Fix error with conflicting declaration of a prototype (Arduino sketch preprocessor)

HISTORY.rst

@@ -7,6 +7,7 @@ PlatformIO 3.0
 3.6.6 (2019-??-??)
 ~~~~~~~~~~~~~~~~~~
 
+* Fixed error with conflicting declaration of a prototype (Arduino sketch preprocessor)
 * Fixed "FileExistsError" when `platformio ci <https://docs.platformio.org/en/latest/userguide/cmd_ci.html>`__ command is used in pair with ``--keep-build-dir`` option
 
 3.6.5 (2019-03-07)

platformio/builder/tools/piomisc.py

@@ -36,7 +36,7 @@ class InoToCPPConverter(object):
         ([a-z_\d\&]+\*?\s+){1,2}    # return type
         ([a-z_\d]+\s*)              # name of prototype
         \([a-z_,\.\*\&\[\]\s\d]*\)  # arguments
-        )\s*\{                      # must end with {
+        )\s*(\{|;)                  # must end with `{` or `;`
         """, re.X | re.M | re.I)
     DETECTMAIN_RE = re.compile(r"void\s+(setup|loop)\s*\(", re.M | re.I)
     PROTOPTRS_TPLRE = r"\([^&\(]*&(%s)[^\)]*\)"
@@ -162,7 +162,14 @@ class InoToCPPConverter(object):
         if not prototypes:
             return contents
 
-        prototype_names = set([m.group(3).strip() for m in prototypes])
+        # skip already declared prototypes
+        declared = set(
+            m.group(1).strip() for m in prototypes if m.group(4) == ";")
+        prototypes = [
+            m for m in prototypes if m.group(1).strip() not in declared
+        ]
+
+        prototype_names = set(m.group(3).strip() for m in prototypes)
         split_pos = prototypes[0].start()
         match_ptrs = re.search(
             self.PROTOPTRS_TPLRE % ("|".join(prototype_names)),

tests/ino2cpp/basic/basic.ino

@@ -49,4 +49,12 @@ void fooCallback(){
 
 }
 
+extern "C" {
+void some_extern(const char *fmt, ...);
+};
+
+void some_extern(const char *fmt, ...) {
+
+}
+
 // юнікод