The "Interfacing to GCC Output" chapter used to be part of the
user-facing GCC documentation but ended up in the GCC internals manual
when the two documents were separated in 2001. It hasn't been updated
in any substantive way since then, and is now very bit-rotten. (PCC is
no longer the "standard compiler" on any target, and the target-specific
issues mentioned are for very old architectures.)
Meanwhile, the GCC user documentation now has a chapter called "Binary
Compatibility" that covers ABI issues in a generic way and also covers
C++ compatibility. Let's keep that one and throw out the obsolete
text that seems to predate the whole notion of an ABI.
gcc/ChangeLog
* Makefile.in (TEXI_GCCINT_FILES): Remove interface.texi.
* doc/gccint.texi (Top): Remove menu entry for the "interface" node,
and include of interface.texi.
* doc/interface.texi: Delete.
---
gcc/Makefile.in | 2 +-
gcc/doc/gccint.texi | 5 +--
gcc/doc/interface.texi | 70 ------------------------------------------
3 files changed, 2 insertions(+), 75 deletions(-)
delete mode 100644 gcc/doc/interface.texi
diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index a8e32e25cf5..c159825e62c 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -3697,7 +3697,7 @@ TEXI_GCC_FILES = gcc.texi gcc-common.texi gcc-vers.texi
frontends.texi \
# the *.texi files have changed.
TEXI_GCCINT_FILES = gccint.texi gcc-common.texi gcc-vers.texi \
contribute.texi makefile.texi configterms.texi options.texi \
- portability.texi interface.texi passes.texi rtl.texi md.texi \
+ portability.texi passes.texi rtl.texi md.texi \
$(srcdir)/doc/tm.texi hostconfig.texi fragments.texi \
configfiles.texi collect2.texi headerdirs.texi funding.texi \
gnu.texi gpl_v3.texi fdl.texi contrib.texi languages.texi \
diff --git a/gcc/doc/gccint.texi b/gcc/doc/gccint.texi
index eea2d48f87a..d88fc1a1c68 100644
--- a/gcc/doc/gccint.texi
+++ b/gcc/doc/gccint.texi
@@ -87,8 +87,7 @@ Compiler Collection (GCC)}.
This manual is mainly a reference manual rather than a tutorial. It
discusses how to contribute to GCC (@pxref{Contributing}), the
characteristics of the machines supported by GCC as hosts and targets
-(@pxref{Portability}), how GCC relates to the ABIs on such systems
-(@pxref{Interface}), and the characteristics of the languages for
+(@pxref{Portability}), and the characteristics of the languages for
which GCC front ends are written (@pxref{Languages}). It then
describes the GCC source tree structure and build system, some of the
interfaces to GCC front ends, and how support for a target system is
@@ -100,7 +99,6 @@ Additional tutorial information is linked to from
@menu
* Contributing:: How to contribute to testing and developing GCC.
* Portability:: Goals of GCC's portability features.
-* Interface:: Function-call interface of GCC output.
* Libgcc:: Low-level runtime library used by GCC.
* Languages:: Languages for which GCC front ends are written.
* Source Tree:: GCC source tree structure and build system.
@@ -141,7 +139,6 @@ Additional tutorial information is linked to from
@include contribute.texi
@include portability.texi
-@include interface.texi
@include libgcc.texi
@include languages.texi
@include sourcebuild.texi
diff --git a/gcc/doc/interface.texi b/gcc/doc/interface.texi
deleted file mode 100644
index 1688d6f66ec..00000000000
--- a/gcc/doc/interface.texi
+++ /dev/null
@@ -1,70 +0,0 @@
-@c Copyright (C) 1988-2025 Free Software Foundation, Inc.
-@c This is part of the GCC manual.
-@c For copying conditions, see the file gcc.texi.
-
-@node Interface
-@chapter Interfacing to GCC Output
-@cindex interfacing to GCC output
-@cindex run-time conventions
-@cindex function call conventions
-@cindex conventions, run-time
-
-GCC is normally configured to use the same function calling convention
-normally in use on the target system. This is done with the
-machine-description macros described (@pxref{Target Macros}).
-
-@cindex unions, returning
-@cindex structures, returning
-@cindex returning structures and unions
-However, returning of structure and union values is done differently on
-some target machines. As a result, functions compiled with PCC
-returning such types cannot be called from code compiled with GCC,
-and vice versa. This does not cause trouble often because few Unix
-library routines return structures or unions.
-
-GCC code returns structures and unions that are 1, 2, 4 or 8 bytes
-long in the same registers used for @code{int} or @code{double} return
-values. (GCC typically allocates variables of such types in
-registers also.) Structures and unions of other sizes are returned by
-storing them into an address passed by the caller (usually in a
-register). The target hook @code{TARGET_STRUCT_VALUE_RTX}
-tells GCC where to pass this address.
-
-By contrast, PCC on most target machines returns structures and unions
-of any size by copying the data into an area of static storage, and then
-returning the address of that storage as if it were a pointer value.
-The caller must copy the data from that memory area to the place where
-the value is wanted. This is slower than the method used by GCC, and
-fails to be reentrant.
-
-On some target machines, such as RISC machines and the 80386, the
-standard system convention is to pass to the subroutine the address of
-where to return the value. On these machines, GCC has been
-configured to be compatible with the standard compiler, when this method
-is used. It may not be compatible for structures of 1, 2, 4 or 8 bytes.
-
-@cindex argument passing
-@cindex passing arguments
-GCC uses the system's standard convention for passing arguments. On
-some machines, the first few arguments are passed in registers; in
-others, all are passed on the stack. It would be possible to use
-registers for argument passing on any machine, and this would probably
-result in a significant speedup. But the result would be complete
-incompatibility with code that follows the standard convention. So this
-change is practical only if you are switching to GCC as the sole C
-compiler for the system. We may implement register argument passing on
-certain machines once we have a complete GNU system so that we can
-compile the libraries with GCC@.
-
-On some machines (particularly the SPARC), certain types of arguments
-are passed ``by invisible reference''. This means that the value is
-stored in memory, and the address of the memory location is passed to
-the subroutine.
-
-@cindex @code{longjmp} and automatic variables
-If you use @code{longjmp}, beware of automatic variables. ISO C says that
-automatic variables that are not declared @code{volatile} have undefined
-values after a @code{longjmp}. And this is all GCC promises to do,
-because it is very difficult to restore register variables correctly, and
-one of GCC's features is that it can put variables in registers without
-your asking it to.
--
2.34.1
