From e1d34bac0b96253789b98aa787ea2147eb2ea229 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Thu, 10 Nov 2005 21:40:01 +0000
Subject: [PATCH] Allow per-character control over what target assemblers allow
 in symbol names.  This also changes the default to allow all of "$_." in
 addition to letters and numbers as symbol names.  If you don't want this, use
 markCharUnacceptable to remove one of these or markCharAcceptable to add to
 the set.  This corresponds with what GAS accepts by default.

Also, this includes some minor speedups

llvm-svn: 24293
---
 llvm/lib/VMCore/Mangler.cpp | 32 +++++++++++++++++++++++++-------
 1 file changed, 25 insertions(+), 7 deletions(-)

diff --git a/llvm/lib/VMCore/Mangler.cpp b/llvm/lib/VMCore/Mangler.cpp
index 418eb9a71a35..44fe1003140c 100644
--- a/llvm/lib/VMCore/Mangler.cpp
+++ b/llvm/lib/VMCore/Mangler.cpp
@@ -22,7 +22,8 @@ static char HexDigit(int V) {
 }
 
 static std::string MangleLetter(unsigned char C) {
-  return std::string("_")+HexDigit(C >> 4) + HexDigit(C & 15) + "_";
+  char Result[] = { '_', HexDigit(C >> 4), HexDigit(C & 15), '_', 0 };
+  return Result;
 }
 
 /// makeNameProper - We don't want identifier names non-C-identifier characters
@@ -30,6 +31,7 @@ static std::string MangleLetter(unsigned char C) {
 ///
 std::string Mangler::makeNameProper(const std::string &X, const char *Prefix) {
   std::string Result;
+  if (X.empty()) return X;  // Empty names are uniqued by the caller.
   
   if (!UseQuotes) {
     // If X does not start with (char)1, add the prefix.
@@ -39,16 +41,16 @@ std::string Mangler::makeNameProper(const std::string &X, const char *Prefix) {
     else
       ++I;  // Skip over the marker.
     
-    // Mangle the first letter specially, don't allow numbers...
+    // Mangle the first letter specially, don't allow numbers.
     if (*I >= '0' && *I <= '9')
       Result += MangleLetter(*I++);
 
-    for (std::string::const_iterator E = X.end(); I != E; ++I)
-      if ((*I < 'a' || *I > 'z') && (*I < 'A' || *I > 'Z') &&
-          (*I < '0' || *I > '9') && *I != '_' && *I != '$')
+    for (std::string::const_iterator E = X.end(); I != E; ++I) {
+      if (!isCharAcceptable(*I))
         Result += MangleLetter(*I);
       else
         Result += *I;
+    }
   } else {
     bool NeedsQuotes = false;
     
@@ -67,8 +69,7 @@ std::string Mangler::makeNameProper(const std::string &X, const char *Prefix) {
       if (*I == '"')
         Result += "_QQ_";
       else {
-        if ((*I < 'a' || *I > 'z') && (*I < 'A' || *I > 'Z') &&
-            (*I < '0' || *I > '9') && *I != '_' && *I != '$' && *I != '.')
+        if (!isCharAcceptable(*I))
           NeedsQuotes = true;
         Result += *I;
       }
@@ -147,6 +148,23 @@ void Mangler::InsertName(GlobalValue *GV,
 
 Mangler::Mangler(Module &M, const char *prefix)
   : Prefix(prefix), UseQuotes(false), Count(0), TypeCounter(0) {
+  std::fill(AcceptableChars, 
+          AcceptableChars+sizeof(AcceptableChars)/sizeof(AcceptableChars[0]),
+            0);
+
+  // Letters and numbers are acceptable.
+  for (unsigned char X = 'a'; X <= 'z'; ++X)
+    markCharAcceptable(X);
+  for (unsigned char X = 'A'; X <= 'Z'; ++X)
+    markCharAcceptable(X);
+  for (unsigned char X = '0'; X <= '9'; ++X)
+    markCharAcceptable(X);
+  
+  // These chars are acceptable.
+  markCharAcceptable('_');
+  markCharAcceptable('$');
+  markCharAcceptable('.');
+    
   // Calculate which global values have names that will collide when we throw
   // away type information.
   std::map<std::string, GlobalValue*> Names;