Device porting issues-IoT Platform (Deprecated)(IoT)-阿里云帮助中心

This topic explains the causes of issues that you may encounter when porting IoT SDK V2.0 to the Qualcomm MDM9206 platform.

Compilation issues

ArmCC does not support mixing variable declarations with statements in C. All declarations must appear at the beginning of a block before any other statements.
ArmCC does not support using braces {} to initialize an anonymous struct instance as a right operand.
GCC and its variants treat enumeration types as int. However, ArmCC performs strict compile-time checks and often treats them as unsigned int.
ArmCC does not support variable assignments within the conditional expressions of if, while, or for statements.
ArmCC reports errors for return statements in unreachable branches. This causes the compilation to fail.
ArmCC does not support functions that return an enumeration type. The return value is treated as an `int` or another data type that `gcc` considers equivalent.
Standard library header files differ between compilers. Definitions such as size_t and typeof are available in GCC but not in ArmCC.
ArmCC does not support GNU-style extension functions, such as vasnprintf and asprintf.
ArmCC does not support GNU-style extension data structures, such as anonymous structs and anonymous member assignments.

When you use the standard library function tolower(), you must include the ctype.h header file. Otherwise, the program hangs.
The Qualcomm serial print function cannot print zero-length strings using the %s format specifier.
The HTTP Client code in files such as src/utils/misc/utils_httpc.c uses the C standard library function sscanf(). The program hangs when this code is executed because of an issue in the Qualcomm C library.