Fix uninformative hp2ps error when the cmdline contains double quotes

The format of hp file didn't allow double quotes inside strings, and
under prof build, we include args in JOB, which may have double quotes.
When this happens, the error message is confusing to the user. This can
also happen under normal build if the executable name contains double
quite, which is unlikely though.

We fix this issue by introducing escaping for double quotes inside a
string by repeating it twice.

We also fix a buffer overflow bug when the length of the string happen
to be multiple of 5000.

Test Plan:
new tests, which used to fail with error message:

```
hp2ps: "T15904".hp, line 2: integer must follow identifier
```

use new ghc and hp2ps to profile a simple program.

Reviewers: simonmar, bgamari, erikd

Reviewed By: simonmar

Subscribers: rwbarton, carter

GHC Trac Issues: #15904

Differential Revision: https://phabricator.haskell.org/D5346

1 files changed, 65 insertions, 68 deletions

diff --git a/utils/hp2ps/HpFile.c b/utils/hp2ps/HpFile.c
index e21acf3f91..bcdf7aa6b3 100644
--- a/utils/hp2ps/HpFile.c
+++ b/utils/hp2ps/HpFile.c
@@ -53,17 +53,17 @@ floatish *samplemap;		/* sample intervals	*/
 floatish *markmap;		/* sample marks		*/
 
 /*
- *	An extremely simple parser. The input is organised into lines of 
+ *	An extremely simple parser. The input is organised into lines of
  *	the form
  *
  *      JOB s              -- job identifier string
- *	DATE s		   -- date string 
- *	SAMPLE_UNIT s	   -- sample unit eg "seconds" 
- *	VALUE_UNIT s	   -- value unit eg "bytes" 
- *	MARK i	   	   -- sample mark 
- *	BEGIN_SAMPLE i 	   -- start of ith sample 
- *	identifier i	   -- there are i identifiers in this sample 
- *	END_SAMPLE i   	   -- end of ith sample 
+ *	DATE s		   -- date string
+ *	SAMPLE_UNIT s	   -- sample unit eg "seconds"
+ *	VALUE_UNIT s	   -- value unit eg "bytes"
+ *	MARK i	   	   -- sample mark
+ *	BEGIN_SAMPLE i 	   -- start of ith sample
+ *	identifier i	   -- there are i identifiers in this sample
+ *	END_SAMPLE i   	   -- end of ith sample
  *
  */
 
@@ -146,7 +146,7 @@ GetHpLine(FILE *infp)
     case SAMPLE_UNIT_TOK:
 	GetHpTok(infp, 0);
 	if (thetok != STRING_TOK) {
-	    Error("%s, line %d: string must follow SAMPLE_UNIT", hpfile, 
+	    Error("%s, line %d: string must follow SAMPLE_UNIT", hpfile,
 	          linenum);
         }
 	sampleunitstring = thestring;
@@ -157,7 +157,7 @@ GetHpLine(FILE *infp)
     case VALUE_UNIT_TOK:
         GetHpTok(infp, 0);
 	if (thetok != STRING_TOK) {
-	    Error("%s, line %d: string must follow VALUE_UNIT", hpfile, 
+	    Error("%s, line %d: string must follow VALUE_UNIT", hpfile,
 	          linenum);
         }
 	valueunitstring = thestring;
@@ -183,11 +183,11 @@ GetHpLine(FILE *infp)
 		markmap = (floatish*) xrealloc(markmap, nmarkmax * sizeof(floatish));
 	    }
 	}
-	markmap[ nmarks++ ] = thefloatish; 
+	markmap[ nmarks++ ] = thefloatish;
         GetHpTok(infp, 1);
         break;
 
-    case BEGIN_SAMPLE_TOK: 
+    case BEGIN_SAMPLE_TOK:
 	insample = 1;
 	GetHpTok(infp, 0);
 	if (thetok != FLOAT_TOK) {
@@ -204,7 +204,7 @@ GetHpLine(FILE *infp)
 		samplemap = (floatish*) xmalloc(nsamplemax * sizeof(floatish));
 	    } else {
 		nsamplemax *= 2;
-		samplemap = (floatish*) xrealloc(samplemap, 
+		samplemap = (floatish*) xrealloc(samplemap,
 	                                      nsamplemax * sizeof(floatish));
 	    }
 	}
@@ -212,11 +212,11 @@ GetHpLine(FILE *infp)
 	GetHpTok(infp, 1);
 	break;
 
-    case END_SAMPLE_TOK: 
+    case END_SAMPLE_TOK:
 	insample = 0;
 	GetHpTok(infp, 0);
 	if (thetok != FLOAT_TOK) {
-	    Error("%s, line %d: floating point number must follow END_SAMPLE", 
+	    Error("%s, line %d: floating point number must follow END_SAMPLE",
                   hpfile, linenum);
 	}
         nsamples++;
@@ -226,7 +226,7 @@ GetHpLine(FILE *infp)
     case IDENTIFIER_TOK:
 	GetHpTok(infp, 0);
 	if (thetok != INTEGER_TOK) {
-	    Error("%s, line %d: integer must follow identifier", hpfile, 
+	    Error("%s, line %d: integer must follow identifier", hpfile,
                   linenum);
 	}
         StoreSample(GetEntry(theident), nsamples, thefloatish);
@@ -274,7 +274,7 @@ TokenToString(token t)
  *	Read the next token from the input and assign its value
  *	to the global variable "thetok". In the case of numbers,
  *	the corresponding value is also assigned to "theinteger"
- *	or "thefloatish" as appropriate; in the case of identifiers 
+ *	or "thefloatish" as appropriate; in the case of identifiers
  *	it is assigned to "theident".
  *
  *	startline argument should be true for the first token on a line
@@ -287,7 +287,7 @@ GetHpTok(FILE *infp, int startline)
     while (isspace(ch)) {		/* skip whitespace */
 	if (ch == '\n') linenum++;
 	ch = getc(infp);
-    } 
+    }
 
     if (ch == EOF) {
 	thetok = EOF_TOK;
@@ -332,7 +332,7 @@ GetHpTok(FILE *infp, int startline)
 
 /*
  *	Read a sequence of digits and convert the result to an integer
- *	or floating point value (assigned to the "theinteger" or 
+ *	or floating point value (assigned to the "theinteger" or
  *	"thefloatish").
  */
 
@@ -343,21 +343,21 @@ GetNumber(FILE *infp)
 {
     int i;
     int containsdot;
- 
+
     ASSERT(isdigit(ch)); /* we must have a digit to start with */
 
     containsdot = 0;
 
     for (i = 0; i < NUMBER_LENGTH && (isdigit(ch) || ch == '.'); i++) {
         numberstring[ i ] = ch;
-        containsdot |= (ch == '.'); 
+        containsdot |= (ch == '.');
         ch = getc(infp);
-    }   
- 
+    }
+
     ASSERT(i <= NUMBER_LENGTH); /* did not overflow */
 
     numberstring[ i ] = '\0';
- 
+
     if (containsdot) {
         thefloatish = (floatish) atof(numberstring);
 	return FLOAT_TOK;
@@ -373,7 +373,7 @@ GetNumber(FILE *infp)
 }
 
 /*
- *	Read a sequence of identifier characters and assign the result 
+ *	Read a sequence of identifier characters and assign the result
  *	to the string "theident".
  */
 
@@ -387,7 +387,7 @@ GetIdent(FILE *infp)
 	idbuffer[ i ] = ch;
 	ch = getc(infp);
     }
-    
+
     idbuffer[ i ] = '\0';
 
     if (theident)
@@ -398,45 +398,42 @@ GetIdent(FILE *infp)
 
 
 /*
- *	Read a sequence of characters that make up a string and 
- *	assign the result to "thestring".
+ * Read a sequence of characters that make up a string and assign the result to
+ * "thestring". A string is surrounded by double quotes, with a double quote
+ * itself escaped as two contiguous double quotes.
  */
 
 void
 GetString(FILE *infp)
 {
-    unsigned int i;
-    char *stringbuffer;
-    size_t stringbuffersize;
+    size_t stringbuffersize = 5000;
+    char *stringbuffer = xmalloc(stringbuffersize);
 
     ASSERT(ch == '\"');
 
-    stringbuffersize = 5000;
-    stringbuffer = xmalloc(stringbuffersize);
-
-    ch = getc(infp);	/* skip the '\"' that begins the string */
+    ch = getc(infp);  /* skip the '\"' that begins the string */
 
-    i = 0;
-    while (ch != '\"') {
+    for (size_t i = 0; ; ++i) {
         if (ch == EOF) {
-	        Error("%s, line %d: EOF when expecting \"", hpfile, linenum, ch);
+            Error("%s, line %d: EOF when expecting \"", hpfile, linenum, ch);
         }
-        else if (i == stringbuffersize - 1) {
-            stringbuffersize = 2 * stringbuffersize;
+        if (i == stringbuffersize) {
+            stringbuffersize *= 2;
             stringbuffer = xrealloc(stringbuffer, stringbuffersize);
         }
-        stringbuffer[ i++ ] = ch;
+        if (ch == '\"') {
+            ch = getc(infp);
+            if (ch != '\"') {
+                stringbuffer[i] = '\0';
+                break;
+            }
+        }
+        stringbuffer[i] = ch;
         ch = getc(infp);
     }
 
-    stringbuffer[i] = '\0'; 
     thestring = copystring(stringbuffer);
-
     free(stringbuffer);
-
-    ASSERT(ch == '\"');
-
-    ch = getc(infp);      /* skip the '\"' that terminates the string */
 }
 
 boolish
@@ -452,7 +449,7 @@ IsIdChar(int ch)
  *	of chunks to be retrieved given an identifier name.
  */
 
-#define N_HASH       	513 
+#define N_HASH       	513
 
 static struct entry* hashtable[ N_HASH ];
 
@@ -460,7 +457,7 @@ static intish
 Hash(char *s)
 {
     int r;
- 
+
     for (r = 0; *s; s++) {
         r = r + r + r + *s;
     }
@@ -471,10 +468,10 @@ Hash(char *s)
 }
 
 /*
- *      Get space for a new chunk. Initialise it, and return a pointer 
+ *      Get space for a new chunk. Initialise it, and return a pointer
  *	to the new chunk.
  */
- 
+
 static struct chunk*
 MakeChunk(void)
 {
@@ -482,10 +479,10 @@ MakeChunk(void)
     struct datapoint* d;
 
     ch = (struct chunk*) xmalloc( sizeof(struct chunk) );
- 
+
     d = (struct datapoint*) xmalloc (sizeof(struct datapoint) * N_CHUNK);
 
-    ch->nd = 0; 
+    ch->nd = 0;
     ch->d = d;
     ch->next = 0;
     return ch;
@@ -493,10 +490,10 @@ MakeChunk(void)
 
 
 /*
- *      Get space for a new entry. Initialise it, and return a pointer 
+ *      Get space for a new entry. Initialise it, and return a pointer
  *	to the new entry.
  */
- 
+
 struct entry *
 MakeEntry(char *name)
 {
@@ -504,12 +501,12 @@ MakeEntry(char *name)
 
     e = (struct entry *) xmalloc(sizeof(struct entry));
     e->chk = MakeChunk();
-    e->name = copystring(name); 
+    e->name = copystring(name);
     return e;
 }
 
 /*
- *	Get the entry associated with "name", creating a new entry if 
+ *	Get the entry associated with "name", creating a new entry if
  *	necessary.
  */
 
@@ -518,17 +515,17 @@ GetEntry(char *name)
 {
     intish h;
     struct entry* e;
- 
+
     h = Hash(name);
- 
+
     for (e = hashtable[ h ]; e; e = e->next) {
         if (strcmp(e->name, name) == 0) {
             break;
         }
     }
- 
+
     if (e) {
-	return (e); 
+	return (e);
     } else {
         nidents++;
         e = MakeEntry(name);
@@ -540,16 +537,16 @@ GetEntry(char *name)
 
 
 /*
- *      Store information from a sample. 
+ *      Store information from a sample.
  */
- 
+
 void
 StoreSample(struct entry *en, intish bucket, floatish value)
 {
-    struct chunk* chk; 
+    struct chunk* chk;
 
     for (chk = en->chk; chk->next != 0; chk = chk->next)
-	; 
+	;
 
     if (chk->nd < N_CHUNK) {
 	chk->d[ chk->nd ].bucket = bucket;
@@ -557,7 +554,7 @@ StoreSample(struct entry *en, intish bucket, floatish value)
 	chk->nd += 1;
     } else {
 	struct chunk* t;
-	t = chk->next = MakeChunk(); 
+	t = chk->next = MakeChunk();
 	t->d[ 0 ].bucket = bucket;
 	t->d[ 0 ].value  = value;
 	t->nd += 1;
@@ -569,7 +566,7 @@ struct entry** identtable;
 
 /*
  *	The hash table is useful while reading the input, but it
- *	becomes a liability thereafter. The code below converts 
+ *	becomes a liability thereafter. The code below converts
  *	it to a more easily processed table.
  */
 
@@ -592,7 +589,7 @@ MakeIdentTable(void)
 
     for (i = 0; i < N_HASH; i++) {
         for (e = hashtable[ i ]; e; e = e->next, j++) {
-	    identtable[ j ] = e; 
+	    identtable[ j ] = e;
         }
     }
 }