streams: maintain integer format string detector.

* configure: provide LONGLONG_TYPE and INTPTR_TYPE macros in
config.h that expand to a string literal capturing the
original tokens of the type that was probed.

* stream.c (struct fmt): Removed size member, replaced with
type string. We can match format strings to the textual type,
which will work even if we cannot compile that type. So that
is to say, for instance the "%I64d" entry in the table is
associated with "int64", whereas an expression like sizeof
(int64) won't compile where that type doesn't exist.
(fmt_tab): Replace sizes with type names. Also fix an issue:
%llx was replicated in three rows of the table.
(detect_format_string): Determine the textual type of cnum. It
is a typedef for intptr_t, and the new INPTR_TYPE macro gives
the tokens that were used to typedef intptr_t. If
INTPTR_TYPE happens to be "longlong_t", we use LONGLONG_TYPE
in its place. Then using the determined type, we can search
the table for an appropriate entry: one which matches the type
and whose conversion specifier works. Also, we now test all
four conversion specifiers rather than assuming that if the
decimal one is okay, the others work. Plus, if a working
format string is not found, we now abort.

1 files changed, 28 insertions, 14 deletions

diff --git a/stream.c b/stream.c
index 23dfc30e..3cacb4dd 100644
--- a/stream.c
+++ b/stream.c
@@ -3071,7 +3071,7 @@ val get_line_as_buf(val stream_in)
 }
 
 struct fmt {
-  size_t minsize;
+  const char *type;
   const char *dec;
   const char *oct;
   const char *hex;
@@ -3079,13 +3079,14 @@ struct fmt {
 };
 
 static struct fmt fmt_tab[] = {
-  { sizeof(short),"%hd",   "%ho",   "%hx",   "%hX"   },
-  { sizeof(int),  "%d",    "%o",    "%x",    "%X"    },
-  { sizeof(long), "%ld",   "%lo",   "%lx",   "%llX"  },
-  { sizeof(cnum), "%lld",  "%llo",  "%llx",  "%llX"  },
-  { sizeof(cnum), "%Ld",   "%Lo",   "%Lx",   "%llX"  },
-  { sizeof(cnum), "%qd",   "%qo",   "%qx",   "%qX",  },
-  { sizeof(cnum), "%I64d", "%I64o", "%I64x", "%I64X" },
+  { "short",      "%hd",   "%ho",   "%hx",   "%hX"   },
+  { "int",        "%d",    "%o",    "%x",    "%X"    },
+  { "long",       "%ld",   "%lo",   "%lx",   "%lX"   },
+  { "long long",  "%lld",  "%llo",  "%llx",  "%llX"  },
+  { "long long",  "%Ld",   "%Lo",   "%Lx",   "%LX"   },
+  { "long long",  "%qd",   "%qo",   "%qx",   "%qX",  },
+  { "int64",      "%I64d", "%I64o", "%I64x", "%I64X" },
+  { "__int64",    "%I64d", "%I64o", "%I64x", "%I64X" },
   { 0,            0,       0,       0,       0       }
 };
 
@@ -3096,16 +3097,29 @@ static void detect_format_string(void)
   struct fmt *f;
   char buf[64];
   cnum num = 1234;
+  const char *cnum_type = if3(strcmp(INTPTR_TYPE, "longlong_t") == 0,
+                              LONGLONG_TYPE, INTPTR_TYPE);
 
-  for (f = fmt_tab; f->minsize != 0; f++) {
+  for (f = fmt_tab; f->type != 0; f++) {
+    if (strcmp(cnum_type, f->type) != 0)
+      continue;
     memset(buf, 0, sizeof buf);
-    if (f->minsize != sizeof num)
+    if (sprintf(buf, f->dec, num) != 4 || strcmp(buf, "1234") != 0)
       continue;
-    if (sprintf(buf, f->dec, num) == 4 && strcmp(buf, "1234") == 0) {
-      num_fmt = f;
-      break;
-    }
+    memset(buf, 0, sizeof buf);
+    if (sprintf(buf, f->oct, num) != 4 || strcmp(buf, "2322") != 0)
+      continue;
+    memset(buf, 0, sizeof buf);
+    if (sprintf(buf, f->hex, num) != 3 || strcmp(buf, "4d2") != 0)
+      continue;
+    memset(buf, 0, sizeof buf);
+    if (sprintf(buf, f->HEX, num) != 3 || strcmp(buf, "4D2") != 0)
+      continue;
+    num_fmt = f;
+    break;
   }
+
+  bug_unless (num_fmt != 0);
 }
 
 enum align { al_left, al_center, al_right };