不同的编译器，不同的输出？ [英] Different compilers, different output?
问题描述
我有一些C代码，我一直在我的Mac上的Xcode。然后我想在Windows机器上使用它，并用TinyC编译它。当我运行它，输出是不同的。
这可能是由于使用不同的编译器？
谢谢！
编辑1
它会打开一个wav文件，将所有样本转换为数组。
#include< stdio.h>
#include< stdlib.h>
#include< string.h>
void read_wav_header（unsigned int * samp_rate，unsigned int * bits_per_samp，
unsigned int * num_samp）;
void read_wav_data（int * data，unsigned int samp_rate，
unsigned int bits_per_samp，unsigned int num_samp）;
int conv_bit_size（unsigned int in，int bps）;
int main（void）
// int read_wav（void）
{
unsigned int samp_rate，bits_per_samp，num_samp;
read_wav_header（& samp_rate，& bit_per_samp，& num_samp）;
printf（samp_rate = [％d] bits_per_samp = [％d] num_samp = [％d] \\\
，
samp_rate，bits_per_samp，num_samp）;
int * data =（int *）malloc（num_samp * sizeof（int））;
read_wav_data（data，samp_rate，bits_per_samp，num_samp）;
unsigned int i;
// for（i = 0; i
for（i = 0; i <100; ++ i）{
printf（％d \\\
，data [i]）;
}
return EXIT_SUCCESS;
}
void read_wav_header（unsigned int * samp_rate，unsigned int * bits_per_samp，
unsigned int * num_samp）
{
unsigned char buf [5] ;
// freopen（/Users/ericbrotto/Desktop/iPhoneData/tmp/Hack.wav\",\"r\",stdin）;
freopen（C：/ Documents and Settings / Eric.Brotto / Desktop / Eric_Other / Files / Hack.wav，r，stdin）
/ * ChunkID（RIFF为小端，RIFX为大端）* /
fread（buf，1,4，stdin）;
buf [4] ='\0';
if（strcmp（（char *）buf，RIFF））exit（EXIT_FAILURE）;
/ * ChunkSize * /
fread（buf，1,4，stdin）;
/ *格式* /
fread（buf，1,4，stdin）;
buf [4] ='\0';
printf（IS THIS WAVE？ - >％s< - \\\
，（char *）buf）;
if（strcmp（（char *）buf，WAVE））exit（EXIT_FAILURE）;
/ * Subchunk1ID * /
fread（buf，1,4，stdin）;
buf [4] ='\0';
printf（IS THIS fmt？ - >％s< - \\\
，（char *）buf）;
if（strcmp（（char *）buf，fmt））exit（EXIT_FAILURE）;
/ * Subchunk1Size（PCM为16）* /
fread（buf，1,4，stdin）;
if（buf [0]！= 16 || buf [1] || buf [2] || buf [3]）exit（EXIT_FAILURE）;
/ * AudioFormat（PCM = 1，其他值表示压缩）* /
fread（buf，1,2，stdin）;
if（buf [0]！= 1 || buf [1]）exit（EXIT_FAILURE）;
/ * NumChannels（Mono = 1，Stereo = 2，etc）* /
fread（buf，1,2，stdin）;
unsigned int num_ch = buf [0] +（buf [1] <8）;
if（num_ch！= 1）exit（EXIT_FAILURE）;
/ * SampleRate（8000，44100等）* /
fread（buf，1,4，stdin）;
* samp_rate = buf [0] +（buf [1] <8）+
（buf [2] <16）+（buf [3] <24 ）;
/ * ByteRate（SampleRate * NumChannels * BitsPerSample / 8）* /
fread（buf，1,4，stdin）;
const unsigned int byte_rate = buf [0] +（buf [1] <8）+
（buf [2] <16）+（buf [3] ; 24）;
/ * BlockAlign（NumChannels * BitsPerSample / 8）* /
fread（buf，1,2，stdin）;
const unsigned int block_align = buf [0] +（buf [1] <8）;
/ * BitsPerSample * /
fread（buf，1，2，stdin）;
* bits_per_samp = buf [0] +（buf [1] <8）;
if（byte_rate！=（（* samp_rate * num_ch * * bits_per_samp）> 3））
exit（EXIT_FAILURE）;
if（block_align！=（（num_ch * * bits_per_samp）> 3））
exit（EXIT_FAILURE）;
/ * Subchunk2ID * /
// fread逐行读取直到结束。
fread（buf，1,4，stdin）;
buf [4] ='\0';
if（strcmp（（char *）buf，data））exit（EXIT_FAILURE）;
/ * Subchunk2Size（NumSamples * NumChannels * BitsPerSample / 8）* /
fread（buf，1,4，stdin）
const unsigned int subchunk2_size = buf [0] +（buf [1] <8）+
（buf [2] <16）+ ] <24）;
* num_samp =（subchunk2_size<<< 3）/（
num_ch * * bits_per_samp）;
}
void read_wav_data（int * data，unsigned int samp_rate，
unsigned int bits_per_samp，unsigned int num_samp）
{
// freopen（/Users/ericbrotto/Desktop/iPhoneData/tmp/Hack.wav\",\"r\",stdin）;
freopen（C：/ Documents and Settings / Eric.Brotto / Desktop / Eric_Other / Files / Hack.wav，r，stdin）;
unsigned char buf;
unsigned int i，j;
for（i = 0; i
for（j = 0; j！= bits_per_samp; j + = 8）{
fread（& buf，1,1，stdin）;
tmp + = buf<< j;
}
data [i] = conv_bit_size（tmp，bits_per_samp）;
}
}
int conv_bit_size（unsigned int in，int bps）
{
const unsigned int max =（1< <（bps-1）） - 1;
return in> max？ in - （max<< 1）：in; //假设这不正确：http://ubuntuforums.org/showthread.php?p=10442711
//返回> max？ in - （（max< 1）+2）：in;
}
strong> EDIT 2
在我的mac上，它输出数组中的所有样本（int大约在-32000到32000之间）。这里我得到你在图像中看到的输出，后面是几百万个零。
即使假设两个编译器都符合ISO标准（这不一定是这样），那么该标准仍然有很多余地。
例如，如果你的程序使用实现定义或语言环境特定的行为，输出可以不同。
如果编写程序的人使用未定义的行为，那么这也是不同输出的可能。 >
您最好的选择是向我们展示正确分析的代码。
如果您对可能不同的内容， C99 的附录J（您可以使用TC1，2和3下载草稿从页面底部 - 它和最终产品之间的差异是最小的）列出了可移植性问题（未指定，未定义，实现定义和特定于语言环境的行为）。
<你> 可能需要小心。这可能不适用于Tiny C，但我知道我使用的Microsoft编译器是那个类
r和rb 在 fopen / freopen 中的处理方式不同。如果你只是指定r，翻译就会发生，这可能会给你一个二进制文件错误的数据，如 wav 文件。 I have a bit of c code that I've been working on in Xcode on my mac. I then wanted to work with it on a Windows machine and compile it with TinyC. When I run it, the output is different.
Is it possible that this is due to using different compilers?
Thanks!
EDIT 1
The code is a simple script that opens up a wav file to throw all the samples into an array.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
void read_wav_header(unsigned int *samp_rate, unsigned int *bits_per_samp,
unsigned int *num_samp);
void read_wav_data(int *data, unsigned int samp_rate,
unsigned int bits_per_samp, unsigned int num_samp);
int conv_bit_size(unsigned int in, int bps);
int main(void)
// int read_wav(void)
{
unsigned int samp_rate, bits_per_samp, num_samp;
read_wav_header(&samp_rate, &bits_per_samp, &num_samp);
printf("samp_rate=[%d] bits_per_samp=[%d] num_samp=[%d]\n",
samp_rate, bits_per_samp, num_samp);
int *data = (int *) malloc(num_samp * sizeof(int));
read_wav_data(data, samp_rate, bits_per_samp, num_samp);
unsigned int i;
// for (i = 0; i < num_samp; ++i) {
for (i = 0; i < 100; ++i) {
printf("%d\n", data[i]);
}
return EXIT_SUCCESS;
}
void read_wav_header(unsigned int *samp_rate, unsigned int *bits_per_samp,
unsigned int *num_samp)
{
unsigned char buf[5];
// freopen ("/Users/ericbrotto/Desktop/iPhoneData/tmp/Hack.wav","r",stdin);
freopen ("C:/Documents and Settings/Eric.Brotto/Desktop/Eric_Other/Files/Hack.wav","r",stdin);
/* ChunkID (RIFF for little-endian, RIFX for big-endian) */
fread(buf, 1, 4, stdin);
buf[4] = '\0';
if (strcmp((char*)buf, "RIFF")) exit(EXIT_FAILURE);
/* ChunkSize */
fread(buf, 1, 4, stdin);
/* Format */
fread(buf, 1, 4, stdin);
buf[4] = '\0';
printf("IS THIS WAVE? -->%s<--\n",(char*)buf);
if (strcmp((char*)buf, "WAVE")) exit(EXIT_FAILURE);
/* Subchunk1ID */
fread(buf, 1, 4, stdin);
buf[4] = '\0';
printf("IS THIS fmt? -->%s<--\n",(char*)buf);
if (strcmp((char*)buf, "fmt ")) exit(EXIT_FAILURE);
/* Subchunk1Size (16 for PCM) */
fread(buf, 1, 4, stdin);
if (buf[0] != 16 || buf[1] || buf[2] || buf[3]) exit(EXIT_FAILURE);
/* AudioFormat (PCM = 1, other values indicate compression) */
fread(buf, 1, 2, stdin);
if (buf[0] != 1 || buf[1]) exit(EXIT_FAILURE);
/* NumChannels (Mono = 1, Stereo = 2, etc) */
fread(buf, 1, 2, stdin);
unsigned int num_ch = buf[0] + (buf[1] << 8);
if (num_ch != 1) exit(EXIT_FAILURE);
/* SampleRate (8000, 44100, etc) */
fread(buf, 1, 4, stdin);
*samp_rate = buf[0] + (buf[1] << 8) +
(buf[2] << 16) + (buf[3] << 24);
/* ByteRate (SampleRate * NumChannels * BitsPerSample / 8) */
fread(buf, 1, 4, stdin);
const unsigned int byte_rate = buf[0] + (buf[1] << 8) +
(buf[2] << 16) + (buf[3] << 24);
/* BlockAlign (NumChannels * BitsPerSample / 8) */
fread(buf, 1, 2, stdin);
const unsigned int block_align = buf[0] + (buf[1] << 8);
/* BitsPerSample */
fread(buf, 1, 2, stdin);
*bits_per_samp = buf[0] + (buf[1] << 8);
if (byte_rate != ((*samp_rate * num_ch * *bits_per_samp) >> 3))
exit(EXIT_FAILURE);
if (block_align != ((num_ch * *bits_per_samp) >> 3))
exit(EXIT_FAILURE);
/* Subchunk2ID */
// fread reads line by line until the end.
fread(buf, 1, 4, stdin);
buf[4] = '\0';
if (strcmp((char*)buf, "data")) exit(EXIT_FAILURE);
/* Subchunk2Size (NumSamples * NumChannels * BitsPerSample / 8) */
fread(buf, 1, 4, stdin);
const unsigned int subchunk2_size = buf[0] + (buf[1] << 8) +
(buf[2] << 16) + (buf[3] << 24);
*num_samp = (subchunk2_size << 3) / (
num_ch * *bits_per_samp);
}
void read_wav_data(int *data, unsigned int samp_rate,
unsigned int bits_per_samp, unsigned int num_samp)
{
// freopen ("/Users/ericbrotto/Desktop/iPhoneData/tmp/Hack.wav","r",stdin);
freopen ("C:/Documents and Settings/Eric.Brotto/Desktop/Eric_Other/Files/Hack.wav","r",stdin);
unsigned char buf;
unsigned int i, j;
for (i=0; i < num_samp; ++i) {
unsigned int tmp = 0;
for (j=0; j != bits_per_samp; j+=8) {
fread(&buf, 1, 1, stdin);
tmp += buf << j;
}
data[i] = conv_bit_size(tmp, bits_per_samp);
}
}
int conv_bit_size(unsigned int in, int bps)
{
const unsigned int max = (1 << (bps-1)) - 1;
return in > max ? in - (max<<1) : in; // Supposedly this is not correct: http://ubuntuforums.org/showthread.php?p=10442711
// return in > max ? in - ((max<<1)+2) : in;
}
EDIT 2
On my mac it outputs all the samples in the array (ints roughly between -32000 and 32000). Here I get the output you see in the image followed by a few million zeros.
Yes. Even assuming that both compilers comply with the ISO standard (which is not necessarily so), there's still a lot of leeway in that standard.
For example, if your program uses implementation defined or locale-specific behaviour, the output can be different.
If whoever wrote the program used undefined behaviour, then that's also a possibility for different output.
Your best bet would be to show us the code for proper analysis.
If you're interested in the sorts of things that can differ, Annex J of C99 (you can downlaod the draft with TC1, 2 and 3 from the bottom of that page - the differences between that and the final product are minimal) lists the portability issues (unspecified, undefined, implementation-defined and locale-specific behaviour).
One thing you may want to be careful of. This may not apply to Tiny C but I know that the Microsoft compilers I've used are one of that class where "r" and "rb" are treated differently in fopen/freopen. If you just specify "r", translation takes place which may give you the wrong data from a binary file such as a wav file.
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