
+      argv_unsafe.no_init_flag = true
+
+      predefined_constants << argc_unsafe
+      predefined_constants << argv_unsafe
+
       # Make sure to initialize `ARGC_UNSAFE` and `ARGV_UNSAFE` as soon as the program starts
       const_initializers << argc_unsafe
       const_initializers << argv_unsafe
@@ -275,7 +283,9 @@ module Crystal
     end
 
     private def define_crystal_constant(name, value)
-      crystal.types[name] = Const.new self, crystal, name, value
+      crystal.types[name] = const = Const.new self, crystal, name, value
+      const.no_init_flag = true
+      predefined_constants << const
     end
 
     property(target_machine : LLVM::TargetMachine) { codegen_target.to_target_machine }

src/compiler/crystal/semantic/main_visitor.cr

@@ -2566,6 +2566,7 @@ module Crystal
       when Path
         exp.accept self
         if const = exp.target_const
+          const.pointer_read = true
           const.value
         end
       when ReadInstanceVar

src/compiler/crystal/types.cr

@@ -3133,6 +3133,10 @@ module Crystal
     property vars : MetaVars?
     property? used = false
     property? visited = false
+
+    # Is this constant accessed with pointerof(...)?
+    property? pointer_read = false
+
     property visitor : MainVisitor?
 
     def initialize(program, namespace, name, @value)