From a2e1021d7dc8040b6e0737397fe9153dcb12191d Mon Sep 17 00:00:00 2001
From: Benoit Blanchon <git@benoitblanchon.fr>
Date: Thu, 30 Dec 2021 10:02:21 +0100
Subject: [PATCH] Use `pgm_read_dword()` instead of `pgm_read_float()` (issue
 #1433)

---
 extras/tests/Helpers/progmem_emulation.hpp    |  4 --
 .../MixedConfiguration/enable_progmem_1.cpp   |  8 ++++
 src/ArduinoJson/Numbers/FloatTraits.hpp       | 42 +++++++++++++------
 .../Polyfills/pgmspace_generic.hpp            |  9 ----
 4 files changed, 38 insertions(+), 25 deletions(-)

diff --git a/extras/tests/Helpers/progmem_emulation.hpp b/extras/tests/Helpers/progmem_emulation.hpp
index 7a977db8..23925ba9 100644
--- a/extras/tests/Helpers/progmem_emulation.hpp
+++ b/extras/tests/Helpers/progmem_emulation.hpp
@@ -27,10 +27,6 @@ inline void* pgm_read_ptr(const void* p) {
   return *reinterpret_cast<void* const*>(convertFlashToPtr(p));
 }
 
-inline float pgm_read_float(const void* p) {
-  return *reinterpret_cast<const float*>(convertFlashToPtr(p));
-}
-
 #define ARDUINOJSON_DEFINE_PROGMEM_ARRAY(type, name, value)        \
   static type const ARDUINOJSON_CONCAT2(name, _progmem)[] = value; \
   static type const* name = reinterpret_cast<type const*>(         \
diff --git a/extras/tests/MixedConfiguration/enable_progmem_1.cpp b/extras/tests/MixedConfiguration/enable_progmem_1.cpp
index 23e98f72..7661f628 100644
--- a/extras/tests/MixedConfiguration/enable_progmem_1.cpp
+++ b/extras/tests/MixedConfiguration/enable_progmem_1.cpp
@@ -50,6 +50,14 @@ TEST_CASE("Flash strings") {
   }
 }
 
+TEST_CASE("parseNumber()") {  // tables are in Flash
+  using ARDUINOJSON_NAMESPACE::parseNumber;
+
+  CHECK(parseNumber<float>("1") == 1.f);
+  CHECK(parseNumber<float>("1.23") == 1.23f);
+  CHECK(parseNumber<float>("-1.23e34") == -1.23e34f);
+}
+
 TEST_CASE("strlen_P") {
   CHECK(strlen_P(PSTR("")) == 0);
   CHECK(strlen_P(PSTR("a")) == 1);
diff --git a/src/ArduinoJson/Numbers/FloatTraits.hpp b/src/ArduinoJson/Numbers/FloatTraits.hpp
index 60b1dfd1..053feb43 100644
--- a/src/ArduinoJson/Numbers/FloatTraits.hpp
+++ b/src/ArduinoJson/Numbers/FloatTraits.hpp
@@ -158,24 +158,42 @@ struct FloatTraits<T, 4 /*32bits*/> {
   }
 
   static T positiveBinaryPowerOfTen(int index) {
-    ARDUINOJSON_DEFINE_STATIC_ARRAY(
-        T, factors,
-        ARDUINOJSON_EXPAND6({1e1f, 1e2f, 1e4f, 1e8f, 1e16f, 1e32f}));
-    return ARDUINOJSON_READ_STATIC_ARRAY(T, factors, index);
+    ARDUINOJSON_DEFINE_STATIC_ARRAY(uint32_t, factors,
+                                    ARDUINOJSON_EXPAND6({
+                                        0x41200000,  // 1e1f
+                                        0x42c80000,  // 1e2f
+                                        0x461c4000,  // 1e4f
+                                        0x4cbebc20,  // 1e8f
+                                        0x5a0e1bca,  // 1e16f
+                                        0x749dc5ae   // 1e32f
+                                    }));
+    return forge(ARDUINOJSON_READ_STATIC_ARRAY(uint32_t, factors, index));
   }
 
   static T negativeBinaryPowerOfTen(int index) {
-    ARDUINOJSON_DEFINE_STATIC_ARRAY(
-        T, factors,
-        ARDUINOJSON_EXPAND6({1e-1f, 1e-2f, 1e-4f, 1e-8f, 1e-16f, 1e-32f}));
-    return ARDUINOJSON_READ_STATIC_ARRAY(T, factors, index);
+    ARDUINOJSON_DEFINE_STATIC_ARRAY(uint32_t, factors,
+                                    ARDUINOJSON_EXPAND6({
+                                        0x3dcccccd,  // 1e-1f
+                                        0x3c23d70a,  // 1e-2f
+                                        0x38d1b717,  // 1e-4f
+                                        0x322bcc77,  // 1e-8f
+                                        0x24e69595,  // 1e-16f
+                                        0x0a4fb11f   // 1e-32f
+                                    }));
+    return forge(ARDUINOJSON_READ_STATIC_ARRAY(uint32_t, factors, index));
   }
 
   static T negativeBinaryPowerOfTenPlusOne(int index) {
-    ARDUINOJSON_DEFINE_STATIC_ARRAY(
-        T, factors,
-        ARDUINOJSON_EXPAND6({1e0f, 1e-1f, 1e-3f, 1e-7f, 1e-15f, 1e-31f}));
-    return ARDUINOJSON_READ_STATIC_ARRAY(T, factors, index);
+    ARDUINOJSON_DEFINE_STATIC_ARRAY(uint32_t, factors,
+                                    ARDUINOJSON_EXPAND6({
+                                        0x3f800000,  // 1e0f
+                                        0x3dcccccd,  // 1e-1f
+                                        0x3a83126f,  // 1e-3f
+                                        0x33d6bf95,  // 1e-7f
+                                        0x26901d7d,  // 1e-15f
+                                        0x0c01ceb3   // 1e-31f
+                                    }));
+    return forge(ARDUINOJSON_READ_STATIC_ARRAY(uint32_t, factors, index));
   }
 
   static T forge(uint32_t bits) {
diff --git a/src/ArduinoJson/Polyfills/pgmspace_generic.hpp b/src/ArduinoJson/Polyfills/pgmspace_generic.hpp
index 070d574f..508e4c53 100644
--- a/src/ArduinoJson/Polyfills/pgmspace_generic.hpp
+++ b/src/ArduinoJson/Polyfills/pgmspace_generic.hpp
@@ -15,15 +15,6 @@ typename enable_if<is_pointer<T>::value, T>::type pgm_read(const void* p) {
   return reinterpret_cast<T>(pgm_read_ptr(p));
 }
 
-template <typename T>
-typename enable_if<is_floating_point<T>::value &&
-                       sizeof(T) == sizeof(float),  // on AVR sizeof(double) ==
-                                                    // sizeof(float)
-                   T>::type
-pgm_read(const void* p) {
-  return pgm_read_float(p);
-}
-
 template <typename T>
 typename enable_if<is_same<T, uint32_t>::value, T>::type pgm_read(
     const void* p) {