同事写了一个三维数组初始化的code, 其大体如下
typedef struct 6 { 7 uint8_t n; 8 uint8_t m; 9 }mipi_clk_ratio; 10 11 static mipi_clk_ratio mipi_clk[2][2][4] = 12 { 13 //CSI 14 {{8,1}, {4,1},{8,3},{2,1}}, //YUV422 15 {{12,1}, {6,1},{4,1},{3,1}}, //RGB888 16 //DSI 17 {{8,1}, {4,1},{8,3},{2,1}}, //YUV422 18 {{12,1}, {6,1},{4,1},{3,1}}, //RGB888 19 };
在keil下编译运行都没有问题,但是在gcc编译就出现下面的warnings
test1.c:14:2: warning: excess elements in array initializer [enabled by default] test1.c:14:2: warning: (near initialization for ‘mipi_clk[0]’) [enabled by default] test1.c:14:2: warning: excess elements in array initializer [enabled by default] test1.c:14:2: warning: (near initialization for ‘mipi_clk[0]’) [enabled by default] test1.c:15:2: warning: excess elements in array initializer [enabled by default] test1.c:15:2: warning: (near initialization for ‘mipi_clk[1]’) [enabled by default] test1.c:15:2: warning: excess elements in array initializer [enabled by default] test1.c:15:2: warning: (near initialization for ‘mipi_clk[1]’) [enabled by default] test1.c:17:2: warning: excess elements in array initializer [enabled by default] test1.c:17:2: warning: (near initialization for ‘mipi_clk[2]’) [enabled by default] test1.c:17:2: warning: excess elements in array initializer [enabled by default] test1.c:17:2: warning: (near initialization for ‘mipi_clk[2]’) [enabled by default] test1.c:17:2: warning: excess elements in array initializer [enabled by default] test1.c:17:2: warning: (near initialization for ‘mipi_clk’) [enabled by default] test1.c:18:2: warning: excess elements in array initializer [enabled by default] test1.c:18:2: warning: (near initialization for ‘mipi_clk[2]’) [enabled by default] test1.c:18:2: warning: excess elements in array initializer [enabled by default] test1.c:18:2: warning: (near initialization for ‘mipi_clk[2]’) [enabled by default] test1.c:18:2: warning: excess elements in array initializer [enabled by default] test1.c:18:2: warning: (near initialization for ‘mipi_clk’) [enabled by default]
仔细分析,应该是gcc编译器不能从初始化的数组数据中分清维数,有歧义。可以添加{}来更清晰定义它,如下所示
typedef struct 6 { 7 uint8_t n; 8 uint8_t m; 9 }mipi_clk_ratio; 10 11 static mipi_clk_ratio mipi_clk[2][2][4] = 12 { 13 //CSI 14 <strong><em><span style="color:#ff0000;">{</span></em></strong>{{8,1}, {4,1},{8,3},{2,1}}, //YUV422 15 {{12,1}, {6,1},{4,1},{3,1}}<strong><em><span style="color:#ff0000;">}</span></em></strong>, //RGB888 16 // //DSI 17 <strong><em><span style="color:#ff0000;">{</span></em></strong>{{8,1}, {4,1},{8,3},{2,1}}, //YUV422 18 {{12,1}, {6,1},{4,1},{3,1}}<strong><span style="color:#ff0000;"><em>}</em></span></strong> //RGB888 19 };
总结一下,有的编译器对多维数组初始化是按行来进行的,所以要求开发者对初始化数据通过添加{}来清晰定义。 此外,为了代码更好的可读性,最好不要定义三维及以上的数组。
时间: 2024-11-04 22:02:03