[libc][arm32] define argc type and stack alignment (#96367)

https://github.com/ARM-software/abi-aa/blob/main/aapcs32/aapcs32.rst#6212stack-constraints-at-a-public-interface
mentions that the stack on ARM32 is double word aligned.

Remove confused comments around ArgcType. argc is always an int, passed on the
stack, so we need to store a pointer to it (regardless of ILP32 or LP64).

1 files changed, 3 insertions, 21 deletions

diff --git a/libc/config/linux/app.h b/libc/config/linux/app.h
index 766cd49..2a3b156 100644
--- a/libc/config/linux/app.h
+++ b/libc/config/linux/app.h
@@ -35,24 +35,6 @@ struct TLSImage {
   uintptr_t align;
 };
 
-#if defined(LIBC_TARGET_ARCH_IS_X86_64) ||                                     \
-    defined(LIBC_TARGET_ARCH_IS_AARCH64) ||                                    \
-    defined(LIBC_TARGET_ARCH_IS_ANY_RISCV)
-// At the language level, argc is an int. But we use uint64_t as the x86_64
-// ABI specifies it as an 8 byte value. Likewise, in the ARM64 ABI, arguments
-// are usually passed in registers.  x0 is a doubleword register, so this is
-// 64 bit for aarch64 as well.
-typedef uintptr_t ArgcType;
-
-// At the language level, argv is a char** value. However, we use uint64_t as
-// ABIs specify the argv vector be an |argc| long array of 8-byte values.
-typedef uintptr_t ArgVEntryType;
-
-typedef uintptr_t EnvironType;
-#else
-#error "argc and argv types are not defined for the target platform."
-#endif
-
 // Linux manpage on `proc(5)` says that the aux vector is an array of
 // unsigned long pairs.
 // (see: https://man7.org/linux/man-pages/man5/proc.5.html)
@@ -65,7 +47,7 @@ struct AuxEntry {
 };
 
 struct Args {
-  ArgcType argc;
+  uintptr_t argc;
 
   // A flexible length array would be more suitable here, but C++ doesn't have
   // flexible arrays: P1039 proposes to fix this. So, for now we just fake it.
@@ -73,7 +55,7 @@ struct Args {
   // (ISO C 5.1.2.2.1) so one is fine. Also, length of 1 is not really wrong as
   // |argc| is guaranteed to be atleast 1, and there is an 8-byte null entry at
   // the end of the argv array.
-  ArgVEntryType argv[1];
+  uintptr_t argv[1];
 };
 
 // Data structure which captures properties of a linux application.
@@ -87,7 +69,7 @@ struct AppProperties {
   TLSImage tls;
 
   // Environment data.
-  EnvironType *env_ptr;
+  uintptr_t *env_ptr;
 
   // Auxiliary vector data.
   AuxEntry *auxv_ptr;