fix #12110: FP signConversion with integer overflow (danmar#7022)

Author: ludviggunne

lib/platform.cpp

@@ -329,24 +329,24 @@ std::string Platform::getLimitsDefines(bool c99) const
     s += ";USHRT_MAX=";
     s += std::to_string(max_value(short_bit+1));
     s += ";INT_MIN=";
-    s += std::to_string(min_value(int_bit));
+    s += "(-" + std::to_string(max_value(int_bit)) + " - 1)";
     s += ";INT_MAX=";
     s += std::to_string(max_value(int_bit));
     s += ";UINT_MAX=";
     s += std::to_string(max_value(int_bit+1));
     s += ";LONG_MIN=";
-    s += std::to_string(min_value(long_bit));
+    s += "(-" + std::to_string(max_value(long_bit)) + "L - 1L)";
     s += ";LONG_MAX=";
-    s += std::to_string(max_value(long_bit));
+    s += std::to_string(max_value(long_bit)) + "L";
     s += ";ULONG_MAX=";
-    s += std::to_string(max_value(long_bit+1));
+    s += std::to_string(max_value_unsigned(long_bit)) + "UL";
     if (c99) {
         s += ";LLONG_MIN=";
-        s += std::to_string(min_value(long_long_bit));
+        s += "(-" + std::to_string(max_value(long_long_bit)) + "LL - 1LL)";
         s += ";LLONG_MAX=";
-        s += std::to_string(max_value(long_long_bit));
+        s += std::to_string(max_value(long_long_bit)) + "LL";
         s += ";ULLONG_MAX=";
-        s += std::to_string(max_value(long_long_bit + 1));
+        s += std::to_string(max_value_unsigned(long_long_bit)) + "ULL";
     }
 
     // cstdint / stdint.h

lib/platform.h

@@ -55,6 +55,12 @@ class CPPCHECKLIB Platform {
         return (1LL << (bit-1)) - 1LL;
     }
 
+    static unsigned long long max_value_unsigned(int bit) {
+        if (bit >= 64)
+            return ~0ULL;
+        return (1ULL << bit) - 1ULL;
+    }
+
     /** provides list of defines specified by the limit.h/climits includes */
     std::string getLimitsDefines(bool c99) const;
 public:

test/testplatform.cpp

@@ -403,8 +403,8 @@ class TestPlatform : public TestFixture {
     void limitsDefines() const {
         Platform platform;
         ASSERT_EQUALS(true, platform.set(Platform::Unix64));
-        const std::string defs = "CHAR_BIT=8;SCHAR_MIN=-128;SCHAR_MAX=127;UCHAR_MAX=255;CHAR_MIN=0;CHAR_MAX=127;SHRT_MIN=-32768;SHRT_MAX=32767;USHRT_MAX=65535;INT_MIN=-2147483648;INT_MAX=2147483647;UINT_MAX=4294967295;LONG_MIN=-9223372036854775808;LONG_MAX=9223372036854775807;ULONG_MAX=9223372036854775807";
-        const std::string defs_c99 = "CHAR_BIT=8;SCHAR_MIN=-128;SCHAR_MAX=127;UCHAR_MAX=255;CHAR_MIN=0;CHAR_MAX=127;SHRT_MIN=-32768;SHRT_MAX=32767;USHRT_MAX=65535;INT_MIN=-2147483648;INT_MAX=2147483647;UINT_MAX=4294967295;LONG_MIN=-9223372036854775808;LONG_MAX=9223372036854775807;ULONG_MAX=9223372036854775807;LLONG_MIN=-9223372036854775808;LLONG_MAX=9223372036854775807;ULLONG_MAX=9223372036854775807";
+        const std::string defs = "CHAR_BIT=8;SCHAR_MIN=-128;SCHAR_MAX=127;UCHAR_MAX=255;CHAR_MIN=0;CHAR_MAX=127;SHRT_MIN=-32768;SHRT_MAX=32767;USHRT_MAX=65535;INT_MIN=(-2147483647 - 1);INT_MAX=2147483647;UINT_MAX=4294967295;LONG_MIN=(-9223372036854775807L - 1L);LONG_MAX=9223372036854775807L;ULONG_MAX=18446744073709551615UL";
+        const std::string defs_c99 = "CHAR_BIT=8;SCHAR_MIN=-128;SCHAR_MAX=127;UCHAR_MAX=255;CHAR_MIN=0;CHAR_MAX=127;SHRT_MIN=-32768;SHRT_MAX=32767;USHRT_MAX=65535;INT_MIN=(-2147483647 - 1);INT_MAX=2147483647;UINT_MAX=4294967295;LONG_MIN=(-9223372036854775807L - 1L);LONG_MAX=9223372036854775807L;ULONG_MAX=18446744073709551615UL;LLONG_MIN=(-9223372036854775807LL - 1LL);LLONG_MAX=9223372036854775807LL;ULLONG_MAX=18446744073709551615ULL";
         ASSERT_EQUALS(defs, platform.getLimitsDefines(Standards::cstd_t::C89));
         ASSERT_EQUALS(defs_c99, platform.getLimitsDefines(Standards::cstd_t::C99));
         ASSERT_EQUALS(defs_c99, platform.getLimitsDefines(Standards::cstd_t::CLatest));

test/testtype.cpp

@@ -352,6 +352,11 @@ class TestType : public TestFixture {
               " return -2 * x;\n"
               "}", settingsDefault);
         ASSERT_EQUALS("[test.cpp:2]: (warning) Expression '-2' has a negative value. That is converted to an unsigned value and used in an unsigned calculation.\n", errout_str());
+
+        checkP("void f() {\n" // #12110 FP signConversion with integer overflow
+               "    if (LLONG_MIN / (-1)) {}\n"
+               "}\n", settingsDefault);
+        ASSERT_EQUALS("", errout_str());
     }
 
     void longCastAssign() {