我的工作,我已經採取了舊代碼(太多c和以小C++爲我自己的口味愛好的小項目(www.github.com/AzP/GLSL-Validate),但是,嘿,什麼都可以你呢?),我試圖在Linux和Windows上運行它。我遇到了一些崩潰(現在有希望修復),但是自從我開始運行Valgrind來查找問題時,我陷入了想要解決我得到的抱怨的困境。Valgrind的抱怨與「大小8的無效寫」
我看不出有什麼不對的代碼與問候到Valgrind的投訴(除了它是相當難有很好的「幻數」讀遍佈的地方)。
我跑Valgrind的使用下面的命令valgrind --track-origins=yes ./Program
291 //
292 // Malloc a string of sufficient size and read a string into it.
293 //
294 # define MAX_SOURCE_STRINGS 5
295 char** ReadFileData(char *fileName)
296 {
297 FILE *in = fopen(fileName, "r");
298 char *fdata;
299 int count = 0;
300 char**return_data=(char**)malloc(MAX_SOURCE_STRINGS+1);
301
302 //return_data[MAX_SOURCE_STRINGS]=NULL;
303 if (!in) {
304 printf("Error: unable to open input file: %s\n", fileName);
305 return 0;
306 }
307
308 // Count size of file by looping through it
309 while (fgetc(in) != EOF)
310 count++;
311
312 fseek(in, 0, SEEK_SET);
313
314
315 if (!(fdata = (char *)malloc(count+2))) {
316 printf("Error allocating memory\n");
317 return 0;
318 }
319 if (fread(fdata, sizeof(char), count, in) != count) {
320 printf("Error reading input file: %s\n", fileName);
321 return 0;
322 }
323 fdata[count] = '\0';
324 fclose(in);
325 if(count==0){
326 return_data[0]=(char*)malloc(count+2);
327 return_data[0][0]='\0';
328 OutputMultipleStrings=0;
329 return return_data;
330 }
331
332 int len = (int)(ceil)((float)count/(float)OutputMultipleStrings);
333 int ptr_len=0,i=0;
334 while(count>0){
335 return_data[i]=(char*)malloc(len+2);
336 memcpy(return_data[i],fdata+ptr_len,len);
337 return_data[i][len]='\0';
338 count-=(len);
339 ptr_len+=(len);
340 if(count<len){
341 if(count==0){
342 OutputMultipleStrings=(i+1);
343 break;
344 }
345 len = count;
346 }
347 ++i;
348 }
349 return return_data;
350 }
這裏來的Valgrind的輸出。 is 0 bytes inside a block of size 6 alloc'd
是否意味着我可以無視它?我的意思是'0字節'聽起來不危險?但是因爲我在這裏發佈了這個問題,我想你可以看到我認爲我應該關注它。
==10570== Invalid write of size 8
==10570== at 0x401602: ReadFileData(char*) (StandAlone.cpp:335)
==10570== by 0x4013D8: CompileFile(char*, void*, int, TBuiltInResource const*) (StandAlone.cpp:255)
==10570== by 0x401016: main (StandAlone.cpp:152)
==10570== Address 0x5f627a0 is 0 bytes inside a block of size 6 alloc'd
==10570== at 0x4C2880D: malloc (vg_replace_malloc.c:236)
==10570== by 0x401475: ReadFileData(char*) (StandAlone.cpp:300)
==10570== by 0x4013D8: CompileFile(char*, void*, int, TBuiltInResource const*) (StandAlone.cpp:255)
==10570== by 0x401016: main (StandAlone.cpp:152)
==10570==
==10570== Invalid read of size 8
==10570== at 0x401624: ReadFileData(char*) (StandAlone.cpp:336)
==10570== by 0x4013D8: CompileFile(char*, void*, int, TBuiltInResource const*) (StandAlone.cpp:255)
==10570== by 0x401016: main (StandAlone.cpp:152)
==10570== Address 0x5f627a0 is 0 bytes inside a block of size 6 alloc'd
==10570== at 0x4C2880D: malloc (vg_replace_malloc.c:236)
==10570== by 0x401475: ReadFileData(char*) (StandAlone.cpp:300)
==10570== by 0x4013D8: CompileFile(char*, void*, int, TBuiltInResource const*) (StandAlone.cpp:255)
==10570== by 0x401016: main (StandAlone.cpp:152)
==10570==
==10570== Invalid read of size 8
==10570== at 0x40163F: ReadFileData(char*) (StandAlone.cpp:337)
==10570== by 0x4013D8: CompileFile(char*, void*, int, TBuiltInResource const*) (StandAlone.cpp:255)
==10570== by 0x401016: main (StandAlone.cpp:152)
==10570== Address 0x5f627a0 is 0 bytes inside a block of size 6 alloc'd
==10570== at 0x4C2880D: malloc (vg_replace_malloc.c:236)
==10570== by 0x401475: ReadFileData(char*) (StandAlone.cpp:300)
==10570== by 0x4013D8: CompileFile(char*, void*, int, TBuiltInResource const*) (StandAlone.cpp:255)
==10570== by 0x401016: main (StandAlone.cpp:152)
編輯:我需要的代碼在C++編譯器來編譯,這就是爲什麼我要不停的malloc
所有的轉換。
也許跟蹤'我'的值,看看他們是否超過5。 –
你的意思是6,如在MAX_SOURCE_STRINGS + 1? – AzP