Hi Gregor, Do you mean like this 'go build -v -x main.go node.c' ? But it does not compile and gives the following output:
WORK=/tmp/go-build714119815 named files must be .go files Thanks, Nitish On Wed, Mar 18, 2020 at 7:44 PM Gregor Best <b...@pferdewetten.de> wrote: > Hi, > > it looks like my initial reply wasn't entirely correct. It should build if > you pass in both the `.go` file and the `.c` file. > On 18.03.20 15:02, Nitish Saboo wrote: > > Hi Gregor, > > nitish > main.go > node.c > node.h > > I compiled using 'go build -v -x main.go' > But if my cgo directive is defined in main.go, this should have compiled > successfully..right? But it fails with the following whereas 'go build -v > -x' works fine. > > /tmp/go-build439591561/b001/_x002.o: In function > `_cgo_5637ad3d75e4_Cfunc_load_pattern_db': > /tmp/go-build/cgo-gcc-prolog:86: undefined reference to `load_pattern_db' > collect2: error: ld returned 1 exit status > > package main > > //#include <stdlib.h> > //#include "node.h" > import "C" > import ( > "fmt" > _ "fmt" > "os" > "path" > "unsafe" > ) > > Please let me know what am I missing here? > > Thanks, > Nitish > > On Wed, Mar 18, 2020 at 7:20 PM Nitish Saboo <nitish.sabo...@gmail.com> > wrote: > >> Hi Gregor, >> >> Got your point.Thank you for your response. >> That explains why the binaries have different names post compilation. >> >> Thanks, >> Nitish >> >> >> On Wed, Mar 18, 2020 at 7:06 PM Gregor Best <b...@pferdewetten.de> wrote: >> >>> Hi, >>> >>> In both `go build main.go`-examples, you tell the compiler to _only_ >>> build `main.go`. >>> >>> In your first example, `main.go` probably imports both `util` and `lib` >>> (you might want to give them less generic names by the way). The go >>> compiler thus knows "to build `main.go`, I need to build both `util` and >>> `lib` and link them in". >>> >>> In the second example, it has no way of knowing where `load_pattern_db` >>> comes from, since you didn't tell it to compile a file that defines that >>> function. >>> >>> The examples where you omit the `main.go` tell the compiler "build the >>> package in this directory", which includes all `.go`-files in the >>> directory. `node.c` and `node.h` are likely built because of `cgo` >>> directives in `a.go`. >>> >>> The compiler and linker did exactly as you told them to. >>> On 18.03.20 14:17, Nitish Saboo wrote: >>> >>> Hi, >>> >>> >>> >>> *Case 1 ---------- * >>> I have a project called 'nitish' where the folder structure looks like >>> the following: >>> >>> nitish >>> main.go >>> util >>> util.go >>> lib >>> node.c >>> node.h >>> a.go >>> >>> When I try compiling this project in the following ways: >>> >>> 1) go build -v - x >>> >>> >> This creates a binary called 'nitish' >>> >>> 2) go build -v - x main.go >>> >>> >> This creates a binary called 'main' >>> >>> ldd output of both the binaries is the same. >>> >>> >>> >>> *Case 2 ----------* >>> >>> Now, when I restructure the project 'nitish' in the following manner: >>> >>> nitish >>> main.go >>> util.go >>> node.c >>> node.h >>> a.go >>> >>> When I try compiling this project in the following ways: >>> >>> 1) go build -v - x >>> >>> >> This creates a binary called 'nitish' >>> >>> 2) go build -v - x main.go >>> >>> >> This error out with the following: >>> >>> /tmp/go-build074530518/b001/_x002.o: In function >>> `_cgo_8eab385aa676_Cfunc_load_pattern_db': >>> /tmp/go-build/cgo-gcc-prolog:86: undefined reference to `load_pattern_db' >>> collect2: error: ld returned 1 exit status >>> >>> >>> 1) In Case 1, why the binaries are created with different names though >>> both the binaries have the same 'ldd output' and work the same manner? >>> >>> 2) Why we see an error with the command 'go build -v - x main.go' in >>> Case 2 but not in Case 1? >>> >>> Thanks, >>> Nitish >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "golang-nuts" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to golang-nuts+unsubscr...@googlegroups.com. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/golang-nuts/CALjMrq6gpXPbED%2BK2xiOKYvRg08FZwkjoPSUaGg%3DFu5hKP-%2BKQ%40mail.gmail.com >>> <https://groups.google.com/d/msgid/golang-nuts/CALjMrq6gpXPbED%2BK2xiOKYvRg08FZwkjoPSUaGg%3DFu5hKP-%2BKQ%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> >>> -- >>> -- >>> Gregor Best >>> b...@pferdewetten.de >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "golang-nuts" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to golang-nuts+unsubscr...@googlegroups.com. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/golang-nuts/d23423e6-f204-8e63-436b-aa3730013392%40pferdewetten.de >>> <https://groups.google.com/d/msgid/golang-nuts/d23423e6-f204-8e63-436b-aa3730013392%40pferdewetten.de?utm_medium=email&utm_source=footer> >>> . >>> >> -- > -- > Gregor Best > b...@pferdewetten.de > > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. 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