git-compat-util: work around fileno(fp) that is a macro

pclouds · gitster · commit 18a4f6be6b4c · 2019-02-12T10:01:59.000-08:00
On various BSD's, fileno(fp) is implemented as a macro that directly
accesses the fields in the FILE * object, which breaks a function that
accepts a "void *fp" parameter and calls fileno(fp) and expect it to
work.

Work it around by adding a compile-time knob FILENO_IS_A_MACRO that
inserts a real helper function in the middle of the callchain.

Signed-off-by: Nguyễn Thái Ngọc Duy &lt;pclouds@gmail.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/Makefile b/Makefile
@@ -427,6 +427,8 @@ all::
 #
 # Define HAVE_GETDELIM if your system has the getdelim() function.
 #
+# Define FILENO_IS_A_MACRO if fileno() is a macro, not a real function.
+#
 # Define PAGER_ENV to a SP separated VAR=VAL pairs to define
 # default environment variables to be passed when a pager is spawned, e.g.
 #
@@ -1773,6 +1775,11 @@ ifdef HAVE_WPGMPTR
 	BASIC_CFLAGS += -DHAVE_WPGMPTR
 endif
 
+ifdef FILENO_IS_A_MACRO
+	COMPAT_CFLAGS += -DFILENO_IS_A_MACRO
+	COMPAT_OBJS += compat/fileno.o
+endif
+
 ifeq ($(TCLTK_PATH),)
 NO_TCLTK = NoThanks
 endif
diff --git a/compat/fileno.c b/compat/fileno.c
@@ -0,0 +1,7 @@
+#define COMPAT_CODE
+#include "../git-compat-util.h"
+
+int git_fileno(FILE *stream)
+{
+	return fileno(stream);
+}
diff --git a/config.mak.uname b/config.mak.uname
@@ -221,6 +221,7 @@ ifeq ($(uname_S),FreeBSD)
 	HAVE_BSD_KERN_PROC_SYSCTL = YesPlease
 	PAGER_ENV = LESS=FRX LV=-c MORE=FRX
 	FREAD_READS_DIRECTORIES = UnfortunatelyYes
+	FILENO_IS_A_MACRO = UnfortunatelyYes
 endif
 ifeq ($(uname_S),OpenBSD)
 	NO_STRCASESTR = YesPlease
@@ -233,6 +234,7 @@ ifeq ($(uname_S),OpenBSD)
 	HAVE_BSD_SYSCTL = YesPlease
 	HAVE_BSD_KERN_PROC_SYSCTL = YesPlease
 	PROCFS_EXECUTABLE_PATH = /proc/curproc/file
+	FILENO_IS_A_MACRO = UnfortunatelyYes
 endif
 ifeq ($(uname_S),MirBSD)
 	NO_STRCASESTR = YesPlease
diff --git a/git-compat-util.h b/git-compat-util.h
@@ -1220,6 +1220,14 @@ struct tm *git_gmtime_r(const time_t *, struct tm *);
 #define getc_unlocked(fh) getc(fh)
 #endif
 
+#ifdef FILENO_IS_A_MACRO
+int git_fileno(FILE *stream);
+# ifndef COMPAT_CODE
+#  undef fileno
+#  define fileno(p) git_fileno(p)
+# endif
+#endif
+
 /*
  * Our code often opens a path to an optional file, to work on its
  * contents when we can successfully open it.  We can ignore a failure

Original file line number	Diff line number	Diff line change
`@@ -427,6 +427,8 @@ all::`
`427`	`427`	`#`
`428`	`428`	`# Define HAVE_GETDELIM if your system has the getdelim() function.`
`429`	`429`	`#`
	`430`	`+# Define FILENO_IS_A_MACRO if fileno() is a macro, not a real function.`
	`431`	`+#`
`430`	`432`	`# Define PAGER_ENV to a SP separated VAR=VAL pairs to define`
`431`	`433`	`# default environment variables to be passed when a pager is spawned, e.g.`
`432`	`434`	`#`
`@@ -1773,6 +1775,11 @@ ifdef HAVE_WPGMPTR`
`1773`	`1775`	`BASIC_CFLAGS += -DHAVE_WPGMPTR`
`1774`	`1776`	`endif`
`1775`	`1777`
	`1778`	`+ifdef FILENO_IS_A_MACRO`
	`1779`	`+ COMPAT_CFLAGS += -DFILENO_IS_A_MACRO`
	`1780`	`+ COMPAT_OBJS += compat/fileno.o`
	`1781`	`+endif`
	`1782`	`+`
`1776`	`1783`	`ifeq ($(TCLTK_PATH),)`
`1777`	`1784`	`NO_TCLTK = NoThanks`
`1778`	`1785`	`endif`