From 586ef26f746108617703f4e863b8b271666e38b5 Mon Sep 17 00:00:00 2001
From: Steven Moreland <smoreland@google.com>
Date: Wed, 8 Aug 2018 16:45:49 -0700
Subject: [PATCH] Add ParseFloat (in parsedouble.h).

Bug: 110758329 # for using here
Test: libbase_test (added float_smoke)
Change-Id: I640f85655567c707cbee625ca9c88db2ab91da66
---
 base/include/android-base/parsedouble.h | 27 ++++++++++++++++++++-----
 base/parsedouble_test.cpp               | 26 +++++++++++++++++++++++-
 2 files changed, 47 insertions(+), 6 deletions(-)

diff --git a/base/include/android-base/parsedouble.h b/base/include/android-base/parsedouble.h
index 9a20eb194..7b1c648b7 100644
--- a/base/include/android-base/parsedouble.h
+++ b/base/include/android-base/parsedouble.h
@@ -24,15 +24,14 @@
 namespace android {
 namespace base {
 
-// Parse double value in the string 's' and sets 'out' to that value if it exists.
+// Parse floating value in the string 's' and sets 'out' to that value if it exists.
 // Optionally allows the caller to define a 'min' and 'max' beyond which
 // otherwise valid values will be rejected. Returns boolean success.
-static inline bool ParseDouble(const char* s, double* out,
-                               double min = std::numeric_limits<double>::lowest(),
-                               double max = std::numeric_limits<double>::max()) {
+template <typename T, T (*strtox)(const char* str, char** endptr)>
+static inline bool ParseFloatingPoint(const char* s, T* out, T min, T max) {
   errno = 0;
   char* end;
-  double result = strtod(s, &end);
+  T result = strtox(s, &end);
   if (errno != 0 || s == end || *end != '\0') {
     return false;
   }
@@ -45,5 +44,23 @@ static inline bool ParseDouble(const char* s, double* out,
   return true;
 }
 
+// Parse double value in the string 's' and sets 'out' to that value if it exists.
+// Optionally allows the caller to define a 'min' and 'max' beyond which
+// otherwise valid values will be rejected. Returns boolean success.
+static inline bool ParseDouble(const char* s, double* out,
+                               double min = std::numeric_limits<double>::lowest(),
+                               double max = std::numeric_limits<double>::max()) {
+  return ParseFloatingPoint<double, strtod>(s, out, min, max);
+}
+
+// Parse float value in the string 's' and sets 'out' to that value if it exists.
+// Optionally allows the caller to define a 'min' and 'max' beyond which
+// otherwise valid values will be rejected. Returns boolean success.
+static inline bool ParseFloat(const char* s, float* out,
+                              float min = std::numeric_limits<float>::lowest(),
+                              float max = std::numeric_limits<float>::max()) {
+  return ParseFloatingPoint<float, strtof>(s, out, min, max);
+}
+
 }  // namespace base
 }  // namespace android
diff --git a/base/parsedouble_test.cpp b/base/parsedouble_test.cpp
index 797a370bc..ec3c10c74 100644
--- a/base/parsedouble_test.cpp
+++ b/base/parsedouble_test.cpp
@@ -18,7 +18,7 @@
 
 #include <gtest/gtest.h>
 
-TEST(parsedouble, smoke) {
+TEST(parsedouble, double_smoke) {
   double d;
   ASSERT_FALSE(android::base::ParseDouble("", &d));
   ASSERT_FALSE(android::base::ParseDouble("x", &d));
@@ -41,3 +41,27 @@ TEST(parsedouble, smoke) {
   ASSERT_FALSE(android::base::ParseDouble("3.0", nullptr, -1.0, 2.0));
   ASSERT_TRUE(android::base::ParseDouble("1.0", nullptr, 0.0, 2.0));
 }
+
+TEST(parsedouble, float_smoke) {
+  float f;
+  ASSERT_FALSE(android::base::ParseFloat("", &f));
+  ASSERT_FALSE(android::base::ParseFloat("x", &f));
+  ASSERT_FALSE(android::base::ParseFloat("123.4x", &f));
+
+  ASSERT_TRUE(android::base::ParseFloat("123.4", &f));
+  ASSERT_FLOAT_EQ(123.4, f);
+  ASSERT_TRUE(android::base::ParseFloat("-123.4", &f));
+  ASSERT_FLOAT_EQ(-123.4, f);
+
+  ASSERT_TRUE(android::base::ParseFloat("0", &f, 0.0));
+  ASSERT_FLOAT_EQ(0.0, f);
+  ASSERT_FALSE(android::base::ParseFloat("0", &f, 1e-9));
+  ASSERT_FALSE(android::base::ParseFloat("3.0", &f, -1.0, 2.0));
+  ASSERT_TRUE(android::base::ParseFloat("1.0", &f, 0.0, 2.0));
+  ASSERT_FLOAT_EQ(1.0, f);
+
+  ASSERT_FALSE(android::base::ParseFloat("123.4x", nullptr));
+  ASSERT_TRUE(android::base::ParseFloat("-123.4", nullptr));
+  ASSERT_FALSE(android::base::ParseFloat("3.0", nullptr, -1.0, 2.0));
+  ASSERT_TRUE(android::base::ParseFloat("1.0", nullptr, 0.0, 2.0));
+}