https://gcc.gnu.org/g:ed6690a0ca911138abd4d707510fd03ef188a28b
commit r15-382-ged6690a0ca911138abd4d707510fd03ef188a28b
Author: Mark Harmstone <m...@harmstone.com>
Date: Sat May 11 08:15:43 2024 -0600
[PATCH v2 2/4] Output file checksums in CodeView section
Outputs the file name and MD5 hash of the main source file into the
CodeView .debug$S section, along with that of any #include'd files.
gcc/
* dwarf2codeview.cc (DEBUG_S_STRINGTABLE): Define.
(DEBUG_S_FILECHKSMS, CHKSUM_TYPE_MD5, HASH_SIZE): Likewise.
(codeview_string, codeview_source_file): New structures.
(struct string_hasher): New class for codeview_string hashing.
(files, last_file, num_files, string_offset): New variables.
(strings_hstab, strings, last_string): Likewise.
(add_string, codevie_start_source_file): New functions.
(write_strings_tabe, write_soruce_files): Likewise.
(codeview_debug_finish): Call new functions.
* dwarf2codeview.h (codeview_start_source_file): Prototype.
* dwarf2out.cc (dwarf2out_start_source_file): Handle codeview.
Diff:
---
gcc/dwarf2codeview.cc | 254 ++++++++++++++++++++++++++++++++++++++++++++++++++
gcc/dwarf2codeview.h | 1 +
gcc/dwarf2out.cc | 5 +
3 files changed, 260 insertions(+)
diff --git a/gcc/dwarf2codeview.cc b/gcc/dwarf2codeview.cc
index f08f5d55ad7c..da8315310b50 100644
--- a/gcc/dwarf2codeview.cc
+++ b/gcc/dwarf2codeview.cc
@@ -39,6 +39,257 @@ along with GCC; see the file COPYING3. If not see
#define CV_SIGNATURE_C13 4
+#define DEBUG_S_STRINGTABLE 0xf3
+#define DEBUG_S_FILECHKSMS 0xf4
+
+#define CHKSUM_TYPE_MD5 1
+
+#define HASH_SIZE 16
+
+struct codeview_string
+{
+ codeview_string *next;
+ uint32_t offset;
+ char *string;
+};
+
+struct string_hasher : free_ptr_hash <struct codeview_string>
+{
+ typedef const char *compare_type;
+
+ static hashval_t hash (const codeview_string *x)
+ {
+ return htab_hash_string (x->string);
+ }
+
+ static bool equal (const codeview_string *x, const char *y)
+ {
+ return !strcmp (x->string, y);
+ }
+
+ static void mark_empty (codeview_string *x)
+ {
+ if (x->string)
+ {
+ free (x->string);
+ x->string = NULL;
+ }
+ }
+
+ static void remove (codeview_string *&x)
+ {
+ free (x->string);
+ }
+};
+
+struct codeview_source_file
+{
+ codeview_source_file *next;
+ unsigned int file_num;
+ uint32_t string_offset;
+ char *filename;
+ uint8_t hash[HASH_SIZE];
+};
+
+static codeview_source_file *files, *last_file;
+static unsigned int num_files;
+static uint32_t string_offset = 1;
+static hash_table<string_hasher> *strings_htab;
+static codeview_string *strings, *last_string;
+
+/* Adds string to the string table, returning its offset. If already present,
+ this returns the offset of the existing string. */
+
+static uint32_t
+add_string (const char *string)
+{
+ codeview_string **slot;
+ codeview_string *s;
+ size_t len;
+
+ if (!strings_htab)
+ strings_htab = new hash_table<string_hasher> (10);
+
+ slot = strings_htab->find_slot_with_hash (string, htab_hash_string (string),
+ INSERT);
+
+ if (*slot)
+ return (*slot)->offset;
+
+ s = (codeview_string *) xmalloc (sizeof (codeview_string));
+ len = strlen (string);
+
+ s->next = NULL;
+
+ s->offset = string_offset;
+ string_offset += len + 1;
+
+ s->string = xstrdup (string);
+
+ if (last_string)
+ last_string->next = s;
+ else
+ strings = s;
+
+ last_string = s;
+
+ *slot = s;
+
+ return s->offset;
+}
+
+/* A new source file has been encountered - record the details and calculate
+ its hash. */
+
+void
+codeview_start_source_file (const char *filename)
+{
+ codeview_source_file *sf;
+ char *path;
+ uint32_t string_offset;
+ FILE *f;
+
+ path = lrealpath (filename);
+ string_offset = add_string (path);
+ free (path);
+
+ sf = files;
+ while (sf)
+ {
+ if (sf->string_offset == string_offset)
+ return;
+
+ sf = sf->next;
+ }
+
+ sf = (codeview_source_file *) xmalloc (sizeof (codeview_source_file));
+ sf->next = NULL;
+ sf->file_num = num_files;
+ sf->string_offset = string_offset;
+ sf->filename = xstrdup (filename);
+
+ f = fopen (filename, "r");
+ if (!f)
+ internal_error ("could not open %s for reading", filename);
+
+ if (md5_stream (f, sf->hash))
+ {
+ fclose (f);
+ internal_error ("md5_stream failed");
+ }
+
+ fclose (f);
+
+ if (last_file)
+ last_file->next = sf;
+ else
+ files = sf;
+
+ last_file = sf;
+ num_files++;
+}
+
+/* Write out the strings table into the .debug$S section. The linker will
+ parse this, and handle the deduplication and hashing for all the object
+ files. */
+
+static void
+write_strings_table (void)
+{
+ codeview_string *string;
+
+ fputs (integer_asm_op (4, false), asm_out_file);
+ fprint_whex (asm_out_file, DEBUG_S_STRINGTABLE);
+ putc ('\n', asm_out_file);
+
+ fputs (integer_asm_op (4, false), asm_out_file);
+ asm_fprintf (asm_out_file, "%LLcv_strings_end - %LLcv_strings_start\n");
+
+ asm_fprintf (asm_out_file, "%LLcv_strings_start:\n");
+
+ /* The first entry is always an empty string. */
+ fputs (integer_asm_op (1, false), asm_out_file);
+ fprint_whex (asm_out_file, 0);
+ putc ('\n', asm_out_file);
+
+ string = strings;
+ while (string)
+ {
+ ASM_OUTPUT_ASCII (asm_out_file, string->string,
+ strlen (string->string) + 1);
+
+ string = string->next;
+ }
+
+ delete strings_htab;
+
+ asm_fprintf (asm_out_file, "%LLcv_strings_end:\n");
+
+ ASM_OUTPUT_ALIGN (asm_out_file, 2);
+}
+
+/* Write out the file checksums data into the .debug$S section. */
+
+static void
+write_source_files (void)
+{
+ fputs (integer_asm_op (4, false), asm_out_file);
+ fprint_whex (asm_out_file, DEBUG_S_FILECHKSMS);
+ putc ('\n', asm_out_file);
+
+ fputs (integer_asm_op (4, false), asm_out_file);
+ asm_fprintf (asm_out_file,
+ "%LLcv_filechksms_end - %LLcv_filechksms_start\n");
+
+ asm_fprintf (asm_out_file, "%LLcv_filechksms_start:\n");
+
+ while (files)
+ {
+ codeview_source_file *next = files->next;
+
+ /* This is struct file_checksum in binutils, or filedata in Microsoft's
+ dumpsym7.cpp:
+
+ struct file_checksum
+ {
+ uint32_t file_id;
+ uint8_t checksum_length;
+ uint8_t checksum_type;
+ } ATTRIBUTE_PACKED;
+
+ followed then by the bytes of the hash, padded to the next 4 bytes.
+ file_id here is actually the offset in the strings table. */
+
+ fputs (integer_asm_op (4, false), asm_out_file);
+ fprint_whex (asm_out_file, files->string_offset);
+ putc ('\n', asm_out_file);
+
+ fputs (integer_asm_op (1, false), asm_out_file);
+ fprint_whex (asm_out_file, HASH_SIZE);
+ putc ('\n', asm_out_file);
+
+ fputs (integer_asm_op (1, false), asm_out_file);
+ fprint_whex (asm_out_file, CHKSUM_TYPE_MD5);
+ putc ('\n', asm_out_file);
+
+ for (unsigned int i = 0; i < HASH_SIZE; i++)
+ {
+ fputs (integer_asm_op (1, false), asm_out_file);
+ fprint_whex (asm_out_file, files->hash[i]);
+ putc ('\n', asm_out_file);
+ }
+
+ ASM_OUTPUT_ALIGN (asm_out_file, 2);
+
+ free (files->filename);
+ free (files);
+
+ files = next;
+ }
+
+ asm_fprintf (asm_out_file, "%LLcv_filechksms_end:\n");
+}
+
/* Finish CodeView debug info emission. */
void
@@ -49,6 +300,9 @@ codeview_debug_finish (void)
fputs (integer_asm_op (4, false), asm_out_file);
fprint_whex (asm_out_file, CV_SIGNATURE_C13);
putc ('\n', asm_out_file);
+
+ write_strings_table ();
+ write_source_files ();
}
#endif
diff --git a/gcc/dwarf2codeview.h b/gcc/dwarf2codeview.h
index efda148eb498..e2d732bb9b6a 100644
--- a/gcc/dwarf2codeview.h
+++ b/gcc/dwarf2codeview.h
@@ -26,5 +26,6 @@ along with GCC; see the file COPYING3. If not see
/* Debug Format Interface. Used in dwarf2out.cc. */
extern void codeview_debug_finish (void);
+extern void codeview_start_source_file (const char *);
#endif /* GCC_DWARF2CODEVIEW_H */
diff --git a/gcc/dwarf2out.cc b/gcc/dwarf2out.cc
index f7e9f90e2746..43ef714b75e5 100644
--- a/gcc/dwarf2out.cc
+++ b/gcc/dwarf2out.cc
@@ -28889,6 +28889,11 @@ dwarf2out_set_ignored_loc (unsigned int line, unsigned
int column,
static void
dwarf2out_start_source_file (unsigned int lineno, const char *filename)
{
+#ifdef CODEVIEW_DEBUGGING_INFO
+ if (codeview_debuginfo_p ())
+ codeview_start_source_file (filename);
+#endif
+
if (debug_info_level >= DINFO_LEVEL_VERBOSE)
{
macinfo_entry e;
