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Message-Id: <20250926030252.2387681-1-kees@kernel.org>
Date: Thu, 25 Sep 2025 20:02:43 -0700
From: Kees Cook <kees@...nel.org>
To: Qing Zhao <qing.zhao@...cle.com>
Cc: Kees Cook <kees@...nel.org>,
Andrew Pinski <pinskia@...il.com>,
Jakub Jelinek <jakub@...hat.com>,
Martin Uecker <uecker@...raz.at>,
Richard Biener <rguenther@...e.de>,
Joseph Myers <josmyers@...hat.com>,
Peter Zijlstra <peterz@...radead.org>,
Ard Biesheuvel <ardb@...nel.org>,
Jeff Law <jeffreyalaw@...il.com>,
Jan Hubicka <hubicka@....cz>,
Richard Earnshaw <richard.earnshaw@....com>,
Richard Sandiford <richard.sandiford@....com>,
Marcus Shawcroft <marcus.shawcroft@....com>,
Kyrylo Tkachov <kyrylo.tkachov@....com>,
Kito Cheng <kito.cheng@...il.com>,
Palmer Dabbelt <palmer@...belt.com>,
Andrew Waterman <andrew@...ive.com>,
Jim Wilson <jim.wilson.gcc@...il.com>,
Dan Li <ashimida.1990@...il.com>,
Sami Tolvanen <samitolvanen@...gle.com>,
Ramon de C Valle <rcvalle@...gle.com>,
Joao Moreira <joao@...rdrivepizza.com>,
Nathan Chancellor <nathan@...nel.org>,
Bill Wendling <morbo@...gle.com>,
gcc-patches@....gnu.org,
linux-hardening@...r.kernel.org
Subject: [PATCH v4 1/7] typeinfo: Introduce KCFI typeinfo mangling API
To support the KCFI typeid and future type-based allocators, which need
to convert unique types into unique 32-bit values, add a mangling system
based on the Itanium C++ mangling ABI, adapted for C types. Introduce
__builtin_typeinfo_hash for the hash, and __builtin_typeinfo_name for
testing and debugging (to see the human-readable mangling form). Add
tests for typeinfo validation and error handling.
An important aspect of the C++ typeinfo behavior that is retained here
is that typedefs are treated as pass-through except when the underlying
type lacks a tag (i.e. anonymous struct, union, or enum). This provides a
distinction between those typedefs and typedefs used to provide _aliases_
(u8, uint16_t).
In the future, an additional "strict mode" builtin helper pair could
also be added to follow strict ISO C type equivalency instead of the
existing typeinfo used here, but that is out of scope for this patch.
gcc/ChangeLog:
* Makefile.in: Add kcfi-typeinfo.o.
* doc/extend.texi: Document typeinfo builtins.
* kcfi-typeinfo.h: New file, typeinfo mangling API.
* kcfi-typeinfo.cc: New file, implement typeinfo mangling.
gcc/c-family/ChangeLog:
* c-common.h (enum rid): Add typeinfo builtins.
* c-common.cc: Add typeinfo builtins.
gcc/c/ChangeLog:
* c-parser.cc (c_parser_get_builtin_type_arg): New function,
parse type.
(c_parser_postfix_expression): Add typeinfo builtins.
gcc/testsuite/ChangeLog:
* gcc.dg/builtin-typeinfo-errors.c: New test, validate bad
arguments are rejected.
* gcc.dg/builtin-typeinfo.c: New test, typeinfo mangling.
Signed-off-by: Kees Cook <kees@...nel.org>
---
gcc/doc/extend.texi | 94 ++++
.../gcc.dg/builtin-typeinfo-errors.c | 28 ++
gcc/testsuite/gcc.dg/builtin-typeinfo.c | 350 +++++++++++++
gcc/Makefile.in | 1 +
gcc/c-family/c-common.h | 1 +
gcc/kcfi-typeinfo.h | 32 ++
gcc/c-family/c-common.cc | 2 +
gcc/c/c-parser.cc | 72 +++
gcc/kcfi-typeinfo.cc | 472 ++++++++++++++++++
9 files changed, 1052 insertions(+)
create mode 100644 gcc/testsuite/gcc.dg/builtin-typeinfo-errors.c
create mode 100644 gcc/testsuite/gcc.dg/builtin-typeinfo.c
create mode 100644 gcc/kcfi-typeinfo.h
create mode 100644 gcc/kcfi-typeinfo.cc
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 596cb5d32598..a030cacfc2d3 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -17545,6 +17545,100 @@ which will cause a @code{NULL} pointer to be used for the unsafe case.
@enddefbuiltin
+@...builtin{{unsigned int} __builtin_typeinfo_hash (@var{type})}
+
+The built-in function @code{__builtin_typeinfo_hash} returns a hash value
+for the given type @var{type} (which is a type, not an expression). The hash
+is computed using the FNV-1a algorithm on the type's mangled name representation,
+which follows a subset of the Itanium C++ ABI conventions adapted for C types.
+(See @code{__buitin_typeinfo_name} for the string representation.)
+
+This built-in is primarily intended for kernel control flow integrity (KCFI)
+implementations and other type-aware runtime systems that need to generate
+consistent type identifiers. The hash value is a 32-bit unsigned integer.
+
+Key characteristics of the hash:
+@...mize @bullet
+@...m
+The hash is consistent for the same type across different translation units.
+@...m
+Typedefs are recursively canonicalized down to integral type name or named
+struct, union, or enum tag name.
+@...m
+Typedefs of anonymous structs, unions, and enums preserve the typedef name
+in the hash calculation (e.g., @code{typedef struct @{ int x; @} foo_t;}
+uses @code{foo_t} in the hash).
+@...m
+Type qualifiers (@code{const}, @code{volatile}, @code{restrict}) affect
+the hash value.
+@...m
+Function types include parameter types and variadic markers in the hash.
+@end itemize
+
+For example:
+@...llexample
+typedef struct @{ int x; @} mytype_t;
+unsigned int hash1 = __builtin_typeinfo_hash(mytype_t);
+unsigned int hash2 = __builtin_typeinfo_hash(struct @{ int x; @});
+/* hash1 != hash2 because the typedef name is preserved */
+
+void func(int x, char y);
+unsigned int hash3 = __builtin_typeinfo_hash(typeof(func));
+/* Returns hash for function type "void(int, char)" */
+@end smallexample
+
+@...h{Note:} This construct is only available for C@. For C++, see
+@...e{std::type_info::hash_code}.
+
+@...defbuiltin
+
+@...builtin{{const char *} __builtin_typeinfo_name (@var{type})}
+
+The built-in function @code{__builtin_typeinfo_name} returns a string
+containing the mangled name representation of the given type @var{type}
+(which is a type, not an expression). The string follows a subset of the
+Itanium C++ ABI mangling conventions adapted for C types. (See
+@...e{__buitin_typeinfo_hash} for the unsigned 32-bit hash representation.)
+
+The returned string is a compile-time constant suitable for use in
+string comparisons, debugging output, or other type introspection needs.
+The string begins with @code{_ZTS} followed by the encoded type information.
+
+Mangling examples:
+@...mize @bullet
+@...m
+@...e{int} becomes @code{"_ZTSi"}
+@...m
+@...e{char *} becomes @code{"_ZTSPc"}
+@...m
+@...e{const int} becomes @code{"_ZTSKi"}
+@...m
+@...e{int[10]} becomes @code{"_ZTSA10_i"}
+@...m
+@...e{void (*)(int)} becomes @code{"_ZTSPFviE"}
+@...m
+@...e{struct foo} becomes @code{"_ZTS3foo"}
+@...m
+@...e{typedef struct @{ int x; @} bar_t;} becomes @code{"_ZTS5bar_t"}
+@end itemize
+
+The mangling preserves typedef names for anonymous compound types, which
+is particularly useful for distinguishing between different typedefs of
+structurally identical anonymous types:
+
+@...llexample
+typedef struct @{ int x; @} type_a;
+typedef struct @{ int x; @} type_b;
+const char *name_a = __builtin_typeinfo_name(type_a); /* "_ZTS6type_a" */
+const char *name_b = __builtin_typeinfo_name(type_b); /* "_ZTS6type_b" */
+/* name_a and name_b are different despite identical structure */
+@end smallexample
+
+@...h{Note:} This construct is only available for C@. For C++, see
+@...e{std::type_info::name}.
+
+@...defbuiltin
+
@defbuiltin{int __builtin_types_compatible_p (@var{type1}, @var{type2})}
You can use the built-in function @code{__builtin_types_compatible_p} to
diff --git a/gcc/testsuite/gcc.dg/builtin-typeinfo-errors.c b/gcc/testsuite/gcc.dg/builtin-typeinfo-errors.c
new file mode 100644
index 000000000000..71ad01337b4e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/builtin-typeinfo-errors.c
@@ -0,0 +1,28 @@
+/* Test error handling for __builtin_typeinfo_name and __builtin_typeinfo_hash. */
+/* { dg-do compile } */
+
+int main() {
+ /* Test missing arguments */
+ const char *result1 = __builtin_typeinfo_name(); /* { dg-error "expected specifier-qualifier-list before '\\)'" } */
+ /* { dg-error "expected type name in '__builtin_typeinfo_name'" "" { target *-*-* } .-1 } */
+ unsigned int result2 = __builtin_typeinfo_hash(); /* { dg-error "expected specifier-qualifier-list before '\\)'" } */
+ /* { dg-error "expected type name in '__builtin_typeinfo_hash'" "" { target *-*-* } .-1 } */
+
+ /* Test wrong argument types (expressions instead of type names) */
+ const char *result3 = __builtin_typeinfo_name(42); /* { dg-error "expected specifier-qualifier-list before numeric constant" } */
+ /* { dg-error "expected type name in '__builtin_typeinfo_name'" "" { target *-*-* } .-1 } */
+ unsigned int result4 = __builtin_typeinfo_hash(42); /* { dg-error "expected specifier-qualifier-list before numeric constant" } */
+ /* { dg-error "expected type name in '__builtin_typeinfo_hash'" "" { target *-*-* } .-1 } */
+
+ int x = 5;
+ const char *result5 = __builtin_typeinfo_name(x); /* { dg-error "expected specifier-qualifier-list before" } */
+ /* { dg-error "expected type name in '__builtin_typeinfo_name'" "" { target *-*-* } .-1 } */
+ unsigned int result6 = __builtin_typeinfo_hash(x); /* { dg-error "expected specifier-qualifier-list before" } */
+ /* { dg-error "expected type name in '__builtin_typeinfo_hash'" "" { target *-*-* } .-1 } */
+
+ /* Test too many arguments */
+ const char *result7 = __builtin_typeinfo_name(int, int); /* { dg-error "expected '\\)' before ','" } */
+ unsigned int result8 = __builtin_typeinfo_hash(int, int); /* { dg-error "expected '\\)' before ','" } */
+
+ return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/builtin-typeinfo.c b/gcc/testsuite/gcc.dg/builtin-typeinfo.c
new file mode 100644
index 000000000000..307657310fec
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/builtin-typeinfo.c
@@ -0,0 +1,350 @@
+/* Test KCFI type mangling using __builtin_typeinfo_name. */
+/* { dg-do run } */
+/* { dg-options "-std=gnu99" } */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdarg.h>
+
+int pass, fail;
+
+#define TEST_STRING(expr, expected_string) \
+ do { \
+ const char *actual_string = __builtin_typeinfo_name(typeof(expr)); \
+ printf("Testing %s: ", #expr); \
+ if (strcmp(actual_string, expected_string) == 0) { \
+ printf("PASS (%s)\n", actual_string); \
+ pass ++; \
+ } else { \
+ printf("FAIL\n"); \
+ printf(" Expected: %s\n", expected_string); \
+ printf(" Actual: %s\n", actual_string); \
+ fail ++; \
+ } \
+ } while (0)
+
+int main(void)
+{
+ printf("Testing KCFI Typeinfo Mangling\n");
+ printf("======================================================\n");
+
+ /* Test basic types */
+ TEST_STRING(void, "v");
+ TEST_STRING(char, "c");
+ TEST_STRING(int, "i");
+ TEST_STRING(short, "s");
+ TEST_STRING(long, "l");
+ TEST_STRING(float, "f");
+ TEST_STRING(double, "d");
+
+ /* Test qualified types */
+ TEST_STRING(const int, "Ki");
+ TEST_STRING(volatile int, "Vi");
+
+ /* Test pointer types */
+ TEST_STRING(char*, "Pc");
+ TEST_STRING(int*, "Pi");
+ TEST_STRING(void*, "Pv");
+ TEST_STRING(const char*, "PKc");
+
+ /* Test array types */
+ TEST_STRING(int[10], "A10_i");
+ TEST_STRING(char[20], "A20_c");
+ TEST_STRING(short[], "A_s");
+
+ /* Test basic function types */
+ extern void func_void(void);
+ extern void func_char(char x);
+ extern void func_short(short x);
+ extern void func_int(int x);
+ extern void func_long(long x);
+ TEST_STRING(func_void, "FvvE");
+ TEST_STRING(func_char, "FvcE");
+ TEST_STRING(func_short, "FvsE");
+ TEST_STRING(func_int, "FviE");
+ TEST_STRING(func_long, "FvlE");
+
+ /* Test functions with unsigned types */
+ extern void func_unsigned_char(unsigned char x);
+ extern void func_unsigned_short(unsigned short x);
+ extern void func_unsigned_int(unsigned int x);
+ TEST_STRING(func_unsigned_char, "FvhE");
+ TEST_STRING(func_unsigned_short, "FvtE");
+ TEST_STRING(func_unsigned_int, "FvjE");
+
+ /* Test functions with signed types */
+ extern void func_signed_char(signed char x);
+ extern void func_signed_short(signed short x);
+ extern void func_signed_int(signed int x);
+ TEST_STRING(func_signed_char, "FvaE");
+ TEST_STRING(func_signed_short, "FvsE");
+ TEST_STRING(func_signed_int, "FviE");
+
+ /* Test functions with pointer types */
+ extern void func_void_ptr(void *x);
+ extern void func_char_ptr(char *x);
+ extern void func_short_ptr(short *x);
+ extern void func_int_ptr(int *x);
+ extern void func_int_array(int arr[]); /* Decays to "int *". */
+ extern void func_long_ptr(long *x);
+ TEST_STRING(func_void_ptr, "FvPvE");
+ TEST_STRING(func_char_ptr, "FvPcE");
+ TEST_STRING(func_short_ptr, "FvPsE");
+ TEST_STRING(func_int_ptr, "FvPiE");
+ TEST_STRING(func_int_array, "FvPiE");
+ TEST_STRING(func_long_ptr, "FvPlE");
+
+ /* Test functions with const qualifiers */
+ extern void func_const_void_ptr(const void *x);
+ extern void func_const_char_ptr(const char *x);
+ extern void func_const_short_ptr(const short *x);
+ extern void func_const_int_ptr(const int *x);
+ extern void func_const_long_ptr(const long *x);
+ TEST_STRING(func_const_void_ptr, "FvPKvE");
+ TEST_STRING(func_const_char_ptr, "FvPKcE");
+ TEST_STRING(func_const_short_ptr, "FvPKsE");
+ TEST_STRING(func_const_int_ptr, "FvPKiE");
+ TEST_STRING(func_const_long_ptr, "FvPKlE");
+
+ /* Test nested pointers */
+ extern void func_int_ptr_ptr(int **x);
+ extern void func_char_ptr_ptr(char **x);
+ TEST_STRING(func_int_ptr_ptr, "FvPPiE");
+ TEST_STRING(func_char_ptr_ptr, "FvPPcE");
+
+ /* Test multiple parameters */
+ extern void func_int_char(int x, char y);
+ extern void func_char_int(char x, int y);
+ extern void func_two_int(int x, int y);
+ TEST_STRING(func_int_char, "FvicE");
+ TEST_STRING(func_char_int, "FvciE");
+ TEST_STRING(func_two_int, "FviiE");
+
+ /* Test return types */
+ extern int func_return_int(void);
+ extern char func_return_char(void);
+ extern void* func_return_ptr(void);
+ TEST_STRING(func_return_int, "FivE");
+ TEST_STRING(func_return_char, "FcvE");
+ TEST_STRING(func_return_ptr, "FPvvE");
+
+ /* Test function pointer parameters */
+ extern void func_fptr_void(void (*fp)(void));
+ extern void func_fptr_int(void (*fp)(int));
+ extern void func_fptr_ret_int(int (*fp)(void));
+ TEST_STRING(func_fptr_void, "FvPFvvEE");
+ TEST_STRING(func_fptr_int, "FvPFviEE");
+ TEST_STRING(func_fptr_ret_int, "FvPFivEE");
+
+ /* Test variadic functions */
+ struct audit_context { int dummy; };
+ extern void func_variadic_simple(const char *fmt, ...);
+ extern void func_variadic_mixed(int x, const char *fmt, ...);
+ extern void func_variadic_multi(int x, char y, const char *fmt, ...);
+ extern void audit_log_pattern(struct audit_context *ctx, unsigned int gfp_mask,
+ int type, const char *fmt, ...);
+ TEST_STRING(func_variadic_simple, "FvPKczE");
+ TEST_STRING(func_variadic_mixed, "FviPKczE");
+ TEST_STRING(func_variadic_multi, "FvicPKczE");
+ TEST_STRING(audit_log_pattern, "FvP13audit_contextjiPKczE");
+
+ /* Test mixed const/non-const */
+ extern void func_const_mixed(int x, const char *fmt);
+ TEST_STRING(func_const_mixed, "FviPKcE");
+
+ /* Test named struct types */
+ struct test_struct_a { int x; };
+ struct test_struct_b { char y; };
+ struct test_struct_c { void *ptr; };
+ TEST_STRING(struct test_struct_a, "13test_struct_a");
+ extern void func_struct_a_ptr(struct test_struct_a *x);
+ extern void func_struct_b_ptr(struct test_struct_b *x);
+ extern void func_struct_c_ptr(struct test_struct_c *x);
+ TEST_STRING(func_struct_a_ptr, "FvP13test_struct_aE");
+ TEST_STRING(func_struct_b_ptr, "FvP13test_struct_bE");
+ TEST_STRING(func_struct_c_ptr, "FvP13test_struct_cE");
+
+ /* Test const named struct types */
+ extern void func_const_struct_a_ptr(const struct test_struct_a *x);
+ extern void func_const_struct_b_ptr(const struct test_struct_b *x);
+ extern void func_const_struct_c_ptr(const struct test_struct_c *x);
+ TEST_STRING(func_const_struct_a_ptr, "FvPK13test_struct_aE");
+ TEST_STRING(func_const_struct_b_ptr, "FvPK13test_struct_bE");
+ TEST_STRING(func_const_struct_c_ptr, "FvPK13test_struct_cE");
+
+ /* Test named union types */
+ union test_union_a { int x; float y; };
+ union test_union_b { char a; void *b; };
+ TEST_STRING(union test_union_a, "12test_union_a");
+ extern void func_union_a_ptr(union test_union_a *x);
+ extern void func_union_b_ptr(union test_union_b *x);
+ TEST_STRING(func_union_a_ptr, "FvP12test_union_aE");
+ TEST_STRING(func_union_b_ptr, "FvP12test_union_bE");
+
+ /* Test enum types: distinct from int */
+ enum test_enum_a { ENUM_A_VAL };
+ enum test_enum_b { ENUM_B_VAL };
+ TEST_STRING(enum test_enum_a, "11test_enum_a");
+ extern void func_enum_a_ptr(enum test_enum_a *x);
+ extern void func_enum_b_ptr(enum test_enum_b *x);
+ TEST_STRING(func_enum_a_ptr, "FvP11test_enum_aE");
+ TEST_STRING(func_enum_b_ptr, "FvP11test_enum_bE");
+
+ /* Test union member discrimination */
+ struct tasklet {
+ int state;
+ union {
+ void (*func)(unsigned long data);
+ void (*callback)(struct tasklet *t);
+ };
+ unsigned long data;
+ } tasklet_instance;
+ TEST_STRING(tasklet_instance, "7tasklet");
+ struct tasklet *p = &tasklet_instance;
+ extern void tasklet_callback_function(struct tasklet *t);
+ extern void tasklet_func_function(unsigned long data);
+ TEST_STRING(tasklet_func_function, "FvmE");
+ TEST_STRING(*p->func, "FvmE");
+ TEST_STRING(tasklet_callback_function, "FvP7taskletE");
+ TEST_STRING(*p->callback, "FvP7taskletE");
+
+ /* Test struct return pointers */
+ extern struct test_struct_a* func_ret_struct_a_ptr(void);
+ extern struct test_struct_b* func_ret_struct_b_ptr(void);
+ extern struct test_struct_c* func_ret_struct_c_ptr(void);
+ TEST_STRING(func_ret_struct_a_ptr, "FP13test_struct_avE");
+ TEST_STRING(func_ret_struct_b_ptr, "FP13test_struct_bvE");
+ TEST_STRING(func_ret_struct_c_ptr, "FP13test_struct_cvE");
+
+ /* Test struct by-value parameters */
+ extern void func_struct_a_val(struct test_struct_a x);
+ extern void func_struct_b_val(struct test_struct_b x);
+ extern void func_struct_c_val(struct test_struct_c x);
+ TEST_STRING(func_struct_a_val, "Fv13test_struct_aE");
+ TEST_STRING(func_struct_b_val, "Fv13test_struct_bE");
+ TEST_STRING(func_struct_c_val, "Fv13test_struct_cE");
+
+ /* Test struct return by-value */
+ extern struct test_struct_a func_ret_struct_a_val(void);
+ extern struct test_struct_b func_ret_struct_b_val(void);
+ extern struct test_struct_c func_ret_struct_c_val(void);
+ TEST_STRING(func_ret_struct_a_val, "F13test_struct_avE");
+ TEST_STRING(func_ret_struct_b_val, "F13test_struct_bvE");
+ TEST_STRING(func_ret_struct_c_val, "F13test_struct_cvE");
+
+ /* Test mixed struct parameters */
+ extern void func_struct_a_b(struct test_struct_a *a, struct test_struct_b *b);
+ extern void func_struct_b_a(struct test_struct_b *b, struct test_struct_a *a);
+ TEST_STRING(func_struct_a_b, "FvP13test_struct_aP13test_struct_bE");
+ TEST_STRING(func_struct_b_a, "FvP13test_struct_bP13test_struct_aE");
+
+ /* Test anonymous struct typedefs */
+ typedef struct { int x; } typedef_struct_x;
+ typedef struct { int y; } typedef_struct_y;
+ TEST_STRING(typedef_struct_x, "16typedef_struct_x");
+ extern void func_typedef_x_ptr(typedef_struct_x *x);
+ extern void func_typedef_y_ptr(typedef_struct_y *y);
+ TEST_STRING(func_typedef_x_ptr, "FvP16typedef_struct_xE");
+ TEST_STRING(func_typedef_y_ptr, "FvP16typedef_struct_yE");
+ extern void func_typedef_x(typedef_struct_x x);
+ TEST_STRING(func_typedef_x, "Fv16typedef_struct_xE");
+
+ /* Test anonymous union typedefs */
+ typedef union { int x; short a; } typedef_union_x;
+ typedef union { int y; short b; } typedef_union_y;
+ TEST_STRING(typedef_union_x, "15typedef_union_x");
+ extern void func_typedef_union_x_ptr(typedef_union_x *x);
+ extern void func_typedef_union_y_ptr(typedef_union_y *y);
+ TEST_STRING(func_typedef_union_x_ptr, "FvP15typedef_union_xE");
+ TEST_STRING(func_typedef_union_y_ptr, "FvP15typedef_union_yE");
+ extern void func_typedef_union_x(typedef_union_x x);
+ TEST_STRING(func_typedef_union_x, "Fv15typedef_union_xE");
+
+ /* Test anonymous enum typedefs */
+ typedef enum { STEP_1, STEP_2 } typedef_enum_x;
+ typedef enum { STEP_A, STEP_B } typedef_enum_y;
+ TEST_STRING(typedef_enum_x, "14typedef_enum_x");
+ extern void func_typedef_enum_x_ptr(typedef_enum_x *x);
+ extern void func_typedef_enum_y_ptr(typedef_enum_y *y);
+ TEST_STRING(func_typedef_enum_x_ptr, "FvP14typedef_enum_xE");
+ TEST_STRING(func_typedef_enum_y_ptr, "FvP14typedef_enum_yE");
+ extern void func_typedef_enum_x(typedef_enum_x x);
+ TEST_STRING(func_typedef_enum_x, "Fv14typedef_enum_xE");
+
+ /* Test basic typedef vs open-coded function types: should be the same. */
+ typedef void (*func_type_typedef)(int, char);
+ TEST_STRING(func_type_typedef, "PFvicE");
+ extern void func_with_typedef_param(func_type_typedef fp);
+ extern void func_with_opencoded_param(void (*fp)(int, char));
+ TEST_STRING(func_with_typedef_param, "FvPFvicEE");
+ TEST_STRING(func_with_opencoded_param, "FvPFvicEE");
+
+ /* Test return function pointer types */
+ typedef int (*ret_func_type_typedef)(void);
+ TEST_STRING(ret_func_type_typedef, "PFivE");
+ extern ret_func_type_typedef func_ret_typedef_param(void);
+ extern int (*func_ret_opencoded_param(void))(void);
+ TEST_STRING(func_ret_typedef_param, "FPFivEvE");
+ TEST_STRING(func_ret_opencoded_param, "FPFivEvE");
+
+ /* Test additional type combos */
+ extern void func_float(float x);
+ extern void func_double_ptr(double *x);
+ extern void func_float_ptr(float *x);
+ extern void func_void_ptr_ptr(void **x);
+ extern void func_ptr_val(int *x, int y);
+ extern void func_val_ptr(int x, int *y);
+ extern float func_return_float(void);
+ extern double func_return_double(void);
+ TEST_STRING(func_float, "FvfE");
+ TEST_STRING(func_double_ptr, "FvPdE");
+ TEST_STRING(func_float_ptr, "FvPfE");
+ TEST_STRING(func_void_ptr_ptr, "FvPPvE");
+ TEST_STRING(func_ptr_val, "FvPiiE");
+ TEST_STRING(func_val_ptr, "FviPiE");
+ TEST_STRING(func_return_float, "FfvE");
+ TEST_STRING(func_return_double, "FdvE");
+
+ /* Test VLA types: should be all the same. */
+ extern void func_vla_1d(int n, int arr[n]);
+ extern void func_vla_empty(int n, int arr[]);
+ extern void func_vla_ptr(int n, int *arr);
+ TEST_STRING(func_vla_1d, "FviPiE");
+ TEST_STRING(func_vla_empty, "FviPiE");
+ TEST_STRING(func_vla_ptr, "FviPiE");
+
+ /* Test 2D VLA with fixed dimension: should be all the same. */
+ extern void func_vla_2d_first(int n, int arr[n][10]);
+ extern void func_vla_2d_empty(int n, int arr[][10]);
+ extern void func_vla_2d_ptr(int n, int (*arr)[10]);
+ TEST_STRING(func_vla_2d_first, "FviPA10_iE");
+ TEST_STRING(func_vla_2d_empty, "FviPA10_iE");
+ TEST_STRING(func_vla_2d_ptr, "FviPA10_iE");
+
+ /* Test 2D VLA with both dimensions variable: should be all the same. */
+ extern void func_vla_2d_both(int rows, int cols, int arr[rows][cols]);
+ extern void func_vla_2d_second(int rows, int cols, int arr[][cols]);
+ extern void func_vla_2d_star(int rows, int cols, int arr[*][cols]);
+ TEST_STRING(func_vla_2d_both, "FviiPA_iE");
+ TEST_STRING(func_vla_2d_second, "FviiPA_iE");
+ TEST_STRING(func_vla_2d_star, "FviiPA_iE");
+
+ /* Test recursive typedef canonicalization */
+ struct recursive_struct_test { int field; };
+ typedef struct recursive_struct_test recursive_struct_typedef_1;
+ typedef recursive_struct_typedef_1 recursive_struct_typedef_2;
+ extern void func_recursive_struct_test(struct recursive_struct_test *x);
+ TEST_STRING(func_recursive_struct_test, "FvP21recursive_struct_testE");
+
+ /* Test anonymous struct, union, enum types */
+ struct { int a; short b; } anon_struct;
+ union { int x; float y; } anon_union;
+ enum { ANON_VAL1, ANON_VAL2 } anon_enum;
+ TEST_STRING(anon_struct, "3$_0"); // <length>$_<counter>
+ TEST_STRING(anon_union, "3$_1"); // <length>$_<counter>
+ TEST_STRING(anon_enum, "3$_2"); // <length>$_<counter>
+
+ printf("\n================================================================\n");
+ printf("Passed: %d Failed: %d (%d total tests)\n", pass, fail, pass + fail);
+ return fail;
+}
diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index 4503dab60372..0e80b6c69c12 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -1592,6 +1592,7 @@ OBJS = \
ira-emit.o \
ira-lives.o \
jump.o \
+ kcfi-typeinfo.o \
langhooks.o \
late-combine.o \
lcm.o \
diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index b6021d241731..e0100837946e 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -112,6 +112,7 @@ enum rid
RID_BUILTIN_SHUFFLEVECTOR, RID_BUILTIN_CONVERTVECTOR, RID_BUILTIN_TGMATH,
RID_BUILTIN_HAS_ATTRIBUTE, RID_BUILTIN_ASSOC_BARRIER, RID_BUILTIN_STDC,
RID_BUILTIN_COUNTED_BY_REF,
+ RID_BUILTIN_TYPEINFO_NAME, RID_BUILTIN_TYPEINFO_HASH,
RID_DFLOAT32, RID_DFLOAT64, RID_DFLOAT128, RID_DFLOAT64X,
/* TS 18661-3 keywords, in the same sequence as the TI_* values. */
diff --git a/gcc/kcfi-typeinfo.h b/gcc/kcfi-typeinfo.h
new file mode 100644
index 000000000000..805f9ebaeca4
--- /dev/null
+++ b/gcc/kcfi-typeinfo.h
@@ -0,0 +1,32 @@
+/* KCFI-compatible type mangling, based on Itanium C++ ABI.
+ Copyright (C) 2025 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
+
+#ifndef GCC_KCFI_TYPEINFO_H
+#define GCC_KCFI_TYPEINFO_H
+
+#include "tree.h"
+#include <string>
+
+/* Get the typeinfo mangled name string for any C type. */
+extern std::string typeinfo_get_name (tree type);
+
+/* Get the typeinfo hash for any C type. */
+extern uint32_t typeinfo_get_hash (tree type);
+
+#endif /* GCC_KCFI_TYPEINFO_H */
diff --git a/gcc/c-family/c-common.cc b/gcc/c-family/c-common.cc
index e7dd4602ac11..94f2c2001ad5 100644
--- a/gcc/c-family/c-common.cc
+++ b/gcc/c-family/c-common.cc
@@ -461,6 +461,8 @@ const struct c_common_resword c_common_reswords[] =
{ "__builtin_stdc_trailing_zeros", RID_BUILTIN_STDC, D_CONLY },
{ "__builtin_tgmath", RID_BUILTIN_TGMATH, D_CONLY },
{ "__builtin_offsetof", RID_OFFSETOF, 0 },
+ { "__builtin_typeinfo_hash", RID_BUILTIN_TYPEINFO_HASH, D_CONLY },
+ { "__builtin_typeinfo_name", RID_BUILTIN_TYPEINFO_NAME, D_CONLY },
{ "__builtin_types_compatible_p", RID_TYPES_COMPATIBLE_P, D_CONLY },
{ "__builtin_c23_va_start", RID_C23_VA_START, D_C23 },
{ "__builtin_va_arg", RID_VA_ARG, 0 },
diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc
index df44a915ed4f..b20ea853e269 100644
--- a/gcc/c/c-parser.cc
+++ b/gcc/c/c-parser.cc
@@ -77,6 +77,7 @@ along with GCC; see the file COPYING3. If not see
#include "asan.h"
#include "c-family/c-ubsan.h"
#include "gcc-urlifier.h"
+#include "kcfi-typeinfo.h"
.
/* We need to walk over decls with incomplete struct/union/enum types
after parsing the whole translation unit.
@@ -11026,6 +11027,38 @@ c_parser_has_attribute_expression (c_parser *parser)
return result;
}
+/* Parse the single type name argument of a builtin that takes a type name.
+ Returns true on success and stores the parsed type in *OUT_TYPE.
+ If successful, *OUT_CLOSE_PAREN_LOC is written with the location of
+ the closing parenthesis. */
+
+static bool
+c_parser_get_builtin_type_arg (c_parser *parser, const char *bname,
+ tree *out_type, location_t *out_close_paren_loc)
+{
+ matching_parens parens;
+ if (!parens.require_open (parser))
+ return false;
+
+ struct c_type_name *type_name = c_parser_type_name (parser);
+ if (type_name == NULL)
+ {
+ error_at (c_parser_peek_token (parser)->location,
+ "expected type name in %qs", bname);
+ return false;
+ }
+
+ *out_close_paren_loc = c_parser_peek_token (parser)->location;
+ parens.skip_until_found_close (parser);
+
+ tree type = groktypename (type_name, NULL, NULL);
+ if (type == error_mark_node)
+ return false;
+
+ *out_type = type;
+ return true;
+}
+
/* Helper function to read arguments of builtins which are interfaces
for the middle-end nodes like COMPLEX_EXPR, VEC_PERM_EXPR and
others. The name of the builtin is passed using BNAME parameter.
@@ -12034,6 +12067,45 @@ c_parser_postfix_expression (c_parser *parser)
set_c_expr_source_range (&expr, loc, close_paren_loc);
}
break;
+ case RID_BUILTIN_TYPEINFO_NAME:
+ {
+ c_parser_consume_token (parser);
+ location_t close_paren_loc;
+ tree type;
+ if (!c_parser_get_builtin_type_arg (parser,
+ "__builtin_typeinfo_name",
+ &type, &close_paren_loc))
+ {
+ expr.set_error ();
+ break;
+ }
+
+ /* Call the typeinfo name function. */
+ std::string type_name = typeinfo_get_name (type);
+ expr.value = build_string_literal (type_name.length () + 1,
+ type_name.c_str ());
+ set_c_expr_source_range (&expr, loc, close_paren_loc);
+ }
+ break;
+ case RID_BUILTIN_TYPEINFO_HASH:
+ {
+ c_parser_consume_token (parser);
+ location_t close_paren_loc;
+ tree type;
+ if (!c_parser_get_builtin_type_arg (parser,
+ "__builtin_typeinfo_hash",
+ &type, &close_paren_loc))
+ {
+ expr.set_error ();
+ break;
+ }
+
+ /* Call the typeinfo hash function. */
+ uint32_t type_hash = typeinfo_get_hash (type);
+ expr.value = build_int_cst (unsigned_type_node, type_hash);
+ set_c_expr_source_range (&expr, loc, close_paren_loc);
+ }
+ break;
case RID_BUILTIN_TGMATH:
{
vec<c_expr_t, va_gc> *cexpr_list;
diff --git a/gcc/kcfi-typeinfo.cc b/gcc/kcfi-typeinfo.cc
new file mode 100644
index 000000000000..72bd8cc5a553
--- /dev/null
+++ b/gcc/kcfi-typeinfo.cc
@@ -0,0 +1,472 @@
+/* KCFI-compatible type mangling, based on Itanium C++ ABI.
+ Copyright (C) 2025 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
+
+/* Produces typeinfo mangling similar to Itanium C++ Mangling ABI, but
+ limited to types exposed within GCC for C language handling. The
+ hashes are used by KCFI (and future type-aware allocator support).
+ The strings are used for testing and debugging. */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tree.h"
+#include "diagnostic-core.h"
+#include "stringpool.h"
+#include "stor-layout.h"
+#include "print-tree.h"
+#include "kcfi-typeinfo.h"
+
+/* Helper to update FNV-1a hash with a single character. */
+
+static inline void
+fnv1a_hash_char (uint32_t *hash_state, unsigned char c)
+{
+ *hash_state ^= c;
+ *hash_state *= 16777619U; /* FNV-1a 32-bit prime. */
+}
+
+/* Helper to append character to optional string and update hash using
+ FNV-1a. */
+
+static void
+append_char (char c, std::string *out_str, uint32_t *hash_state)
+{
+ if (out_str)
+ *out_str += c;
+ if (!hash_state)
+ return;
+ fnv1a_hash_char (hash_state, (unsigned char) c);
+}
+
+/* Helper to append string to optional string and update hash using
+ FNV-1a. */
+
+static void
+append_string (const char *str, std::string *out_str, uint32_t *hash_state)
+{
+ if (out_str)
+ *out_str += str;
+ if (!hash_state)
+ return;
+ for (const char *p = str; *p; p++)
+ fnv1a_hash_char (hash_state, (unsigned char) *p);
+}
+
+/* Forward declaration for recursive type mangling. */
+
+static void mangle_type (tree type, std::string *out_str, uint32_t *hash_state);
+
+/* Mangle a builtin type following Itanium C++ ABI for C types. */
+
+static void
+mangle_builtin_type (tree type, std::string *out_str, uint32_t *hash_state)
+{
+ gcc_assert (type != NULL_TREE);
+
+ switch (TREE_CODE (type))
+ {
+ case VOID_TYPE:
+ append_char ('v', out_str, hash_state);
+ return;
+
+ case BOOLEAN_TYPE:
+ append_char ('b', out_str, hash_state);
+ return;
+
+ case INTEGER_TYPE:
+ if (type == char_type_node)
+ append_char ('c', out_str, hash_state);
+ else if (type == signed_char_type_node)
+ append_char ('a', out_str, hash_state);
+ else if (type == unsigned_char_type_node)
+ append_char ('h', out_str, hash_state);
+ else if (type == short_integer_type_node)
+ append_char ('s', out_str, hash_state);
+ else if (type == short_unsigned_type_node)
+ append_char ('t', out_str, hash_state);
+ else if (type == integer_type_node)
+ append_char ('i', out_str, hash_state);
+ else if (type == unsigned_type_node)
+ append_char ('j', out_str, hash_state);
+ else if (type == long_integer_type_node)
+ append_char ('l', out_str, hash_state);
+ else if (type == long_unsigned_type_node)
+ append_char ('m', out_str, hash_state);
+ else if (type == long_long_integer_type_node)
+ append_char ('x', out_str, hash_state);
+ else if (type == long_long_unsigned_type_node)
+ append_char ('y', out_str, hash_state);
+ else
+ {
+ /* Fallback for other integer types - use precision-based
+ encoding. */
+ append_char ('i', out_str, hash_state);
+ append_string (std::to_string (TYPE_PRECISION (type)).c_str (),
+ out_str, hash_state);
+ }
+ return;
+
+ case REAL_TYPE:
+ if (type == float_type_node)
+ append_char ('f', out_str, hash_state);
+ else if (type == double_type_node)
+ append_char ('d', out_str, hash_state);
+ else if (type == long_double_type_node)
+ append_char ('e', out_str, hash_state);
+ else
+ {
+ /* Fallback for other real types. */
+ append_char ('f', out_str, hash_state);
+ append_string (std::to_string (TYPE_PRECISION (type)).c_str (),
+ out_str, hash_state);
+ }
+ return;
+
+ case VECTOR_TYPE:
+ {
+ /* Handle vector types:
+ Dv<num-elements>_<element-type-encoding>
+ Example: uint8x16_t -> Dv16_h (vector of 16 unsigned char) */
+ tree vector_size = TYPE_SIZE_UNIT (type);
+ tree element_type = TREE_TYPE (type);
+ tree element_size = TYPE_SIZE_UNIT (element_type);
+
+ if (vector_size && element_size
+ && TREE_CODE (vector_size) == INTEGER_CST
+ && TREE_CODE (element_size) == INTEGER_CST)
+ {
+ append_char ('D', out_str, hash_state);
+ append_char ('v', out_str, hash_state);
+
+ unsigned HOST_WIDE_INT vec_bytes = tree_to_uhwi (vector_size);
+ unsigned HOST_WIDE_INT elem_bytes = tree_to_uhwi (element_size);
+ unsigned HOST_WIDE_INT num_elements = vec_bytes / elem_bytes;
+
+ /* Append number of elements. */
+ append_string (std::to_string (num_elements).c_str (),
+ out_str, hash_state);
+ append_char ('_', out_str, hash_state);
+
+ /* Recursively mangle the element type. */
+ mangle_type (element_type, out_str, hash_state);
+ return;
+ }
+ /* Fail for vectors with unknown size. */
+ }
+ break;
+
+ default:
+ break;
+ }
+
+ /* Unknown builtin type: this should never happen in a well-formed C. */
+ debug_tree (type);
+ internal_error ("mangle: Unknown builtin type - please report this as a bug");
+}
+
+/* Canonicalize typedef types to their underlying named struct/union types. */
+
+static tree
+canonicalize_typedef_type (tree type)
+{
+ /* Handle typedef types: canonicalize to named structs when possible. */
+ if (TYPE_NAME (type) && TREE_CODE (TYPE_NAME (type)) == TYPE_DECL)
+ {
+ tree type_decl = TYPE_NAME (type);
+
+ /* Check if this is a typedef (not the original struct declaration) */
+ if (DECL_ORIGINAL_TYPE (type_decl))
+ {
+ tree original_type = DECL_ORIGINAL_TYPE (type_decl);
+
+ /* Handle struct/union/enum types. */
+ if (TREE_CODE (original_type) == RECORD_TYPE
+ || TREE_CODE (original_type) == UNION_TYPE
+ || TREE_CODE (original_type) == ENUMERAL_TYPE)
+ {
+ /* Preserve typedef of anonymous struct/union/enum types. */
+ if (!TYPE_NAME (original_type))
+ return type;
+
+ /* Named compound type: canonicalize to it. */
+ return canonicalize_typedef_type (original_type);
+ }
+
+ /* For basic type typedefs (e.g., u8 -> unsigned char),
+ canonicalize to original type. */
+ if (TREE_CODE (original_type) == INTEGER_TYPE
+ || TREE_CODE (original_type) == REAL_TYPE
+ || TREE_CODE (original_type) == POINTER_TYPE
+ || TREE_CODE (original_type) == ARRAY_TYPE
+ || TREE_CODE (original_type) == FUNCTION_TYPE
+ || TREE_CODE (original_type) == METHOD_TYPE
+ || TREE_CODE (original_type) == BOOLEAN_TYPE
+ || TREE_CODE (original_type) == COMPLEX_TYPE
+ || TREE_CODE (original_type) == VECTOR_TYPE)
+ {
+ /* Recursively canonicalize in case the original type is
+ also a typedef. */
+ return canonicalize_typedef_type (original_type);
+ }
+ }
+ }
+
+ return type;
+}
+
+/* Recursively mangle a C type following Itanium C++ ABI. */
+
+static void
+mangle_type (tree type, std::string *out_str, uint32_t *hash_state)
+{
+ gcc_assert (type != NULL_TREE);
+
+ /* Canonicalize typedef types to their underlying named struct types. */
+ type = canonicalize_typedef_type (type);
+
+ /* Save original qualified type for cases where we need typedef
+ information. */
+ tree qualified_type = type;
+
+ /* Centralized qualifier handling: emit qualifiers for this type,
+ then continue with unqualified version. */
+ if (TYPE_QUALS (type) != TYPE_UNQUALIFIED)
+ {
+ /* Emit qualifiers in Itanium ABI order: restrict, volatile, const. */
+ if (TYPE_QUALS (type) & TYPE_QUAL_RESTRICT)
+ append_char ('r', out_str, hash_state);
+ if (TYPE_QUALS (type) & TYPE_QUAL_VOLATILE)
+ append_char ('V', out_str, hash_state);
+ if (TYPE_QUALS (type) & TYPE_QUAL_CONST)
+ append_char ('K', out_str, hash_state);
+
+ /* Get unqualified version for further processing. */
+ type = TYPE_MAIN_VARIANT (type);
+ }
+
+ switch (TREE_CODE (type))
+ {
+ case POINTER_TYPE:
+ {
+ /* Pointer type: 'P' + pointed-to type. */
+ append_char ('P', out_str, hash_state);
+
+ /* Recursively mangle the pointed-to type. */
+ tree pointed_to_type = TREE_TYPE (type);
+ mangle_type (pointed_to_type, out_str, hash_state);
+ break;
+ }
+
+ case ARRAY_TYPE:
+ /* Array type: 'A' + size + '_' + element type (simplified). */
+ append_char ('A', out_str, hash_state);
+ if (TYPE_DOMAIN (type) && TYPE_MAX_VALUE (TYPE_DOMAIN (type)))
+ {
+ tree max_val = TYPE_MAX_VALUE (TYPE_DOMAIN (type));
+ /* Check if array size is compile-time constant to handle VLAs. */
+ if (TREE_CODE (max_val) == INTEGER_CST && tree_fits_shwi_p (max_val))
+ {
+ HOST_WIDE_INT size = tree_to_shwi (max_val) + 1;
+ append_string (std::to_string ((long) size).c_str (),
+ out_str, hash_state);
+ }
+ /* For VLAs or non-constant dimensions, emit empty size (A_). */
+ append_char ('_', out_str, hash_state);
+ }
+ else
+ {
+ /* No domain or no max value: emit A_. */
+ append_char ('_', out_str, hash_state);
+ }
+ mangle_type (TREE_TYPE (type), out_str, hash_state);
+ break;
+
+ case REFERENCE_TYPE:
+ /* Reference type: 'R' + referenced type.
+ Note: We must handle references to builtin types including compiler
+ builtins like __builtin_va_list used in functions like va_start. */
+ append_char ('R', out_str, hash_state);
+ mangle_type (TREE_TYPE (type), out_str, hash_state);
+ break;
+
+ case FUNCTION_TYPE:
+ {
+ /* Function type: 'F' + return type + parameter types + 'E' */
+ append_char ('F', out_str, hash_state);
+ mangle_type (TREE_TYPE (type), out_str, hash_state);
+
+ /* Add parameter types. */
+ tree param_types = TYPE_ARG_TYPES (type);
+
+ if (param_types == NULL_TREE)
+ {
+ /* func () - no parameter list (could be variadic). */
+ }
+ else
+ {
+ bool found_real_params = false;
+ for (tree param = param_types; param; param = TREE_CHAIN (param))
+ {
+ tree param_type = TREE_VALUE (param);
+ if (param_type == void_type_node)
+ {
+ /* Check if this is the first parameter (explicit void) or a
+ sentinel. */
+ if (!found_real_params)
+ {
+ /* func (void) - explicit empty parameter list.
+ Mangle void to distinguish from variadic func (). */
+ mangle_type (void_type_node, out_str, hash_state);
+ }
+ /* If we found real params before this void, it's a sentinel
+ so stop here. */
+ break;
+ }
+
+ found_real_params = true;
+
+ /* For value parameters, ignore const/volatile qualifiers as
+ they don't affect the calling convention. "const int" and
+ "int" are passed identically by value. */
+ tree canonical_param_type = param_type;
+
+ if (TREE_CODE (param_type) != POINTER_TYPE
+ && TREE_CODE (param_type) != REFERENCE_TYPE
+ && TREE_CODE (param_type) != ARRAY_TYPE)
+ {
+ /* For non-pointer/reference value parameters, strip
+ qualifiers by default. */
+ canonical_param_type = TYPE_MAIN_VARIANT (param_type);
+
+ /* Exception: preserve typedef information for anonymous
+ compound types. */
+ if (TYPE_NAME (param_type)
+ && TREE_CODE (TYPE_NAME (param_type)) == TYPE_DECL
+ && DECL_ORIGINAL_TYPE (TYPE_NAME (param_type)))
+ {
+ tree original_type
+ = DECL_ORIGINAL_TYPE (TYPE_NAME (param_type));
+ if ((TREE_CODE (original_type) == RECORD_TYPE
+ || TREE_CODE (original_type) == UNION_TYPE
+ || TREE_CODE (original_type) == ENUMERAL_TYPE)
+ && !TYPE_NAME (original_type))
+ {
+ /* Preserve typedef of an anonymous
+ struct/union/enum. */
+ canonical_param_type = param_type;
+ }
+ }
+ }
+
+ mangle_type (canonical_param_type, out_str, hash_state);
+ }
+ }
+
+ /* Check if this is a variadic function and add 'z' marker. */
+ if (stdarg_p (type))
+ {
+ append_char ('z', out_str, hash_state);
+ }
+
+ append_char ('E', out_str, hash_state);
+ break;
+ }
+
+ case RECORD_TYPE:
+ case UNION_TYPE:
+ case ENUMERAL_TYPE:
+ {
+ /* Struct/union/enum: use simplified representation for C types. */
+ const char *name = NULL;
+
+ /* For compound types, use the original qualified type to preserve
+ typedef info. */
+ if (TYPE_QUALS (qualified_type) != TYPE_UNQUALIFIED)
+ {
+ type = qualified_type;
+ }
+
+ if (TYPE_NAME (type))
+ {
+ if (TREE_CODE (TYPE_NAME (type)) == TYPE_DECL)
+ {
+ /* TYPE_DECL case: both named structs and typedef structs. */
+ tree decl_name = DECL_NAME (TYPE_NAME (type));
+ if (decl_name && TREE_CODE (decl_name) == IDENTIFIER_NODE)
+ {
+ name = IDENTIFIER_POINTER (decl_name);
+ }
+ }
+ else if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
+ {
+ /* Direct identifier case. */
+ name = IDENTIFIER_POINTER (TYPE_NAME (type));
+ }
+ }
+
+ if (name)
+ {
+ append_string (std::to_string (strlen (name)).c_str (),
+ out_str, hash_state);
+ append_string (name, out_str, hash_state);
+ break;
+ }
+
+ /* If no name found, use anonymous type format: <length>$_<counter>. */
+ static unsigned anon_counter = 0;
+ std::string anon_name = "$_" + std::to_string (anon_counter++);
+
+ append_string (std::to_string (anon_name.length ()).c_str (),
+ out_str, hash_state);
+ append_string (anon_name.c_str (), out_str, hash_state);
+ break;
+ }
+
+ default:
+ /* Handle builtin types. */
+ mangle_builtin_type (type, out_str, hash_state);
+ break;
+ }
+}
+
+/* Get the typeinfo mangled name string for any C type.
+ Returns the mangled type string following Itanium C++ ABI conventions. */
+
+std::string
+typeinfo_get_name (tree type)
+{
+ gcc_assert (type != NULL_TREE);
+ std::string result = "";
+
+ mangle_type (type, &result, nullptr);
+ return result;
+}
+
+/* Get the typeinfo hash for any C type.
+ Returns the FNV-1a hash of the mangled type string. */
+
+uint32_t
+typeinfo_get_hash (tree type)
+{
+ gcc_assert (type != NULL_TREE);
+ uint32_t hash_state = 2166136261U; /* FNV-1a 32-bit offset basis. */
+
+ mangle_type (type, nullptr, &hash_state);
+ return hash_state;
+}
--
2.34.1
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