ada: remove setjmp() longjmp()

setjmp() and longjmp() may cause memory leaks and are better to avoid.
The ada parser actually doesn't seem to use them normally, there are proper
checks for EOF in the code, and longjmp() is used only when something
goes wrong after 1000 hits of EOF.

I went through all the loops and all of them seem to check for EOF so
there should be no need for setjmp()/longjmp().

Author: techee

parsers/ada.c

@@ -95,7 +95,6 @@
 
 #include <string.h>     /* to declare strxxx() functions */
 #include <ctype.h>      /* to define isxxx() macros */
-#include <setjmp.h>
 
 #include "parse.h"      /* always include */
 #include "read.h"       /* to define file readLineFromInputFile() */
@@ -104,13 +103,8 @@
 #include "debug.h"      /* for Assert */
 #include "xtag.h"
 
-typedef enum eAdaException
-{
-	EXCEPTION_NONE,
-	EXCEPTION_EOF
-} adaException;
 
-static adaException exception;
+static bool eof_reached;
 
 typedef enum eAdaParseMode
 {
@@ -301,13 +295,6 @@ static const char *AdaKeywords[] =
 	"with"
 };
 
-/* a jump buffer for fail-safe error prevention */
-static jmp_buf eofError;
-
-/* a simple var to keep track of how many times we hit EOF... If we hit it
- * say, about 1000 times, we will print an error, jump to the end of the
- * program, and store what tags we have */
-static int eofCount;
 
 /* variables for managing the input string, position as well as input line
  * number and position */
@@ -624,17 +611,8 @@ static void readNewLine (void)
 		if (line == NULL)
 		{
 			lineLen = 0;
-			exception = EXCEPTION_EOF;
-			eofCount++;
-
-			if (eofCount >= 1000)
-			{
-				longjmp (eofError, exception);
-			}
-			else
-			{
-				return;
-			}
+			eof_reached = true;
+			return;
 		}
 
 		lineLen = strlen (line);
@@ -649,7 +627,7 @@ static void readNewLine (void)
 static void movePos (int amount)
 {
 	pos += amount;
-	if (exception != EXCEPTION_EOF && pos >= lineLen)
+	if (!eof_reached && pos >= lineLen)
 	{
 		readNewLine ();
 	}
@@ -709,10 +687,10 @@ static bool adaCmp (const char *match)
 {
 	bool status = false;
 
-	/* first check to see if line is empty, if it is, throw an exception */
+	/* first check to see if line is empty */
 	if (line == NULL)
 	{
-		exception = EXCEPTION_EOF;
+		eof_reached = true;
 		return status;
 	}
 
@@ -735,10 +713,10 @@ static bool adaKeywordCmp (adaKeyword keyword)
 {
 	bool status = false;
 
-	/* first check to see if line is empty, if it is, throw an exception */
+	/* first check to see if line is empty, if it is */
 	if (line == NULL)
 	{
-		exception = EXCEPTION_EOF;
+		eof_reached = true;
 		return status;
 	}
 
@@ -762,7 +740,7 @@ static void skipUntilWhiteSpace (void)
 	 * check to be true immediately */
 	skipComments ();
 
-	while (exception != EXCEPTION_EOF && !isspace (line[pos]))
+	while (!eof_reached && !isspace (line[pos]))
 	{
 		/* don't use movePos () because if we read in a new line with this function
 		 * we need to stop */
@@ -778,7 +756,7 @@ static void skipUntilWhiteSpace (void)
 			if (line == NULL)
 			{
 				lineLen = 0;
-				exception = EXCEPTION_EOF;
+				eof_reached = true;
 				return;
 			}
 
@@ -798,7 +776,7 @@ static void skipWhiteSpace (void)
 	 * check to fail immediately */
 	skipComments ();
 
-	while (exception != EXCEPTION_EOF && isspace (line[pos]))
+	while (!eof_reached && isspace (line[pos]))
 	{
 		movePos (1);
 
@@ -809,7 +787,7 @@ static void skipWhiteSpace (void)
 
 static void skipComments (void)
 {
-	while (exception != EXCEPTION_EOF && isAdaComment (line, pos, lineLen))
+	while (!eof_reached && isAdaComment (line, pos, lineLen))
 	{
 		readNewLine ();
 	}
@@ -819,18 +797,18 @@ static void skipComments (void)
  * Return false if no string literal (nor char literal) is found. */
 static bool skipStringLiteral (void)
 {
-	if (exception != EXCEPTION_EOF && isAdaStringLiteral (line, pos, lineLen))
+	if (!eof_reached && isAdaStringLiteral (line, pos, lineLen))
 	{
 		do {
 			movePos (1);
-		} while (exception != EXCEPTION_EOF && !isAdaStringLiteral (line, pos, lineLen));
+		} while (!eof_reached && !isAdaStringLiteral (line, pos, lineLen));
 
 		/* Go to the next char of " */
 		movePos (1);
 
 		return true;
 	}
-	else if (exception != EXCEPTION_EOF && isAdaCharLiteral (line, pos, lineLen))
+	else if (!eof_reached && isAdaCharLiteral (line, pos, lineLen))
 	{
 		movePos (3);
 		return true;
@@ -855,7 +833,7 @@ static void skipPast (const char *past)
 	skipCommentsAndStringLiteral ();
 
 	/* now look for the keyword */
-	while (exception != EXCEPTION_EOF && !adaCmp (past))
+	while (!eof_reached && !adaCmp (past))
 	{
 		movePos (1);
 
@@ -871,7 +849,7 @@ static void skipPastKeyword (adaKeyword keyword)
 	skipComments ();
 
 	/* now look for the keyword */
-	while (exception != EXCEPTION_EOF && !adaKeywordCmp (keyword))
+	while (!eof_reached && !adaKeywordCmp (keyword))
 	{
 		movePos (1);
 
@@ -888,7 +866,7 @@ static void skipPastWord (void)
 
 	/* now increment until we hit a non-word character... Specifically,
 	 * whitespace, '(', ')', ':', and ';' */
-	while (exception != EXCEPTION_EOF && !isspace (line[pos]) &&
+	while (!eof_reached && !isspace (line[pos]) &&
 		   line[pos] != '(' && line[pos] != ')' && line[pos] != ':' &&
 		   line[pos] != ';')
 	{
@@ -906,7 +884,7 @@ static void skipPastWord (void)
 			if (line == NULL)
 			{
 				lineLen = 0;
-				exception = EXCEPTION_EOF;
+				eof_reached = true;
 				return;
 			}
 
@@ -927,7 +905,7 @@ static void skipPastLambda (skipCompFn cmpfn, void *data)
 	skipCommentsAndStringLiteral ();
 
 	/* now call the predicate */
-	while (exception != EXCEPTION_EOF && !cmpfn (data))
+	while (!eof_reached && !cmpfn (data))
 	{
 		movePos (1);
 
@@ -1019,9 +997,9 @@ static adaTokenInfo *adaParseBlock (adaTokenInfo *parent, adaKind kind)
 	skipWhiteSpace ();
 
 	/* task and protected types are allowed to have discriminants */
-	if (exception != EXCEPTION_EOF && line[pos] == '(')
+	if (!eof_reached && line[pos] == '(')
 	{
-		while (exception != EXCEPTION_EOF && line[pos] != ')')
+		while (!eof_reached && line[pos] != ')')
 		{
 			movePos (1);
 			adaParseVariables (token, ADA_KIND_AUTOMATIC_VARIABLE);
@@ -1088,7 +1066,7 @@ static adaTokenInfo *adaParseBlock (adaTokenInfo *parent, adaKind kind)
 			skipUntilWhiteSpace ();
 		}
 
-		if (exception == EXCEPTION_EOF)
+		if (eof_reached)
 		{
 			freeAdaToken (&parent->children, token);
 			token = NULL;
@@ -1123,9 +1101,9 @@ static adaTokenInfo *adaParseSubprogram (adaTokenInfo *parent, adaKind kind)
 	skipWhiteSpace ();
 
 	/* if we find a '(' grab any parameters */
-	if (exception != EXCEPTION_EOF && line[pos] == '(' && token != NULL)
+	if (!eof_reached && line[pos] == '(' && token != NULL)
 	{
-		while (exception != EXCEPTION_EOF && line[pos] != ')')
+		while (!eof_reached && line[pos] != ')')
 		{
 			movePos (1);
 			tmpToken = adaParseVariables (token, ADA_KIND_AUTOMATIC_VARIABLE);
@@ -1141,9 +1119,9 @@ static adaTokenInfo *adaParseSubprogram (adaTokenInfo *parent, adaKind kind)
 			 * pair */
 			skipWhiteSpace ();
 
-			if (exception != EXCEPTION_EOF && line[pos] == '(')
+			if (!eof_reached && line[pos] == '(')
 			{
-				while (exception != EXCEPTION_EOF && line[pos] != ')')
+				while (!eof_reached && line[pos] != ')')
 				{
 					movePos (1);
 					adaParseVariables (token, ADA_KIND_AUTOMATIC_VARIABLE);
@@ -1156,7 +1134,7 @@ static adaTokenInfo *adaParseSubprogram (adaTokenInfo *parent, adaKind kind)
 	/* loop infinitely until we hit a "is", "do" or ";", this will skip over
 	 * the returns keyword, returned-type for functions as well as any one of a
 	 * myriad of keyword qualifiers */
-	while (exception != EXCEPTION_EOF && token != NULL)
+	while (!eof_reached && token != NULL)
 	{
 		skipWhiteSpace ();
 
@@ -1235,11 +1213,11 @@ static adaTokenInfo *adaParseType (adaTokenInfo *parent, adaKind kind)
 	movePos (i);
 	skipWhiteSpace ();
 
-	if (exception != EXCEPTION_EOF && line[pos] == '(')
+	if (!eof_reached && line[pos] == '(')
 	{
 		/* in this case there is a discriminant to this type, gather the
 		 * variables */
-		while (exception != EXCEPTION_EOF && line[pos] != ')')
+		while (!eof_reached && line[pos] != ')')
 		{
 			movePos (1);
 			adaParseVariables (token, ADA_KIND_AUTOMATIC_VARIABLE);
@@ -1254,7 +1232,7 @@ static adaTokenInfo *adaParseType (adaTokenInfo *parent, adaKind kind)
 	{
 		skipWhiteSpace ();
 		/* check to see if this may be a record or an enumeration */
-		if (exception != EXCEPTION_EOF && line[pos] == '(')
+		if (!eof_reached && line[pos] == '(')
 		{
 			movePos (1);
 			adaParseVariables (token, ADA_KIND_ENUM_LITERAL);
@@ -1292,7 +1270,7 @@ static adaTokenInfo *adaParseType (adaTokenInfo *parent, adaKind kind)
 			{
 				/* A and B */
 				/* until we hit "end record" we need to gather type variables */
-				while (exception != EXCEPTION_EOF)
+				while (!eof_reached)
 				{
 					skipWhiteSpace ();
 
@@ -1373,7 +1351,7 @@ static adaTokenInfo *adaParseVariables (adaTokenInfo *parent, adaKind kind)
 	 * bufLen match */
 	buf[bufLen] = '\0';
 
-	while (exception != EXCEPTION_EOF)
+	while (!eof_reached)
 	{
 		/* make sure that we don't count anything in a comment as being valid to
 		 * parse */
@@ -1454,7 +1432,7 @@ static adaTokenInfo *adaParseVariables (adaTokenInfo *parent, adaKind kind)
 
 		/* if we just incremented beyond the length of the current buffer, we need
 		 * to read in a new line */
-		if (exception != EXCEPTION_EOF && bufPos >= bufLen)
+		if (!eof_reached && bufPos >= bufLen)
 		{
 			readNewLine ();
 
@@ -1592,14 +1570,14 @@ static adaTokenInfo *adaParse (adaParseMode mode, adaTokenInfo *parent)
 	initAdaTokenList (&genericParamsRoot.children);
 
 	/* if we hit the end of the file, line will be NULL and our skip and match
-	 * functions will hit this jump buffer with EXCEPTION_EOF */
-	while (exception == EXCEPTION_NONE)
+	 * functions will hit this jump buffer with eof_reached */
+	while (!eof_reached)
 	{
 		/* find the next place to start */
 		skipWhiteSpace ();
 
 		/* check some universal things to check for first */
-		if (exception == EXCEPTION_EOF)
+		if (eof_reached)
 		{
 			break;
 		}
@@ -1655,7 +1633,7 @@ static adaTokenInfo *adaParse (adaParseMode mode, adaTokenInfo *parent)
 				skipWhiteSpace ();
 
 				/* skip over the "(" until we hit the tag */
-				if (exception != EXCEPTION_EOF && line[pos] == '(')
+				if (!eof_reached && line[pos] == '(')
 				{
 					movePos (1);
 					skipWhiteSpace ();
@@ -1782,9 +1760,9 @@ static adaTokenInfo *adaParse (adaParseMode mode, adaTokenInfo *parent)
 				movePos (i);
 
 				/* now gather the parameters to this subprogram */
-				if (exception != EXCEPTION_EOF && line[pos] == '(')
+				if (!eof_reached && line[pos] == '(')
 				{
-					while (exception != EXCEPTION_EOF && line[pos] != ')')
+					while (!eof_reached && line[pos] != ')')
 					{
 						movePos (1);
 						adaParseVariables (genericParamsRoot.children.tail,
@@ -2366,11 +2344,10 @@ static void findAdaTags (void)
 	adaTokenInfo *tmp;
 
 	/* init all global data now */
-	exception = EXCEPTION_NONE;
+	eof_reached = false;
 	line = NULL;
 	pos = 0;
 	matchLineNum = 0;
-	eofCount = 0;
 
 	/* cannot just set matchFilePos to 0 because the fpos_t is not a simple
 	 * integer on all systems. */
@@ -2386,12 +2363,11 @@ static void findAdaTags (void)
 
 	/* read in the first line */
 	readNewLine ();
-	if (exception == EXCEPTION_EOF)
+	if (eof_reached)
 		goto out;
 
 	/* tokenize entire file */
-	exception = setjmp (eofError);
-	while (exception != EXCEPTION_EOF && adaParse (ADA_ROOT, &root) != NULL);
+	while (!eof_reached && adaParse (ADA_ROOT, &root) != NULL);
 
 	/* store tags */
 	tmp = root.children.head;