Add missing debug locations to constant / class variable read calls (#…

…11417)

Fixes #11416.

Although the constant read functions have a debug location, for some reason the calls themselves to the read functions do not. This PR adds them.

spec/compiler/codegen/debug_spec.cr

@@ -252,4 +252,23 @@ describe "Code gen: debug" do
       LibFoo.foo = ->{ }
       ), debug: Crystal::Debug::All)
   end
+
+  it "doesn't fail on constant read calls (#11416)" do
+    codegen(%(
+      require "prelude"
+
+      class Foo
+        def foo
+        end
+      end
+
+      def a_foo
+        Foo.new
+      end
+
+      THE_FOO.foo
+
+      THE_FOO = a_foo
+      ), debug: Crystal::Debug::All)
+  end
 end

spec/llvm-ir/class-var-read-debug-loc.cr

@@ -0,0 +1,19 @@
+require "prelude"
+
+class Foo
+  def foo
+    @@x
+    # CHECK:      call %String** @"~Bar::x:read"
+    # CHECK-SAME: !dbg [[LOC:![0-9]+]]
+    # CHECK:      [[LOC]] = !DILocation
+    # CHECK-SAME: line: [[# @LINE - 4]]
+    # CHECK-SAME: column: 5
+  end
+
+  @@x = ""
+end
+
+class Bar < Foo
+end
+
+Bar.new.foo

spec/llvm-ir/const-read-debug-loc.cr

@@ -0,0 +1,19 @@
+require "prelude"
+
+class Foo
+  def foo
+  end
+end
+
+def a_foo
+  Foo.new
+end
+
+THE_FOO.foo
+# CHECK:      call %Foo** @"~THE_FOO:read"()
+# CHECK-SAME: !dbg [[LOC:![0-9]+]]
+# CHECK:      [[LOC]] = !DILocation
+# CHECK-SAME: line: 12
+# CHECK-SAME: column: 1
+
+THE_FOO = a_foo

spec/llvm-ir/test.sh

@@ -34,6 +34,12 @@ pushd $BUILD_DIR >/dev/null
 
 test argless-initialize-debug-loc.cr "--cross-compile --target x86_64-unknown-linux-gnu --prelude=empty"
 test proc-pointer-debug-loc.cr "--cross-compile --target x86_64-unknown-linux-gnu --prelude=empty"
+test const-read-debug-loc.cr "--cross-compile --target x86_64-unknown-linux-gnu --prelude=empty"
+
+# #11416
+test class-var-read-debug-loc.cr "--cross-compile --target x86_64-unknown-linux-gnu --prelude=empty"
+test virtual-class-var-read-debug-loc.cr "--cross-compile --target x86_64-unknown-linux-gnu --prelude=empty"
+test virtual-metaclass-var-read-debug-loc.cr "--cross-compile --target x86_64-unknown-linux-gnu --prelude=empty"
 
 test memset.cr "--cross-compile --target i386-apple-darwin --prelude=empty --no-debug" X32
 test memset.cr "--cross-compile --target i386-unknown-linux-gnu --prelude=empty --no-debug" X32

spec/llvm-ir/virtual-class-var-read-debug-loc.cr

@@ -0,0 +1,17 @@
+class Foo
+  def foo
+    @@x
+    # CHECK:      call i32* @"~Foo+::x:read"
+    # CHECK-SAME: !dbg [[LOC:![0-9]+]]
+    # CHECK:      [[LOC]] = !DILocation
+    # CHECK-SAME: line: [[# @LINE - 4]]
+    # CHECK-SAME: column: 5
+  end
+
+  @@x = 1
+end
+
+class Bar < Foo
+end
+
+(Foo.new || Bar.new).foo

spec/llvm-ir/virtual-metaclass-var-read-debug-loc.cr

@@ -0,0 +1,17 @@
+class Foo
+  def self.foo
+    @@x
+    # CHECK:      call i32* @"~Foo+.class::x:read"
+    # CHECK-SAME: !dbg [[LOC3:![0-9]+]]
+    # CHECK:      [[LOC3]] = !DILocation
+    # CHECK-SAME: line: [[# @LINE - 4]]
+    # CHECK-SAME: column: 5
+  end
+
+  @@x = 1
+end
+
+class Bar < Foo
+end
+
+(Foo || Bar).foo

src/compiler/crystal/codegen/class_var.cr

@@ -166,6 +166,7 @@ class Crystal::CodeGenVisitor
   end
 
   def read_class_var(node : ClassVar)
+    set_current_debug_location node if @debug.line_numbers?
     read_class_var(node.var)
   end
 

src/compiler/crystal/codegen/codegen.cr

@@ -1470,7 +1470,7 @@ module Crystal
 
     def visit(node : Path)
       if const = node.target_const
-        read_const(const)
+        read_const(const, node)
       elsif replacement = node.syntax_replacement
         accept replacement
       else

src/compiler/crystal/codegen/const.cr

@@ -190,7 +190,7 @@ class Crystal::CodeGenVisitor
     end
   end
 
-  def read_const(const)
+  def read_const(const, node)
     # We inline constants. Otherwise we use an LLVM const global.
     @last =
       case value = const.compile_time_value
@@ -205,6 +205,7 @@ class Crystal::CodeGenVisitor
       when UInt32 then int32(value)
       when UInt64 then int64(value)
       else
+        set_current_debug_location node if @debug.line_numbers?
         last = read_const_pointer(const)
         to_lhs last, const.value.type
       end