[Patch for libcxxabi] Don't use bzero() and prevent unneeded copying

[Ed Schouten]

Hi there,

While building libcxxabi on a new platform (more news on that later :-), I
noticed libcxxabi uses bzero() in a single place, causing the build to fail
in my environment. We could just use memset() instead.

At the same time, I received a compiler warning for strcpy(), as it is
advised to use str[nl]cpy() instead. In this specific case we could argue
we don't need to copy the string in the first place. The patch changes the
code to just assign a constant string to a pointer.

Best regards,
-- 
Ed Schouten <ed at 80386.nl>
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Index: src/Unwind/DwarfParser.hpp
===================================================================
--- src/Unwind/DwarfParser.hpp	(revision 228935)
+++ src/Unwind/DwarfParser.hpp	(working copy)
@@ -347,7 +347,7 @@
                                          const CIE_Info &cieInfo, pint_t upToPC,
                                          PrologInfo *results) {
   // clear results
-  bzero(results, sizeof(PrologInfo));
+  memset(results, '\0', sizeof(PrologInfo));
   PrologInfoStackEntry *rememberStack = NULL;
 
   // parse CIE then FDE instructions
Index: src/Unwind/Unwind-EHABI.cpp
===================================================================
--- src/Unwind/Unwind-EHABI.cpp	(revision 228935)
+++ src/Unwind/Unwind-EHABI.cpp	(working copy)
@@ -470,11 +470,12 @@
 
     // When tracing, print state information.
     if (_LIBUNWIND_TRACING_UNWINDING) {
-      char functionName[512];
+      char functionBuf[512];
+      const char *functionName = functionBuf;
       unw_word_t offset;
-      if ((unw_get_proc_name(&cursor1, functionName, 512, &offset) !=
+      if ((unw_get_proc_name(&cursor1, functionBuf, 512, &offset) !=
            UNW_ESUCCESS) || (frameInfo.start_ip + offset > frameInfo.end_ip))
-        strcpy(functionName, ".anonymous.");
+        functionName = ".anonymous.";
       unw_word_t pc;
       unw_get_reg(&cursor1, UNW_REG_IP, &pc);
       _LIBUNWIND_TRACE_UNWINDING(
@@ -600,11 +601,12 @@
 
     // When tracing, print state information.
     if (_LIBUNWIND_TRACING_UNWINDING) {
-      char functionName[512];
+      char functionBuf[512];
+      const char *functionName = functionBuf;
       unw_word_t offset;
-      if ((unw_get_proc_name(&cursor2, functionName, 512, &offset) !=
+      if ((unw_get_proc_name(&cursor2, functionBuf, 512, &offset) !=
            UNW_ESUCCESS) || (frameInfo.start_ip + offset > frameInfo.end_ip))
-        strcpy(functionName, ".anonymous.");
+        functionName = ".anonymous.";
       _LIBUNWIND_TRACE_UNWINDING(
           "unwind_phase2(ex_ojb=%p): start_ip=0x%llX, func=%s, sp=0x%llX, "
           "lsda=0x%llX, personality=0x%llX\n",
Index: src/Unwind/UnwindLevel1.c
===================================================================
--- src/Unwind/UnwindLevel1.c	(revision 228935)
+++ src/Unwind/UnwindLevel1.c	(working copy)
@@ -60,11 +60,12 @@
 
     // When tracing, print state information.
     if (_LIBUNWIND_TRACING_UNWINDING) {
-      char functionName[512];
+      char functionBuf[512];
+      const char *functionName = functionBuf;
       unw_word_t offset;
-      if ((unw_get_proc_name(&cursor1, functionName, 512, &offset) !=
+      if ((unw_get_proc_name(&cursor1, functionBuf, 512, &offset) !=
            UNW_ESUCCESS) || (frameInfo.start_ip + offset > frameInfo.end_ip))
-        strcpy(functionName, ".anonymous.");
+        functionName = ".anonymous.";
       unw_word_t pc;
       unw_get_reg(&cursor1, UNW_REG_IP, &pc);
       _LIBUNWIND_TRACE_UNWINDING(
@@ -156,11 +157,12 @@
 
     // When tracing, print state information.
     if (_LIBUNWIND_TRACING_UNWINDING) {
-      char functionName[512];
+      char functionBuf[512];
+      const char *functionName = functionBuf;
       unw_word_t offset;
-      if ((unw_get_proc_name(&cursor2, functionName, 512, &offset) !=
+      if ((unw_get_proc_name(&cursor2, functionBuf, 512, &offset) !=
            UNW_ESUCCESS) || (frameInfo.start_ip + offset > frameInfo.end_ip))
-        strcpy(functionName, ".anonymous.");
+        functionName = ".anonymous.";
       _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): start_ip=0x%" PRIx64
                                  ", func=%s, sp=0x%" PRIx64 ", lsda=0x%" PRIx64
                                  ", personality=0x%" PRIx64 "\n",
@@ -246,11 +248,12 @@
 
     // When tracing, print state information.
     if (_LIBUNWIND_TRACING_UNWINDING) {
-      char functionName[512];
+      char functionBuf[512];
+      const char *functionName = functionBuf;
       unw_word_t offset;
-      if ((unw_get_proc_name(&cursor2, functionName, 512, &offset) !=
+      if ((unw_get_proc_name(&cursor2, functionBuf, 512, &offset) !=
            UNW_ESUCCESS) || (frameInfo.start_ip + offset > frameInfo.end_ip))
-        strcpy(functionName, ".anonymous.");
+        functionName = ".anonymous.";
       _LIBUNWIND_TRACE_UNWINDING(
           "unwind_phase2_forced(ex_ojb=%p): start_ip=0x%" PRIx64
           ", func=%s, lsda=0x%" PRIx64 ", personality=0x%" PRIx64 "\n",