[Pdbg] [PATCH] template.S: Fix prefix mangling

[Joel Stanley]

When I reworked Thomas' fix, I put the symbol prefix in the wrong spot.
This resolves that bug and makes it clearer what is going on in the
template.

Fixes: 8275ca370476a3 (template.S: fix to build on architecture with non-empty __USER_LABEL_PREFIX__)
Signed-off-by: Joel Stanley <joel at jms.id.au>
---
 template.S | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/template.S b/template.S
index 2b231f9de2e1..e56b7b4b0203 100644
--- a/template.S
+++ b/template.S
@@ -1,14 +1,16 @@
-#ifdef __USER_LABEL_PREFIX__
-#define CONCAT1(a, b) CONCAT2(a, b)
-#define CONCAT2(a, b) a ## b
-#define SYM(x) CONCAT1 (__USER_LABEL_PREFIX__, x)
-#else
-#define SYM(x) x
+// On platforms that define this macro, a symbol called "foo" in C must be
+// named "_foo" in assembler. GCC Should always define the macro, but
+// we add a fallback just in case
+#ifndef __USER_LABEL_PREFIX__
+#define __USER_LABEL_PREFIX__ ""
 #endif
 
-#define SYM_START(x)	CONCAT1(CONCAT1(_binary_, SYM(x)), _start)
-#define SYM_END(x)	CONCAT1(CONCAT1(_binary_, SYM(x)), _end)
-#define SYM_SIZE(x)	CONCAT1(CONCAT1(_binary_, SYM(x)), _size)
+#define CONCAT1(a, b, c, d) CONCAT2(a, b, c, d)
+#define CONCAT2(a, b, c, d) a ## b ## c ## d
+
+#define SYM_START(x)    CONCAT1(__USER_LABEL_PREFIX__, _binary_, x, _start)
+#define SYM_END(x)      CONCAT1(__USER_LABEL_PREFIX__, _binary_, x, _end)
+#define SYM_SIZE(x)     CONCAT1(__USER_LABEL_PREFIX__, _binary_, x, _size)
 
 .section .data
 SYM_START(SYMBOL_PREFIX):
-- 
2.14.1