[libc-commits] [libc] [libc][test] make `str_to_float_comparison_test` independent of C++ headers. (PR #133978)

[Muhammad Bassiouni via libc-commits]

================
@@ -54,80 +56,112 @@ static inline uint64_t fastHexToU64(const char *inStr) {
   return result;
 }
 
-int checkFile(char *inputFileName, int *totalFails, int *totalBitDiffs,
-              int *detailedBitDiffs, int *total) {
-  int32_t curFails = 0;    // Only counts actual failures, not bitdiffs.
-  int32_t curBitDiffs = 0; // A bitdiff is when the expected result and actual
-                           // result are off by +/- 1 bit.
-  std::string line;
-  std::string num;
+static void parseLine(char *line, int *total, int *detailedBitDiffs,
+                      int32_t &curFails, int32_t &curBitDiffs) {
 
-  std::ifstream fileStream(inputFileName, std::ifstream::in);
-
-  if (!fileStream.is_open()) {
-    std::cout << "file '" << inputFileName << "' failed to open. Exiting.\n";
-    return 1;
+  if (line[0] == '#') {
+    return;
   }
-  while (getline(fileStream, line)) {
-    if (line[0] == '#') {
-      continue;
-    }
-    *total = *total + 1;
-    uint32_t expectedFloatRaw;
-    uint64_t expectedDoubleRaw;
+  *total = *total + 1;
+  uint32_t expectedFloatRaw;
+  uint64_t expectedDoubleRaw;
 
-    expectedFloatRaw = fastHexToU32(line.c_str() + 5);
-    expectedDoubleRaw = fastHexToU64(line.c_str() + 14);
-    num = line.substr(31);
+  expectedFloatRaw = fastHexToU32(line + 5);
+  expectedDoubleRaw = fastHexToU64(line + 14);
 
-    float floatResult = strtof(num.c_str(), nullptr);
+  char *num = line + 31;
 
-    double doubleResult = strtod(num.c_str(), nullptr);
+  float floatResult = LIBC_NAMESPACE::strtof(num, nullptr);
 
-    uint32_t floatRaw = *(uint32_t *)(&floatResult);
+  double doubleResult = LIBC_NAMESPACE::strtod(num, nullptr);
 
-    uint64_t doubleRaw = *(uint64_t *)(&doubleResult);
+  uint32_t floatRaw = LIBC_NAMESPACE::cpp::bit_cast<uint32_t>(floatResult);
 
-    if (!(expectedFloatRaw == floatRaw)) {
-      if (expectedFloatRaw == floatRaw + 1 ||
-          expectedFloatRaw == floatRaw - 1) {
-        curBitDiffs++;
-        if (expectedFloatRaw == floatRaw + 1) {
-          detailedBitDiffs[0] = detailedBitDiffs[0] + 1; // float low
-        } else {
-          detailedBitDiffs[1] = detailedBitDiffs[1] + 1; // float high
-        }
+  uint64_t doubleRaw = LIBC_NAMESPACE::cpp::bit_cast<uint64_t>(doubleResult);
+
+  if (!(expectedFloatRaw == floatRaw)) {
+    if (expectedFloatRaw == floatRaw + 1 || expectedFloatRaw == floatRaw - 1) {
+      curBitDiffs++;
+      if (expectedFloatRaw == floatRaw + 1) {
+        detailedBitDiffs[0] = detailedBitDiffs[0] + 1; // float low
       } else {
-        curFails++;
-      }
-      if (curFails + curBitDiffs < 10) {
-        std::cout << "Float fail for '" << num << "'. Expected " << std::hex
-                  << expectedFloatRaw << " but got " << floatRaw << "\n"
-                  << std::dec;
+        detailedBitDiffs[1] = detailedBitDiffs[1] + 1; // float high
       }
+    } else {
+      curFails++;
+    }
+    if (curFails + curBitDiffs < 10) {
+      LIBC_NAMESPACE::printf("Float fail for '%s'. Expected %x but got %x\n",
+                             num, expectedFloatRaw, floatRaw);
     }
+  }
 
-    if (!(expectedDoubleRaw == doubleRaw)) {
-      if (expectedDoubleRaw == doubleRaw + 1 ||
-          expectedDoubleRaw == doubleRaw - 1) {
-        curBitDiffs++;
-        if (expectedDoubleRaw == doubleRaw + 1) {
-          detailedBitDiffs[2] = detailedBitDiffs[2] + 1; // double low
-        } else {
-          detailedBitDiffs[3] = detailedBitDiffs[3] + 1; // double high
-        }
+  if (!(expectedDoubleRaw == doubleRaw)) {
+    if (expectedDoubleRaw == doubleRaw + 1 ||
+        expectedDoubleRaw == doubleRaw - 1) {
+      curBitDiffs++;
+      if (expectedDoubleRaw == doubleRaw + 1) {
+        detailedBitDiffs[2] = detailedBitDiffs[2] + 1; // double low
       } else {
-        curFails++;
-      }
-      if (curFails + curBitDiffs < 10) {
-        std::cout << "Double fail for '" << num << "'. Expected " << std::hex
-                  << expectedDoubleRaw << " but got " << doubleRaw << "\n"
-                  << std::dec;
+        detailedBitDiffs[3] = detailedBitDiffs[3] + 1; // double high
       }
+    } else {
+      curFails++;
+    }
+    if (curFails + curBitDiffs < 10) {
+      LIBC_NAMESPACE::printf("Double fail for '%s'. Expected %lx but got %lx\n",
+                             num, expectedDoubleRaw, doubleRaw);
     }
   }
+}
+
+int checkBuffer(int *totalFails, int *totalBitDiffs, int *detailedBitDiffs,
+                int *total) {
+  const char *lines[6] = {"3C00 3F800000 3FF0000000000000 1",
----------------
bassiounix wrote:

No not really

```txt
libc/test/src/__support/str_to_float_comparison_test.cpp:120:31: warning: ISO C++11 does not allow conversion from string literal to 'char *const' [-Wwritable-strings]
  120 |   constexpr char *lines[6] = {"3C00 3F800000 3FF0000000000000 1",
```

https://github.com/llvm/llvm-project/pull/133978