Merge pull request #248 from nipunn1313/master

Goto with incorrect label now suggests labels based on string distance

ctx.cpp

@@ -1155,6 +1155,19 @@ FunctionEmitContext::GetLabeledBasicBlock(const std::string &label) {
         return NULL;
 }
 
+std::vector<std::string>
+FunctionEmitContext::GetLabels() {
+    // Initialize vector to the right size
+    std::vector<std::string> labels(labelMap.size());
+
+    // Iterate through labelMap and grab only the keys
+    std::map<std::string, llvm::BasicBlock*>::iterator iter;
+    for (iter=labelMap.begin(); iter != labelMap.end(); iter++)
+        labels.push_back(iter->first);
+
+    return labels;
+}
+
 
 void
 FunctionEmitContext::CurrentLanesReturned(Expr *expr, bool doCoherenceCheck) {

ctx.h

@@ -248,6 +248,10 @@ public:
         new basic block that it starts. */
     llvm::BasicBlock *GetLabeledBasicBlock(const std::string &label);
 
+    /** Returns a vector of all labels in the context. This is
+        simply the key set of the labelMap */
+    std::vector<std::string> GetLabels();
+
     /** Called to generate code for 'return' statement; value is the
         expression in the return statement (if non-NULL), and
         doCoherenceCheck indicates whether instructions should be generated

lex.ll

@@ -704,7 +704,7 @@ lEscapeChar(char *str, char *pChar, SourcePos *pos)
             str = tail - 1;
             break;
         default:
-            Error(*pos, "Bad character escape sequence: '%s'\n.", str);
+            Error(*pos, "Bad character escape sequence: '%s'.", str);
             break;
         }
     }

stmt.cpp

@@ -2281,10 +2281,22 @@ GotoStmt::EmitCode(FunctionEmitContext *ctx) const {
 
     llvm::BasicBlock *bb = ctx->GetLabeledBasicBlock(label);
     if (bb == NULL) {
-        // TODO: use the string distance stuff to suggest alternatives if
-        // there are some with names close to the label name we have here..
-        Error(identifierPos, "No label named \"%s\" found in current function.",
-              label.c_str());
+        /* Label wasn't found. Look for suggestions that are close */
+        std::vector<std::string> labels = ctx->GetLabels();
+        std::vector<std::string> matches = MatchStrings(label, labels);
+        std::string match_output;
+        if (! matches.empty()) {
+            /* Print up to 5 matches. Don't want to spew too much */
+            match_output += "\nDid you mean:";
+            for (unsigned int i=0; i<matches.size() && i<5; i++)
+                match_output += "\n " + matches[i] + "?";
+        }
+
+        /* Label wasn't found. Emit an error */
+        Error(identifierPos, 
+                "No label named \"%s\" found in current function.%s",
+              label.c_str(), match_output.c_str());
+
         return;
     }
 

tests_errors/goto-5.ispc

@@ -0,0 +1,6 @@
+
+void func(int x) {
+completelydifferentlabel:
+    goto label;
+}
+

tests_errors/goto-6.ispc

@@ -0,0 +1,9 @@
+
+void func(int x) {
+libel:
+babel:
+lbel:
+label2:
+    goto label;
+}
+

util.cpp

@@ -237,6 +237,20 @@ lPrintWithWordBreaks(const char *buf, int indent, int columnWidth, FILE *out) {
             } while (*msgPos != '\0' && *msgPos != 'm');
             continue;
         }
+        else if (*msgPos == '\n') {
+            // Handle newlines cleanly
+            column = indent;
+            outStr.push_back('\n');
+            for (int i = 0; i < indent; ++i)
+                outStr.push_back(' ');
+            // Respect spaces after newlines
+            ++msgPos;
+            while (*msgPos == ' ') {
+                outStr.push_back(' ');
+                ++msgPos;
+            }
+            continue;
+        }
 
         while (*msgPos != '\0' && isspace(*msgPos))
             ++msgPos;
@@ -314,7 +328,7 @@ lPrint(const char *type, bool isError, SourcePos p, const char *fmt,
     int indent = 0;
     if (p.first_line == 0) {
         // We don't have a valid SourcePos, so create a message without it
-        if (asprintf(&formattedBuf, "%s%s%s%s%s: %s%s\n", lStartBold(),
+        if (asprintf(&formattedBuf, "%s%s%s%s%s: %s%s", lStartBold(),
                      isError ? lStartRed() : lStartBlue(), type,
                      lResetColor(), lStartBold(), errorBuf, 
                      lResetColor()) == -1) {
@@ -325,7 +339,7 @@ lPrint(const char *type, bool isError, SourcePos p, const char *fmt,
     }
     else {
         // Create an error message that includes the file and line number
-        if (asprintf(&formattedBuf, "%s%s:%d:%d: %s%s%s%s: %s%s\n", 
+        if (asprintf(&formattedBuf, "%s%s:%d:%d: %s%s%s%s: %s%s", 
                      lStartBold(), p.name, p.first_line, p.first_column, 
                      isError ? lStartRed() : lStartBlue(), type, 
                      lResetColor(), lStartBold(), errorBuf,