From d993c5a108563b6fd307506fae9863e4caf69ad0 Mon Sep 17 00:00:00 2001
From: Chun-Chieh Li <ccli8@nuvoton.com>
Date: Wed, 2 Oct 2019 16:43:23 +0800
Subject: [PATCH] NUVOTON: Re-implement __PC() with toolchain built-in

Re-implement __PC() by replacing BSP assembly with toolchain built-in.
---
 .../TARGET_M2351/device/M2351_funcs.S         | 37 -------------------
 .../TARGET_M2351/device/system_M2351.c        | 16 ++++++++
 .../TARGET_M261/device/system_M261.c          | 16 ++++++++
 3 files changed, 32 insertions(+), 37 deletions(-)
 delete mode 100644 targets/TARGET_NUVOTON/TARGET_M2351/device/M2351_funcs.S

diff --git a/targets/TARGET_NUVOTON/TARGET_M2351/device/M2351_funcs.S b/targets/TARGET_NUVOTON/TARGET_M2351/device/M2351_funcs.S
deleted file mode 100644
index 16b8b2f74a..0000000000
--- a/targets/TARGET_NUVOTON/TARGET_M2351/device/M2351_funcs.S
+++ /dev/null
@@ -1,37 +0,0 @@
-#if defined(__CC_ARM)  || (defined (__ARMCC_VERSION) && (__ARMCC_VERSION >= 6010050))
-        AREA    |.text|, CODE, READONLY
-__PC        PROC
-            EXPORT      __PC        
-#elif defined(__GNUC__)
-    .text
-    .thumb
-    .thumb_func    
-    .globl    __PC
-    .type    __PC, %function
-__PC:
-#else   ;; for IAR, __ICCARM__ seems not defined in IAR asm
-    MODULE  nvtfunc
-        
-    SECTION .text:CODE:REORDER:NOROOT(1)        
-    THUMB     
-
-    PUBLIC  __PC
-__PC        
-#endif
-                
-    MOV     r0, lr
-    BLX     lr
-
-
-#if defined(__CC_ARM)  || (defined (__ARMCC_VERSION) && (__ARMCC_VERSION >= 6010050))
-    ALIGN
-    ENDP
-    END
-#elif defined(__GNUC__)                
-    .align 
-    .pool
-    .size __PC, . - __PC
-    .end
-#else       ;; for IAR, __ICCARM__ seems not defined in IAR asm 
-     END   
-#endif
\ No newline at end of file
diff --git a/targets/TARGET_NUVOTON/TARGET_M2351/device/system_M2351.c b/targets/TARGET_NUVOTON/TARGET_M2351/device/system_M2351.c
index e7cc9daed5..fa19e4857b 100644
--- a/targets/TARGET_NUVOTON/TARGET_M2351/device/system_M2351.c
+++ b/targets/TARGET_NUVOTON/TARGET_M2351/device/system_M2351.c
@@ -115,3 +115,19 @@ void AssertError(uint8_t * file, uint32_t line)
 }
 #endif
 
+/* Return LR (return address)
+ *
+ * Replace BSP assembly implementation with toolchain built-in (borrow MBED_CALLER_ADDR())
+ */
+uint32_t __PC(void)
+{
+#if (defined(__GNUC__) || defined(__clang__)) && !defined(__CC_ARM)
+    return (uint32_t) __builtin_extract_return_addr(__builtin_return_address(0));
+#elif defined(__CC_ARM)
+    return (uint32_t) __builtin_return_address(0);
+#elif defined(__ICCARM__)
+    return (uint32_t) __get_LR();
+#else
+    #error("__PC() not implemented")
+#endif
+}
diff --git a/targets/TARGET_NUVOTON/TARGET_M261/device/system_M261.c b/targets/TARGET_NUVOTON/TARGET_M261/device/system_M261.c
index 848cb2e18e..c68229592a 100644
--- a/targets/TARGET_NUVOTON/TARGET_M261/device/system_M261.c
+++ b/targets/TARGET_NUVOTON/TARGET_M261/device/system_M261.c
@@ -116,3 +116,19 @@ void AssertError(uint8_t * file, uint32_t line)
 }
 #endif
 
+/* Return LR (return address)
+ *
+ * Replace BSP assembly implementation with toolchain built-in (borrow MBED_CALLER_ADDR())
+ */
+uint32_t __PC(void)
+{
+#if (defined(__GNUC__) || defined(__clang__)) && !defined(__CC_ARM)
+    return (uint32_t) __builtin_extract_return_addr(__builtin_return_address(0));
+#elif defined(__CC_ARM)
+    return (uint32_t) __builtin_return_address(0);
+#elif defined(__ICCARM__)
+    return (uint32_t) __get_LR();
+#else
+    #error("__PC() not implemented")
+#endif
+}