tools/build/fixdep.c
Source file repositories/reference/linux-study-clean/tools/build/fixdep.c
File Facts
- System
- Linux kernel
- Corpus path
tools/build/fixdep.c- Extension
.c- Size
- 3805 bytes
- Lines
- 171
- Domain
- Support Tooling And Documentation
- Bucket
- tools
- Inferred role
- Support Tooling And Documentation: implementation source
- Status
- source implementation candidate
Why This File Exists
Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
sys/types.hsys/stat.hsys/mman.hunistd.hfcntl.hstring.hstdlib.hstdio.hlimits.h
Detected Declarations
function usagefunction print_cmdlinefunction parse_dep_filefunction print_depsfunction main
Annotated Snippet
if (is_target) {
/* The /next/ file is the first dependency */
is_first_dep = 1;
has_target = 1;
} else if (has_target) {
/* Save this token/filename */
memcpy(s, m, p-m);
s[p - m] = 0;
/*
* Do not list the source file as dependency,
* so that kbuild is not confused if a .c file
* is rewritten into .S or vice versa. Storing
* it in source_* is needed for modpost to
* compute srcversions.
*/
if (is_first_dep) {
/*
* If processing the concatenation of
* multiple dependency files, only
* process the first target name, which
* will be the original source name,
* and ignore any other target names,
* which will be intermediate temporary
* files.
*/
if (!saw_any_target) {
saw_any_target = 1;
printf("source_%s := %s\n\n",
target, s);
printf("deps_%s := \\\n",
target);
}
is_first_dep = 0;
} else
printf(" %s \\\n", s);
}
/*
* Start searching for next token immediately after the first
* "whitespace" character that follows this token.
*/
m = p + 1;
}
if (!saw_any_target) {
fprintf(stderr, "fixdep: parse error; no targets found\n");
exit(1);
}
printf("\n%s: $(deps_%s)\n\n", target, target);
printf("$(deps_%s):\n", target);
}
static void print_deps(void)
{
struct stat st;
int fd;
void *map;
fd = open(depfile, O_RDONLY);
if (fd < 0) {
fprintf(stderr, "fixdep: error opening depfile: ");
perror(depfile);
exit(2);
}
if (fstat(fd, &st) < 0) {
fprintf(stderr, "fixdep: error fstat'ing depfile: ");
perror(depfile);
exit(2);
}
if (st.st_size == 0) {
fprintf(stderr, "fixdep: %s is empty\n", depfile);
close(fd);
return;
}
map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
if ((long) map == -1) {
perror("fixdep: mmap");
close(fd);
return;
}
parse_dep_file(map, st.st_size);
munmap(map, st.st_size);
close(fd);
}
int main(int argc, char **argv)
Annotation
- Immediate include surface: `sys/types.h`, `sys/stat.h`, `sys/mman.h`, `unistd.h`, `fcntl.h`, `string.h`, `stdlib.h`, `stdio.h`.
- Detected declarations: `function usage`, `function print_cmdline`, `function parse_dep_file`, `function print_deps`, `function main`.
- Atlas domain: Support Tooling And Documentation / tools.
- Implementation status: source implementation candidate.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.