1 /* Test to verify that the return value of calls to __builtin_sprintf
2    is not folded if the call isn't fully specified, even if it would
3    otherwise produce a known number of bytes on output, and that if
4    the return value is in a known range the range is not made
5    available to subsequent passes and doesn't affect branching and
6    the removal of code.
7    The test is compiled with warnings disabled to make sure the absence
8    of optimizations does not depend on the presence of warnings.  */
9 /* { dg-do compile } */
10 /* { dg-options "-O2 -fprintf-return-value -fdump-tree-optimized -w" } */
11 
12 #ifndef LINE
13 # define LINE 0
14 #endif
15 
16 #define INT_MAX    __INT_MAX__
17 #define INT_MIN    (-INT_MAX - 1)
18 
19 #define LONG_MAX   __LONG_MAX__
20 #define LONG_MIN   (-LONG_MAX - 1)
21 
22 char *buf;
23 char buf8k [8192];
24 
25 #define concat(a, b)   a ## b
26 #define CAT(a, b)      concat (a, b)
27 
28 /* Calls to this function must not be eliminated.  */
29 void must_not_eliminate (void);
30 
31 #define EQL(expect, size, fmt, ...)					\
32   void __attribute__ ((noinline, noclone))				\
33   CAT (test_on_line_, __LINE__)(void)					\
34   {									\
35     if (!LINE || LINE == __LINE__)					\
36       {									\
37 	char *dst = size < 0 ? buf : buf8k + sizeof buf8k - size;	\
38 	int result = __builtin_sprintf (dst, fmt, __VA_ARGS__);		\
39 	if (result != expect)						\
40 	  must_not_eliminate ();					\
41       }									\
42   }
43 
44 /* Verify that the return value or range or return values from the call
45    to the formatted function is not treated as a constant or made available
46    to subsequent optimization passes.  */
47 #define RNG(min, max, size, fmt, ...)					\
48   void __attribute__ ((noinline, noclone))				\
49   CAT (test_on_line_, __LINE__)(void)					\
50   {									\
51     if (!LINE || LINE == __LINE__)					\
52       {									\
53 	char *dst = size < 0 ? buf : buf8k + sizeof buf8k - size;	\
54 	int result = __builtin_sprintf (dst, fmt, __VA_ARGS__);		\
55 	if (result < min || max < result)				\
56 	  must_not_eliminate ();					\
57       }									\
58   }
59 
60 typedef __SIZE_TYPE__ size_t;
61 
62 volatile int i;
63 volatile unsigned u;
64 volatile long li;
65 volatile unsigned long lu;
66 volatile size_t sz;
67 volatile char *str;
68 
69 volatile double d;
70 volatile long double ld;
71 
72 /* Verify that overflowing the destination object disables the return
73    value optimization.  */
74 EQL (0, 0, "%c",  ' ');
75 EQL (0, 0, "%c",  i)
76 EQL (0, 0, "%-s", "");
77 
78 EQL (1, 1, "%c",  'x');
79 EQL (1, 1, "%-s", "x");
80 
81 EQL (1, 2, "%c",  'x');
82 
83 EQL (4, 4, "%4c", 'x');
84 
85 /* Verify that exceeding the environmental limit of 4095 bytes for
86    a single conversion specification disables the return value
87    folding.  */
88 EQL (   4096, sizeof buf8k, "%4096c", 'x');
89 
90 EQL (INT_MAX, -1, "%*c", INT_MAX, 'x');
91 
92 EQL (   4096, sizeof buf8k, "%4096.4094f", 1.0);
93 EQL (   4096, sizeof buf8k, "%.4094f",     1.0);
94 EQL (   4097, sizeof buf8k, "%.4095f",     1.0);
95 
96 enum { imax2 = (INT_MAX / 2) * 2 };
97 EQL (imax2, -1, "%*c%*c", INT_MAX / 2, 'x', INT_MAX / 2, 'y');
98 
99 /* Verify that range information for calls that overflow the destination
100    isn't available.
101 
102      +-- lower bound of the tested range
103      |   +-- upper bound of the tested range
104      |   |   +-- size of destination buffer
105      |   |   |  +-- format string
106      |   |   |  |       +-- argument(s)
107      |   |   |  |       |
108      V   V   V  V       V  */
109 RNG (0,  0,  0, "%hhi", i)
110 RNG (0,  0,  1, "%hhi", i)
111 RNG (0,  1,  1, "%hhi", i)
112 RNG (0,  0,  2, "%hhi", i)
113 RNG (0,  1,  2, "%hhi", i)
114 RNG (0,  2,  2, "%hhi", i)
115 RNG (0,  0,  3, "%hhi", i)
116 RNG (0,  1,  3, "%hhi", i)
117 RNG (0,  2,  3, "%hhi", i)
118 RNG (0,  3,  3, "%hhi", i)
119 RNG (0,  0,  4, "%hhi", i)
120 RNG (0,  1,  4, "%hhi", i)
121 RNG (0,  2,  4, "%hhi", i)
122 RNG (0,  3,  4, "%hhi", i)
123 RNG (0,  4,  4, "%hhi", i)
124 
125 RNG (0,  0,  0, "%hhu", i)
126 RNG (0,  0,  1, "%hhu", i)
127 RNG (0,  1,  1, "%hhu", i)
128 RNG (0,  0,  2, "%hhu", i)
129 RNG (0,  1,  2, "%hhu", i)
130 RNG (0,  2,  2, "%hhu", i)
131 RNG (0,  0,  3, "%hhu", i)
132 RNG (0,  1,  3, "%hhu", i)
133 RNG (0,  2,  3, "%hhu", i)
134 RNG (0,  3,  3, "%hhu", i)
135 
136 RNG (0,  0,  0, "%i", i)
137 
138 RNG (0,  0,  1, "%i", i)
139 RNG (0,  1,  1, "%i", i)
140 
141 RNG (0,  0,  2, "%i", i)
142 RNG (0,  1,  2, "%i", i)
143 RNG (0,  2,  2, "%i", i)
144 
145 RNG (0,  0,  3, "%i", i)
146 RNG (0,  1,  3, "%i", i)
147 RNG (0,  2,  3, "%i", i)
148 RNG (0,  3,  3, "%i", i)
149 
150 RNG (0,  0,  4, "%i", i)
151 RNG (0,  1,  4, "%i", i)
152 RNG (0,  2,  4, "%i", i)
153 RNG (0,  3,  4, "%i", i)
154 RNG (0,  4,  4, "%i", i)
155 
156 RNG (0,  0,  5, "%i", i)
157 RNG (0,  1,  5, "%i", i)
158 RNG (0,  2,  5, "%i", i)
159 RNG (0,  3,  5, "%i", i)
160 RNG (0,  4,  5, "%i", i)
161 RNG (0,  5,  5, "%i", i)
162 
163 RNG (0,  0,  6, "%i", i)
164 RNG (0,  1,  6, "%i", i)
165 RNG (0,  2,  6, "%i", i)
166 RNG (0,  3,  6, "%i", i)
167 RNG (0,  4,  6, "%i", i)
168 RNG (0,  5,  6, "%i", i)
169 RNG (0,  6,  6, "%i", i)
170 
171 RNG (0,  0,  7, "%i", i)
172 RNG (0,  1,  7, "%i", i)
173 RNG (0,  2,  7, "%i", i)
174 RNG (0,  3,  7, "%i", i)
175 RNG (0,  4,  7, "%i", i)
176 RNG (0,  5,  7, "%i", i)
177 RNG (0,  6,  7, "%i", i)
178 
179 RNG (4,  4, 32, "%i", i)
180 RNG (4,  4, 32, "%u", u)
181 RNG (4,  4, 32, "%li", li)
182 RNG (4,  4, 32, "%lu", lu)
183 RNG (4,  4, 32, "%zu", sz)
184 
185 /* Exercise bug 78586.  */
186 RNG (4,  4, 32, "%lu", (unsigned long)i)
187 RNG (4,  4, 32, "%lu", (unsigned long)u)
188 RNG (4,  4, 32, "%lu", (unsigned long)li)
189 RNG (4,  4, 32, "%lu", (unsigned long)lu)
190 RNG (4,  4, 32, "%lu", (unsigned long)sz)
191 
192 
193 #if __SIZEOF_INT__ == 4
194 
195 /* A 32-bit int takes up at most 11 bytes (-2147483648) not including
196    the terminating nul.  */
197 RNG (0,  7,  7, "%i", i)
198 
199 RNG (0,  0,  8, "%i", i)
200 RNG (0,  1,  8, "%i", i)
201 RNG (0,  2,  8, "%i", i)
202 RNG (0,  3,  8, "%i", i)
203 RNG (0,  4,  8, "%i", i)
204 RNG (0,  5,  8, "%i", i)
205 RNG (0,  6,  8, "%i", i)
206 RNG (0,  7,  8, "%i", i)
207 RNG (0,  8,  8, "%i", i)
208 
209 RNG (0,  0,  9, "%i", i)
210 RNG (0,  1,  9, "%i", i)
211 RNG (0,  2,  9, "%i", i)
212 RNG (0,  3,  9, "%i", i)
213 RNG (0,  4,  9, "%i", i)
214 RNG (0,  5,  9, "%i", i)
215 RNG (0,  6,  9, "%i", i)
216 RNG (0,  7,  9, "%i", i)
217 RNG (0,  8,  9, "%i", i)
218 RNG (0,  9,  9, "%i", i)
219 
220 RNG (0,  0, 10, "%i", i)
221 RNG (0,  1, 10, "%i", i)
222 RNG (0,  2, 10, "%i", i)
223 RNG (0,  3, 10, "%i", i)
224 RNG (0,  4, 10, "%i", i)
225 RNG (0,  5, 10, "%i", i)
226 RNG (0,  6, 10, "%i", i)
227 RNG (0,  7, 10, "%i", i)
228 RNG (0,  8, 10, "%i", i)
229 RNG (0,  9, 10, "%i", i)
230 RNG (0, 10, 10, "%i", i)
231 
232 #endif
233 
234 /* Verify that the output of a "%a" directive with no precision is not
235    considered constant or within a known range (the number of digits
236    after the decimal point is unspecified in this case).  The hardcoded
237    ranges correspond to Glibc values.  */
238 RNG (6,  6,  7, "%a",       0.0)    /* Glibc output: "0x0p+0"  */
239 RNG (6,  6,  7, "%a",       d)
240 RNG (6,  6,  7, "%.4096a",  d)
241 
242 RNG (6,  6,  7, "%La",      0.0L)   /* Glibc output: "0x0p+0"  */
243 RNG (6,  6,  7, "%La",      ld)
244 RNG (6,  6,  7, "%.4096La", ld)
245 
246 /* Verify that the pound flag with unknown precision prevents the %g
247    directive from trimming trailing zeros as it otherwise does.  As
248    a consequence, the result must be assumed to be as large as
249    precision.  */
250 RNG (1,  315,  316, "%#.*g", i, d);
251 RNG (1, 4095, 4096, "%#.*g", i, d);
252 RNG (1, 4095, 4096, "%#.*g", i, 0.0);
253 
254 /* Verify that the result of formatting an unknown string isn't optimized
255    into a non-negative range.  The string could be longer that 4,095 bytes,
256    resulting in the formatting function having undefined behavior (and
257    returning a negative value as Glibc can for some directives).  */
258 RNG (0,  INT_MAX, -1, "%-s", str);
259 
260 /* Verify the result of a conditional expression involving a string
261    literal and an unknown string isn't optimized.  */
262 RNG (0,  1,   4, "%-s", i ? str : "123");
263 RNG (0,  1,   4, "%-s", i ? "123" : str);
264 
265 /* Verfy that the output involving wide strings is not optimized
266    (the output is actually bounded by a function of MB_LEN_MAX
267    which should be at least 6 to accommodate UTF-8 but this isn't
268    implemented yet).  */
269 RNG (0,  5,   7, "%ls",   L"1");
270 RNG (0,  6,   8, "%s%ls", "1", L"2");
271 
272 /* Verify that no call to abort has been eliminated and that each call
273    is at the beginning of a basic block (and thus the result of a branch).
274    This latter test tries to verify that the test preceding the call to
275    the must_not_eliminate() function has not been eliminated either.
276 
277    The expected output looks something like this:
278 
279    <bb 2>:
280    result_3 = __builtin_sprintf (&MEM[(void *)&buf8k + 8192B], "%c", 32);
281    if (result_3 != 0)
282      goto <bb 3>; [50.0%] [count: INV]
283    else
284      goto <bb 4>; [50.0%] [count: INV]
285 
286    <bb 3>[50.0%] [count: INV]:
287    must_not_eliminate ();
288 
289 */
290 
291 /*  Only conditional calls to must_not_eliminate must be made (with
292     any probability):
293     { dg-final { scan-tree-dump-times "> \\\[local count: \[0-9INV\]*\\\]:\n *must_not_eliminate" 127 "optimized" { target { ilp32 || lp64 } } } }
294     { dg-final { scan-tree-dump-times "> \\\[local count: \[0-9INV\]*\\\]:\n *must_not_eliminate" 96 "optimized" { target { { ! ilp32 } && { ! lp64 } } } } }
295     No unconditional calls to abort should be made:
296     { dg-final { scan-tree-dump-not ";\n *must_not_eliminate" "optimized" } } */
297