From f2e79b0670d1c56205ae89ac248de53f46d56ee8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Wed, 10 Aug 2011 15:14:36 +0200
Subject: Refactor 'too_old_compiler' handling

In the handling of generic instructions, we used to always
test whether the instruction was 'too_old_compiler' and abort
loading with a special error message.

Refactor the code so that we only do test if we an error
has occurred. That will allow us to make the test more expensive
in the future, allowing us to customize error messages for certain
opcode without any cost in the successful case.
---
 erts/emulator/beam/beam_emu.c  |  1 -
 erts/emulator/beam/beam_load.c | 22 +++++++++++++---------
 erts/emulator/beam/ops.tab     |  2 +-
 3 files changed, 14 insertions(+), 11 deletions(-)

(limited to 'erts/emulator/beam')

diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c
index eec9ecb410..5691f7aec1 100644
--- a/erts/emulator/beam/beam_emu.c
+++ b/erts/emulator/beam/beam_emu.c
@@ -5155,7 +5155,6 @@ void process_main(void)
 
  OpCase(int_code_end):
  OpCase(label_L):
- OpCase(too_old_compiler):
  OpCase(on_load):
  OpCase(line_I):
     erl_exit(1, "meta op\n");
diff --git a/erts/emulator/beam/beam_load.c b/erts/emulator/beam/beam_load.c
index 655b5496a8..7c32518ba9 100644
--- a/erts/emulator/beam/beam_load.c
+++ b/erts/emulator/beam/beam_load.c
@@ -1886,14 +1886,6 @@ load_code(LoaderState* stp)
 	    goto get_next_instr;
 	}
 
-	/*
-	 * Special error message instruction.
-	 */
-	if (stp->genop->op == genop_too_old_compiler_0) {
-	    LoadError0(stp, "please re-compile this module with an " 
-		       ERLANG_OTP_RELEASE " compiler");
-	}
-
 	/*
 	 * From the collected generic instruction, find the specific
 	 * instruction.
@@ -1945,7 +1937,17 @@ load_code(LoaderState* stp)
 			       ERLANG_OTP_RELEASE " compiler ");
 		}
 
-		LoadError0(stp, "no specific operation found");
+		/*
+		 * Some generic instructions should have a special
+		 * error message.
+		 */
+		switch (stp->genop->op) {
+		case genop_too_old_compiler_0:
+		    LoadError0(stp, "please re-compile this module with an "
+			       ERLANG_OTP_RELEASE " compiler");
+		default:
+		    LoadError0(stp, "no specific operation found");
+		}
 	    }
 
 	    stp->specific_op = specific;
@@ -2409,6 +2411,8 @@ load_code(LoaderState* stp)
 #define no_fpe_signals(St) 0
 #endif
 
+#define never(St) 0
+
 /*
  * Predicate that tests whether a jump table can be used.
  */
diff --git a/erts/emulator/beam/ops.tab b/erts/emulator/beam/ops.tab
index fc98c399c1..327c4e8651 100644
--- a/erts/emulator/beam/ops.tab
+++ b/erts/emulator/beam/ops.tab
@@ -30,7 +30,7 @@
 # needs to be re-compiled with a modern compiler.
 
 too_old_compiler/0
-too_old_compiler
+too_old_compiler | never() =>
 
 # In R9C and earlier, the loader used to insert special instructions inside
 # the module_info/0,1 functions. (In R10B and later, the compiler inserts
-- 
cgit v1.2.3