Refactor clang-tidy script to use actual compiler flags and includes (#2133)

Co-authored-by: Otto winter <otto@otto-winter.com>

platformio.ini

@@ -1,12 +1,28 @@
-; This file is so that the C++ files in this repo
-; can be edited with IDEs like VSCode or CLion
-; with the platformio system
+; This PlatformIO project is for development purposes *only*: clang-tidy derives its compilation
+; database from here, and IDEs like CLion and VSCode also use it. This does not actually create a
+; usable binary.
 ; It's *not* used during runtime.
 
 [platformio]
-default_envs = livingroom8266
+default_envs = esp8266
 src_dir = .
-include_dir = include
+include_dir =
+
+[runtime]
+; This are the flags as set by the runtime.
+build_flags =
+    -Wno-unused-variable
+    -Wno-unused-but-set-variable
+    -Wno-sign-compare
+
+[clangtidy]
+; This are the flags for clang-tidy.
+build_flags =
+    -Wall
+    -Wunreachable-code
+    -Wfor-loop-analysis
+    -Wshadow-field
+    -Wshadow-field-in-constructor
 
 [common]
 lib_deps =
@@ -19,17 +35,13 @@ lib_deps =
     6865@1.0.0  ; TM1651 Battery Display
     6306@1.0.3  ; HM3301
 build_flags =
-    -fno-exceptions
-    -Wno-sign-compare
-    -Wno-unused-but-set-variable
-    -Wno-unused-variable
-    -DCLANG_TIDY
     -DESPHOME_LOG_LEVEL=ESPHOME_LOG_LEVEL_VERY_VERBOSE
 src_filter =
     +<esphome>
     +<tests/dummy_main.cpp>
+    +<.temp/all-include.cpp>
 
-[env:livingroom8266]
+[common:esp8266]
 ; use Arduino framework v2.4.2 for clang-tidy (latest 2.5.2 breaks static code analysis, see #760)
 platform = platformio/espressif8266@1.8.0
 framework = arduino
@@ -42,7 +54,7 @@ lib_deps =
 build_flags = ${common.build_flags}
 src_filter = ${common.src_filter}
 
-[env:livingroom32]
+[common:esp32]
 platform = platformio/espressif32@3.2.0
 framework = arduino
 board = nodemcu-32s
@@ -56,3 +68,19 @@ build_flags =
 src_filter =
     ${common.src_filter}
     -<esphome/components/esp8266_pwm>
+
+[env:esp8266]
+extends = common:esp8266
+build_flags = ${common:esp8266.build_flags} ${runtime.build_flags}
+
+[env:esp8266-tidy]
+extends = common:esp8266
+build_flags = ${common:esp8266.build_flags} ${clangtidy.build_flags}
+
+[env:esp32]
+extends = common:esp32
+build_flags = ${common:esp32.build_flags} ${runtime.build_flags}
+
+[env:esp32-tidy]
+extends = common:esp32
+build_flags = ${common:esp32.build_flags} ${clangtidy.build_flags}